=============================================================================== International Comprehensive Ocean-Atmosphere Data Set (ICOADS): Release 2.3 Translation Specifications: US Marine Meteorological Journals 16 April 2015 ================================================================= Document Revision Information (previous version: 11 September 2006): Author: S. Lubker Translation of Sea surface temperature method was amplified. ------------------------------------------------------------------------------- {1. Introduction} This document provides the detailed specifications for the translation of the US Marine Meteorological Journals (MMJ) to LMR6 format. The LMR were subsequently converted to IMMA. As defined in the digitization format, the MMJ input data contain five types of records: 1st char record type -------- ----------------------------------------- 1 Journal header record (117 characters) 2 Voyage header record (52 characters) 3 Daily information record (61 characters) 4 Data record (97 characters) 5 Data record (103 characters) Notation below such as "[3] 45-50" or "[4|5] 17-20" is used to designate single record type or two alternative record types, character through character. References to Jackson et al. (2000) refer to declination data and software received from KNMI (Frits Koek), which are stored in the "Leeds" directory. See the README there for additional information. {2. Translation to LMR6 location and regular fields} 1) B10 10-degree box calculated by {wrlmr6} 2) YR year input = Year [4|5] 17-20 3) MO month input = Month [4|5] 21-22 4) DY day input = Day [4|5] 23-24 5) HR hour input = Year, Month, Day, Time indicator, and Hour [4|5] 17-27 (a) Convert year, month, and day to julian day using {ixdtnd}. (b) Convert from noon, julian day, and noon longitude to UTC hour and UTC julian day using {rxltut}. (c) Apply local offset from noon to UTC hour, adjust UTC hour to between 0 and 23, and if applicable subtract or add one to UTC julian day. (d) If applicable convert adjusted UTC julian day to year, month, and day using {rxnddt}. Externals: {lmrlib.01G:ixdtnd,rxltut,rxnddt} 6) TI time indicator input = no corresponding field (a) TI=0 (nearest whole hour). 7) LON longitude input = Longitude by chronometer from forenoon observation [3] 45-50 or else Longitude by account at noon [3] 34-39, 8) LAT latitude input = Latitude by observation at noon [3] 40-44 or else Latitude by account at noon [3] 29-33 (a) Convert degrees, minutes, and hemisphere to degrees and hundredths. (b) If ship's course or speed is not extant skip (c)-(d). Longitude and latitude do not change from the previous longitude and latitude. (c) Convert ship's course and speed doubled (bihourly observations) to longitude and latitude components using {rxdvuv}. Reverse the sign (direction not from but toward) and divide by 60 knots per degree. Divide the longitude component by the cosine of the noon latitude. (d) Accumulate the longitude and latitude components and subtract from the noon location before noon or add to the noon location after noon (contingent upon the input file being sorted noon-2am, 2pm-midnight). External: {lmrlib.01G:rxdvuv} 9) LI lat/lon indicator input = no corresponding field (a) If local noon LI=4 (degrees and minutes) else LI=6 (other (refer to metadata)). 10) DCK deck input = no corresponding field (a) DCK=704 (US Marine Meteorological Journals). 11) SID source ID input = no corresponding field (a) SID=125 (US Marine Meteorological Journals). 12) PT platform type input = no corresponding field (a) Set PT=5 (ship). 13) QI quality indicator input = no corresponding field 14) DS dup status input = no corresponding field 15) DC dup check input = no corresponding field 16) TC track check input = no corresponding field (a) If longitude or latitude was corrected TC = 1 (track checked). 17) PB pressure bias input = no corresponding field (a) PB=1 (temperature and gravity corrections applied) or PB=2 (only gravity correction applied). 18) DI wind direction indicator input = no corresponding field (a) DI=1 (32-point compass). However, directions were often reported to a finer resolution than a 32 point scale by using fractions of a point. 19) D wind direction input = True wind direction [4|5] 55-61 or else Wind direction (magnetic) [4|5] 48-54 and Compass correction indicator, Compass correction, and Direction of correction [5] 98-103 or else Jackson et. al. 2000 (a) Convert alphanumeric direction (alpha direction and possibly numeric points and/or fractions of points alpha direction) to degrees partly using {ix32dd}. (b) If applicable apply compass correction. (c) Round to nearest integer 1-360 or C (calm) to 361 or V (variable) to 362. External: {lmrlib.01G:ix32dd} 20) WI wind speed indicator input = no corresponding field (a) WI=5 (Beaufort force) 21) W wind speed input = Mean Beaufort force [4|5] 62-63 (a) Convert force to meters per second using {fxbfms}. External: {lmrlib.01G:fxbfms} 22) VI visibility indicator input = no corresponding field 23) VV visibility input = no corresponding field 24) WW present weather input = no corresponding field 25) W1 past weather input = no corresponding field 26) W2 second past weather input = no corresponding field 27) SLP sea level pressure input = Barometer type [1] 74, Barometer correction [1] 111-115, Barometer [4|5] 64-67, and Attached thermometer [4|5] 69-72 (a) Apply the barometer correction to the barometer value. (b) If barometer type is mercurial and the attached thermometer temperature is between -50 and 50 degrees Centigrade, apply a temperature correction using temperature in Fahrenheit {fwbptf} or temperature in Centigrade {fwbptc}. (c) Apply a gravity correction using {fwbpgv} with the latitude. (d) Convert from inches or millimeters to millibars using {fxeimb} or {fxmmmb}. Externals: {lmrlib.01G:fwbptf,fwbptc,fwbpgv,fxeimb,fxmmmb} 28) T1 temperature indicator input = Temperature indicator [4|5] 68 (a) Convert to numeric code. Temperature indicator of 7 was undocumented but was interpreted: 7 = Dry bulb and water temperature are Centigrade with other temperatures in Fahrenheit. 