Development and evaluation of high-resolution climate simulations over the mountainous northeastern United States

Authors

Jonathan M. Winter, Dartmouth College
Brian Beckage, University of Vermont
Gabriela Bucini, University of Vermont
Radley M. Horton, Columbia University in the City of New York
Patrick J. Clemins, University of Vermont

Document Type

Article

Publication Date

1-1-2016

Abstract

The mountain regions of the northeastern United States are a critical socioeconomic resource for Vermont, New York State, New Hampshire, Maine, and southern Quebec. While global climate models (GCMs) are important tools for climate change risk assessment at regional scales, even the increased spatial resolution of statistically downscaled GCMs (commonly ~1/8°) is not sufficient for hydrologic, ecologic, and land-use modeling of small watersheds within the mountainous Northeast. To address this limitation, an ensemble of topographically downscaled, high-resolution (30"), daily 2-m maximum air temperature; 2-m minimum air temperature; and precipitation simulations are developed for the mountainous Northeast by applying an additional level of downscaling to intermediately downscaled (1/8°) data using high-resolution topography and station observations. First, observed relationships between 2-m air temperature and elevation and between precipitation and elevation are derived. Then, these relationships are combined with spatial interpolation to enhance the resolution of intermediately downscaled GCM simulations. The resulting topographically downscaled dataset is analyzed for its ability to reproduce station observations. Topographic downscaling adds value to intermediately downscaled maximum and minimum 2-m air temperature at high-elevation stations, as well as moderately improves domain-averaged maximum and minimum 2-m air temperature. Topographic downscaling also improves mean precipitation but not daily probability distributions of precipitation. Overall, the utility of topographic downscaling is dependent on the initial bias of the intermediately downscaled product and the magnitude of the elevation adjustment. As the initial bias or elevation adjustment increases, more value is added to the topographically downscaled product.

Rights Information

© 2016 American Meteorological Society.

Recommended Citation

Winter JM, Beckage B, Bucini G, Horton RM, Clemins PJ. Development and evaluation of high-resolution climate simulations over the mountainous northeastern United States. Journal of Hydrometeorology. 2016 Mar;17(3):881-96.

DOI

10.1175/JHM-D-15-0052.1