ORNL/CDIAC-142 NDP-026D CLOUD CLIMATOLOGY FOR LAND STATIONS WORLDWIDE, 1971-1996 Carole J. Hahn Department of Atmospheric Sciences University of Arizona Tucson, Arizona 85721-0081 and Stephen G. Warren Department of Atmospheric Sciences University of Washington Seattle, Washington 98195-1640 March 17, 2003 CONTENTS LIST OF TABLES LIST OF APPENDICES ABSTRACT 1. INTRODUCTION 2. DATA SOURCE AND STATIONS INCLUDED 2.1. Data Source 2.2. Cloud Type Definitions 2.3. Selection of Stations 3. DATA SET CONTENTS AND DATA FORMATS 3.1. General 3.2. Details of Organization 3.3. Data Formats 3.4. Averaging methods 4. SPECIFIC COMMENTS ON THE DATA FILE CATEGORIES 4.1. File Category 1 Station Identification 4.2. File Category 2 Mean Annual Cloud Amount 4.3. File Categories 3-5 Mean Seasonal Amount, Frequency & Amount-when-present 4.4. File Category 6 Mean Seasonal Non-overlapped Amount for Upper Clouds 4.5. File Category 7 Mean Seasonal Low Cloud Base Height 4.6. File Categories 8, 9 Mean Monthly Cloud Amount & Frequency 4.7. File Categories 10-13 Mean Seasonal Averages by Synoptic Hour 4.8. File Category 14 Annual and Diurnal Cycles 4.9. File Categories 15-30 Seasonal Averages by Year 4.10. File Categories 31-42 Monthly Daytime Averages by Year 5. IMPORTANT NOTES ON USE OF THIS DATA SET 5.1. Stations with Bogus Amount-When-Present 5.2. Minimum Observations, the Missing-Value Code, and the A-code 6. HOW TO OBTAIN THE DATA ACKNOWLEDGMENTS REFERENCES LIST OF TABLES 1. Cloud Information Contained in Synoptic Weather Reports 2. Cloud Type and Weather Type Definitions Used 3. Data File Categories for Land Station Cloud Archive, 1971-1996 4. Data Organization for Land Station Cloud Archive, 1971-1996 5. Header Record Format and Codes Used 6. Data Formats for Reading Land Station Cloud Climatology 7. Glossary of Terms and Abbreviations Used 8. Examples of Contents of Data Files LIST OF APPENDICES APPENDIX A. NUMBERS OF STATIONS AND OBSERVATIONS USED A1. Number of Stations from EECRA with 20 or More Reports Containing Cloud Type Data for Specified Number of Years for January or July A2. Regional Distribution of Contributing Stations A3a. Number of Stations with 20 or More Observations per Month for Julys A3b. Number of Observations per Month Obtained from 5388 Stations for Januarys and for Julys A4. Number of Stations with Specified Station Data Code (SDC) APPENDIX B. 155 STATIONS FOR WHICH BOGUS AMOUNT-WHEN-PRESENT WAS USED FOR MIDDLE AND HIGH CLOUDS APPENDIX C. LAND-STATION CLOUD ARCHIVE FILE NAMES, NDP-026D ABSTRACT Hahn, C.J., and S.G. Warren, 2002: Cloud Climatology for Land Stations Worldwide, 1971-1996. NDP-026D, Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, Oak Ridge, TN. doi: 10.3334/CDIAC/cli.ndp026d Surface synoptic weather reports for 26 years were processed to provide a climatology of clouds for each of over 5000 land-based weather stations with long periods of record both day and night. For each station, this digital archive includes: multi-year annual, seasonal and monthly averages for day and night separately; seasonal and monthly averages by year; averages for eight times per day; and analyses of the first harmonic for the annual and diurnal cycles. Averages are given for total cloud cover, clear-sky frequency, and 9 cloud types: 5 in the low level (fog, St, Sc, Cu, Cb), 3 in the middle level (Ns, As, Ac), and one in the high level (all cirriform clouds combined). Cloud amounts and frequencies of occurrence are given for all types. In addition, non-overlapped amounts are given for middle and high cloud types, and average base heights are given for low cloud types. Nighttime averages were obtained by using only those reports that met an "illuminance criterion" (i.e., made under adequate moonlight or twilight), thus making possible the determination of diurnal cycles and nighttime trends for cloud types. 1. INTRODUCTION This report describes an archive of cloud climatological data for 5388 land stations around the globe. The climatology was constructed using surface synoptic weather reports for the 26-year period 1971 through 1996. For each station, this digital archive includes: multi-year annual, seasonal and monthly averages for day and night separately; seasonal and monthly averages by year; averages for eight times per day; and analyses of the first harmonic for the annual and diurnal cycles. Averages are given for total cloud cover, clear-sky frequency, and 9 cloud types [5 in the low level: fog, St, Sc, Cu, Cb; 3 in the middle level: Ns, As, Ac; and one in the high level: Ci (all cirriform clouds combined)]. Mean base heights are given for the low cloud types. Cloud amounts and frequencies of occurrence are given for all types. The frequency given is the "actual" frequency of occurrence (not the "frequency of sighting") and amounts given are the "actual" amounts, using the random-overlap assumption where necessary for Ci, Ac and As, and the maximum-overlap assumption where necessary for Ns. In addition, non-overlapped amounts are given for middle and high cloud types. These concepts are discussed in detail by Warren et al. (1986) and by Hahn and Warren (1999). This archive updates and improves on previous cloud climatologies in this series (NDP-026 and NDP-026A; Hahn et al. 1988, 1994). It uses the illuminance criterion of Hahn et al. (1995) in order to minimize the night-detection bias, making it possible to prepare a climatology of cloud types for both day and night and to meaningfully evaluate diurnal cycles of the cloud types. It covers a greater span of time (26 years) so that interannual variations and trends may be better evaluated. Some cloud types that were grouped together in the earlier climatology are reported separately here: we now distinguish between As and Ac and between Sc, St and fog. Finally, this is a climatology for individual land stations, not grid boxes, so that trends and diurnal cycles can be evaluated without biases that may arise when using data from more than one station within a box. CAUTION: It is important to note the cautions described in the various sections below so as to avoid erroneous use of the data. For example, not checking the number of observations when required could lead to using unrepresentative values (as has happened in the past in publications by some users of our climatologies), and not checking for the "missing-value code" (a negative number) could lead to erroneous analyses. Numerous abbreviations will be employed throughout this text. Most will be defined in context or in associated tables. For convenience, Table 7 defines many of the terms used. Tables 1-8, which are required for understanding and use of the data, are grouped in the "TABLES" section, while supplementary tables and figures are put in the APPENDIX. 2. DATA SOURCE AND STATIONS INCLUDED 2.1. Data Source The data source for this analysis was the "Extended Edited Cloud Reports Archive" (EECRA, Hahn & Warren, 1999), also available from CDIAC as NDP-026C. Land station reports included in the EECRA were originally taken from the "SPOT" archive of the Fleet Numerical Oceanography Center (FNOC) for the years 1971-76 and from an archive of the National Centers for Environmental Prediction (NCEP, formerly NMC) for the years 1977-96. These archives are maintained at the National Center for Atmospheric Research (NCAR) in Boulder, Colorado. Because of changes in procedures at NCEP (Gregg Walters, NCAR, personal communication, 2002), the NCEP data do not contain cloud-type information after March 1997. Thus this climatology terminates with 1996 data. Other problems with these data sets have been discussed by Hahn & Warren (1999). Several features designed into the EECRA simplified the present cloud analysis. Synoptic weather reports were included in the EECRA only if they contained cloud information and they were put through extensive quality control procedures. These screened reports were then re-written to include additional information that was not directly recorded in, though implicit in, the original report. For example, reports in the EECRA contain both the overlapped and non-overlapped amounts for middle and high clouds. Each report also contains a flag indicating whether the report satisfies the illuminance criterion of Hahn et al. (1995). For the present climatology we used only those reports that satisfied the illuminance criterion ("light obs") and that contained cloud type information (thus the number of reports used for low cloud types is the same as the number used for total cloud). 2.2. Cloud Type Definitions Table 1 lists the cloud information contained in a synoptic weather report. These quantities, along with the station identification and the time of the report, are the basic data used to create this climatology. Synoptic reports are made every three hours beginning with 00 GMT, though some stations report less frequently. Some stations report only every 6 hours or only during daytime. Table 2 lists the cloud types analyzed for this climatology and provides their definitions in terms of the synoptic code as defined by the World Meteorological Organization (WMO, 1988) and as modified in the EECRA. Precipitation codes are also given because they are used in our definitions of nimbostratus and cumulonimbus cloud types. The synoptic code is the only system of reporting weather data that is used worldwide, thus providing a degree of uniformity for a global climatology. As noted above, in contrast to our previous climatology (NDP-026), we now distinguish between St, Sc and Fo in the low level, and between As and Ac in the middle level. In preparation for the present climatology, we tried to distinguish between cirrostratus, cirrocumulus and dense cirrus in the high level but, after mapping the frequencies of occurrence of these individual types, we saw discontinuities at some international boundaries, indicating that reporting procedures were not uniform worldwide. Therefore we group all high clouds together in this dataset. 