29) AT air temperature input = Air temperature [4|5] 73-76 (a) If applicable convert Fahrenheit to Centigrade using {fxtftc}. External: {lmrlib.01G:fxtftc} 30) WBT wet bulb temperature input = Wet bulb temperature [4|5] 77-80 (a) If applicable convert Fahrenheit to Centigrade using {fxtftc}. External: {lmrlib.01G:fxtftc} 31) DPT dew point temperature input = no corresponding field 32) SST sea surface temperature input = Water temperature [4|5] 81-84 (a) If applicable convert Fahrenheit to Centigrade using {fxtftc}. External: {lmrlib.01G:fxtftc} 33) SI sea surface temperature method indicator input = Sea surface temperature method [1] 117 (a) Convert "1 = bucket" and "2 = intake" to numeric code. 34) N total cloud amount input = Clear Skies [4|5] 92-93 (a) Convert from clear sky in tenths to covered sky in octas using {ixt0ok}. External: {lmrlib.01G:ixt0ok} 35) NH lower cloud amount input = no corresponding field 36) CL low cloud type input = no corresponding field 37) HI cloud height indicator input = no corresponding field 38) H cloud height input = no corresponding field 39) CM middle cloud type input = no corresponding field 40) CH high cloud type input = no corresponding field 41) WD wave direction input = no corresponding field 42) WP wave period input = no corresponding field 43) WH wave height input = no corresponding field 44) SD swell direction input = no corresponding field 45) SP swell period input = no corresponding field 46) SH swell height input = no corresponding field 47) C1 country code input = no corresponding field 48) C2 second country code input = no corresponding field 49) SC ship course input = Ship's true course [4|5] 41-47 or else Course steered by compass [4|5] 32-38 and Compass correction indicator, Compass correction, and Direction of correction [5] 98-103 or else Jackson et. al. 2000 (a) Convert alphanumeric direction (alpha direction and possibly numeric points and/or fractions of points alpha direction) to degrees partly using {ix32dd}. (b) If applicable apply compass correction. [1] (c) Use in longitude and latitude calculation. (d) Round to nearest numeric code or C (calm) to 0. External: {lmrlib.01G:ix32dd} 50) SS ship speed input = Ship's speed [4|5] 28-30 (a) Use in longitude and latitude calculation. (b) Convert knots to numeric code. 51) A barometric tendency input = no corresponding field 52) PPP amount of SLP change input = no corresponding field 53) IS ice accretion input = no corresponding field 54) ES ice thickness input = no corresponding field 55) RS ice accretion rate input = no corresponding field 56) II ID indicator input = no corresponding field (a) II=10 (composite information from early ship data) 57-64) ID(8) ID/call sign input = Microfilm reel number, Journal # [4|5] 2-8 (a) Concatenate reel and journal numbers. [2] 65) OS observation source input = no corresponding field 66) OP observation platform input = no corresponding field 67) T2 second temperature indicator input = no corresponding field 68) IX station/weather indicator input = no corresponding field 69) WX wave period indicator input = no corresponding field 70) SX swell period indicator input = no corresponding field 71) IRD IMM receipt date input = no corresponding field 72) A6 allowance 6 flag input = no corresponding field {3. Contents of supplemental attachment} Data stored in the LMR Supplemental data attachment consist of only record type 4 or 5. Data stored in the IMMA Supplemental data attachment consist of the concatenation of entire record types 1-4 or 5 (333 characters minus any trailing blanks). The complete supplemental data were joined with the IMMA by a one-to-one matchup process. {4. Notes} [1] Compass correction was not applied to directions (record type 4) from ships with the following ID because directions appeared (ship's tracks) to be true: 0050104 0090177 0110224 0210444 0680984 0901138 0901139 1121321 1131323 1281445 1341491 1341492 1341493 1381528 1511651 1511655 1601742 1601743 1601744 1631769 1641770 1651794 1661802 1661803 1681819 1681820 1701843 1721854 1801910 1841944 1851946 [2] The concatenation of reel and journal numbers was used for ID in the LMR but the first nine characters from Name of ship [1] 13-38 was used in the IMMA. {Reference} Andrew Jackson, Art R. T. Jonkers, Matthew R. Walker, Four centuries of geomagnetic secular variation from historical records, Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences , Volume 358, Issue 1768, 15 Mar 2000, Pages 957 - 990, DOI 10.1098/rsta.2000.0569, URL http://dx.doi.org/10.1098/rsta.2000.0569