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Event attribution frameworks for quantifying climate change impacts on hurricane rainfall

Presentation Date
Monday, December 14, 2020 at 4:20am



Changes in extreme events, such as the recent devastating events of Hurricanes Florence and Dorian, are a visible way in which climate change can directly impact coastal communities. Recently, important advances have been made in attribution frameworks to help quantify climate change impacts on individual hurricanes. This work presents the results of the hindcast attribution methodology, previously developed and tested in the Community Earth System Model, as applied to recent North Atlantic Hurricanes (including Hurricanes Florence and Dorian). The variable-resolution configuration of the Community Atmosphere Model (CAM) with a high-resolution nest, with a grid spacing equal to 28 km, over the North Atlantic Ocean is used to quantify the impact of human-induced climate change on the characteristics of each storm. Ensemble CAM hindcasts are initialized at various times in an inidividual storm’s lifetime with the atmospheric and ocean surface analyses from NOAA’s Global Data Assimilation System and Optimum Interpolation Sea Surface Temperature analysis products. This suite of hindcasts represent the “actual” ensemble. An additional suite of hindcasts in which the climate change signal is removed from the observed air temperature, specific humidity, and sea surface temperature initial conditions represents the “counterfactual” ensemble. A comparison and statistical analysis of the actual and counterfactual ensembles allows for an assessment of the impact of climate change on tropical cyclone-related rainfall which has direct consequences for society, including the East Coast of the U.S. This work is part of a growing effort in the scientific community to refine the application of attribution frameworks for quantification of the impact of climate change on recent extreme weather events.

Funding Program Area(s)