Dynamical Downscaling to Improve Adaptation Strategies and Increase Sustainability in New England Under A High Impact Climate Change Scenario

Abstract:

In the last decade, dynamical downscaling of global model projections using high-resolution regional models has been commonly used to simulate climate change impacts at the regional and local level. Many studies utilizing high-resolution models have led to improvements in the experiment design and model configuration for regional problems. In this study, our aim is to simulate climate change in New England using a model explicitly resolving convection and to analyze impacts of climate change in this region. We use Weather Research and Forecasting model (WRF) to dynamically downscale Community Earth System Model (CESM) projections of the future with Representative Concentration Pathway (RCP) 8.5 for New England. WRF simulations are performed on nested grids with 27, 9 and 3 km horizontal grid spacing, and the smallest grid sized nest is focused over New England. In our simulations, the simulated domains are kept large to minimize any numerical artifacts and the innermost domain is kept large in size and high in resolution to resolve convection. This is done to eliminate the model dependency to convection parameterization as has been observed in previous studies We are focusing on three time-slice runs of 20 years each representing near, mid and far future totaling 60 years. The high-resolution climate variables obtained from these simulations are used as forcing in smaller scale ecosystem, land surface hydrology and economy models to predict regional climate change impacts under a high emissions scenario. When presenting our results, we will focus on future changes in extreme events and societal, economical and health related impacts associated with these changes. We will state potential problems when using regional models for dynamical downscaling and when providing downscaled output to application models. Finally, we will describe how our results can be utilized to improve regional sustainability and adaptation strategies in New England.