Yaping Zhou - 613 Seminar Series


A quite consistent picture has emerged from recent studies on current climate change and future climate projections under increased greenhouse gases regarding the mean precipitation distribution and extreme precipitation. First, although global mean precipitation changes at a much slower rate than the atmospheric water vapor per degree of surface temperature increase, there are strong regional patterns of positive and negative trends that cancel each other. The regional trends of precipitation associated with tropical overturning circulations derived from GPCP are remarkably consistent with the CMIP5 projections. Second, both observations and the models have shown a more robust increase in extreme precipitation events in current and future climate. In this talk, I will present some research on the observed precipitation trends associated with tropical overturning circulations, i.e., intensification of tropical precipitation in the rising regions of the Hadley and Walker circulations and weakening over the sinking regions of the respective overturning circulations. To understand the extremes in precipitation, we examined the relationship between the trends in mean precipitation and extreme precipitation in different precipitation data records, investigated precipitation characteristics and associated large-scale environments for millions of TRMM observed instantaneous extreme precipitation systems. To conclude the talk, I will present a prototype TRMM extreme precipitation monitoring system that aims at capturing locally severe extreme precipitation events by mapping the real-time TRMM 3B42RT data into Averaged Recurrence Interval (ARI) or return year.