P70  Evaluation of Temperature and Precipitation Extremes and   Climate Variability over United States as Simulated by the   Nested Regional Climate Model (NRCM)

PaiMazumder, Debasish, and James Done, National Center for Atmospheric Research

Extremes in precipitation and temperature bring enormous environmental, social, and political impacts. It is therefore essential to investigate the climate variability and extremes at the regional and fine temporal scales to enable improved adaptation strategies. Coupled Atmosphere–Ocean Global Climate Models (AOGCM) used in the Fourth Assessment Report from the IPCC cannot be applied directly at the regional scale without further downscaling of the information due to their too coarse resolution to realistically represent climate variability and extremes. Regional Climate Models (RCMs) is a useful tool to develop high-resolution climate scenarios at higher temporal and spatial scales by allowing for greater topographic complexity and finer-scale atmospheric dynamics, and thereby representing a more adequate tool for generating climate change information required for many impact and adaptation studies.

The aim of this study is to assess the dynamical downscaling ability of the NRCM when driven by GCM data and bias corrected GCM data, to reproduce the observed extreme and high- and low-frequency climate variability. To achieve this goal, a sensitivity study is performed using Community Climate System Model (CCSM) simulation, NRCM simulations driven by CCSM at 36-km and 12-km grid spacing in one-way nesting configuration.