Intercomparison of water vapor transport datasets

In 2008, we publicly released the Passive Microwave Water Cycle (PMWC) dataset, which was developed as part of the NASA Energy and Water Cycle Study (NEWS). This dataset integrates passive microwave observations from a variety of different sensors on different satellites to provide a complete characterization of the atmospheric branch of the water cycle over the global oceans. The Version-1b dataset provides monthly average, 0.25-degree maps of water vapor transport zonal (u) and meridional (v) components, water vapor transport divergence (D), evaporation (E), precipitation (P), and column-integrated water vapor (WV) spanning the last 20 years: 1987-2006.

In this poster, we will perform a water vapor transport intercomparison using our Version-1b PMWC dataset, the Version-2 and 3 Xie and Liu water vapor transport datasets, and MERRA – The Modern Era Retrospective-analysis for Research and Applications. We will be evaluating the integrated vapor flux from the ocean into the continents, including: South America, North America, Africa, Eurasia, Australia, and Antarctica. Time series for each continent will be shown, and we will assess: annual mean flux, amplitude of the seasonal cycle, and phase of the seasonal cycle. The flux estimates will be compared against estimates of continental-scale E-P and runoff prepared by the NEWS Climatology Working Group. For the PMWC dataset, we will attempt to determine the sensitivity of our vapor transports to assumptions in the algorithm.