1. Feasibility of Deriving Surface and Atmospheric Parameters over Land using TRMM-TMI B. S. Gohil, Atul K. Varma and A. K. Mathur Oceanic Sciences Division Meteorology and Oceanography Group Space Applications Centre (ISRO) Ahmedabad 380 015, India.

2. TB ( ,p) = TB DN  (  )(1-  (T S, ,p)) +T S  (T S, ,p)  (  )+TB UP The brightness temperature received by microwave radiometer looking towards earth in non-scattering atmosphere in a thermodynamic equilibrium is given by: TB DN TBUP Surface Ts,  TB TB S    For attenuation by atmospheric gases – Liebe (1992) model  Absorption by non-precipitating clouds – Paris (1971)

3. Emissivities of (1) first year ice, (2) multiyear ice and (3) open water at H-polarization and 50 o incidence angle (Pedersen, 1988) Assumption:  V19   V23   V37 =  V  H19   H23   H37 =  H  V or  H  0

4. Constitution of database , T S, TB UP, TB DN, CLW, WV T S – from Climatology Pressure profiles simulated from hydrostatic equation  V and  H are proxy  V is moved from 0.4 tp 1.0 and  H such that  H <  V  V-H =  V -  H = 0 to 0.6 ParameterMinMaxMeanSD SST (K)255315282.617.5 WV (g/cm 2 )0.038.992.132.27 CLW (g/cm 2 )00.190.050.05

5. Simulation of Water Vapor profiles RH is linearly varied from surface to tropopause RH is varied at the surface Temperature Lapse Rate of Standard Atmosphere are adopted WV profile is derived using RH and T profiles If clouds present RH = 100% at the base of the clouds Surface Tropopause (16 km) RH=0

6. Simulation of Clouds Case: 1 Case: 2 Case: 3 Freezing level  CLW is maximum at freezing level  CLW (max) = 5% or 10% of cloud thickness in gm/m 3  Raining clouds have not been considered

7. Minimization Wi is weight, that for water vapor taken as: 0.5 for 19 GHz 0.8 for 23 GHz 0.7 for 37 GHz

8. TMI Characteristics

9. Examples of IWV

10. IWV-July 15 2002

11. IWV - July 16 2002

12. IWV - July 17 2002

13. IWV - June 1 2003

14. IWV - June 2 2003

15. Examples of Emissivity

16. Emissivity (V) -July 15 2002

17. Emissivity (V) - July 16 2002

18. Emissivity - July 17 2002

19. Emissivity - June 1 2003

20. Emissivity - June 2 2003

21. Examples of Emissivity Diff. (V-H)

22. Emissivity Difference (V-H) -July 15 2002

23. Emissivity Difference (V-H) -July 16 2002

24. Emissivity Difference (V-H) -July 17 2002

25. Emissivity Difference (V-H) -June 1 2003

26. Emissivity Difference (V-H) -June 2 2003

27. Examples of Land Surface Temperature (LST)

28. LST -July 15 2002

29. LST -July 16 2002

30. LST -July 17 2002

31. LST -June 1 2003

32. LST -June 2 2003

33. Examples of CLW

34. CLW - July 15 2002

35. CLW – July 16 2002

36. CLW - July 17 2002

37. CLW - June 1 2003

38. CLW - June 2 2003

39. TMI DERIVED GEOPHYSICAL PARAMETERS OVER LAND (JUN 3, ’03-15GMT) (Gohil, et al, 2003)Abs

40. Comparison NCEP Reanalysis Jun 03, 2003 (Daily Mean) TMI Derived WVC over Land (Jun 03, 2003/15 GMT)(Over ocean – Wentz Product)

41. Conclusion Study shows good prospects for estimation of Atmospheric and Surface parameters, especially water vapor over land. Study needs to be more refined with more case studies and inter-comparison/validation.

42. Thanks