2.3. Selection of Stations Hahn & Warren (1999) listed 11,586 stations (by their 5-digit station-identification numbers) for which cloud type information was reported at least once in the EECRA. [Names and further information about each station are given by WMO (1988).] For the present climatology we wanted stations that have sufficiently long periods of record for trend analyses and sufficient numbers of observations (obs) at night for diurnal analyses. Appendix A1 shows the number of stations that had 20 or more obs for specified numbers of years of January or July. For example, 1680 stations had no years with at least 20 obs in either January or July, of which 961 stations had only one year of any obs (not shown). On the other end of the scale, 2639 stations had 26 years of at least 20 obs in either January or July, of which 2020 stations had at least 20 obs in both months. [The criterion of 20 observations in a month allows a station that routinely reports only once per day to contribute to some analyses but excludes station numbers that appear only spuriously.] Hahn & Warren (1999) also listed 939 stations that did not normally report cloud types; these stations were excluded from this analysis. For use in this climatology, we initially selected stations if they met three criteria: 1) they normally report cloud types, 2) they had at least 20 obs in at least 15 years (during the 26-yr period) for either January or July, and 3) the number of "night" obs [defined here to be 18 to 06 local time (LT)] was at least about 15% of the total number of obs. (Night obs average about 30% of the total because of screening by the illuminance criterion.) The number of stations meeting these criteria was 5158 (5838 stations met criteria 1 & 2). However, this group of stations left vast land areas south of 30 N underrepresented (in Africa, South America, Australia and Antarctica). We therefore included also 230 stations south of 30 N that did not meet criterion 2 or 3. (Many island stations in the Indonesian region were included in the group of added stations.) File 1 of the archive (discussed below) lists the resulting 5388 stations selected and contains a code that distinguishes these two groups. The regional distribution of the land stations used for this climatology is given in Appendix A2. The number of these stations that had 20 or more obs per month (shown for July but similar for all months) for each year is plotted in Appendix A3a. The number of such stations was rising in the 1970s but has been declining since 1990. The number of observations associated with the 5388 land stations is plotted in Appendix A3b for Januarys and Julys. More light obs are available for July because more stations are located in the Northern Hemisphere. The total number of observations used in this climatology is 185 million. Of these, 70% are for "daytime" (defined here as 06 to 18 LT). It is notable that very few stations in the United States (USA) have 26 years of synoptic cloud reports. With the installation of the Automatic Surface Observing System (ASOS) in the mid 1990s, most USA stations stopped reporting cloud observations in the synoptic code format, despite objections from the climate community (Warren et al., 1991). In addition, many of the synoptic reports still being made are not appearing in the NCEP data set. It is also unfortunate that stations from some major cities in Australia (e.g. Sydney, Melbourne, and Hobart) are not included in this climatology because most of their nighttime reports did not appear in the NCEP data set. 3. DATA SET CONTENTS AND DATA FORMATS 3.1. General The cloud data provided in this archive are divided into 42 numbered "File Categories" as outlined in Table 3. The category divisions are based on the content of the data. The categories are named and given abbreviations intended to be suggestive of the content. Thus Category 1 contains data relating to station identification (STID) and Category 2 contains mean annual cloud amounts (MACA) for 13 cloud types (identified and discussed below). Categories 3 - 7 give mean seasonal averages for five different cloud parameters (amount, frequency, amount-when-present, non-overlapped amount, and base height), and so on. Categories 2-14 contain the multi-year averages, while Categories 15-42 contain averages for individual years, either seasonally (Categories 15-30) or monthly (Categories 31-42), which can be used for analyses of trends. Numbered categories listed with the same category name, such as Categories 15-18 or Categories 31-42, might logically be listed under a single category number, but the seasonal mean and monthly mean files are so large that these categories are split further by season or month. The organization of the data is described in more detail in the following section. 3.2. Details of Organization The details of the organization of the archive are displayed in Table 4. The data for any particular cloud quantity, such as "multi-year average amount of cumulus cloud for July" (or any other cloud type or parameter or season), are given for all stations, listed consecutively by station ID number, before going on to some other cloud quantity. This grouping is referred to as a "station cloud data group" (SCDG; or "data group" for short). Each file contains a series of one or more SCDGs. A data group consists of 5388 data records (one for each of 5388 stations) and a header record that identifies the group: | Header record identifying data group | Data record for first station | Data record for second station | etc. for 5388 stations The header record specifies the season, cloud type, cloud parameter and data format for the data records in the group. (Formats for the header and data records are discussed in Section 3.3.) The order in which data groups appear within a multi-group file is: first season, first type, averages for all stations; first season, second type, averages for all stations; etc. This order is indicated by the order of listing in Table 4. The order in which the data groups appear for the various cloud types is as shown for Category 2 in Table 4. This same sequence (also given in Table 5) is used for all the files. However, some quantities are not applicable to all types. For example, there is no "amount" for clear-sky frequency, so Cr does not appear in Category 3. Thus for most files only a subset of the 13 types is given; these subsets are listed in a footnote to Table 4. Each data group is assigned a unique sequence number (the SCDG number) which is indicated in Table 4 and contained in the header record. There are 862 SCDGs in this archive. These sequence numbers are included as a redundant convenience for identifying a desired data group although the group header record contains other information which uniquely defines the group contents. The header record is described in the next section. Physical files. The size of the entire archive is about 1.6 gigabytes. The File Categories 2-42 each contain a fairly large amount of data (Table 3) so, in practice, they are physically divided into smaller files for ease of handling. The resulting files are given names that indicate their contents. The names contain the File Category number, the category name abbreviation, and several name extensions to indicate the season and/or cloud type(s) whose station cloud data group(s) (SCDGs) is (are) contained in the file. The 862 SCDGs in the 42 File Categories are contained in 433 physical files. A complete list of the physical file names is given in Appendix C. The means for obtaining the files are available from CDIAC (Section 6). Examples of the contents of the files are given in Table 8; these will be discussed in Section 4. 3.3. Data Formats The header record is described in Table 5. It defines the content of a data group by specifying the parameters: TYPE, PCODE, YEAR, SN and FMT. (Here all data are for land stations, so LO=1 and SIZE=0 in all headers.) Only numerical values are included in the header record so the various cloud types, seasons, etc. are given numerical codes. These codes and their equivalencies are listed as values under the respective parameter name. (Definitions of the cloud types are given in Table 2, and other terms are defined in Table 7.) Each header also has a unique SCDG number which indicates the File Category number and the sequence of the group within the file category. The format number (FMT) given in the header record indicates the format (defined in Table 6) to be used for reading the data records. The header formats (110 and 120) are also listed in Table 6. Format 110 differs from 120 only in that the parameters TYPE, PCODE and SN are not applicable for Category 1 and so a value of "-9" is located in those positions in the header to Category 1. The data formats used are defined in Table 6. The format of a data record depends on the category of data given. Categories 2-9 and 15-30 (formats 121, 122, 126, 127) all have similar content. The station ID number (StaID, which is the first variable in every data record) is followed by three pairs of numbers. Each pair is made up of a number of obs (or the number of seasons for Category 2) and an average (which may be for amount, frequency or height). The first pair gives daytime values (NobD, AvgDy), the second pair gives nighttime values (NobN, AvgNt), and the third pair gives the total number of obs and the average over both day and night (NobDN, AvgDN). Finally, the ACODE is a coded message providing information regarding NobD and NobN used in obtaining AvgDN (described in Section 3.4 below). Format 122 differs from format 121 only in that the variable formatted is height (in meters, f6.0) rather than amount or frequency (in percent, f6.2). Format 126 is similar to format 121 except that averages are given for each of 26 years for each station. Again, format 127 gives height rather than amount or frequency. Data lines in Categories 10-13 (formats 138, 139) contain only a single data pair (Nobs and Avg for an individual synoptic hour) but 8 such pairs are given consecutively for each station. The synoptic hour is included in these data records. Format 162 is unique in that it contains amount, frequency and amount-when-present in the same data record. It is used for Categories 31-42, the daytime averages for 26 years (monthly). It contains the year (last 2 digits) for each data line and NC, the number of obs used in computing AWP. Formats 140 and 148 (used in Category 14) give the parameters of the first harmonic of either the annual or diurnal cycles. Details for the format contents are given in Section 4 for the particular files. All data appear as integers (the "I" format) in the data files. To indicate the number of decimal places to which some values are given, the "F" format is shown above the relevant variables in Table 6. For example, the integer "1234" should be read as "12.34" if read under format 121 (F6.2) or as "1234." if read under format 122 (F6.0). If read in this way, amounts and frequencies are given in percent and base heights are given in whole meters. This principle applies to other variables in other formats. 