ISLSCP II Data Intercomparison Workshop

1. Subjective Evaluation of ISLSCP II SRB Parameters for January-1992 [Eric A. Smith & Amita V. Mehta] • ISLSCP II Data Intercomparison Workshop • Eric A. Smith; NASA/Goddard Space Flight Center, Greenbelt, MD 20771 [tel: 301-286-5770; fax: 301-286-1626;easmith@pop900.gsfc.nasa.gov] • March 12-14, 2002; Greenbelt, MD

2. Documentation Provided Notes: Archives are zipped. Use unzip or pkunzip to unpack. Diurnal in the filename means that the file contains monthly averagesat 8 synoptic hours (00, 03, 06, 09, 12, 15, 18, and 21 Z). All fluxes are in Watts per meter sq. Other units are given above. toa - top-of-atmosphere par - photosynthetically active radiation MSMM - File contains mean, standard deviation, maximum, and minimum in that order (order very important) Mean - File contains just the mean values Net total flux in files 22 and 23 is: net sw + net lw Each record in a file is a global field on a 1 deg x 1 deg grid, i.e., 360 x180 = 64800 values. The grid starts at the North Pole-Dateline and goes East and South from there. This orientation was requested by ISLSCP folks. The files are written as floating point values with 3 significant digits. All files are space delimited with one space between fields. Parameter values are undefined (=-999.000) where they were not available or could not be computed. Shortwave fluxes, when there was no Sun, were put equal to zero (not undefined). In the absence of Sun, albedos (csalb and sfalb) are considered undefined (not zero). Filename Variable Name Stats Records 1. cldamt_monthly total cloud amount (%) MSMM 4 2. cldtopp_monthly cloud-top pressure (mb) MSMM 4 3. cldtopt_monthly cloud-top temperature (K) MSMM 4 4. csalb_monthly clear-sky surface albedo MSMM 4 5. csdsf_diurnal clear-sky downward sw flux MSMM 32 6. csdsf_monthly clear-sky downward sw flux MSMM 4 7. cwv_monthlyq column water vapor (gm/cm2) MSMM 4 8. dif_diurnal all-sky diffuse sw flux MSMM 32 9. dif_monthly all-sky diffuse sw flux MSMM 4 10. dlf_3hourly all-sky downward lw flux Mean 248 11. dlf_diurnal all-sky downward lw flux MSMM 32 12. dlf_monthly all-sky downward lw flux MSMM 4 13. dsf_3hourly all-sky downward sw flux Mean 248 14. dsf_diurnal all-sky downward sw flux MSMM 32 15. dsf_monthly all-sky downward sw flux MSMM 4 16. nlf_3hourly all-sky net lw flux Mean 248 17. nlf_diurnala all-sky net lw flux MSMM 32 18. nlf_monthly all-sky net lw flux MSMM 4 19. nsf_3hourly all-sky net sw flux Mean 248 20. nsf_diurnal all-sky net sw flux MSMM 32 21. nsf_monthly all-sky net sw flux MSMM 4 22. ntf_diurnal all-sky net total flux MSMM 32 23. ntf_monthly all-sky net total flux MSMM 4 24. ozone_monthly column ozone (dobson units) MSMM 4 25. par_diurnal all-sky par flux MSMM 32 26. par_monthly all-sky par flux MSMM 4 27. sfalb_monthly all-sky surface albedo MSMM 4 28. skint_monthly surface skin temperature (K) MSMM 4 29. tau_monthly cloud optical depth MSMM 4 30. toains_diurnal toa insolation Mean 8 31. toains_monthlyt toa insolation Mean 1 32. toaref_diurnal toa reflected sw flux MSMM 32 33. toaref_monthly toa reflected sw flux MSMM 4 34. ulf_diurnal surface upward lw flux MSMM 32 35. ulf_monthly surface upward lw flux MSMM 4 36. usf_diurnal surface upward sw flux MSMM 32 37. usf_monthly surface upward sw flux MSMM 4 38. waterpath_monthly cloud liquid water path (gm/m2) MSMM 4

3. Monthly Means

4. TOA Insolation

5. Clear Sky Downward SWF

6. Downward SWF

7. Downward LWF

8. Upward SWF

9. Net SWF

10. Net LWF

11. Downward PAR Flux

12. Summary 1. Documentation: Brief but clear. 2. Data Files: Appear to be end-of-line problems with 3-hourly files. 3. Data Quality: Mostly OK but with apparently some significant problems: a. continental clear sky shortwave flux contains noise -- maybe interpretting large desert albedos as cloud b. cloud contamination in reflected shortwave flux c. tropical net longwave fluxes seem to be too large