Journal of the Korean earth science society (한국지구과학회지)

The Korean Earth Science Society (한국지구과학회)
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Radiative Transfer Simulation of Microwave Brightness Temperature from Rain Rate

  • Published : 2002.01.31
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Abstract

Theoretical models of radiative transfer are developed to simulate the 85 GHz brightness temperature (T85) observed by the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) radiometer as a function of rain rate. These simulations are performed separately over regions of the convective and stratiform rain. TRMM Precipitation Radar (PR) observations are utilized to construct vertical profiles of hydrometeors in the regions. For a given rain rate, the extinction in 85 GHz due to hydrometeors above the freezing level is found to be relatively weak in the convective regions compared to that in the stratiform. The hydrometeor profile above the freezing level responsible for the weak extinction in convective regions is inferred from theoretical considerations to contain two layers: 1) a mixed (or mixed-phase) layer of 2 km thickness with mixed-phase particles, liquid drops and graupel above the freezing level, and 2) a layer of graupel extending from the top of the mixed layer to the cloud top. Strong extinction in the stratiform regions is inferred to result from slowly-falling, low-density ice aggregates (snow) above the freezing level. These theoretical results are consistent with the T85 measured by TMI, and with the rain rate deduced from PR for the convective and stratiform rain regions. On the basis of this study, the accuracy of the rain rate sensed by TMI is inferred to depend critically on the specification of the convective or stratiform nature of the rain.

Keywords

References

  1. Journal of the Atmospheric Sciences v.47 Estimation of rain and hail rates in mixed-phase precipitation Balakrishnan, N.;Zrnic, D.S. https://doi.org/10.1175/1520-0469(1990)047<0565:EORAHR>2.0.CO;2
  2. Journal of the Atmospheric Sciences v.57 Combined cloud-microwave radiative transfer modeling of stratiform rainfall Bauer, P.;Khain, A.;Pokrovsky, A.;Meneghini, R.;Kummerow, C.;Marzano, F.;Poiares Baptista, J.P.V. https://doi.org/10.1175/1520-0469(2000)057<1082:CCMRTM>2.0.CO;2
  3. Journal of Applied Meteorology v.40 The sensitivity of microwave remote sensing observations of precipitation to ice particle size distributions Bennartz, R.;Petty, G.W. https://doi.org/10.1175/1520-0450(2001)040<0345:TSOMRS>2.0.CO;2
  4. Monthly Weather Review v.125 Evolution of a Florida thunderstorm during the Convective and Precipitation/Electrification Experiment: The case of 9 August 1991 Bringi, V.N.;Knupp, K.;Detwiler, A.;Lui, L.;Caylor, I.J.;Black, R.A. https://doi.org/10.1175/1520-0493(1997)125<2131:EOAFTD>2.0.CO;2
  5. Radiative Transfer Chandrasekhar, S.
  6. Bulletin of American Meteorological Society v.77 Results from the GPCP algorithm Inter-comparison Programme Ebert, E.E.;Manton, M.J.;Arkin, P.A.;Allam, R.J.;Holpin, G.E.;Gruber, A. https://doi.org/10.1175/1520-0477(1996)077<2875:RFTGAI>2.0.CO;2
  7. Journal of Applied Meteorology v.8 Terminal velocity of raindrops aloft Foote, G.B.;Du Toit, P.S. https://doi.org/10.1175/1520-0450(1969)008<0249:TVORA>2.0.CO;2
  8. Cloud Dynamics Houze Jr., R.A.
  9. Bulletin of American Meteorological Society v.78 Stratiform precipitation in regions of convection: A meteorological paradox? Houze Jr., R.A. https://doi.org/10.1175/1520-0477(1997)078<2179:SPIROC>2.0.CO;2
  10. Journal of Applied Meteorology v.39 Rain-profiling algorithm for the TRMM Precipitatio Radar Iguchi, T.;Kozu, T.;Meneghini, R.;Awaka, J.;Okamoto, K https://doi.org/10.1175/1520-0450(2001)040<2038:RPAFTT>2.0.CO;2
  11. An Introduction to Atmospheric Radiation Liou, K.
  12. Journal of Geophysical Research v.79 Fall speeds and masses of solid precipitation particles Locatelli, J.D.;Hobbs, P.V. https://doi.org/10.1029/JC079i015p02185
  13. Journal of Applied Meteorology v.35 Comparisons of cross sections for melting hydrometeors as derived from dielectric mixing formulas and a numerical method Meneghini, R.;Liao, L. https://doi.org/10.1175/1520-0450(1996)035<1658:COCSFM>2.0.CO;2
  14. Journal of Atmospheric and Oceanic Technology v.17 Effective dielectric constants of mixed-phase hydrometeors Meneghini, R.;Liao, L https://doi.org/10.1175/1520-0426(2000)017<0628:EDCOMP>2.0.CO;2
  15. Journal of Climate v.12 Prevalence of precipitation from warm-topped clouds over Eastern Asia and the Western Pacific Petty, G.W. https://doi.org/10.1175/1520-0442-12.1.220
  16. Applied Optics v.11 Broadband complex refractive indicies of ice and water Ray, P.S. https://doi.org/10.1364/AO.11.001836
  17. Journal of Applied Meteorology v.19 Water-ice and water-updraft relationships near -10℃ with populations of Florida cumuli Sax, R.I.;Keller, V.W. https://doi.org/10.1175/1520-0450(1980)019<0505:WIAWUR>2.0.CO;2
  18. Journal of the Atmospheric Sciences v.27 Snow size spectra and radar reflectivity Sekhon, R.S.;Srivastava, R.C. https://doi.org/10.1175/1520-0469(1970)027<0299:SSSARR>2.0.CO;2
  19. Bulletin of American Meteorological Society v.78 Shipboard radar rainfall patterns within the TOGA COARE IFA Short, D.A.;Kucera, P.A.;Ferrier, B.S.;Gerlach, J.C.;Rutledge, S.A.;Thiele, O.W. https://doi.org/10.1175/1520-0477(1997)078<2817:SRRPWT>2.0.CO;2
  20. Journal of Applied Meteorology v.38 Observations of mixed-phase precipitation withing a CaPE thunderstorm Smith, P.L.;Musil, D.J.;Detwiler, A.G.;Ramachandran, R. https://doi.org/10.1175/1520-0450(1999)038<0145:OOMPPW>2.0.CO;2
  21. Applied Optics v.19 IMproved Mie scattering algorithms Wiscombe, W. https://doi.org/10.1364/AO.19.001505
  22. Journal of Geophysical Research v.89 Microwave radiances from precipitating clouds containing aspherical ice, combined phase, and liquid hydrometeors Wu, R.;Weinman, J.A. https://doi.org/10.1029/JD089iD05p07170
  23. Journal of the Atmospheric Sciences v.29 Fall patterns and fall velocities of rimed ice crystals Zikmundu, J.;Vali, G. https://doi.org/10.1175/1520-0469(1972)029<1334:FPAFVO>2.0.CO;2