3.4. Averaging methods. Except for amounts of middle and high clouds, which will be discussed below, averages for the various cloud variables (amt, fq, awp, nol and hgt) for day, night, and the individual synoptic hours were computed as the simple average of the available obs. The averages were computed even if only one observation was available. The number of obs contributing to each average is included in the data record. If no obs were available for a particular average (Nobs=0), the missing-value code (MCODE; usually -90000, see Table 7) was inserted for that average. One must check for the missing-value code and/or the Nobs when using the data. Note that, because the sky may be overcast with lower clouds, the Nobs for middle clouds (MOBS) and high clouds (HOBS) will generally be less than the Nobs for low (or total) clouds (LOBS = MOBS = HOBS). To reduce the "partial-undercast bias" (Warren et al. 1986), frequencies for upper-level clouds (As, Ac, Hi) were computed only from reports in which the coverage of a lower cloud layer was less than 7/8. This is simpler than the method used by Warren et al. (1986) to reduce this bias, but we found no significant difference between the two methods. Amounts of middle and high clouds. Because the synoptic code allows reporting of only two amounts even if clouds are present at all three levels (Table 1), it is possible for the amount of a middle or high cloud to be indeterminate even if the cloud is visible. Therefore we compute an amount-when-present (awp) from the obs for which the amount can be determined ("number of computable obs", NC) and obtain the cloud amount as: amt = fq x awp. (1) Again, to reduce the partial-undercast bias, reports in which the coverage of a lower cloud layer was 7/8 were not used in computing awp for upper level clouds, further reducing NC. Thus there may be obs from which to compute fq but no obs from which to compute awp or amt (unless fq=0, in which case amt=0). The Nobs for awp is NC. The Nobs given in the data records for amt is the number of obs used in computing the frequency. To avoid reporting unrepresentative amounts, we imposed a minimum (mina) on NC for reporting amt: mina = min x fq x 0.6, where min has a value that is specified for each File Category (Section 4). If mina was not met, the Mcode was entered for amt. As always, it is necessary to check for the Mcode when using the data. The non-overlapped amount is the amount actually seen by an observer from below; i.e., the amount not obscured by lower clouds. It is analogous to the quantity reported by most satellite-derived climatologies where the amount reported is the amount not obscured by higher clouds. The sum of non-overlapped amounts is equal to the total cloud cover, whereas the sum of the other cloud-type amounts reported in this archive is greater than the total cloud cover because of overlap. Because one can know that an upper cloud cannot be seen (NOL=0) even if one does not know, because of lower overcast, whether or not it is present, Nobs for NOL is larger than MOBS or HOBS. Indeed, NOL was given in 94% of the EECRs used for this climatology. NOL was not given in EECRs for cases with clouds present in 3 levels because the distribution of the upper amount (N-Nh) between Mid and Hi cannot be computed. However we were able to include this class of reports in the present climatology by apportioning (N-Nh) by reference to the average AWPs of the cloud types when they were computable. We used the following algorithm: if middle cloud is Ac, then assign NOL(Ac) = 0.7(N-Nh) and NOL(Hi) = 0.3(N-Nh) or if middle cloud is As or Ns, then assign NOL(As or Ns) = 0.9(N-Nh) and NOL(Hi) = 0.1(N-Nh). Using this approximation, NOL was computable in 99% of the reports. Only unusual reports, such as those for China in the 1970s (with CL=0 and Nh=/; see below), did not contribute. The amount of a low cloud can always be determined: it is equal to Nh when it is present, and equal to zero when it is not present (CL=0). Thus it is not necessary to compute awp, as was shown above for middle and high clouds, to obtain low cloud amounts. We do, however, include awp for low clouds in the archive. For a low cloud, the number of computable obs (NC) is equal to the number of times the cloud was present (NTy). The "daily" (or "diurnal") average (avgDN) was computed by one of three methods depending on the variable averaged. For frequencies, amounts, and non-overlapped amounts, avgDN was computed as the average of the Dy and Nt values. This method of forming avgDN weights day and night equally; it is the preferred method, if sufficient obs are available for both day and night, because there are generally fewer usable obs at night due to screening by the illuminance criterion. If NobD or NobN was less than the specified minimum (Section 4), then an average was computed using all available obs, regardless of time of day. A flag, the "averaging code" (Acode), is included in the data record to identify the DN-averaging method employed. Acode values and their meanings are given in Table 7. Note that, since both day and night averages and their Nobs are given, a user is free to obtain a DN average by a method different from the one used here. For base height, avgDN was always computed as the simple average of all the obs of a low cloud type when it is present, regardless of time of day. The Acode supplied in this case does not represent the averaging method, which never varies, but does indicate the relationship between NobD, NobN and a specified min as defined in Table 7. Nobs for height may be less than the number of occurrences of a type (NTy) because h (Table 1) is sometimes not reported. AwpDN is computed as: amtDN / fqDN (if fq=0, then awp=Mcode). This preserves the relationship in Eqn. (1) but, in general, awpDN computed in this way does NOT equal (awpD+awpN)/2. For example, if cumulus occurs frequently during daytime but rarely at night, then the awpDN should be weighted toward the daytime awp, as this method ensures. As for base height, the Acode supplied for awpDN indicates not the averaging method, which does not vary, but the relationship between NC(Dy), NC(Nt) and a specified minimum as defined in Table 7. 4. SPECIFIC COMMENTS ON THE DATA FILE CATEGORIES Refer to Tables 4 and 6 throughout this discussion. The discussion of an individual File Category includes comments on the data content, data format and minima applied. Counts of the number of stations meeting minima for selected cloud variables will be listed. Reference will be made to examples given in Table 8. 4.1. File Category 1: Station Identification (STID) Category 1 (Format 111) provides information about the land stations used. Data records for the 5388 selected stations are listed in ascending order of the 5-digit, WMO station identifiers (StaID) which here range from 01001 to 98851. Latitude and longitude are given in degrees (-90 to 90 N, 0 to 360 E) to 2 decimal places, and elevation is given in meters. The variables ny1, fy1 and ly1 give the number of years of Januarys with at least 20 obs, the first of such years and the last such year (e.g. "96" for 1996), respectively. The variables ny7, fy7 and ly7 give the same information for July. The "station data code" (SDC) indicates whether a station had at least 15 or more years of 20 or more obs in January or July and whether the number of night obs exceeded a certain fraction (about 15%) of the total. The meanings of the five possible values for SDC are given in Appendix A4. The table also lists the number of stations that have each value. A station reporting reliably both day and night for many years in all seasons will have SDC=2; there are 5053 such stations. Two stations with SDC=2 are shown in Example (a) in Table 8. Station 01001, located at 70.93 deg N and 351.33 deg E at an elevation of 9 meters, has 20 or more obs in all 26 years for both January and July, while station 98851 has at least 20 obs/month in 21 of the years from 1971-96. Station 62700, in Africa, had only 3 Januarys and 2 Julys with 20 or more obs (SDC=0); these years were all between 1980 and 1991. Finally, the variable b5c gives the number of the grid box, on the "5c" grid, that contains the station. We have used this grid in previous climatological data bases (NDP-026, NDP-026A) and in our atlas (Warren et al. 1986) but do not refer to it further here. The variable b5c can be ignored. 4.2. File Category 2: Mean Annual Cloud Amount (MACA) Category 2 (Format 121) gives the annual average Dy, Nt, and DN amounts for all the cloud types, the clear-sky frequency, the sum of the low-level amounts, and the sum of the middle-level amounts. Annual averages were computed by averaging the seasonal values from Categories 3 (amounts) and 4 (Cr frequency). A seasonal value contributed to the annual average if there were at least 100 obs for the season. NSN is the number of seasons contributing. There were 5383 stations that had 4 seasons contributing to Tc. The Acode assigned here for AvgDN was based on the Acodes of the seasonal averages contributing (Table 7). Acode was assigned as 2 if all seasons contributing to the annual average had Acode=2. If any contributing season had Acode=3, then Acode=3 also for the annual average. Acode=1 does not apply here. Acode=0 if no seasons had 100 obs. Acode=2 was obtained by 5338 stations for Tc and by 5278 stations for Hi amount. Example (b) in Table 8 shows the annual average total cloud amount for station 21749. These averages were obtained from the seasonal values shown in Examples (c-f). The annual averages were computed from only 3 seasons because DJF, shown in Example (c), contained too few obs. The 3 seasons contributing to AvgDN [75.99 = (74.97 + 77.72 + 75.28) /3] all had Acode=2 so the Acode for the annual average is also 2. 4.3. File Categories 3-5: Mean Seasonal Amount, Frequency & Amount-when-present (MSCA, MSCF, MSAW) Categories 3-5 (Format 121) contain the mean-seasonal (multi-year) averages for amt, fq and awp, respectively. Amounts for the low and middle levels (LoL and MiL) are included in Category 3. Category 5 does not include awp for Tc, for which none is computed, or for Fo (sky obscured by fog) which is, by definition, always 100%. Fo is included in both Categories 3 & 4 even though fq_Fo = amt_Fo. These averages were obtained by summing, seasonally, all obs over the span of years for each station; they were not obtained by averaging the season averages of individual years. Nobs for awp is NC, the number of occurrences of a cloud type for which an amount was computable. (For low clouds NC=NTy; for upper clouds NC is generally less than NTy.) The Nobs given in a data record for amt is the same as that for fq, though amt may be missing for middle or high clouds (assigned the Mcode) if NC is inadequate (NC < mina as described in Section 3.4). The minimum used in computing avgDN and Acode was 100 for fq and amt, and 50 for awp. In DJF, Acode=2 was obtained by 5352 stations for Tc and by 4877 stations for Hi awp. Examples (g-i) in Table 8 show amt, fq and awp, respectively, for St for station 15235 in DJF. The nighttime frequency here is quite low (0.93%) so although NobN=1941, there are only 18 occurrences of St from which to compute awp (90.28%). Although the Acode for both fq and amt is 2, and awpDN is computed as amtDN/fqDN (Section 3.4), the Acode assigned to awpDN here is 3, signifying that NC for either Dy or Nt (or both) is less than 50 while NC for DN is =50 (221 in this case). In these examples only one of the 4 or 5 SCDGs contained in the file (see Appendix C) is shown. Example (j) lists all 4 SCDGs in the file for middle and high cloud frequency for JJA. Data records are shown for station 30692. Example (k) shows the sum of low cloud amounts for DJF for 3 stations. Station 21749 has few obs in this season as was seen in Example (c). Station 62840 in Africa has only a small amount of low clouds (1.40%) while station 89065 on the Antarctic Peninsula has much more (40.29%). Example (l) shows the use of bogus awp (see Section 5.1 below) for Hi (46%) for station 97760. 