CLIMAP SURFACE CONFIGURATION DATA BASE THIS DATA BASE CONTAINS RAW DATA FOR CERTAIN CLIMATIC BOUNDARY CONDITIONS (EG. SEA SURFACE TEMPERATURE) DURING THE LAST GLACIAL MAXIMUM AND EQUIVALENT DATA FOR THE PRESENT. THE MEAN ESTIMATED DATE FOR THE LAST GLACIAL MAXIMUM IS 18,000 YEARS BP. THE DATA HAVE BEEN USED BY CLIMAP PROJECT MEMBERS FOR A RE- CONSTRUCTION OF GLACIAL CONDITIONS AND COMPARISON WITH PRESENT CONDITIONS. SEE REFERENCE 1 FOR FURTHER INFORMATION. ALL FILES ARE CODED FOR EASY REFERENCE, ALL RECORDS HAVE IDENTICAL PHYSICAL FORMATS, AND ALL NUMERIC FIELDS ARE IN INTEGER FORMAT. EACH DATA VALUE IS A GENERALIZED ESTIMATE FOR A TWO DEGREE GRID CELL. THE CO-ORDINATES OF EACH DATA VALUE ARE FOR THE CENTER POINT OF THE GRID CELL. SOME FILES USE AN EVEN DEGREE GRID SCHEME (TYPES A AND D - SEE BELOW ), OTHERS AN ODD DEGREE SCHEME. ALL FILES HAVE COMPLETE LONGITUDINAL (EAST-WEST) COVERAGE. SOME FILES (TYPE A) HAVE COMPLETE LATITUDINAL (NORTH-SOUTH I.E. +90 TO-90) COVERAGE. THE REMAINDER OF THIS DOCUMENTATION CONSISTS OF FILE DESCRIPTIONS AND, WHERE NECESSARY, INSTRUCTIONS FOR COMPUTATION OF NEW DATA. PHYSICAL RECORD STRUCTURE COLUMN 1- 2 ALPHA 3- 4 2 BYTE NUMERIC 5-72 17 FOUR BYTE NUMERIC FIELDS LOGICAL RECORD STRUCTURE COLUMN 1 ALPHA TIME PERIOD CODE M = MODERN DATA P = 18,000 YBP DATA 2 ALPHA FILE TYPE CODE A = SEA SURFACE TEMPERATURE D = ELEVATION/BATHYMERTY E = VEGETATION TYPE CODE F = SOIL TYPE CODE G = RELIEF TYPE CODE H = WATER AS PERCENT OF GRID CELL I = EXPOSED SOIL AS PERCENT OF GRID CELL J = GLACIAL ICE AS PERCENT OF GRID CELL K = VEGETATION AS PERCENT OF GRID CELL 3- 4 MONTH ( SEASON ) 2 = FEBRUARY ( NORTHERN HEMISPHERE WINTER ) 8 = AUGUST ( NORTHERN HEMISPHERE SUMMER ) 0 = NOT APPLICABLE TO DATA TYPE 5- 8 LATITUDE ( SOUTH NEGATIVE ) 9-12 LONGITUDE OF FIRST DATA VALUE ( WEST NEGATIVE ) NOTE EACH RECORD CONTAINS 15 DATA VALUES REPRESENTING A 30 DEGREE SWATH OF LONGITUDE. THE LONGITUDE OF THE SECOND AND SUBSEQUENT DATA VALUES EQUALS THE PREVIOUS LONGITUDE PLUS TWO DEGREES. 13-72 FIFTEEN DATA VALUES IN I4 FORMAT DESCRIPTION OF FILES TYPE A - SEA SURFACE TEMPERATURE ALL VALUES IN TENTHS OF DEGREES CELSIUS EXCEPT FOR THE FOLLOWING SPECIAL CODES CODE MEANING -444 SEA ICE ( GENERALLY ASSUMED TO BE -1.9 DEGREES C ) -555 GLACIAL ICE -999 LAND TYPE D - ELEVATION/BATHYMETRY LAND ELEVATION AND OCEAN DEPTHS IN TENS OF METERS. MODERN DATA GENERALIZED FROM GATES AND NELSON ( REFERENCES 2 AND 3 ). 18K DATA EQUALS MODERN PLUS 150 METERS TO ADJUST FOR DIFFERENCES IN SEA LEVEL. ICE ELEVATIONS HAVE BEEN SUBSTITUTED, WHERE APPROPRIATE. (OCEAN DEPTHS NEGATIVE ) TYPE E THROUGH K WITH THE EXCEPTION OF TYPE G ( RELIEF ), THESE FILES HAVE BEEN USED BY CLIMAP PROJECT MEMBERS FOR COMPUTATION OF ALBEDO. ALBEDO IS COMPUTED AS FOLLOWS: A = (PW*8 + PI*70 + PV*VAE + PS*SAE ) / 100 WHERE A = ALBEDO AS PERCENT REFLECTIVITY PW = PERCENT WATER (TYPE H ) PI = PERCENT GLACIAL ICE ( TYPE J ) PV = PERCENT VEGETATION ( TYPE K ) VAE = ALBEDO EQUIVALENT FOR CLASS OF VEGETATION AS CODED IN TYPE E ( SEE BELOW ) PS = PERCENT EXPOSED SOIL (TYPE I ) SAE = ALBEDO EQUIVALENT FOR CLASS OF SOIL AS CODED IN TYPE F (SEE BELOW ) ALBEDO EQUIVALENTS ARE AVAILABLE FOR DRY, WET, AND SNOW COVERED SUFACES. IN THE FOLLOWING TABLES AED = DRY, AEW = WET, AND AES = SNOW COVERED SURFACES. VEGETATION CODE AED AEW AES 00 00 00 00 11 12 10 20 12 14 11 29 13 16 12 38 19 14 11 29 21 14 12 25 22 15 13 33 23 16 13 41 29 15 13 33 31 16 13 35 32 17 13 41 33 18 14 47 39 17 13 41 41 16 13 40 42 17 13 45 43 18 14 50 49 17 13 45 51 20 17 50 52 20 17 53 53 20 16 56 59 20 17 53 61 18 15 49 62 18 15 52 63 18 15 55 69 18 15 52 71 18 14 55 72 19 15 60 73 20 15 65 74 19 15 60 81 18 12 58 82 18 11 64 83 18 11 70 89 18 11 64 87 15 10 NO VALUE 91 15 11 70 SOIL CODE AED AEW AES 00 00 00 00 11 10 8 70 12 12 10 70 13 14 12 70 19 12 10 70 21 16 13 70 22 18 15 70 23 20 17 70 29 18 15 70 31 22 18 70 32 26 22 70 33 30 25 70 39 26 22 70 41 34 28 70 42 38 30 70 43 42 32 70 49 38 30 70 51 46 35 70 52 50 35 70 53 55 40 70 59 50 35 70 RELIEF CODE SEE REFERENCE 1, TABLE 2 FOR THIS DATA AND FOR A MORE COMPLETE BREAKDOWN OF VEGETATION AND SOIL CODES. NOTE THAT ALL VALUES ARE FOR A 30 DEGREE SUN ANGLE AND PEAK GROWING SEASON. NOTE ALSO THAT NO PROVISION HAS BEEN MADE FOR SEA ICE. AREA OF SURFACE COVERED BY FILE TYPE TYPE LATITUDE LONGITUDE A +90 TO -90 0 TO +178 TO -180 TO -2 D +88 TO -88 SAME E-K +83 TO -55 +1 TO +179 TO -179 TO -1 REFERENCES 1 CLIMAP PROJECT MEMBERS - *SEASONAL RECONSTRUCTION OF THE EARTH"S SURFACE AT THE LAST GLACIAL MAXIMUM* - GEOLOGICAL SOCIETY OF AMERICA - MAP AND CHART SERIES - IN PRESS. 2 GATES, W.L. AND A.B. NELSON - * A NEW ( REVISED ) TABULATION OF THE SCRIPPS TOPOGRAPHY ON A 1 DEGREE GLOBAL GRID. PARTII OCEAN DEPTHS * - THE RAND CORPORATION, ARPA ORDER NO. 189-1 - OCTOBER, 1975. 3 GATES, W.L. AND A.B. NELSON - * A NEW ( REVISED ) TABULATION OF THE SCRIPPS TOPOGRAPHY ON A 1 DEGREE GLOBAL GRID. PART I TERRAIN HEIGHTS * - THE RAND CORPORATION, R-1276-1-ARPA - SEPTEMBER, 1975. EXAMPLES. PA 2 74 -30-555-555-999-444-444 -17 -10 2 10.......... *** * * * * * * *** * * * * * * SEA SURFACE TEMPERATURE *** * * * * * * -1.7 DEGREES C AT 20 DEGREES WEST, *** * * * * * * 74 DEGREES NORTH *** * * * * * ************************************* *** * * * * *** * * * * SEA ICE AT 24 DEGREES WEST, 74 NORTH *** * * * * ********************************************* *** * * * * *** * * * * LAND AT 26 DEGREES WEST, 74 NORTH *** * * * ************************************************* *** * * * *** * * * GLACIAL ICE AT 30 DEGREES WEST, 74 NORTH *** * * ********************************************************* *** * * *** * * LONGITUDE OF FIRST VALUE IS 30 DEGREES WEST *** * ************************************************************* *** * *** * LATITUDE