ITEM METADATA RECORD
Title: Characteristics of summer airflow over the Antarctic Peninsula in response to recent strengthening of westerly circumpolar winds
Authors: Orr, Andrew ×
Marshall, Gareth J
Hunt, Julian C. R
Sommeria, Joel
Wang, Chang-Gui
Van Lipzig, Nicole
Cresswell, Doug
King, John C #
Issue Date: Apr-2008
Publisher: Amer meteorological soc
Series Title: Journal of the atmospheric sciences vol:65 issue:4 pages:1396-1413
Abstract: Summer near-surface temperatures over the northeast coast of the Antarctic Peninsula have increased by more than 2 degrees C over the past 40 years, a temperature increase 3 times greater than that on the northwest coast. Recent analysis has shown a strong correlation between this striking warming trend and significant change in the summer Southern Hemisphere annular mode (SAM), which has resulted in greatly increased summer westerlies across the northern peninsula. It has been proposed that the strengthening westerlies have resulted in increased vertical deflection of relatively warm maritime air over the northern peninsula, contributing significantly to the observed warming and the recent collapse of northern sections of the Larsen Ice Shelf. In this study, laboratory and numerical modeling of airflow incident to the peninsula are employed to further understand this mechanism. It is shown that the effect of the strengthening westerlies has led to a distinct transition from a "blocked" regime to a "flow-over" regime, that is, confirmation of the proposed warming mechanism. The blocked regime is dominated by flow stagnation upstream (i.e., little vertical deflection) and consequent lateral deflection of flow along the western side of the peninsula. The flow-over regime is dominated by vertical deflection of mid/upper-level air over the peninsula, with strong downslope winds following closely to the leeward slope transporting this air (which warms adiabatically as it descends) to the near-surface of the northeast peninsula. The strong rotation typical of high latitudes considerably increases the flow over the peninsula, particularly strengthening it over the southern side (verified by aircraft measurements), suggesting that the warming trend is not solely confined to the northeast. Globally, flow regime transitions such as this may be responsible for other local climate variations.
ISSN: 0022-4928
Publication status: published
KU Leuven publication type: IT
Appears in Collections:Division of Geography & Tourism
× corresponding author
# (joint) last author

Files in This Item:

There are no files associated with this item.

Request a copy

 




All items in Lirias are protected by copyright, with all rights reserved.

© Web of science