To date, the main geographical and seasonal focus of high-resolution remote-sensing precipitation techniques have been equator-ward of 60oS/N and for non-winter time regimes respectively. While estimates generated by blended satellite techniques for these locations and seasons present reasonable skill in depicting precipitation variations over both land and ocean, complete pole-to-pole analyses are required to truly define the global hydrological cycle and balance. Blended satellite precipitation estimates are derived from the integration of information from passive microwave (PMW) retrievals from low earth orbiters (LEO) and visible/infrared (IR) observations from geostationary (GEO) platforms. The 60oS/N spatial coverage restriction is mainly due to the use of GEO data required for derivation of precipitation estimates and/or computation of precipitation system propagation vectors. The non-winter seasonal restriction is due to the limited capability of precipitation estimation using LEO-GEO retrievals over cold, snow, and sea-ice surfaces.

The objective of this work is to determine the best possible high-resolution polar-region/winter-season satellite precipitation estimates needed to geographically extend the current CMORPH technique to cover the entire globe. To this end, a comprehensive examination is being conducted to evaluate a collection of information sources for their performance in depicting precipitation variations over mid/hi-latitudes and for cold seasons. Precipitation fields derived from PMW and IR-based LEO satellite observations are inter-compared for their capability of solid and liquid phase precipitation estimation using newly available ground truth precipitation validation data sets over high latitude regions. Particular attention on the PMW algorithms will examine the ability to not only estimate precipitation over cold, snow, and sea-ice surface, but also for the abstinence of anomalous estimation. Preliminary experiments have been conducted using data for two testbed periods: July-August 2009, and January-February 2010.