Regional climate change modeling for Alaska

Alaska and surrounding coastal areas are prominent geographical features that are largely covered by sea ice on a seasonal basis over the ocean and exhibit sharply varied topography on land. The complex geographical features significantly complicate Alaska regional climate systems. Thus the representation of complex topography in high resolution model is needed for accurately modeling Alaska regional climate change. A study has been established to use the high resolution regional model, such as MM5, to conduct dynamical downscaling of global climate simulations for the Alaska region. The CCSM3 20th century climate simulation (1979-1999) was first downscaled and the downscaled present-day climate was verified against the observations and has correctable biases. The bias-reduced downscalings compare favorably to the observations. The downscaled future A1B scenario of the CCSM3 21st century simulation for 2010-19, 2050-59 and 2090-99 over Alaska will be presented.