The importance of diurnal processes for the seasonal cycle of sea-ice microwave brightness temperatures during early summer in the Weddell Sea, Antarctica.

Willmes, Sascha, Bareiss, Jörg, Haas, Christian and Nicolaus, Marcel (2006) The importance of diurnal processes for the seasonal cycle of sea-ice microwave brightness temperatures during early summer in the Weddell Sea, Antarctica. Annals of Glaciology, 44 (1). pp. 297-302. DOI 10.3189/172756406781811817.

Full text not available from this repository. (Contact)

Supplementary data:

Abstract

Over the perennial sea ice in the western and central Weddell Sea, Antarctica, the onset of summer is accompanied by a significant decrease of sea-ice brightness temperatures (Tb) as observed by passive-microwave radiometers such as the Special Sensor Microwave/Imager (SSM/I). The summer-specific Tb drop is the dominant feature in the seasonal cycle of Tb data and represents a conspicuous difference to most Arctic sea-ice regions, where the onset of summer is mostly marked by a rise in Tb. Data from a 5 week drift station through the western Weddell Sea in the 2004/05 austral summer, Ice Station POLarstern (ISPOL), helped with identifying the characteristic processes for Antarctic sea ice. In situ glaciological and meteorological data, in combination with SSM/I swath satellite data, indicate that the cycle of repeated diurnal thawing and refreezing of snow ('freeze–thaw cycles') is the dominant process in the summer season, with the absence of complete snow wetting. The resulting metamorphous snow with increased grain size, as well as the formation of ice layers, leads to decreasing emissivity, enhanced volume scattering and increased backscatter. This causes the summer Tb drop.

Document Type: Article
Keywords: Sea-ice; Weddel Sea, Antarctica; Sea-ice brightness temperatures
Research affiliation: AWI
Refereed: Yes
DOI etc.: 10.3189/172756406781811817
ISSN: 0260-3055
Projects: Permafrost, Laptev Sea System
Date Deposited: 17 Apr 2015 09:24
Last Modified: 27 Apr 2015 14:36
URI: http://oceanrep.geomar.de/id/eprint/28545

Actions (login required)

View Item View Item