Merging And Application Of Multi-source Oceanic Precipitation Information

In this study, eight different precipitation products, COADS, ECMWF, NCEP, GPCP_GPI,SSM/I_EMISS, SSM/I_SCATT, TRMM_PR, and TOPEX-TMR, have been intercompared to understand the correlation and the difference among them. An optimal weighted coefficient method has been given based on the characteristics of the spatial-temporal distributions of these products. A merged new precipitation product has been derived based on this new method. This merged product has been validated by using nine coastal rain gauge station measurements and other eight products.The merged new precipitation dataset spanning from 1980 through 2003 has an enlarged spatial coverage and higher spatial/temporal resolution. The averaged relative discrepancy of this new product is–0.56%～40% when compared with the coastal rain gauge station measurements, suggesting that the merged new precipitation product is better in terms of its relative discrepancy.The relationship between the precipitation pattern and El Ni?o–Southern Oscillation (ENSO) has been investigated based on this merged new rainfall dataset. The characteristics of the precipitation patterns during warm and cold events of ENSO are as follows.1) The global mean precipitation has a decreasing (increasing) trend during an El Ni?o (La Ni?a) event.2) A striking feature of the precipitation pattern during ENSO events is the latitude dependency. In the Southern Hemisphere, the rainfall estimates are much higher during a cold event than that of a warm event of ENSO at the same latitude. In the Northern Hemisphere, a...