4.4. File Category 6: Mean Seasonal Non-overlapped Amount for Upper Clouds (MSUU) Category 6 (Format 121) contains the mean-seasonal averages of the non-overlapped amount for the four middle and high cloud types. The min used in computing avgDN and Acode for non-overlapped amounts was 100, and the consequent number of stations with Acode=2 is 5352 for Hi in DJF, for example. Example (m) in Table 8 shows NOL for the four upper types for MAM for two stations. Station 46734 has a small NOL_Hi averaged over day and night (AvgDN= 1.67%, Acode=2), while station 89544 has much larger amount averaged from mostly daytime obs (14.90%, Acode=3). 4.5. File Category 7: Mean Seasonal Low Cloud Base Height (MSLH) Category 7 (Format 122) contains the base heights for the four low cloud types: St, Sc, Cu, Cb (Hgt for Fo is, by definition, zero). Format 122 differs from Format 121 only in that Avg for Hgt is given to whole meters (F6.0). Nobs for height may be less than NTy since h (Table 1) is not always reported. AvgDN for base height was computed from all available obs, as explained in Section 3.4. Using a min of 50 to determine Acodes, 4463 stations have Acode=2 for Sc in DJF. Fewer stations had Acode=2 for other types which occur less frequently. Example (n) in Table 8 lists data records for two stations in the SCDGs for low cloud base heights for JJA. The average height of St at station 98851 is 513m as computed from only 52 obs. Cu is far more common in this case with 5331 obs and an average height of 516m. Station 21749, by contrast, has a height of 310m for St from 1189 obs and a height of 798m for Cu from 162 obs. 4.6. File Categories 8&9: Mean Monthly Cloud Amount & Frequency (MMCA, MMCF) Categories 8 & 9 (Format 121) contain the mean-monthly averages for amt and fq. The min used in the computation of AvgDN for these files was 75. The number of stations with Acode=2 for January, for example, is 5283 for Tc, 5082 for fq_Hi and 5059 for amt_Hi. No examples are shown in Table 8 because the principles are the same as for Categories 3 & 4 discussed above. These files were used in computing the annual cycles in Category 14. 4.7. File Categories 10-13: Mean Seasonal Averages by Synoptic Hour (MSAT, MSFT, MSUT, MSHT) Categories 10-13 (Formats 138 and 139) give cloud variable averages (seasonally) for the eight synoptic hours. Formats 138 and 139 contain fewer variables than Formats 121 and 122 used above but eight data lines (one for each hour) are given for each station. No min was applied for computing these averages (except mina for amt of upper clouds) so the user must check Nobs (and Mcode for amt) to evaluate the representativeness of the average given. These files were used in computing the diurnal cycles in Category 14. Example (o) in Table 8 lists the data records for two stations for the frequency of clear sky in SON. Station 84782 (Tacna, Peru) has at least 300 obs for all 8 hours while station 72469 (Denver) exceeds 75 obs at only the four 6-hourly times. Cr is reported more frequently at night at Denver but more frequently in the daytime at Tacna. (GMT can be converted to LT by using the station longitude given in Category 1.) 4.8. File Category 14: Annual and Diurnal Cycles (HARM) Category 14 (Formats 140 and 148) gives the phase (PHASE), amplitude (AMP), and variance accounted for (VAF) of the first harmonic of the annual cycle (DN averages only) and diurnal cycle for cloud amount and frequency. PHASE is the time of maximum of the fitted cosine curve. Formats 140 and 148 differ only in that the label "140" is used to signify that the values of PHASE and NT are representative of months whereas the label "148" is used to signify that PHASE and NT are representative of hours of the day (see Table 7). AVG is the average of the 12 monthly (annual cycle) or 8 (or 4) hourly (diurnal cycle) values; these averages may differ slightly from each other and from the annual averages given in Category 2. Annual cycles were computed from the monthly (DN) averages in Categories 8-9 and are given for a station only if all 12 months had Acode=2 (min 75 both day and night). Mcode was inserted for the variables if the number of months (NT) was less than 12. In this way, annual cycles were obtained for 5240 stations for Tc, 4913 stations for Fq_Hi and 4829 stations for Amt_Hi. Example (p) in Table 8 shows the annual harmonic parameters for Tc for 4 stations. Station 89544 did not have 75 obs both day and night in any year so the Mcode was inserted for the variables. The other 3 stations are located in the USA (Tucson, Denver and Seattle, respectively) and have distinctly different climates from each other. Tucson, with the lowest annual cloud amount (38.6%) of the three, shows a small maximum (AMP=1.39% absolute cloud cover) in early December (PHASE=11.86), but VAF is quite small (0.12%). Denver, with an annual cloud amount of 52.6%, shows a larger and more significant cycle (AMP=6.44%) with the maximum in late March (PHASE=3.30) and VAF= 69.6%. Seattle has the greatest cloud cover (69.3%) and the largest variation (AMP=12.35%, VAF= 69.1%) with its maximum in early Feb (PHASE=1.55). Diurnal cycles were computed from the 3-hourly averages given in Categories 10 & 11. The diurnal parameters for a station are given, in the Category 14 files, if each of the 8 hours had a minimum of 75 obs or if each of the four 6-hourly times (0,6,12,18 GMT) had the minimum 75 obs. A station with 8 hours by this test was then tested for the ratio N6/N3, where N6 is the total number of obs at the 6-hourly times and N3 is the total number of obs at the intermediate 3-hourly times. If this ratio exceeded 4.0 then the diurnal cycle was computed from only the four 6-hourly averages. This was done to reduce a possible bias which may result if reports are made at the intermediate 3-hourly times only in special weather conditions. Diurnal cycles for Tc in DJF, for example, were computed for 4755 stations. Of those, 993 cycles were computed from only 4 hours; of these, 16 had 75 obs for all 8 hours but failed the N6/N3 test. Example (q) in Table 8 gives the diurnal parameters for Fq_Cr in SON for the two stations listed in Example (o) discussed in Section 4.7. With all 8 hours contributing, station 84782 shows an amplitude of 30.66% (around a mean of 32.4%) with the maximum around 3 PM local time. Only 4 hours contributed to the computations for station 72469 which shows an amplitude of 14.06% around an average of 16.9% with the maximum occurring around 2 AM. Both stations showed a large VAF (77.0 and 73.8, respectively) indicating that the first harmonic represents the diurnal cycle fairly well. 4.9. File Categories 15-30: Seasonal Averages by Year (SMCA, SMCF, SMUU, SMHL) Categories 15-30 (Formats 126 and 127) provide Dy, Nt and DN averages of the cloud variables for the individual years (1971-96) of each season. The data record for a station contains 26 lines, one for each year, listed in ascending order by year (the year is not included in the data line). The min used in the computation of AvgDN in these files varied with the cloud type because LOBS = MOBS = HOBS, and Nobs becomes limiting as the period of averaging becomes small. A station making one report each night could have a maximum NobN of about 90 for a 3-month season. About 60% of these reports will be excluded by the illuminance criterion and reports are occasionally missing from the source data set due to failures in data transmission or archiving. Considering these factors, we used the mins listed in the following table in computing AvgDN and in setting the Acode for an individual year-season. min variable 35 Tc, Cr, low clouds, NOL and Fq_Ns 30 As, Ac and Amt_Ns 25 Hi 20 Hgt (min used for Acode only; Hgt is computed from all available obs) Using these mins, for DJF for example, the number of stations with Acode=2 in 15 or more years for Tc is 4119 while the number for Amt_Hi is 3536. Example (r) in Table 8 lists the Cu amounts by year for MAM for station 94248 (Centre Island, northern Australia). This example demonstrates a variety of averaging possibilities. There are 18 years with Acode=2 for AvgDN, such as in 1980 for which AvgDN = 6.44% = (9.76 + 3.12)/2. In 1971 there were 64 obs, all for daytime, so Mcode appears for AvgNt, and AvgDN (7.42) was computed from the daytime obs with Acode=3. In 1976 there were 131 obs but only 22 for nighttime so AvgDN was computed from all the obs with Acode=3. In 1972 there were only 3 obs so Acode=1. There were no obs at all for 1975 so all averages were assigned the Mcode and Acode=0. This example also shows the increase in the number of reports from 1988 to 1989, as is seen for many Australian stations, due to inclusion of intermediate 3-hourly reports beginning at that time. These files can be used in analyzing trends in cloud cover. Again, mins were not applied for Dy and Nt averages so NobD and NobN must be consulted to choose representative averages. Middle and high cloud amounts must also be checked for the Mcode. 4.10. File Categories 31-42: Monthly Daytime Averages by Year (MNYD) Categories 31-42 (Format 162) give monthly averages for individual years (1971-96) for selected cloud variables. Because more than half of nighttime reports are excluded by the illuminance criterion, nighttime averages for a single month cannot be fully representative of that month. Therefore we give only daytime averages for cloud variables for individual months. It is then convenient to include the three cloud variables (amt, fq, awp) in a single data record (Format 162). The data record for a single year includes Nobs, Amt, Fq, AWP and NC. NC is the number (note exception below) of occurrences of a cloud type for which AWP was computable (and Amt = Fq * AWP). Again, to allow for user flexibility, no min is applied in presenting these averages so the user is responsible for checking Nobs (the maximum possible NobD per month is 124) to determine reliability of Fq, and for checking NC to determine the reliability of AWP and Amt. There are two special situations, involving AWP for middle and high cloud types, for which NC is assigned a code value (<0) instead of the number of computable occurrences. Values of -1 or -2 are used to indicate that one of two types of bogus values for AWP has been used to compute Amt (see Section 5.1 below). NC is not applicable for Tc or Cr and is there assigned the value -9 (and AWP=Mcode). Example (s) in Table 8 shows a few years of data (Ac cloud variables for Januarys) for each of three stations. For station 01035 in 1978 there were 19 obs and Fq_Ac was 15.79% (NTy=3) but AWP was not computable in any report (NC=0) so AWP and Amt contain the Mcode. NC=0 also in 1977 so AWP=Mcode but Amt=0 because Fq=0. The sample listing for the China station 54511 shows NC=-2 for 1978 and 1979 indicating that AWP (29.83) was obtained from 1980-89 data (Section 5.1). For station 97900, a bogus value of AWP (51% for Ac; Section 5.1) was used in all years. Example (t) shows a partial listing of high cloud data for Decembers for a station in the USA (72290, San Diego). Synoptic weather reports no longer appeared in the source data set after 1995 for this and many other USA stations (Hahn & Warren 1999). 