Title: High-resolution ensemble projections of near-term regional climate over the continental United States

Abstract

We present high-resolution near-term ensemble projections of hydro-climatic changes over the contiguous U.S. using a regional climate model (RegCM4) that dynamically downscales 11 Global Climate Models from the 5th phase of Coupled Model Inter-comparison Project at 18km horizontal grid spacing. All model integrations span 41 years in the historical period (1965 – 2005) and 41 years in the near-term future period (2010 – 2050) under Representative Concentration Pathway 8.5 and cover a domain that includes the contiguous U.S. and parts of Canada and Mexico. Should emissions continue to rise, surface temperatures in every region within the U.S. will reach a new climate norm well before mid 21st century regardless of the magnitudes of regional warming. Significant warming will likely intensify the regional hydrological cycle through the acceleration of the historical trends in cold, warm and wet extremes. The future temperature response will be partly regulated by changes in snow hydrology over the regions that historically receive a major portion of cold season precipitation in the form of snow. Our results indicate the existence of the Clausius-Clapeyron scaling at regional scales where per degree centigrade rise in surface temperature will lead to a 7.4% increase in precipitation from extremes. More importantly,more » both winter (snow) and summer (liquid) extremes are projected to increase across the U.S. These changes in precipitation characteristics will be driven by a shift towards shorter and wetter seasons. Altogether, projected changes in the regional hydro-climate can have substantial impacts on the natural and human systems across the U.S.« less

Authors:

Ashfaq, Moetasim ^[1]; Rastogi, Deeksha ^[1]; Mei, Rui ^[1]; Kao, Shih -Chieh  ^[1];

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• Search DOE PAGES for ORCID "0000-0002-3207-5328"

Gangrade, Sudershan ^[1]; Naz, Bibi S. ^[1]; Touma, Danielle ^[2]

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+ Show Author Affiliations

1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
2. Stanford Univ., Stanford, CA (United States)

Publication Date:

Thu Sep 01 00:00:00 EDT 2016

Research Org.:

Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). Oak Ridge Leadership Computing Facility (OLCF)

Sponsoring Org.:

USDOE Laboratory Directed Research and Development (LDRD) Program; USDOE Office of Science (SC)

OSTI Identifier:

1326511

Grant/Contract Number:  

AC05-00OR22725

Resource Type:

Accepted Manuscript

Journal Name:

Journal of Geophysical Research: Atmospheres

Additional Journal Information:

Journal Volume: 121; Journal Issue: 17; Journal ID: ISSN 2169-897X

Publisher:

American Geophysical Union

Country of Publication:

United States

Language:

English

Subject:

54 ENVIRONMENTAL SCIENCES