An SSM/I - SSMI/S Application for Climate Research: the Extension of Hydrological Products Climate Records Daniel Vila – R. Ferraro – J. Turk – F. Weng Cooperative Institute for Climate Studies University of Maryland
OUTLINES Introduction – SSMI-based Monthly Hydrological Products SSMI – SSMIS similarities and differences. Intercomparison strategy: the Simultaneous Conical Overpass (SCO) approach Validation results for Rainfall Rate (RR) Can we extend application to F17? Beacon interference in DMSP F15 22V: evaluation of a correction scheme
SSMI-based Monthly Hydrological Products Global monthly rainfall estimates (RR) and other hydrological products like integrated Cloud Liquid Water (CLW) and Total Precipitable Water (TPW) have been produced from 1987 to present using measurements from the Defense Meteorological Satellite Program (DMSP) series of Special Sensor Microwave Imager (SSM/I) Ferraro, 1997 Weng and Grody, 1994 Alihouse et al., 1990
SSMI – SSMIS similarities and differences
SSMI – SSMIS similarities and differences Comparison of SSMI and SSMI/S Sensors characteristics for those specific channels used in the hydrological product generation
Image courtesy of Eric Nelkin, NASA/GSFC SSMI – SSMIS similarities and differences F13 – Sensor degradation? F14 – Recorders have failed F15 - RADCAL F17 – Replacement for F13 F16 – Replacement for F14/F15 Image courtesy of Eric Nelkin, NASA/GSFC
How to continue with the Climate Data Records?
Simultaneous Conical Overpass (SCO) approach A Simultaneous Conical Overpass (SCO) is defined as the data pair generated when two polar-orbiting satellites (SSM/I F15 and SSMI/S F16 cross the same area at similar local times (t < 7 minutes).
Simultaneous Conical Overpass (SCO) approach Develop empirical fits between SSM/I F15 and SSMI/S F16 during period of close overpass times (3/06 – 2/07) All channels Stratify via land/ocean; rain/no-rain RADCAL correction applied to F15 8/06 and forward Improves Rain/No-Rain threshold Rain rate PDF’s Other products (e.g., TPW, CLW, etc.) Can be extended to F17 as well, although procedure should be duplicated
Scattering Index (SI) Simultaneous Conical Overpass (SCO) approach Uncorrected
Scattering Index (SI) Simultaneous Conical Overpass (SCO) approach Uncorrected Corrected
SSMI/S F16 - Uncorrected April 2008 SSMI/S F16 - Corrected
SSMI F15 April 2008 SSMI/S F16 - Corrected
Validation results Ocean Land Uncorrected Corrected
Validation results
Image courtesy of Eric Nelkin, NASA/GSFC SSMI – SSMIS similarities and differences F13 – Sensor degradation? F14 – Recorders have failed F15 - RADCAL F17 – Replacement for F13 F16 – Replacement for F14/F15 Image courtesy of Eric Nelkin, NASA/GSFC
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