Publication Date:
2022-05-26
Description:
Author Posting. © American Meteorological Society, 2014. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Climate 27 (2014): 1343–1363, doi:10.1175/JCLI-D-13-00148.1.
Description:
The climate of West Antarctica is strongly influenced by remote forcing from the tropical Pacific. For example, recent surface warming over West Antarctica reflects atmospheric circulation changes over the Amundsen Sea, driven by an atmospheric Rossby wave response to tropical sea surface temperature (SST) anomalies. Here, it is demonstrated that tropical Pacific SST anomalies also influence the source and transport of marine-derived aerosols to the West Antarctic Ice Sheet. Using records from four firn cores collected along the Amundsen coast of West Antarctica, the relationship between sea ice–modulated chemical species and large-scale atmospheric variability in the tropical Pacific from 1979 to 2010 is investigated. Significant correlations are found between marine biogenic aerosols and sea salts, and SST and sea level pressure in the tropical Pacific. In particular, La Niña–like conditions generate an atmospheric Rossby wave response that influences atmospheric circulation over Pine Island Bay. Seasonal regression of atmospheric fields on methanesulfonic acid (MSA) reveals a reduction in onshore wind velocities in summer at Pine Island Bay, consistent with enhanced katabatic flow, polynya opening, and coastal dimethyl sulfide production. Seasonal regression of atmospheric fields on chloride (Cl−) reveals an intensification in onshore wind velocities in winter, consistent with sea salt transport from offshore source regions. Both the source and transport of marine aerosols to West Antarctica are found to be modulated by similar atmospheric dynamics in response to remote forcing. Finally, the regional ice-core array suggests that there is both a temporally and a spatially varying response to remote tropical forcing.
Description:
This research was supported
by an award from the Department of Energy Office of
Science Graduate Fellowship Program (DOE SCGF) to
ASC, a James E. and Barbara V. Moltz Research Fellowship
to SBD, and grants from NSF-OPP (ANT-
0632031 and ANT-0631973), NSF-MRI (EAR-
1126217), and the NASA Cryosphere Program
(NNX10AP09G), and a WHOI Andrew W. Mellon
Foundation Award for Innovative Research.
Description:
2014-08-01
Keywords:
Antarctica
;
Sea ice
;
Teleconnections
;
Atmosphere-ocean interaction
;
Climate records
;
Interannual variability
Repository Name:
Woods Hole Open Access Server
Type:
Article
Format:
application/pdf
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