5. IMPORTANT NOTES ON USE OF THIS DATA SET 5.1. Stations with Bogus Amount-When-Present China. Because of problems in China's reporting procedures in the 1970's [described in detail by Warren et al. (1986) and by Hahn and Warren (1999)], we assigned to AWP, for middle cloud types for the years 1971-79, a value obtained by averaging AWP for 1980-89 (averaged and applied for each of the 12 months separately). This is indicated in Categories 31-42 by the value "-2" assigned to NC (Format 162) for all China stations (StaID begins with "5") for data records for the years 1971-79. Thus any interannual variations of middle cloud amounts obtained in China for these years will be due solely to interannual variations of frequency. Indonesia and South America. During preliminary analyses, we discovered that there were two equatorial regions in which the ratio NC/NTy for upper cloud types (the number of times the cloud amount was computable, divided by the number of times the cloud was present) was quite small (<0.25 compared to 0.7 globally). Our analysis suggested that the average AWPs obtained from this small sample were unrepresentative. We chose therefore to apply appropriate mean values to AWP for the stations in the affected region. Global, mean annual values for DN averages of AWP were obtained in the preliminary analysis. The values (applied to all seasons and times) used for AWP are 98% for Ns, 80% for As, 51% for Ac, and 46% for Hi. The stations affected lie in an irregular region between latitudes 10N and 10S and between longitudes 95E and 175E (includes Indonesia and other islands) and in a much smaller region of South America from 0 to 10N and 55 to 60W. StaIDs for the 155 stations affected are listed in Appendix B. Ten stations were added to a preliminary list of 145 stations after completion of Categories 2-14. These "bogus" values of AWP appear in the Dy, Nt and DN avgs in Category 5 for these stations. In Categories 31-42 a "-1" appears in the NC variable. Interannual and diurnal variations of middle or high cloud amounts for these stations will be due solely to variations of frequency. 5.2. Minimum Observations, the Missing-Value Code, and the A-code We did not impose a minimum number of observations to report averages for the individual synoptic hours, the day average or the night average. This allows the user to aggregate the data in any manner. However, this also REQUIRES THE USER TO CHECK the sum of Nobs against a user-specified min, and to check an Amt for Mcode before using the data. (The amount of middle or high clouds may be "missing" even when Nobs>0 if AWP is unavailable, as discussed above.) The Acode is a convenient guide for evaluating DN averages if one accepts the mins applied in creating this archive. 6. HOW TO OBTAIN THE DATA This documentation and the data described herein are available from: Carbon Dioxide Information Analysis Center Oak Ridge National Laboratory Post Office Box 2008 Oak Ridge, TN 37831-6335, U.S.A. (http://cdiac.esd.ornl.gov/by_new/bynumber.html) The following citation should be used for referencing this archive and/or this documentation report: Hahn, C.J., and S.G. Warren, 2002: Cloud Climatology for Land Stations Worldwide, 1971-96. NDP-026D, Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, Oak Ridge, TN. (Email to authors: hahn@atmo.arizona.edu; sgw@atmos.washington.edu.) ACKNOWLEDGMENTS This work was supported by NSF Climate Dynamics (Geosystems Database Infrastructure Program), and NOAA Climate Change Data and Detection Program, under grants ATM-99-08699 and ATM-99-08700, and by a computing grant from NCAR. REFERENCES Hahn, C.J., S.G. Warren, J. London, and R.L. Jenne, 1988: Climatological Data for Clouds Over the Globe from Surface Observations. NDP-026, Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, Oak Ridge, TN. (Also available from Data Support Section, National Center for Atmospheric Research, Boulder, CO.) Hahn, C.J., S.G. Warren, and J. London, 1994: Climatological Data for Clouds Over the Globe from Surface Observations, 1982-1991: The Total Cloud Edition. NDP-026A, Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, Oak Ridge, TN. (Also available from Data Support Section, National Center for Atmospheric Research, Boulder, CO.) Hahn,C.J., S.G.Warren and J. London, 1995: The effect of moonlight on observation of cloud cover at night, and application to cloud climatology. J. Climate, 8, 1429-1446. Hahn, C.J., and S.G. Warren, 1999: Extended Edited Synoptic Cloud Reports from Ships and Land Stations Over the Globe, 1952-1996. NDP-026C, Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, Oak Ridge, TN. Warren, S.G., C.J. Hahn, J. London, R.M. Chervin and R.L. Jenne, 1986 (W86): Global Distribution of Total Cloud Cover and Cloud Type Amounts over Land. NCAR Technical Note TN-273+STR, Boulder, CO, 29 pp. + 200 maps (also DOE/ER/60085-H1). Warren, S.G., J. London and C.J.Hahn, 1991: Cloud Hole Over the United States? Bull. Amer. Meteor. Soc., 72, 237-238. World Meteorological Organization, 1988: Weather Reporting/Messages Meteorologiques, Volume A, Stations. ( WMO Publ. No. 9), WMO, Geneva. World Meteorological Organization, 1988: Manual on Codes, Volume 1. (WMO Publ. No. 306), WMO, Geneva. TABLE 1. CLOUD INFORMATION CONTAINED IN SYNOPTIC WEATHER REPORTS^ ________________________________________________________________ Symbol Meaning Codes# ________________________________________________________________ N total cloud cover 0-8 oktas 9= sky obscured Nh lower* cloud amount 0-8 oktas h lower* cloud base height 0-9 CL low cloud type 0-9 CM middle cloud type 0-9 CH high cloud type 0-9 ww present weather 00-99 Ix present weather indicator 1-6 ________________________________________________________________ ^ Reports are made 8 times per day: 00, 03, 06, 09, 12, 15, 18, 21 GMT. # Oktas are eights of sky cover, with "0" meaning completely clear sky and "8" meaning completely overcast sky. Any category for which information is lacking is coded as "/". * The "lower" cloud is the middle level if there are no low clouds. TABLE 2. CLOUD TYPE AND WEATHER TYPE DEFINITIONS USED ______________________________________________________________________________ Shorthand Extended Level notation Meaning Synoptic codes codes# ______________________________________________________________________________ Tc total cloud cover N = 0-9 0-8 Cr completely clear sky N = 0 Ppt precipitation ww= 50-75,77,79,80-99 D drizzle 50-59 R rain 60-69 S snow 70-75,77,79 Ts thunderstorm or shower 80-99 Low CL= Fo sky obscured by fog / with N=9 and 11 ww=10-12,40-49 St stratus 6,7 Sc stratocumulus 4,5,8 Cu cumulus 1,2 Cb cumulonimbus 3,9, or N=9 with ww=Ts 10 LoL Fo + St + Sc + Cu + Cb Mid CM= Ns nimbostratus 2,7, or N=9 with ww=DRS 12,11,10 / with ww=DRS and CL=0,7 10 / with ww= RS and CL=4-8 10 As altostratus 1; 2 if not DRS Ac altocumulus 3,4,5,6,8,9; 7 if not DRS MiL Ns + As + Ac High CH= Ci or Hi cirriform clouds 1-9 ______________________________________________________________________________ # Used in the source data set, the EECRA (NDP-026C). Extended codes are shown where they differ from synoptic codes. In the extended code the value "-1", rather than "/", is used to signify missing information. TABLE 3. DATA FILE CATEGORIES FOR LAND STATION CLOUD ARCHIVE, 1971-1996 ________________________________________________________________________________ File Category General contents* Num of Logical Char per fmt Mega- Cat. abbrev. (for 5388 Stations) Types records data_rec num Bytes ____ _______ ______________________________ ___ _________ ________ ___ ______ _ RDME README (brief documentation) 812 80 80 0.07 1 STID STATION ID, Lat, Lon, Elev 5,389 48 111 0.26 & Number of Years Contributing ------------------------------------------------------------------------------- 2 MACA Mean Annual Cloud AMOUNT 13 70,057 46 121 3.2 ------------------------------------------------------------------------------- 3 MSCA Mean Seasonal Cloud AMOUNT 12 258,672 46 121 11.9 4 MSCF Mean Seasonal Cloud FREQUENCY 10 215,560 46 121 9.9 5 MSAW Mean Seasonal AMT-WHEN-PRESENT 8 172,448 46 121 7.9 6 MSUU Mean Seasonal Mid,Hi Cloud NOL 4 86,224 46 121 4.0 7 MSLH Mean Seasonal Low Cloud Base HGT 4 86,224 46 122 4.0 ------------------------------------------------------------------------------- 8 MMCA Mean Monthly Cloud AMOUNT 10 646,680 46 121 29.7 9 MMCF Mean Monthly Cloud FREQUENCY 10 646,680 46 121 29.7 ------------------------------------------------------------------------------- 10 MSAT Mean Seasonal Cloud AMOUNT 10 215,560 8*20 138 34.5 by synoptic hour 11 MSFT Mean Seasonal Cloud FREQUENCY 10 215,560 8*20 138 34.5 by synoptic hour 12 MSUT Mean Seasonal Mid,Hi NOL 4 86,224 8*20 138 13.8 by synoptic hour 13 MSHT Mean Seasonal Low Base HEIGHT 4 86,224 8*20 139 13.8 by synoptic hour 14 HARM Harmonics: DIURNAL, ANNUAL 11 291,006 26 140 7.6 ------------------------------------------------------------------------------- 15 SMCA Seasonal Mean Cloud AMT, DJF 10 53,890 26*46 126 64.4 16 SMCA Seasonal Mean Cloud AMT, MAM 10 53,890 26*46 126 64.4 17 SMCA Seasonal Mean Cloud AMT, JJA 10 53,890 26*46 126 64.4 18 SMCA Seasonal Mean Cloud AMT, SON 10 53,890 26*46 126 64.4 19 SMCF Seasonal Mean Cloud FQ, DJF 10 53,890 26*46 126 64.4 20 SMCF Seasonal Mean Cloud FQ, MAM 10 53,890 26*46 126 64.4 21 SMCF Seasonal Mean Cloud FQ, JJA 10 53,890 26*46 126 64.4 22 SMCF Seasonal Mean Cloud FQ, SON 10 53,890 26*46 126 64.4 23 SMUU Seasonal Mean Mid,Hi NOL, DJF 4 21,556 26*46 126 25.8 24 SMUU Seasonal Mean Mid,Hi NOL, MAM 4 21,556 26*46 126 25.8 25 SMUU Seasonal Mean Mid,Hi NOL, JJA 4 21,556 26*46 126 25.8 26 SMUU Seasonal Mean Mid,Hi NOL, SON 4 21,556 26*46 126 25.8 27 SMHL Seasonal Mean Base HEIGHT, DJF 4 21,556 26*46 127 25.8 28 SMHL Seasonal Mean Base HEIGHT, MAM 4 21,556 26*46 127 25.8 29 SMHL Seasonal Mean Base HEIGHT, JJA 4 21,556 26*46 127 25.8 30 SMHL Seasonal Mean Base HEIGHT, SON 4 21,556 26*46 127 25.8 ------------------------------------------------------------------------------- 31 MNYD Monthly Day AMT, FQ, AWP JAN 11 59,279 26*34 162 52.4 | | 42 MNYD Monthly Day AMT, FQ, AWP DEC 11 59,279 26*34 162 52.4 ________________________________________________________________________________ 1-14 (long term averages) 3,082,508 205 15-30 (individual year-season avgs) 603,568 722 31-42 (individual year-month avgs) 711,348 629 1-42 3,397,424 1,555 * The specific cloud types given within each category are listed in footnote to Table 4. Data formats are given in Table 6. Abbreviations used are defined in Table 7. TABLE 4. DATA ORGANIZATION FOR LAND STATION CLOUD ARCHIVE,1971-1996 ______________________________________________________________________________ File Num of SCDG Data Cat.