T100 Climate Change in the Interior Western United States from the Last Glacial Maximum to the Holocene
Monday, 28 October 2013
8:00 AM - 12:00 PM
Mile High Ballroom 3C
THE INFLUENCE OF LAKE BONNEVILLE ON GLACIATION IN THE UINTA MOUNTAINS: A HIGH-RESOLUTION MODELING PERSPECTIVE
Paper number: T100-12
Program: Technical Sessions
Time: 10:50 AM – 11:05 AM
Authors
Abstract
Reconstructed equilibrium line altitudes (ELAs) for alpine glaciers in the Uinta Mountains at the Last Glacial Maximum (LGM) increase with distance from the shoreline of pluvial Lake Bonneville, an effect that has been linked at least in part to enhanced precipitation derived from Lake Bonneville. While this result is broadly consistent with relatively large-scale climate modeling studies, the precise meteorological mechanisms by which Lake Bonneville may have influenced ELAs in the Uinta Mountains remain poorly understood. New, high resolution (4km grid spacing) quasi-idealized regional paeoclimate simulations of the LGM computed with the Weather Research and Forecast (WRF) model provide new insights into these processes. Preliminary results indicate that moisture derived from Lake Bonneville likely would not have exerted a significant impact on regional precipitation unless the lake temperature exceeded about 4 degrees C. However, an ice-free Lake Bonneville would have likely exerted a modest (at least 1-2C) local warming, with associated impacts on precipitation and snowpack development. These results suggest that the local temperature influence of pluvial lakes on regional glaciatio may be of similar magnitude to the effects of enhanced evaporation from those lakes.