FOR THIS RECORD IS 74 DEGREES NORTH *** ***************************************************************** *** *** MONTH IS 2 ( FEBRUARY - NORTHEN HEMISPHERE WINTER ) ********************************************************************* ** ** FILE TYPE IS A ( SEA SURFACE TEMPERATURE ) ********************************************************************* * * TIME PERIOD CODE IS P ( 18,000 YEARS BP ) ********************************************************************* MH O 73 -31 20.... *** * *** * 20 PERCENT WATER AT 31 WEST, 73 NORTH *** ********************************************************* *** *** MONTH NOT APPLICABLE TO THIS DATA ********************************************************************* ** ** FILE TYPE H ( PERCENT WATER ) ********************************************************************* * * TIME PERIOD CODE M ( MODERN DATA ) ********************************************************************* MJ O 73 -31 15.... * * 15 PERCENT GLACIAL ICE AT 31 WEST, 73 NORTH ********************************************************* MK O 73 -31 30.... * * 30 PERCENT VEGETATION AT 31 WEST, 73 NORTH ********************************************************* MI O 73 -31 35.... * * 35 PERCENT EXPOSED SOIL AT 31 WEST, 73 NORTH ********************************************************* ME O 73 -31 91.... * * VEGETATION CODE 91 ( LICHEN ) AT 31 WEST, 73 NORTH ********************************************************* MF O 73 -31 41.... * * SOIL CODE 41 ( GRAYISH WHITE LOESS ) AT 31 WEST, 73 NORTH ********************************************************* COMPUTING ALBEDO OF DRY SURFACE USING ABOVE EXAMPLES OF CODE AND PERCENT FILES PLUS SOIL AND VEGETATION TABLES PRESENTED EARLIER. A = ( 20*8 + 15*70 + 30*15 + 35*34 ) / 100 * * * * * * * * * * * * * * * * * * CONSTANT * * * * * * * * ******************************* * * * * * * * * * * * * * * * * FROM AED COLUMN TYPE 41 SOIL * * * * * * * ************************************* * * * * * * * * * * * * * * PERCENT SOIL FROM MI FILE EXAMPLE ABOVE * * * * * * **************************************** * * * * * * * * * * * * FROM AED COLUMN TYPE 91 VEGETATION * * * * * ********************************************* * * * * * * * * * * PERCENT VEGETATION FROM MK FILE EXAMPLE ABOVE * * * * ************************************************ * * * * * * * * CONSTANT ALBEDO EQUIVALENT FOR GLACIAL ICE * * * ***************************************************** * * * * * * PERCENT GLACIAL ICE FROM MJ FILE EXAMPLE ABOVE * * ******************************************************** * * * * CONSTANT ALBEDO EQUIVALENT FOR WATER * ************************************************************ * * PERCENT WATER FROM MH FILE EXAMPLE ABOVE *************************************************************** A = ( 160 + 1050 + 450 + 1190 ) / 100 A = 28.5 PERCENT AT 31 DEGREES WEST, 73 DEGREES NORTH