OP-E5.3 E3SM land cryosphere biases
| Poster Title | Land cryosphere biases and their impact on atmosphere-surface exchange in E3SMv1 |
|---|---|
| Authors | Michael Brunke, Jack Reeves Eyre (Unlicensed), Xubin Zeng |
| First Author | Michael Brunke |
| Session Type | E3SM/Integrated Session |
| Session ID | E5 |
| Submission Type | Presentation |
| Group | Land, Water Cycle |
| Experiment | Watercycle |
| Poster Link |
Abstract
The presence of snow on the land surface fundamentally changes the surface energy exchange and affects the annual cycle of land hydrology. Global climate models and Earth system models like E3SM can simulate snow cover fairly well, but the accurate simulation of snow depth (SD) and snow water equivalent (SWE) remains elusive. Such biases in historical SD and SWE put future projections of snowpack into doubt. We compare SD and SWE simulated by E3SMv1 in the low-resolution AMIP and historical simulations with our 4-km snow product that consistently assimilates all in situ (SNOTEL and COOP) measurements across the contiguous U.S. (CONUS) constrained by the PRISM precipitation and temperature data . Maximum SWE and SD are both underestimated by E3SMv1 across the higher terrain of the Intermountain West but are overestimated across the Upper Midwest and New England. The effect of these snow biases on the simulated atmosphere-surface energy and water exchange will be explored.
The E3SM-simulated snowpack provides the surface mass balance forcing for the Greenland and Antarctic ice sheet models when the ice sheet model is active. We investigate near-surface air temperature (SAT) over the Greenland ice sheet in order to understand how surface-atmosphere interactions and atmosphere model biases can affect snowpack and ice sheet mass balance. We also demonstrate that choice of downscaling method affects the SAT assessment and therefore could similarly affect the modeled ice sheet surface mass balance.