Narrowing uncertainties in precipitation and the hydrological cycle in climate models1>
Co-Author: Kevin Trenberth
Co-Author: Aiguo Dai
Co-Author: John Fasullo
The goal is to evaluate all aspects of precipitation characteristics (amount, frequency, intensity, duration, diurnal cycle, annual cycle, variability on multiple time scales, and extremes). The model results will be compared with available observationally based datasets, which are expected to improve with the launch of GPM: the flagship satellite is expected to launch in 2014 and the constellation of satellites under GPM will enable 3-hourly global estimates of precipitation. We further plan to extensively explore interannual and decadal variability of both the mean and characteristics of precipitation using the NCAR large ensemble of model runs with a focus on natural modes of variability such as ENSO and the Pacific Decadal Oscillation that have been earmarked as the keys to the recent hiatus in global mean temperature rise.