Title: Linkages of remote sea surface temperatures and Atlantic tropical cyclone activity mediated by the African monsoon

Abstract

Abstract Warm sea surface temperatures (SSTs) in North Atlantic and Mediterranean (NAMED) can influence tropical cyclone (TC) activity in the tropical East Atlantic by modulating summer convection over western Africa. Analysis of 30 years of observations demonstrates that warm NAMED SST is linked to a strengthening of the Saharan heat low and enhancement of moisture and moist static energy in the lower troposphere over West Africa, which favors a northward displacement of the monsoonal front. These processes also lead to a northward shift of the African easterly jet that introduces an anomalous positive vorticity from western Africa to the main development region (50°W–20°E; 10°N–20°N) of Atlantic TCs. By modulating multiple African monsoon processes, NAMED SST explains comparable and approximately one third of the interannual variability of Atlantic TC frequency as that explained by local wind shear and local SST, respectively, which are known key factors that influence Atlantic TC development.

Authors:

Taraphdar, Sourav ^[1]; Leung, L. Ruby ^[1]; Hagos, Samson ^[1]

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+ Show Author Affiliations

1. Atmospheric Sciences and Global Change Division Pacific Northwest National Laboratory Richland Washington USA

Publication Date:

Tue Jan 20 00:00:00 EST 2015

Sponsoring Org.:

USDOE

OSTI Identifier:

1402368

Resource Type:

Publisher's Accepted Manuscript

Journal Name:

Geophysical Research Letters

Additional Journal Information:

Journal Name: Geophysical Research Letters Journal Volume: 42 Journal Issue: 2; Journal ID: ISSN 0094-8276

Publisher:

American Geophysical Union (AGU)

Country of Publication:

United States

Language:

English