Status of the TRMM 2A12 Land Precipitation Algorithm

Kaushik Gopalan Earth System Science Interdisciplinary Center, University of Maryland, College Park, College Park, Maryland

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Nai-Yu Wang Earth System Science Interdisciplinary Center, University of Maryland, College Park, College Park, Maryland

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Ralph Ferraro NOAA/NESDIS/Center for Satellite Applications and Research (STAR)/SCSB, Camp Springs, and Cooperative Institute of Climate Studies, ESSIC, University of Maryland, College Park, College Park, Maryland

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Chuntao Liu Department of Atmospheric Sciences, University of Utah, Salt Lake City, Utah

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Abstract

This paper describes improvements to the Tropical Rainfall Measurement Mission (TRMM) Microwave Imager (TMI) land rainfall algorithm in version 7 (v7) of the TRMM data products. The correlations between rain rates and TMI 85-GHz brightness temperatures (Tb) for convective and stratiform rain are generated using 7 years of collocated TMI and TRMM precipitation radar (PR) data. The TMI algorithm for estimating the convective ratio of rainfall is also modified. This paper highlights both the improvements in the v7 algorithm and the continuing problems with the land rainfall retrievals. It is demonstrated that the proposed changes to the algorithm significantly lower the overestimation by TMI globally and over large sections of central Africa and South America. Also highlighted are the problems with the 2A12 land algorithm that have not been addressed in the version 7 algorithm, such as large regional and seasonal dependence of biases in the TMI rain estimates, and potential changes to the algorithm to resolve these problems are discussed.

Corresponding author address: Kaushik Gopalan, Earth System Science Interdisciplinary Center, University of Maryland, College Park, 5825 University Research Ct. Ste. 4001, College Park, MD 20740. Email: kaushik@umd.edu

Abstract

This paper describes improvements to the Tropical Rainfall Measurement Mission (TRMM) Microwave Imager (TMI) land rainfall algorithm in version 7 (v7) of the TRMM data products. The correlations between rain rates and TMI 85-GHz brightness temperatures (Tb) for convective and stratiform rain are generated using 7 years of collocated TMI and TRMM precipitation radar (PR) data. The TMI algorithm for estimating the convective ratio of rainfall is also modified. This paper highlights both the improvements in the v7 algorithm and the continuing problems with the land rainfall retrievals. It is demonstrated that the proposed changes to the algorithm significantly lower the overestimation by TMI globally and over large sections of central Africa and South America. Also highlighted are the problems with the 2A12 land algorithm that have not been addressed in the version 7 algorithm, such as large regional and seasonal dependence of biases in the TMI rain estimates, and potential changes to the algorithm to resolve these problems are discussed.

Corresponding author address: Kaushik Gopalan, Earth System Science Interdisciplinary Center, University of Maryland, College Park, 5825 University Research Ct. Ste. 4001, College Park, MD 20740. Email: kaushik@umd.edu

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  • Awaka, J., Iguchi T. , and Okamoto K. , 1998: Early results on rain type classification by the Tropical Rainfall Measuring Mission (TRMM) precipitation radar. Proc. Eighth URSI Commission F Open Symp., Aveiro, Portugal, URSI, 143–146.

    • Search Google Scholar
    • Export Citation
  • Dinku, T., and Anagnostou E. , 2005: Regional differences in overland rainfall estimation from PR-calibrated TMI algorithm. J. Appl. Meteor., 44 , 189205.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Ferraro, R., and Marks G. , 1995: The development of SSM/I rain-rate retrieval algorithms using ground-based radar measurements. J. Atmos. Oceanic Technol., 12 , 755770.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Grecu, M., and Anagnostou E. , 2001: Overland precipitation estimation from TRMM passive microwave observations. J. Appl. Meteor., 40 , 13671380.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Grody, N., 1991: Classification of snow cover and precipitation using the Special Sensor Microwave Imager. J. Geophys. Res., 96 , 74237435.

  • Iguchi, T., Kozu T. , Meneghini R. , Awaka J. , and Okamoto K. , 2000: Rain-profiling algorithm for the TRMM Precipitation Radar. J. Appl. Meteor., 39 , 20382052.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Kummerow, C., and Coauthors, 2001: The evolution of the Goddard Profiling Algorithm (GPROF) for rainfall estimation from passive microwave sensors. J. Appl. Meteor., 40 , 18011820.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Liu, C., and Zipser E. , 2009: “Warm rain” in the tropics: Seasonal and regional distributions based on 9 yr of TRMM data. J. Climate, 22 , 767779.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Liu, C., Zipser E. , Cecil D. , Nesbitt S. , and Sherwood S. , 2008: A cloud and precipitation feature database from nine years of TRMM observations. J. Appl. Meteor. Climatol., 47 , 27122728.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • McCollum, J., and Ferraro R. , 2003: Next generation of NOAA/NESDIS TMI, SSM/I, and AMSR-E microwave land rainfall algorithms. J. Geophys. Res., 108 , 8382. doi:10.1029/2001JD001512.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Olson, W. S., Hong Y. , Kummerow C. D. , and Turk J. , 2001: A texture-polarization method for estimating convective–stratiform precipitation area coverage from passive microwave radiometer data. J. Appl. Meteor., 40 , 15771591.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Prabhakara, C., Icovazzi R. Jr., Weinman J. A. , and Dalu G. , 2000: A TRMM microwave radiometer rain rate estimation method with convective and stratiform discrimination. J. Meteor. Soc. Japan, 78 , 241258.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Schneider, U., Fuchs T. , Meyer-Christoffer A. , and Rudolf B. , 2008: Global Precipitation Analysis Products of the GPCC. Global Precipitation Climatology Centre, DWD, 12 pp. [Available online at ftp://ftp-anon.dwd.de/pub/data/gpcc/PDF/GPCC_intro_products_2008.pdf].

    • Search Google Scholar
    • Export Citation
  • Wang, N-Y., Liu C. , Ferraro R. , Wolff D. , Zipser E. , and Kummerow C. , 2009: TRMM 2A12 land precipitation product—Status and future plans. J. Meteor. Soc. Japan, 87A , 237253.

    • Crossref
    • Search Google Scholar
    • Export Citation
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