J2.10
CMORPH: An 8KM, Half-Hourly Global Precipitation Monitoring Tool
John Janowiak, NOAA/CPC, Camp Springs, MD; and R. Joyce, P. Arkin, and P. Xie
Drought is a global concern and measurements of precipitation are vital for monitoring drought during all phases of the evolution of that phenomenon. However, good quality measurements of precipitation are still lacking over many important regions of the world. We present a method that provides near-radar quality estimates of precipitation at high spatial and temporal resolution. The resulting analyses are useful for global monitoring of precipitation, including drought initiation, evolution and mitigation.
It has been demonstrated in the scientific literature that precipitation estimates that are produced from passive microwave instrumentation are clearly superior to estimates derived from infrared (IR) sensors. The reason is that microwave observations detect information that is more physically related to precipitation than is possible from infrared data. However, because of the antenna size considerations due to the microwave frequencies involved, these instruments currently reside on low altitude, polar or other non-geostationary orbiting platforms, thus temporal sampling is a major drawback toward the use of these data for the production of near real-time and spatially complete global precipitation analyses. Infrared data on the other hand, while inferior to passive microwave data for precipitation estimation, are available globally nearly everywhere, nearly all the time. An obvious solution is to meld the two diverse data types to yield a hybrid in which the accuracy of the passive microwave data is combined with the excellent sampling that the IR data afford. Several products have been developed and published in which the IR data are used in a statistical fashion to mimic microwave estimates to fill in the gaps when microwave data are not available. We present a technique in which passive microwave-derived precipitation features are propagated by IR data. The resulting fields are then "morphed" by linearly interpolating between the most recent microwave observations, which modifies the shape and intensity of the precipitation features that have been propagated by IR. This process yields spatially and temporally complete microwave-derived precipitation analyses.
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Joint Session 2, Drought: Variability Monitoring, Impacts, and Prediction (Joint between the 15th Symposium on Global Change and Climate Variations and the 14th Conference on Applied Climatology; Room 6C)
Monday, 12 January 2004, 1:30 PM-5:30 PM, Room 6C
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