* SCDGs numbers# Contents** (File Category name abbreviation) Format _____ ______ _________ _______________________________________________ ______ STATION ID (STID) 1 1 01001 LAND_STATION_ID, Lat,Lon, Elev, Yrs of data 111 ------------------------------------------------------------------------------ MEAN-ANNUAL AVERAGES (MACA) 2 13 02001-13 Mean-Annual CLOUD AMOUNT & CLEAR-SKY FQ 121 ANN: 1 Tc 5388 Stations 2 Cr 5388 Stations 3 Fo " 4 St " 5 Sc " 6 Cu " 7 Cb " 8 Ns " 9 As " 10 Ac " 11 Hi " 12 MiL " 13 LoL " ------------------------------------------------------------------------------ MEAN-SEASONAL AVERAGES 3 48 03001-48 Mean-Seasonal Cloud AMOUNT (MSCA) 121 1-12 DJF: 12 TYPES, 5388 Stations 13-24 MAM: 12 TYPES, 5388 Stations 25-36 JJA: 12 TYPES, 5388 Stations 37-48 SON: 12 TYPES, 5388 Stations 4 40 04001-40 Mean-Seasonal Cloud FREQUENCY (MSCF) 121 1-10 DJF: 10 TYPES, 5388 Stations 11-20 MAM: 10 TYPES, 5388 Stations 21-30 JJA: 10 TYPES, 5388 Stations 31-40 SON: 10 TYPES, 5388 Stations 5 32 05001-32 Mean-Seasonal AMOUNT-WHEN-PRESENT (MSAW) 121 1-8 DJF: 8 TYPES, 5388 Stations 9-16 MAM: 8 TYPES, 5388 Stations 17-24 JJA: 8 TYPES, 5388 Stations 25-32 SON: 8 TYPES, 5388 Stations 6 16 06001-16 Mean-Seasonal NON-OVERLAPPED AMT Upper (MSUU) 121 4 SEASONS, 4 TYPES, 5388 Stations 7 16 07001-16 Mean-Seasonal BASE HEIGHTs Low Clouds (MSLH) 122 4 SEASONS, 4 TYPES, 5388 Stations ------------------------------------------------------------------------------ MEAN-MONTHLY AVERAGES 8 120 08001-120 Mean-Monthly Cloud AMOUNT (MMCA) 121 12 MONTHS (Jan-Dec), 10 TYPES, 5388 Stations 9 120 09001-120 Mean-Monthly Cloud FREQUENCY (MMCF) 121 12 MONTHS, 10 TYPES, 5388 Stations ------------------------------------------------------------------------------ MEAN-SEASONAL by SYNOPTIC HOUR 10 40 10001-40 Mean-Seasonal Cloud AMOUNT by Hour (MSAT) 138 4 SEASONS, 10 TYPES, 5388 Stations, 8 Hrs 11 40 11001-40 Mean-Seasonal Cloud FREQUENCY by Hour (MSFT) 138 4 SEASONS, 10 TYPES, 5388 Stations, 8 Hrs 12 16 12001-16 Mean-Seasonal NOL Upper Clouds by Hour (MSUT) 138 4 SEASONS, 4 TYPES, 5388 Stations, 8 Hrs 13 16 13001-16 Mean-Seasonal BASE HGT Low by Hour (MSHT) 139 4 SEASONS, 4 TYPES, 5388 Stations, 8 Hrs ------------------------------------------------------------------------------ HARMONIC ANALYSES (HARM) 14 100 14001-100 Annual and Diurnal Cycles, First Harmonic 1-10 ANNUAL CYCLE AMOUNT (DN) 140 10 TYPES, 5388 Stations 11-20 ANNUAL CYCLE FREQUENCY (DN) 140 10 TYPES, 5388 Stations 21-60 DIURNAL CYCLE AMOUNT 148 4 SEASONS, 10 TYPES, 5388 Stations 61-100 DIURNAL CYCLE FREQUENCY 148 4 SEASONS, 10 TYPES, 5388 Stations ------------------------------------------------------------------------------ SEASONAL-MEAN AVERAGES each SEASON: 10 TYPES, 5388 Stations, 26 Yrs (SMCA) 15 10 15001-10 Seasonal-Mean CLOUD AMOUNT, DJF 126 16 10 16001-10 Seasonal-Mean CLOUD AMOUNT, MAM 126 17 10 17001-10 Seasonal-Mean CLOUD AMOUNT, JJA 126 18 10 18001-10 Seasonal-Mean CLOUD AMOUNT, SON 126 each SEASON: 10 TYPES, 5388 Stations, 26 Yrs (SMCF) 19 10 19001-10 Seasonal-Mean CLOUD FREQUENCY, DJF 126 20 10 20001-10 Seasonal-Mean CLOUD FREQUENCY, MAM 126 21 10 21001-10 Seasonal-Mean CLOUD FREQUENCY, JJA 126 22 10 22001-10 Seasonal-Mean CLOUD FREQUENCY, SON 126 each SEASON: 4 TYPES, 5388 Stations, 26 Yrs (SMUU) 23 4 23001-4 Seasonal-Mean NOL Upper Clouds, DJF 126 24 4 24001-4 Seasonal-Mean NOL Upper Clouds, MAM 126 25 4 25001-4 Seasonal-Mean NOL Upper Clouds, JJA 126 26 4 26001-4 Seasonal-Mean NOL Upper Clouds, SON 126 each SEASON: 4 TYPES, 5388 Stations, 26 Yrs (SMHL) 27 4 27001-4 Seasonal-Mean BASE HGT Low Clouds, DJF 127 28 4 28001-4 Seasonal-Mean BASE HGT Low Clouds, MAM 127 29 4 29001-4 Seasonal-Mean BASE HGT Low Clouds, JJA 127 30 4 30001-4 Seasonal-Mean BASE HGT Low Clouds, SON 127 ------------------------------------------------------------------------------ MONTHLY-MEAN AVERAGES, DAY (MNYD) each MONTH: 11 TYPES, 5388 Stations, 26 Yrs 31 11 31001-11 Monthly-Mean Daytime Cloud AMT,FQ,AWP, JAN 162 32 11 42001-11 Monthly-Mean Daytime CLOUD AMT,FQ,AWP, FEB 162 33 11 42001-11 Monthly-Mean Daytime CLOUD AMT,FQ,AWP, MAR 162 34 11 42001-11 Monthly-Mean Daytime CLOUD AMT,FQ,AWP, APR 162 35 11 42001-11 Monthly-Mean Daytime CLOUD AMT,FQ,AWP, MAY 162 36 11 42001-11 Monthly-Mean Daytime CLOUD AMT,FQ,AWP, JUN 162 37 11 42001-11 Monthly-Mean Daytime CLOUD AMT,FQ,AWP, JUL 162 38 11 42001-11 Monthly-Mean Daytime CLOUD AMT,FQ,AWP, AUG 162 39 11 42001-11 Monthly-Mean Daytime CLOUD AMT,FQ,AWP, SEP 162 40 11 42001-11 Monthly-Mean Daytime CLOUD AMT,FQ,AWP, OCT 162 41 11 42001-11 Monthly-Mean Daytime CLOUD AMT,FQ,AWP, NOV 162 42 11 42001-11 Monthly-Mean Daytime CLOUD AMT,FQ,AWP, DEC 162 ______________________________________________________________________________ * Abbreviations and non-standard terms are defined in Table 7. # Data group (SCDG) numbers encoded in header format 120 are: (file_category_number x 1000) + (sequence-number within file category). Order of data groups in a multi-group file is: hold LEFT (upper) group qualifier constant and increment RIGHT (lower) qualifier. ** Not all types are given in every file. The rule applied is: "13 types" means Tc, Cr, Fo, St, Sc, Cu, Cb, Ns, As, Ac, Hi, MiL, LoL. "12 types" means Tc, Fo, St, Sc, Cu, Cb, Ns, As, Ac, Hi, MiL, LoL. "11 types" means Tc, Cr, Fo, St, Sc, Cu, Cb, Ns, As, Ac, Hi. "10 types" means Tc, Fo, St, Sc, Cu, Cb, Ns, As, Ac, Hi (for Amt). or means Cr, Fo, St, Sc, Cu, Cb, Ns, As, Ac, Hi (for Fq). " 8 types" means St, Sc, Cu, Cb, Ns, As, Ac, Hi (for Awp). " 4 types" means Ns, As, Ac, Hi (for NOL), or means St, Sc, Cu, Cb (for Hgt). TABLE 5. HEADER RECORD FORMAT (Format 120) AND CODES* USED FOR LAND STATION CLOUD CLIMATOLOGY ARCHIVE# ___________________________________________________________________________ Format I5 I5 I3 I2 I3 I2 I5 I3 I4 Parameter SCDG NSTA SIZE LO TYPE PCODE YEAR SN FMT Values 10001 5388 0 1=Land 1=Tc 0=AFW (1951) 0=ANN 111 | (820) (5) (2=Ocean) 2=Cr 1=AMT | 121 42011 (1820) (10) (3=Global) (3=Ppt) 2=FQ 1971 1=Jan 122 11=Fo 3=AWP | | 126 12=St 4=NOL 1996 12=Dec 127 13=Sc 5=HGT (5296) 138 14=Cu 7196 41=DJF 139 15=Cb 42=MAM 140 21=Ns 43=JJA 148 22=As 44=SON 162 23=Ac 30=Hi 20=MiL 10=LoL ___________________________________________________________________________ * Terms are defined in text or in Tables 2 & 7. # Values in parentheses are not used in this Land Station Archive but are included to show generalized header record to be used also in land and ocean gridded climatologies. TABLE 6. DATA FORMATS* FOR READING LAND STATION CLOUD CLIMATOLOGY ______________________________________________________________________________ Format Variables (Num of characters Files# in number & Format in record) which used ______ ______________________________________________________________________ 80 Text: 812A80 (80) F0 ------ 110 I5 I5 I3 I2 I3 I2 I5 I3 I4 (32) F1,Header SCDG NSTA SIZE LO -9 -9 YR -9 FMT 111 I5 F6.2 F6.2 I5 I3 I3 I3 I3 I3 I3 I3 I5 (48) F1,Data StaID LAT LON ELEV ny1 fy1 ly1 ny7 fy7 ly7 SDC b5c ------ 120 I5 I5 I3 I2 I3 I2 I5 I3 I4 (32) Headers SCDG NSTA SIZE LO TYPE PCODE YR SN FMT Data: 121 I5 I7 F6.2 I7 F6.2 I7 F6.2 I2 (46) StaID NobD AvgDy NobN AvgNt NobDN AvgDN Acode F3-6,8-9 StaID NSNd AvgDy NSNn AvgNt NSNdn AvgDN Acode F2 122 I5 I7 F6.0 I7 F6.0 I7 F6.0 I2 (46) F7 StaID NobD AvgDy NobN AvgNt NobDN AvgDN Acode 126 26(I5 I7 F6.2 I7 F6.2 I7 F6.2 I2) (26x 46) F15-26 StaID NobD AvgDy NobN AvgNt NobDN AvgDN Acode 127 26(I5 I7 F6.0 I7 F6.0 I7 F6.0 I2) F27-30 138 8( I5 I3 I6 F6.2) (8x 20) F10-12 StaID HR Nobs Avg 139 8( I5 I3 I6 F6.0) F13 140 I5 F5.2 F5.2 F4.1 I3 F4.1 (26) F14 StaID PHASE AMP VAF NT AVG 148 " " " " " " 162 26( I5 I3 I4 F6.2 F6.2 F6.2 I4 ) (26x 34) F31-42 StaID YR Nobs Amt Fq AWP NC ______________________________________________________________________________ * Abbreviations are defined in text or in Table 7. The value "-9" in Format 110 means that the variable (used in Format 120) is not applicable. # File categories (F1-F42) are listed in Tables 3 & 4 and discussed in Section 4. TABLE 7. GLOSSARY OF TERMS AND ABBREVIATIONS USED ______________________________________________________________________________ Term Meaning and description ---- ---------------------------------------------------------- Acode "Average code" for avgDN; indicates relations between NobD, NobN and min: Acode Nobs AvgDN 0 0 missing value entered 1 NobD+NobN < min avg all obs [except awp=amt/fq] 2 NobD>min and NobN>min (avgDy+avgNt)/2 [except awp=amt/fq and avg all obs for Hgt] 3 NobD+NobN>min avg all obs [except awp=amt/fq] AFW Amount, Frequency, Amount-When-Present. AMP Absolute amplitude of harmonic (not normalized). Amt Amount of cloud cover (actual). ANN Annual. Avg Average (of Amt, Fq, AWP, NOL or Hgt). AvgDy, AvgNt Average of daytime or nighttime obs. AvgDN Average over day and night ("daily" or "diurnal" average). AWP Amount-When-Present. B5c One of 1820 grid boxes distributed over the globe such that the dimensions (lat x lon) of the boxes are 5x5 deg between 50N and 50S, 5x10 deg for lats 50-70, 5x20 deg for lats 70-80, 5x40 deg for lats 80-85, and 5x360 deg for lats 85-90. The boxes are numbered east-to-west (beginning at the Greenwich Meridian) and north-to-south. Cat. Category. D, Dy Abbreviation or suffix meaning "daytime". day Refers to either the full 24-hour day or to "daytime" (q.v.), depending on context. daytime Local time 06-18. Abbreviations used are Dy and D. DJF December, January, February. EECRA Extended Edited Cloud Report Archive (Hahn & Warren, 1999). EECR A report in the EECRA. ELEV Station elevation in meters. FMT Data format number (see Table 6). Fq Frequency of occurrence (actual). GMT Greenwich Mean Time. Hgt Low cloud base height (given in meters). HR Hour. (00, 03, 06, 09, 12, 15, 18, 21 GMT) HOBS Number of obs with cloud information for the high level. JJA June, July, August. Lat Latitude (-90 to 90 degrees North). Lon Longitude (0 to 360 degrees East). light obs Obs that satisfy the illuminance criterion of Hahn et al.(1995). LOBS Number of obs with cloud information for low level. LoL Sum of all clouds in the low level. Low Low level cloud types (Fo, St, Sc, Cu, Cb). LT Local time; determined from Lon in File Cat. 1. MAM March, April, May. Mcode Missing-value code (q.v.). mean seasonal Average over several years for a season. Mid Middle level cloud types (Ns, As, Ac). MiL Sum of all clouds in the middle level (if none missing). min Minimum number of obs used for averaging or reporting. mina = minimum NC required for computing amts for Hi or Mid clouds. = min * Fq * 0.6. missing-value code The integer -90000 (-900 for hgt and harmonic parameters); put in data record where no legitimate value is computed. mns Months. (Jan,Feb,Mar,Apr,May,Jun,Jul,Aug,Sep,Oct,Nov,Dec) MOBS Number of obs with cloud information for middle level. N 1) Number (of obs, etc.); used with other abbreviations. 2) Used as suffix for "night" (as in "NobN"). 