Characterization of Extreme Precipitation Under Atmospheric River Events

• Activity Number: 469
• Type: Contributed
• Date/Time: Wednesday, August 6, 2014 : 8:30 AM to 10:20 AM
• Sponsor: Section on Statistics and the Environment
• Author(s): Soyoung Jeon*+ and Mr. Prabhat and Surendra Byna and William Collins and Michael Wehner
• Companies: Lawrence Berkeley National Laboratory and Lawrence Berkeley National Laboratory and Lawrence Berkeley National Laboratory and Lawrence Berkeley National Laboratory and Lawrence Berkeley National Laboratory
• Keywords: spatial dependence ; extreme value theory ; climate extremes ; climate change

Abstract

Atmospheric Rivers (ARs) are large spatially coherent weather systems with high concentrations of elevated water vapor that often cause severe downpours and flooding over western coastal United States. We have recently developed TECA (Toolkit for Extreme Climate Analysis) for automatically identifying and tracking features in climate datasets. In particular, we are able to identify ARs that make landfall on the western coast of North America. This detection tool examines integrated water vapor field above a certain threshold and performs geometric analysis. Based on the detection procedure, we investigate impacts of ARs by exploring spatial extent of AR precipitation for CMIP5 simulations, and characterize spatial pattern of dependence for future projections under climate change within the framework of extreme value theory. The results show that AR events in RCP8.5 scenario (2076-2100) tend to produce heavier rainfall with higher frequency and longer duration than the events from historical run (1981-2005). Range of spatial dependence between extreme precipitations is concentrated on smaller localized area in California under the highest emission scenario than present day.