Ultra high-resolution ensemble projections of the near-term climate change over the U.S.

Abstract:

We present near-term hydro-meteorological projections over the continental United States from a hierarchical high-resolution regional modeling framework that consists of the dynamical downscaling of 12 (CCSM4, ACCESS1-0, NorESM1-M, MRI-CGCM3, GFDL-ESM2M, FGOALS-g2, bcc-csm1-1, MIROC5, CanESM2, MPI-ESM-MR, IPSL-ESM-MR, CMCC-CM5) Global Climate Models from the 5^th phase of Coupled Model Inter-comparison Project at 4km horizontal grid spacing, using a combination of a regional climate model (RegCM4) and a macroscale hydrological model (VIC). All models’ integrations consist of 41 years in the historic period (1965-2005) and 41 years in the near-term future period (2010-2050) under the Representative Concentration Pathway 8.5. RegCM4 domain covers Continental U.S., and parts of Canada and Mexico at 18km horizontal grid spacing whereas VIC domain covers the continental U.S. at 4km horizontal grid spacing. We will present results from the analyses that are focused on the investigation of added value of high-resolution regional climate projections with a particular emphasis on precipitation, temperature and runoff extremes, and their future responses to increase in radiative forcing. We will also discuss uncertainties in the driving Global Climate Models projections and relatively robust fine-scale responses in the dynamically downscaled regional hydro-climate ensemble.