Retrieval of Surface Melt Magnitude over Ross Ice Shelf, Antarctica Using Coupled Optical and Thermal Satellite Measurements

• Main Authors: C. C. Karmosky, D. J. Lampkin
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Antarctica; ice shelves; remote sensing; snowmelt; climatology; cryosphere; Antarctic; The Antarctic; Ross Ice Shelf; Antarc*; Ice Shelf; Ice Shelves
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.596.1737; http://www.easternsnow.org/proceedings/2008/karmosky_lampkin.pdf

Recent studies have indicated that Antarctic snowmelt is increasing at a staggering rate, contributing to dramatic sea-level rise, upwards of 60m, if current trends continue indefinitely. Unfortunately, we are not able to quantify snowmelt accurately from ground-based methods because there is sparse coverage in automatic weather stations. Satellite based assessments of melt from passive microwave systems are limited in that they only provide an indication of melt occurrence. Though this is useful in tracking the duration of melt, melt amount of magnitude is still unknown. Coupled optical/thermal surface measurements from MODIS were calibrated by estimates of liquid water fraction (LWF) in the upper 3cm of the firn using a one-dimensional thermal snowmelt model (SNTHERM). SNTHERM was forced by hourly meteorological data from automatic weather station data at reference sites spanning a range of melt conditions across the Ross Ice Shelf. Melt intensities or LWF were derived for satellite composite periods covering the Antarctic summer months. This empirical retrieval model allows determination of melt magnitude over other Antarctic Ice Shelves, such as Larsen, where surface melt has been well documented in contributing to the disintegration of the ice shelf.