3) Symbol for total cloud cover in Synoptic Code.) NC Number of obs with cloud type present and amount computable. night(time) Local time 18-06. Abbreviations used are Nt and N. Nobs Number of observations; generic for LOBS,MOBS,HOBS, NTy, NC. NOL Non-overlapped amount; the amount of a middle or high cloud visible from below. NSN Number of seasons contributing to the annual average. NSTA Number of land stations for which data are given (5388). Nt Abbreviation or suffix for "nighttime" (distinct from NT). NT Number of HRs used (4 or 8) for diurnal harmonic analysis or number of months used (12) for annual harmonic analysis. NTy Number of times a cloud type was reported present. Num Number. obs Cloud reports or observations. PC Pcode (q.v.). Pcode Parameter code: 0=AFW, 1=Amt, 2=Fq, 3=AWP, 4=NOL, 5=Hgt. PHASE Phase of first harmonic (time of maximum). Diurnal: 0-24 hours mean solar time of station longitude; when indeterminate (AMP=0), value was set to "-899". Annual: month (0.5 to 12.4 [1.0 = middle of January, etc.]; 0 if AMP=0). SCDG Station Cloud Data Group number. Aid in identifying data. SDC Station data code. See text for File Cat. 1 (Section 4.1) and Appendix A4. seasonal mean Average for an individual year for a particular season. SN Season or month indicator in header record or file names. SON September, October, November. StaID Station identification number (5 digits) assigned by WMO. upper cloud Clouds in middle or high levels. VAF Percent variance accounted for by the first harmonic. WMO World Meteorological Organization. YEAR, YR Year(s) that apply to data group. Coded as 19yr or as yfyl for multi-year averages where yf=yr of the first year and yl=yr of the last year of the period analyzed. (For example, "7196" means 1971 through 1996.) _________________________________________________________________________ TABLE 8. EXAMPLES OF CONTENTS OF DATA FILES ________________________________________________________________________________ Example Header* and sample Data^ Records Comments File_name *SCDG NSta sz lo Ty PC YR SN FMT _________________ _________________________________________________ _________ a) 01_STID 1001 5388 0 1 -9-9 7196 -9 111 01001 7093 35133 9 26 71 96 26 71 96 2 46 first 62700 1670 3343 360 3 80 82 2 81 91 0 629 Africa 98851 612 12518 15 21 71 96 21 71 96 2 792 last b) 02_MACA.tc 2001 5388 0 1 1 1 7196 00 121 21749 3 7472 3 7727 3 7599 2 ann c) 03_MSCA.41.tc 3001 5388 0 1 1 1 7196 41 121 21749 18 6667 2 4375 20 6437 1 djf d) 03_MSCA.42.tc 3013 5388 0 1 1 1 7196 42 121 21749 475 7326 497 7669 972 7497 2 mam e) 03_MSCA.43.tc 3025 5388 0 1 1 1 7196 43 121 21749 2446 7693 2525 7852 4971 7772 2 jja f) 03_MSCA.44.tc 3037 5388 0 1 1 1 7196 44 121 21749 2357 7396 911 7661 3268 7528 2 son g) 03_MSCA.41.low 3003 5388 0 1 12 1 7196 41 121 15235 6676 257 1941 84 8617 170 2 amt_St h) 04_MSCF.41.low 4003 5388 0 1 12 2 7196 41 121 15235 6676 304 1941 93 8617 198 2 fq_St i) 05_MSAW.41.low 5001 5388 0 1 12 3 7196 41 121 15235 203 8454 18 9028 221 8588 3 awp_St j) 04_MSCF.43.mh 4027 5388 0 1 21 2 7196 43 121 fq_Ns 30692 8428 247 4832 321 13260 284 2 4028 5388 0 1 22 2 7196 43 121 fq_As 30692 6787 417 3948 436 10735 426 2 4029 5388 0 1 23 2 7196 43 121 fq_Ac 30692 6787 2929 3948 3873 10735 3401 2 4030 5388 0 1 30 2 7196 43 121 fq_Hi 30692 5903 6353 3351 6121 9254 6237 2 k) 03_MSCA.41.lol 3012 5388 0 1 10 1 7196 41 121 sum_low 21749 18 2777 2 0 20 2499 1 62840 1545 176 168 104 1713 140 2 89065 644 4274 585 3784 1229 4029 2 l) 05_MSAW.41.mh 5008 5388 0 1 30 3 7196 41 121 97760 976 4600 83 4600 1059 4600 3 bogus_awp 97900 1132 4122 311 3969 1443 4052 2 *App.B m) 06_MSUU.42 6005 5388 0 1 21 4 7196 42 121 nol_Ns 46734 7852 24 2706 22 10558 23 2 89544 367 722 3 2917 370 740 3 6006 5388 0 1 22 4 7196 42 121 nol_As 46734 7852 107 2706 104 10558 105 2 89544 367 1454 3 2917 370 1466 3 6007 5388 0 1 23 4 7196 42 121 nol_Ac 46734 7852 647 2706 590 10558 619 2 89544 367 1206 3 0 370 1196 3 6008 5388 0 1 30 4 7196 42 121 nol_Hi 46734 7845 212 2702 121 10547 167 2 89544 366 1492 3 1250 369 1490 3 n) 07_MSLH.43 7009 5388 0 1 12 5 7196 43 122 hgt_St 21749 583 299 606 321 1189 310 2 98851 35 533 17 472 52 513 3 7010 5388 0 1 13 5 7196 43 122 hgt_Sc 21749 795 501 656 510 1451 505 2 98851 137 652 54 583 191 632 2 7011 5388 0 1 14 5 7196 43 122 hgt_Cu 21749 127 750 35 976 162 798 3 98851 3811 523 1520 500 5331 516 2 7012 5388 0 1 15 5 7196 43 122 hgt_Cb 21749 112 410 97 466 209 436 2 98851 1259 534 265 475 1524 524 2 o) 11_MSFT.44.cr 11031 5388 0 1 2 2 7196 44 138 72469 0 2097 544 4 hrs 72469 3 7 0 72469 6 643 2784 72469 9 15 1333 72469 12 815 2589 72469 15 35 1429 72469 18 2050 854 72469 21 25 800 84782 0 498 3233 8 hrs 84782 3 497 1529 84782 6 528 1402 84782 9 364 934 84782 12 2018 971 84782 15 1799 4380 84782 18 2040 7059 84782 21 1706 6419 p) 14_HARM.aa.tc 14001 5388 0 1 1 1 7196 0 140 annual cycle 72274 1186 139 12 12 386 Tucson 72469 330 644 696 12 526 Denver 72793 155 1235 691 12 693 Seattle 89544 -900 -900-900 0-900 Mcode q) 14_HARM.df.44.cr 14091 5388 0 1 2 2 7196 44 148 diurnal cycle 72469 212 1406 738 4 169 4 hrs 84782 1462 3066 770 8 324 8 hrs r) 16_SMCA.42.cu 16005 5388 0 1 14 1 7196 42 126 94248 64 742 0-90000 64 742 3 1971 94248 2 0 1 0 3 0 1 94248 0-90000 0-90000 0-90000 0 94248 0-90000 0-90000 0-90000 0 94248 0-90000 0-90000 0-90000 0 1975 94248 109 1330 22 511 131 1193 3 94248 145 1241 29 690 174 1149 3 94248 163 1097 42 30 205 563 2 94248 160 1305 47 346 207 825 2 94248 169 976 52 312 221 644 2 1980 94248 159 1164 45 278 204 721 2 94248 161 683 36 312 197 498 2 94248 158 578 52 96 210 337 2 94248 151 745 41 183 192 464 2 94248 137 940 30 0 167 771 3 1985 94248 170 618 35 36 205 327 2 94248 169 703 45 139 214 421 2 94248 150 767 43 291 193 529 2 94248 350 1450 133 893 483 1171 2 94248 286 1010 107 432 393 721 2 1990 94248 357 886 140 286 497 586 2 94248 351 1068 139 279 490 674 2 94248 359 912 141 204 500 558 2 94248 359 609 131 153 490 381 2 94248 338 758 138 344 476 551 2 1995 94248 361 436 181 221 542 329 2 s) 31_MNYD.01.ac 31010 5388 0 1 23 0 7196 1 162 | 01035 77 2 0 0-90000 0 fq=0 01035 78 19-90000 1579-90000 0 NTy=3,NC=0 01035 79 29 453 1034 4375 2 | 54511 78 121 592 1983 2983 -2 China_70s 54511 79 116 334 1121 2983 -2 54511 80 118 487 1780 2738 21 China_80s 54511 81 117 687 2393 2870 27 | 97900 79 103 2377 4660 5100 -1 bogus_awp 97900 80 104 3237 6346 5100 -1 t) 42_MNYD.12.hi 42011 5388 0 1 30 0 7196 12 162 72290 71 49 2022 4490 4504 18 | 72290 92 52 1949 5385 3620 22 72290 93 57 2611 6140 4252 33 72290 94 49 1738 3878 4482 17 72290 95 96 2231 4583 4867 43 72290 96 0-90000-90000-90000 0 USA_1996 ________________________________________________________________________________ ^ Only 1 to 3 station data records are shown in any sample data group. APPENDIX A. NUMBERS OF STATIONS AND OBSERVATIONS USED Appendix A1. Number of Stations from EECRA with 20 or More Reports Containing Cloud Type Data for Specified Number of Years for January or July 1971-1996 ____________________________________________________________________ Num Yrs: 0 1-2 3-5 6-10 11-15 16-20 21-25 26 -------- ---- ---- ---- ---- ----- ----- ----- ---- Total Num Sta: 1680 1220 930 1235 849 1127 1906 2639 11,586 ____________________________________________________________________ Appendix A2. REGIONAL DISTRIBUTION OF CONTRIBUTING STATIONS Station ID Number Region Number of Range* Stations _________________ _______________________ _________ 0nnnn and 1nnnn Europe# 1190 2nnnn and 3nnnn Soviet Union (former) 1558 4nnnn Asia## 507 5nnnn China 586 6nnnn Africa 452 7nnnn North & Central America 498 80000 to 88962 South America 268 88963 to 89999 Antarctica 29 94100 to 94999 Australia 74 91000 to 98999** SW Pacific Islands 226 --------- 01001 to 98851 TOTAL 5388 ______________________________________________________ * Synoptic weather stations are assigned (by WMO) 5-digit identification numbers ranging from 01001 to 98999. Each country is assigned a specific range of numbers. # Excluding former Soviet Union. ## Excluding former Soviet Union and China. ** Excluding Australia. (Appendices A3a and A3b contain graphics which cannot be shown in this ASCII text file. To see these graphics, please see: http://cdiac.ornl.gov/ftp/ndp026d/ndp-026d.pdf) Appendix A4. NUMBER OF STATIONS WITH SPECIFIED STATION DATA CODE (SDC) _________________________________________________________ SDC* -2 -1 0 1 2 Numumber of Stations** 102 14 114 105 5053 _________________________________________________________ * SDC meaning: 2 both Jan and Jul have "Y" and R < 6, 1 either Jan or Jul has "Y" and R < 6, 0 neither Jan nor Jul has "Y", R unspecified, -1 either Jan or Jul has "Y" and R > 6, -2 both Jan and Jul have "Y" and R > 6, where "Y" means: at least 15 yrs with at least 20 obs, and R means: NobDy/NobNt. ** All stations with SDC < 1 are located south of 30 deg N. APPENDIX B 155 STATIONS# FOR WHICH BOGUS^ AMOUNT-WHEN-PRESENT WAS USED FOR MIDDLE AND HIGH CLOUDS ______________________________________________________________________ 48077 48096 48108 48110 48112 48300 48303 48325 48327 48328 48330 48331 48351 48352 48353 48354 48356 48357 48375 48376 48377 48378 48379 48381 48383 48400 48403 48405 48407 48425 48426 48430 48431 48432 48450 48455 48456 48459 48460 48462 48475 48477 48480 48500 48501 48517 48532 48550 48551 48552 48564 48565 48567 48568 48569 48580 48583 48601 48615 48620 48647 48657 48665 48698 48917 59995 81200 81202 81225 81250 81251 81253 91203 91212 91217 91317 91324 91334 91348 91353 91356 91366 91367 91371 91376 91408 91413 91425 91434 94044 94085 96001 96009 96011 96015 96035 96073 96075 96091 96109 96145 96147 96163 96171 96179 96221 96237 96249 96253 96295* 96413 96421 96441 96449 96471 96491 96581 96633 96685 96743* 96747* 96797* 96805* 96839 96925 96933 97008 97016 97048 97072 97086 97096 97146 97180 97230 97260 97300 97340 97388* 97390* 97395* 97406 97430 97502 97530 97560 97630 97690 97698 97724 97748 97760 97900* 97980* 98618 ______________________________________________________________________ # The stations affected lie in an irregular region between latitudes 10N and 10S and between longitudes 95E and 175E (includes Indonesia and other islands) and in a much smaller region of South America from 0 to 10N and 55 to 60W. ^ The values used for AWP are 98% for Ns, 80% for As, 51% for Ac, and 46% for Hi. * Added to a preliminary list of 145 stations after completion of Files 2-14. APPENDIX C. LAND-STATION CLOUD ARCHIVE FILE NAMES, NDP-026D 862 SCDGs in 433 files in 42 File Categories SCDGs bytes File_Name --------- ------- ----------------- 48164 README 01001 264045 01_STID 02001 253269 02_MACA.tc 02002 253269 02_MACA.cr 02003-07 1266345 02_MACA.low 02008-11 1013076 02_MACA.mh 02012 253269 02_MACA.mil 02013 253269 02_MACA.lol 03001 253269 03_MSCA.41.tc 03002-06 1266345 03_MSCA.41.low 03007-10 1013076 03_MSCA.41.mh 03011 253269 03_MSCA.41.mil 03012 253269 03_MSCA.41.lol 03013 253269 03_MSCA.42.tc 03014-18 1266345 03_MSCA.42.low 03019-22 1013076 03_MSCA.42.mh 03023 253269 03_MSCA.42.mil 03024 253269 03_MSCA.42.lol 03025 253269 03_MSCA.43.tc 03026-30 1266345 03_MSCA.43.low 03031-34 1013076 03_MSCA.43.mh 03035 253269 03_MSCA.43.mil 03035 253269 03_MSCA.43.lol 03037 253269 03_MSCA.44.tc 03038-42 1266345 03_MSCA.44.low 03043-46 1013076 03_MSCA.44.mh 03047 253269 03_MSCA.44.mil 03048 253269 03_MSCA.44.lol 04001 253269 04_MSCF.41.cr 04002-06 1266345 04_MSCF.41.low 04007-10 1013076 04_MSCF.41.mh 04011 253269 04_MSCF.42.cr 04012-16 1266345 04_MSCF.42.low 04017-20 1013076 04_MSCF.42.mh 04021 253269 04_MSCF.43.cr 04022-26 1266345 04_MSCF.43.low 04027-30 1013076 04_MSCF.43.mh 04031 253269 04_MSCF.44.cr 04032-36 1266345 04_MSCF.44.low 04037-40 1013076 04_MSCF.44.mh 05001-04 1013076 05_MSAW.41.low 05005-08 1013076 05_MSAW.41.mh 05009-12 1013076 05_MSAW.42.low 05013-16 1013076 05_MSAW.42.mh 05017-20 1013076 05_MSAW.43.low 05021-24 1013076 05_MSAW.43.mh 05025-28 1013076 05_MSAW.44.low 05029-32 1013076 05_MSAW.44.mh 06001-04 1013076 