학술논문

Delayed Antarctic melt season reduces albedo feedback.
Document Type
Article
Source
National Science Review. Sep2023, Vol. 10 Issue 9, p1-11. 11p.
Subject
*ALBEDO
*SNOWMELT
*SOLAR radiation
*EDDY flux
*SEASONS
*SEA ice
Language
ISSN
2095-5138
Abstract
Antarctica's response to climate change varies greatly both spatially and temporally. Surface melting impacts mass balance and also lowers surface albedo. We use a 43-year record (from 1978 to 2020) of Antarctic snow melt seasons from space-borne microwave radiometers with a machine-learning algorithm to show that both the onset and the end of the melt season are being delayed. Granger-causality analysis shows that melt end is delayed due to increased heat flux from the ocean to the atmosphere at minimum sea-ice extent from warming oceans. Melt onset is Granger-caused primarily by the turbulent heat flux from ocean to atmosphere that is in turn driven by sea-ice variability. Delayed snowmelt season leads to a net decrease in the absorption of solar irradiance, as a delayed summer means that higher albedo occurs after the period of maximum solar radiation, which changes Antarctica's radiation balance more than sea-ice cover. [ABSTRACT FROM AUTHOR]