Authors: Christopher Karmosky*, SUNY - Oneonta, Nicholas J Morgan, University of Georgia
Topics: Polar Regions, Cryosphere, Climatology and Meteorology
Keywords: Antarctica, Climatology, Ice Sheet, Ice Shelf, Ross Ice Shelf, Melting, Polar Geography, Atmosphere-Surface Interactions, Cryosphere. Polar Climatology
Session Type: Poster
Start / End Time: 1:20 PM / 3:00 PM
Room: Napoleon Foyer/Common St. Corridor, Sheraton, 3rd Floor
Presentation File: No File Uploaded
Ross Ice Shelf, Antarctica, is the world’s largest and southernmost ice shelf. While typical conditions there preclude the appearance of surface melting, the lack of persistent melt provides an opportunity to isolate specific meteorological conditions that can temporarily increase temperatures above 0C during those few times in the recent record that have exhibited surface melt. The majority of surface melting on Ross Ice Shelf is caused by an inflow of maritime air over coastal regions, however there have been several instances of surface melting that are better explained by the presence of downsloping “Föhn-like” winds from either the Transantarctic Mountains or down the ice streams on the eastern edge of the shelf (e.g. Bindschadler and MacAyeal, formerly Ice Streams D and E respectively). Recent works have outlined the presence of downsloping winds leading to surface melt on more temperate ice shelves such as Larsen. While typically these downsloping winds are cold, density-driven winds, the presence of a surface low in the Ross Sea can draw air down the steep topography around Ross Ice Shelf and causes the air to warm adiabatically as it descends. This work examines several case studies of surface melt resulting from these downsloping winds and outlines meteorological conditions both at the surface and aloft using NCEP/NCAR reanalysis data. Surface melt occurrence was determined using passive microwave (SSM/I) imagery and the Cross-Polarized Gradient Ratio (XPGR) technique.