06_MSUU.41 06005-08 1013076 06_MSUU.42 06009-12 1013076 06_MSUU.43 06013-16 1013076 06_MSUU.44 07001-04 1013076 07_MSLH.41 07005-08 1013076 07_MSLH.42 07009-12 1013076 07_MSLH.43 07013-16 1013076 07_MSLH.44 08001 253269 08_MMCA.01.tc 08002-06 1266345 08_MMCA.01.low 08007-10 1013076 08_MMCA.01.mh 08011 253269 08_MMCA.02.tc 08012-16 1266345 08_MMCA.02.low 08017-20 1013076 08_MMCA.02.mh 08021 253269 08_MMCA.03.tc 08022-26 1266345 08_MMCA.03.low 08027-30 1013076 08_MMCA.03.mh 08031 253269 08_MMCA.04.tc 08032-36 1266345 08_MMCA.04.low 08037-40 1013076 08_MMCA.04.mh 08041 253269 08_MMCA.05.tc 08042-46 1266345 08_MMCA.05.low 08047-50 1013076 08_MMCA.05.mh 08051 253269 08_MMCA.06.tc 08052-56 1266345 08_MMCA.06.low 08057-60 1013076 08_MMCA.06.mh 08061 253269 08_MMCA.07.tc 08062-66 1266345 08_MMCA.07.low 08067-70 1013076 08_MMCA.07.mh 08071 253269 08_MMCA.08.tc 08072-76 1266345 08_MMCA.08.low 08077-80 1013076 08_MMCA.08.mh 08081 253269 08_MMCA.09.tc 08082-86 1266345 08_MMCA.09.low 08087-90 1013076 08_MMCA.09.mh 08091 253269 08_MMCA.10.tc 08092-96 1266345 08_MMCA.10.low 08097-100 1013076 08_MMCA.10.mh 08101 253269 08_MMCA.11.tc 08102-106 1266345 08_MMCA.11.low 08107-110 1013076 08_MMCA.11.mh 08111 253269 08_MMCA.12.tc 08112-116 1266345 08_MMCA.12.low 08117-120 1013076 08_MMCA.12.mh 09001 253269 09_MMCF.01.cr 09002-06 1266345 09_MMCF.01.low 09007-10 1013076 09_MMCF.01.mh 09011 253269 09_MMCF.02.cr 09012-16 1266345 09_MMCF.02.low 09017-20 1013076 09_MMCF.02.mh 09021 253269 09_MMCF.03.cr 09022-26 1266345 09_MMCF.03.low 09027-30 1013076 09_MMCF.03.mh 09031 253269 09_MMCF.04.cr 09032-36 1266345 09_MMCF.04.low 09037-40 1013076 09_MMCF.04.mh 09041 253269 09_MMCF.05.cr 09042-46 1266345 09_MMCF.05.low 09047-50 1013076 09_MMCF.05.mh 09051 253269 09_MMCF.06.cr 09052-56 1266345 09_MMCF.06.low 09057-60 1013076 09_MMCF.06.mh 09061 253269 09_MMCF.07.cr 09062-66 1266345 09_MMCF.07.low 09067-70 1013076 09_MMCF.07.mh 09071 253269 09_MMCF.08.cr 09072-76 1266345 09_MMCF.08.low 09077-80 1013076 09_MMCF.08.mh 09081 253269 09_MMCF.09.cr 09082-86 1266345 09_MMCF.09.low 09087-90 1013076 09_MMCF.09.mh 09091 253269 09_MMCF.10.cr 09092-96 1266345 09_MMCF.10.low 09097-100 1013076 09_MMCF.10.mh 09101 253269 09_MMCF.11.cr 09102-106 1266345 09_MMCF.11.low 09107-110 1013076 09_MMCF.11.mh 09111 253269 09_MMCF.12.cr 09112-116 1266345 09_MMCF.12.low 09117-120 1013076 09_MMCF.12.mh 10001 905217 10_MSAT.41.tc 10002-06 4526085 10_MSAT.41.low 10007-10 3620868 10_MSAT.41.mh 10011 905217 10_MSAT.42.tc 10012-16 4526085 10_MSAT.42.low 10017-20 3620868 10_MSAT.42.mh 10021 905217 10_MSAT.43.tc 10022-26 4526085 10_MSAT.43.low 10027-30 3620868 10_MSAT.43.mh 10031 905217 10_MSAT.44.tc 10032-36 4526085 10_MSAT.44.low 10037-40 3620868 10_MSAT.44.mh 11001 905217 11_MSFT.41.cr 11002-06 4526085 11_MSFT.41.low 11007-10 3620868 11_MSFT.41.mh 11011 905217 11_MSFT.42.cr 11012-16 4526085 11_MSFT.42.low 11017-20 3620868 11_MSFT.42.mh 11021 905217 11_MSFT.43.cr 11022-26 4526085 11_MSFT.43.low 11027-30 3620868 11_MSFT.43.mh 11031 905217 11_MSFT.44.cr 11032-36 4526085 11_MSFT.44.low 11037-40 3620868 11_MSFT.44.mh 12001-04 3620868 12_MSUT.41 12005-08 3620868 12_MSUT.42 12009-12 3620868 12_MSUT.43 12013-16 3620868 12_MSUT.44 13001-04 3620868 13_MSHT.41 13005-08 3620868 13_MSHT.42 13009-12 3620868 13_MSHT.43 13013-16 3620868 13_MSHT.44 14001 145509 14_HARM.aa.tc 14002-06 727545 14_HARM.aa.low 14007-10 582036 14_HARM.aa.mh 14011 145509 14_HARM.af.cr 14012-16 727545 14_HARM.af.low 14017-20 582036 14_HARM.af.mh 14021 145509 14_HARM.da.41.tc 14022-26 727545 14_HARM.da.41.low 14027-30 582036 14_HARM.da.41.mh 14031 145509 14_HARM.da.42.tc 14032-36 727545 14_HARM.da.42.low 14037-40 582036 14_HARM.da.42.mh 14041 145509 14_HARM.da.43.tc 14042-46 727545 14_HARM.da.43.low 14047-50 582036 14_HARM.da.43.mh 14051 145509 14_HARM.da.44.tc 14052-56 727545 14_HARM.da.44.low 14057-60 582036 14_HARM.da.44.mh 14061 145509 14_HARM.df.41.cr 14062-66 727545 14_HARM.df.41.low 14067-70 582036 14_HARM.df.41.mh 14071 145509 14_HARM.df.42.cr 14072-76 727545 14_HARM.df.42.low 14077-80 582036 14_HARM.df.42.mh 14081 145509 14_HARM.df.43.cr 14082-86 727545 14_HARM.df.43.low 14087-90 582036 14_HARM.df.43.mh 14091 145509 14_HARM.df.44.cr 14092-96 727545 14_HARM.df.44.low 14097-100 582036 14_HARM.df.44.mh 15001 6584169 15_SMCA.41.tc 15002 6584169 15_SMCA.41.fo 15003 6584169 15_SMCA.41.st 15004 6584169 15_SMCA.41.sc 15005 6584169 15_SMCA.41.cu 15006 6584169 15_SMCA.41.cb 15007 6584169 15_SMCA.41.ns 15008 6584169 15_SMCA.41.as 15009 6584169 15_SMCA.41.ac 15010 6584169 15_SMCA.41.hi 16001 6584169 16_SMCA.42.tc 16002 6584169 16_SMCA.42.fo 16003 6584169 16_SMCA.42.st 16004 6584169 16_SMCA.42.sc 16005 6584169 16_SMCA.42.cu 16006 6584169 16_SMCA.42.cb 16007 6584169 16_SMCA.42.ns 16008 6584169 16_SMCA.42.as 16009 6584169 16_SMCA.42.ac 16010 6584169 16_SMCA.42.hi 17001 6584169 17_SMCA.43.tc 17002 6584169 17_SMCA.43.fo 17003 6584169 17_SMCA.43.st 17004 6584169 17_SMCA.43.sc 17005 6584169 17_SMCA.43.cu 17006 6584169 17_SMCA.43.cb 17007 6584169 17_SMCA.43.ns 17008 6584169 17_SMCA.43.as 17009 6584169 17_SMCA.43.ac 17010 6584169 17_SMCA.43.hi 18001 6584169 18_SMCA.44.tc 18002 6584169 18_SMCA.44.fo 18003 6584169 18_SMCA.44.st 18004 6584169 18_SMCA.44.sc 18005 6584169 18_SMCA.44.cu 18006 6584169 18_SMCA.44.cb 18007 6584169 18_SMCA.44.ns 18008 6584169 18_SMCA.44.as 18009 6584169 18_SMCA.44.ac 18010 6584169 18_SMCA.44.hi 19001 6584169 19_SMCF.41.cr 19002 6584169 19_SMCF.41.fo 19003 6584169 19_SMCF.41.st 19004 6584169 19_SMCF.41.sc 19005 6584169 19_SMCF.41.cu 19006 6584169 19_SMCF.41.cb 19007 6584169 19_SMCF.41.ns 19008 6584169 19_SMCF.41.as 19009 6584169 19_SMCF.41.ac 19010 6584169 19_SMCF.41.hi 20001 6584169 20_SMCF.42.cr 20002 6584169 20_SMCF.42.fo 20003 6584169 20_SMCF.42.st 20004 6584169 20_SMCF.42.sc 20005 6584169 20_SMCF.42.cu 20006 6584169 20_SMCF.42.cb 20007 6584169 20_SMCF.42.ns 20008 6584169 20_SMCF.42.as 20009 6584169 20_SMCF.42.ac 20010 6584169 20_SMCF.42.hi 21001 6584169 21_SMCF.43.cr 21002 6584169 21_SMCF.43.fo 21003 6584169 21_SMCF.43.st 21004 6584169 21_SMCF.43.sc 21005 6584169 21_SMCF.43.cu 21006 6584169 21_SMCF.43.cb 21007 6584169 21_SMCF.43.ns 21008 6584169 21_SMCF.43.as 21009 6584169 21_SMCF.43.ac 21010 6584169 21_SMCF.43.hi 22001 6584169 22_SMCF.44.cr 22002 6584169 22_SMCF.44.fo 22003 6584169 22_SMCF.44.st 22004 6584169 22_SMCF.44.sc 22005 6584169 22_SMCF.44.cu 22006 6584169 22_SMCF.44.cb 22007 6584169 22_SMCF.44.ns 22008 6584169 22_SMCF.44.as 22009 6584169 22_SMCF.44.ac 22010 6584169 22_SMCF.44.hi 23001 6584169 23_SMUU.41.ns 23002 6584169 23_SMUU.41.as 23003 6584169 23_SMUU.41.ac 23004 6584169 23_SMUU.41.hi 24001 6584169 24_SMUU.42.ns 24002 6584169 24_SMUU.42.as 24003 6584169 24_SMUU.42.ac 24004 6584169 24_SMUU.42.hi 25001 6584169 25_SMUU.43.ns 25002 6584169 25_SMUU.43.as 25003 6584169 25_SMUU.43.ac 25004 6584169 25_SMUU.43.hi 26001 6584169 26_SMUU.44.ns 26002 6584169 26_SMUU.44.as 26003 6584169 26_SMUU.44.ac 26004 6584169 26_SMUU.44.hi 27001 6584169 27_SMHL.41.st 27002 6584169 27_SMHL.41.sc 27003 6584169 27_SMHL.41.cu 27004 6584169 27_SMHL.41.cb 28001 6584169 28_SMHL.42.st 28002 6584169 28_SMHL.42.sc 28003 6584169 28_SMHL.42.cu 28004 6584169 28_SMHL.42.cb 29001 6584169 29_SMHL.43.st 29002 6584169 29_SMHL.43.sc 29003 6584169 29_SMHL.43.cu 29004 6584169 29_SMHL.43.cb 30001 6584169 30_SMHL.44.st 30002 6584169 30_SMHL.44.sc 30003 6584169 30_SMHL.44.cu 30004 6584169 30_SMHL.44.cb 31001 4903113 31_MNYD.01.tc 31002 4903113 31_MNYD.01.cr 31003 4903113 31_MNYD.01.fo 31004 4903113 31_MNYD.01.st 31005 4903113 31_MNYD.01.sc 31006 4903113 31_MNYD.01.cu 31007 4903113 31_MNYD.01.cb 31008 4903113 31_MNYD.01.ns 31009 4903113 31_MNYD.01.as 31010 4903113 31_MNYD.01.ac 31011 4903113 31_MNYD.01.hi 32001 4903113 32_MNYD.02.tc 32002 4903113 32_MNYD.02.cr 32003 4903113 32_MNYD.02.fo 32004 4903113 32_MNYD.02.st 32005 4903113 32_MNYD.02.sc 32006 4903113 32_MNYD.02.cu 32007 4903113 32_MNYD.02.cb 32008 4903113 32_MNYD.02.ns 32009 4903113 32_MNYD.02.as 32010 4903113 32_MNYD.02.ac 32011 4903113 32_MNYD.02.hi 33001 4903113 33_MNYD.03.tc 33002 4903113 33_MNYD.03.cr 33003 4903113 33_MNYD.03.fo 33004 4903113 33_MNYD.03.st 33005 4903113 33_MNYD.03.sc 33006 4903113 33_MNYD.03.cu 33007 4903113 33_MNYD.03.cb 33008 4903113 33_MNYD.03.ns 33009 4903113 33_MNYD.03.as 33010 4903113 33_MNYD.03.ac 33011 4903113 33_MNYD.03.hi 34001 4903113 34_MNYD.04.tc 34002 4903113 34_MNYD.04.cr 34003 4903113 34_MNYD.04.fo 34004 4903113 34_MNYD.04.st 34005 4903113 34_MNYD.04.sc 34006 4903113 34_MNYD.04.cu 34007 4903113 34_MNYD.04.cb 34008 4903113 34_MNYD.04.ns 34009 4903113 34_MNYD.04.as 34010 4903113 34_MNYD.04.ac 34011 4903113 34_MNYD.04.hi 35001 4903113 35_MNYD.05.tc 35002 4903113 35_MNYD.05.cr 35003 4903113 35_MNYD.05.fo 35004 4903113 35_MNYD.05.st 35005 4903113 35_MNYD.05.sc 35006 4903113 35_MNYD.05.cu 35007 4903113 35_MNYD.05.cb 35008 4903113 35_MNYD.05.ns 35009 4903113 35_MNYD.05.as 35010 4903113 35_MNYD.05.ac 35011 4903113 35_MNYD.05.hi 36001 4903113 36_MNYD.06.tc 36002 4903113 36_MNYD.06.cr 36003 4903113 36_MNYD.06.fo 36004 4903113 36_MNYD.06.st 36005 4903113 36_MNYD.06.sc 36006 4903113 36_MNYD.06.cu 36007 4903113 36_MNYD.06.cb 36008 4903113 36_MNYD.06.ns 36009 4903113 36_MNYD.06.as 36010 4903113 36_MNYD.06.ac 36011 4903113 36_MNYD.06.hi 37001 4903113 37_MNYD.07.tc 37002 4903113 37_MNYD.07.cr 37003 4903113 37_MNYD.07.fo 37004 4903113 37_MNYD.07.st 37005 4903113 37_MNYD.07.sc 37006 4903113 37_MNYD.07.cu 37007 4903113 37_MNYD.07.cb 37008 4903113 37_MNYD.07.ns 37009 4903113 37_MNYD.07.as 37010 4903113 37_MNYD.07.ac 37011 4903113 37_MNYD.07.hi 38001 4903113 38_MNYD.08.tc 38002 4903113 38_MNYD.08.cr 38003 4903113 38_MNYD.08.fo 38004 4903113 38_MNYD.08.st 38005 4903113 38_MNYD.08.sc 38006 4903113 38_MNYD.08.cu 38007 4903113 38_MNYD.08.cb 38008 4903113 38_MNYD.08.ns 38009 4903113 38_MNYD.08.as 38010 4903113 38_MNYD.08.ac 38011 4903113 38_MNYD.08.hi 39001 4903113 39_MNYD.09.tc 39002 4903113 39_MNYD.09.cr 39003 4903113 39_MNYD.09.fo 39004 4903113 39_MNYD.09.st 39005 4903113 39_MNYD.09.sc 39006 4903113 39_MNYD.09.cu 39007 4903113 39_MNYD.09.cb 39008 4903113 39_MNYD.09.ns 39009 4903113 39_MNYD.09.as 39010 4903113 39_MNYD.09.ac 39011 4903113 39_MNYD.09.hi 40001 4903113 40_MNYD.10.tc 40002 4903113 40_MNYD.10.cr 40003 4903113 40_MNYD.10.fo 40004 4903113 40_MNYD.10.st 40005 4903113 40_MNYD.10.sc 40006 4903113 40_MNYD.10.cu 40007 4903113 40_MNYD.10.cb 40008 4903113 40_MNYD.10.ns 40009 4903113 40_MNYD.10.as 40010 4903113 40_MNYD.10.ac 40011 4903113 40_MNYD.10.hi 41001 4903113 41_MNYD.11.tc 41002 4903113 41_MNYD.11.cr 41003 4903113 41_MNYD.11.fo 41004 4903113 41_MNYD.11.st 41005 4903113 41_MNYD.11.sc 41006 4903113 41_MNYD.11.cu 41007 4903113 41_MNYD.11.cb 41008 4903113 41_MNYD.11.ns 41009 4903113 41_MNYD.11.as 41010 4903113 41_MNYD.11.ac 41011 4903113 41_MNYD.11.hi 42001 4903113 42_MNYD.12.tc 42002 4903113 42_MNYD.12.cr 42003 4903113 42_MNYD.12.fo 42004 4903113 42_MNYD.12.st 42005 4903113 42_MNYD.12.sc 42006 4903113 42_MNYD.12.cu 42007 4903113 42_MNYD.12.cb 42008 4903113 42_MNYD.12.ns 42009 4903113 42_MNYD.12.as 42010 4903113 42_MNYD.12.ac 42011 4903113 42_MNYD.12.hi _________________________________________ SCDG bytes File_Name (Land-Station Cloud Archive, NDP-026D)