ISCCP D1 Native Data Set Readme File 1.0 Introduction This file contains information about the International Satellite Cloud Climatology Project (ISCCP) D1 native (NAT) data set. (ISCCP_D1_NAT) The data files are in native format. The home page for ISCCP is located at http://isccp.giss.nasa.gov/ This readme file also includes the following sections: Section 2.0 - provides general information about the data set. Section 3.0 - describes the format of the data. Section 4.0 - provides the user with science parameter information Section 5.0 - describes the sample read software. Section 6.0 - discusses how to invoke the run-time executable. Section 7.0 - provides an example of an actual run of the sample read software. If users have questions while using the ISCCP_D1_NAT sample read software, please contact the Langley Data Center, User and Data Services office at: Langley Atmospheric Science Data Center NASA Langley Research Center 2 South Wright Street, Mail Stop 157D Hampton, VA 23681-2199 U.S.A. Email: support-asdc@earthdata.nasa.gov Phone: (757) 864-8656 FAX: (757) 864-8807 URL: http://eosweb.larc.nasa.gov 2.0 Data Set Description Documentation on the ISCCP_D1_NAT data set can be obtained from the following URL: http://isccp.giss.nasa.gov/doc/documents.html Contact for scientific inquiries: Dr. William B. Rossow NASA Goddard Institute for Space Studies 2880 Broadway New York, NY 10025 email: clwbr@giss.nasa.gov Phone: 212-678-5567 FAX: 212-678-5662 Contact for technical assistance: Violeta Golea NASA Goddard Institute for Space Studies 2880 Broadway, Rm 322A New York, NY 10025 email: vgolea@giss.nasa.gov 3.0 Format and Packaging There are 2 naming conventions for these files. The first convention is as follows: d1.YYYYMMDDHH YYYY is the year, MM is the month, DD is the day HH is the GMT hour (00, 03, 06, 09, 12, 15, 18 or 21) There are 3 files that would go with these ISCCP_D1_NAT data files. They are a volume identification file, a table of contents file and ancillary data file. Each month has two volume identification (volid) files and two table of contents (toc) files, but only one ancillary file. To determine which volid or toc file you need you must use the day of the data file. These two readme files cover the first day through (and including) the 16th of the month, and the second the 17th to the end of the month. For example: d1.1987020100 d1volid1.198702 d1toc1.198702 d1volid2.198702 d1toc2.198702 d1ancil.198702 The second file naming convention is as follows: ISCCP.TTTTTT.V.SATID.YYYY.MM.DD.HH.MM.DCN TTTTTT - data type D1 - ISCCP D1 data file D1READ - ISCCP D1 Read software D1TOC - table of contents D1GRID - ancillary file V - version number SATID - GLOBAL - used if multiple or no satellites apply YYYY - year = 1981...2005 (always 4 numbers, fill = 9999) MM - month number = 1...12 (always 2 numbers, fill = 99) DD - day of month = 1...31 (always 2 numbers, fill = 99) HHMM - hour-minute GMT = 0000...2100 (always 4 characters, fill = 9999) DCN - data center name where data originated. For non-data files, the date and time fields may be fill values. Example: ISCCP.D1.0.GLOBAL.1995.10.01.0300.GPC (data file) ISCCP.D1TOC.0.GLOBAL.1995.10.99.9999.GPC (table of contents) ISCCP.D1GRID.0.GLOBAL.1995.10.99.9999.GPC (ancillary file) 4.0 Science Parameters Information The ISCCP_D1_NAT data set contains 3-hourly, 280 KM equal-area grid data from various polar and geostationary satellites. More information on the ancillary and data files can be obtained from the International Satellite Cloud Climatology Project (ISCCP) Documentation of New Cloud Datasets documentation available at URL http://isccp.giss.nasa.gov/doc/documents.html 5.0 Description of Sample Read Software The FORTRAN program isccp_d1_nat_read.f has been provided by the data producer as a sample program. It is up to the user to modify the program to output the data of interest. The code was developed using a f77 compiler, it has not been approved for use with f90 or f95 compilers. 