报告题目: |
全球变化科学紫荆论坛（第201期）：A new mechanism for warm-season precipitation response to global warming |
报告人: |
Prof. Aiguo Dai |
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Depeartment of Atmospheric and Environmental Sciences,
University at Albany, SUNY, Albany, New York, USA
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报告时间: |
2017-06-22 10:30 |
报告地点: |
蒙民伟科技大楼南楼S1021 |
主办单位: |
地球系统科学系 |
简介: |
Climate models project increasing precipitation intensity but decreasing frequency as greenhouse gases (GHGs) increase. However, the exact mechanism for the frequency decrease remains unclear. Here we investigate this by analyzing hourly data from regional climate change simulations with 4km grid spacing covering most of North America using the Weather Research and Forecasting (WRF) model. The model was forced with present and future boundary conditions, with the latter being derived by adding the CMIP5 19-model ensemble mean changes to the ERA-interim reanalysis. The model reproduces well the observed seasonal and spatial variations in precipitation frequency and histograms, and the dry interval between rain events over the contiguous U.S. (CONUS). Results show that overall precipitation frequency indeed decreases during the warm season mainly due to fewer light-moderate precipitation (0.1£2.0mm/hr) events, while heavy (2£10mm/hr) to very heavy precipitation (P>10mm/hr) events increase. |
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