Let me introduce myself. I was trained as a scientist and an engineer, with a degree in Aeronautics and Astronautics from MIT and a Ph.D. in Applied Physics from Harvard. I joined Goddard in 1990 when Joanne Simpson had a grand vision of improving weather prediction using space-based precipitation data. I took on rainfall assimilation at a time when there was considerable skepticism about just how useful such data might be. With the launch of TRMM, which vouched for passive microwave radiometer rain retrievals with a space-radar, the data assimilation community has come to embrace rainfall observations from space, and made great strides in a relatively short time. The benefits of GPM data for weather prediction and climate analysis are, by now, taken for granted. As a climate researcher, I share the anticipation of GPM’s contributions to new sciences. With the growing recognition that interactions of precipitation, clouds, and aerosols are central to understanding climate feedbacks and climate change, detailed microphysical measurements from the first-ever dual-frequency radar on the GPM core spacecraft will provide critical information for making advances in this area. Another major thrust for GPM comes from the hydrology community, which has waited for a long time for high-quality precipitation measurements with enough temporal resolution and spatial coverage to test and refine hydrometeorological models for flood hazard prediction and fresh water utilization. Much of the scientific progress and societal benefits, I believe, will come from these new frontiers in the GPM era. The GPM Project and the Precipitation Measurement Missions (PMM) Science Team will play a key role in making this happen. At Goddard, I have benefited from an insider’s look at NASA’s unique role in Earth sciences—which is to provide new measurement technology together with applications research to do end-to-end problem-solving in partnership with academia, sister agencies, and international partners. I learned about the mechanics of a satellite mission as the Deputy TRMM Project Scientist. However, with the vantage of that experience, I would like to say that, as a mission, GPM is far more than a global rendition of TRMM. My reasons are as follows. TRMM is a research satellite, which has also yielded direct societal benefits. By contrast, GPM is driven not only by scientific discovery but also by anticipated benefits in societal applications. This means that the success of GPM does not depend on measurements per se but also on data utilization in a fairly wide range of applications. The challenges for the GPM team are therefore two fold:
Our experience has taught us that knowing how to use precipitation data well in any application area does not happen overnight; and more importantly, jump-starting the applications/operational community in GPM-sponsored research is one effective way to bridge the divide between research and operations. I look forward to having the opportunity to work with many of you as members of the GPM Project, the PMM Science Team, and GPM partner organizations to make GPM a resounding success. Arthur Hou |
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