6.0 Implementing Sample Read Software The program can be compiled with a simple f77 command line argument. A sample of the compilation output a user can expect to see follows: - For SunOS f77 -o rd_d1 isccp_d1_nat_read.f isccp_d1_nat_read.f: MAIN sample: d1open: d1read: d1rec: eq2sq: d1phys: midprs: rdanc: printi: printr: center: totir: totvis: cldhgt: BLOCK DATA: - For SGI's f77 -o rd_D1 -bytereclen isccp_d1_nat_read.f Prior to running the program, the data file must be an linked to fort.10 and the ancillary file must be linked to fort.9 These files are what the program will open and read. There are several ways to create this file: We recommend the unix "ln" command: ln -s fort.9 ln -s fort.10 In addition, the program writes output to a file called fort.90. 7.0 A sample run After the program has been successfully compiled and the file fort.10 has been created, the read program can be executed. A sample of the output follows: D1 PREFIX INFORMATION: YEAR 83 MONTH 7 DAY 1 UTC 0 D1PHYS: LAT BAND 1 CONVERTED TO PHYSICAL VALUES D1PHYS: LAT BAND 2 CONVERTED TO PHYSICAL VALUES D1PHYS: LAT BAND 3 CONVERTED TO PHYSICAL VALUES . . . . . D1PHYS: LAT BAND 35 CONVERTED TO PHYSICAL VALUES D1PHYS: LAT BAND 36 CONVERTED TO PHYSICAL VALUES *************************************************************************************** ************* PROCESSING EQUAL-AREA LON/LAT 1 36 PRINTI: COUNT VALUES FOR ALL VARIABLES 1 2 3 4 5 6 7 8 9 10 VARIABLE (001-010) 36 1 1 1 41 101 0 99 255 255 VARIABLE (011-020) 100 4 4 255 0 0 4 255 0 0 VARIABLE (021-030) 81 255 0 0 0 0 0 0 4 255 VARIABLE (031-040) 255 255 255 255 255 255 255 255 255 255 VARIABLE (041-050) 255 255 255 255 255 255 255 255 . . . VARIABLE (191-200) 38 19 21 13 21 40 65 30 14 8 VARIABLE (201-202) 4 133 PRINTR: PHYSICAL VALUES FOR ALL VARIABLES 1 2 3 4 5 6 7 8 9 10 VARIABLE (001-010) 36.00 1.00 1.00 1.00 41.00 101.00 0.00 0.99-100 0.00-1000.00 VARIABLE (011-020) 100.00 4.00 4.00-1000.00 0.00 0.00 4.00-1000.00 0.00 0.00 VARIABLE (021-030) 0.81-1000.00 0.00 0.00 0.00 0.00 0.00 0.00 4.00-1000.00 VARIABLE (031-040)-1000.00-1000.00-1000.00-1000.00-1000.00-1000.00-1000.00-1000.00-100 0.00-1000.00 VARIABLE (041-050)-1000.00-1000.00-1000.00-1000.00-1000.00-1000.00-1000.00-1000.00-100 0.00-1000.00 . . . VARIABLE (191-200) 230.60 206.20 100.00 195.70 209.70 232.70 1.92 0.87 0.39 0.21 VARIABLE (201-202) 0.09 264.00 CENTER: CENTER LON/LAT 1.25 -1.25 TOTIR: IR RADIANCES USING IR CLOUD/CLEAR CATEGORIES NUMBER OF PIXELS CLOUD/CLEAR/TOTAL 4 96 100 RADIANCE (K) CLOUD/CLEAR/TOTAL 288.30 292.70 292.70 USING VIS/IR CLOUD/CLEAR CATEGORIES NUMBER OF PIXELS CLOUD/CLEAR/TOTAL 4 96 100 RADIANCE (K) CLOUD/CLEAR/TOTAL -1000.00 -1000.00 -1000.00 TOTVIS: VIS RADIANCES 1 USING IR CLOUD/CLEAR CATEGORIES NUMBER OF PIXELS CLOUD/CLEAR/TOTAL 4 96 100 RADIANCE (REFLECTANCE) CLOUD/CLEAR/TOTAL -1000.00 -1000.00 -1000.00 USING VIS/IR CLOUD/CLEAR CATEGORIES NUMBER OF PIXELS CLOUD/CLEAR/TOTAL 4 96 100 RADIANCE (REFLECTANCE) CLOUD/CLEAR/TOTAL -1000.00 -1000.00 -1000.00 MIDPRS: ACTUAL PRESSURE LAYER MID-POINTS (MB) 900.00 740.00 620.00 500.00 375.00 245.00 140.00 CLDHGT: CLOUD TOP PRESSURE (MB) 860. CLOUD TOP HEIGHT (M) 1368. . . . . D1PHYS: LAT BAND 70 CONVERTED TO PHYSICAL VALUES D1PHYS: LAT BAND 71 CONVERTED TO PHYSICAL VALUES D1PHYS: LAT BAND 72 CONVERTED TO PHYSICAL VALUES NUMBER OF FULL BOXES: 5192 NORMAL END OF PROGRAM Last updated: June 1, 2006 April 30, 2009