We have recently publicly released the Version-1a Passive Microwave Water Cycle (PMWC) product developed for the NASA Energy and Water Cycle Study (NEWS). This product 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. This product 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: 1987-2007.

The development and evaluation of this product has generated many science questions, and we will discuss our new results. Recently we have shown that precipitation is increasing with global warming at a rate comparable to the increase in water vapor. This is in contrast to climate models that generally predict a muted response of precipitation to global warming. Recently, we have determined that the increases in precipitation are due to increases in heavy rain. This finding is consistent with changes in water vapor transport, and we will examine the relative roles of wind changes and vapor changes in the global transport changes. We will also discuss what water cycle closure implies for mid- and high-latitude precipitation as well as for ocean-land exchanges.