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

 [1];  [1];  [1]
  1. Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland Washington USA
Publication Date:
Sponsoring Org.:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23)
OSTI Identifier:
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Geophysical Research Letters
Additional Journal Information:
Journal Volume: 42; Journal Issue: 2; Related Information: CHORUS Timestamp: 2017-10-23 18:08:27; Journal ID: ISSN 0094-8276
Wiley Blackwell (John Wiley & Sons)
Country of Publication:
United States

Citation Formats

Taraphdar, Sourav, Leung, L. Ruby, and Hagos, Samson. Linkages of remote sea surface temperatures and Atlantic tropical cyclone activity mediated by the African monsoon: Remote SST influences Atlantic hurricane. United States: N. p., 2015. Web. doi:10.1002/2014GL062600.
Taraphdar, Sourav, Leung, L. Ruby, & Hagos, Samson. Linkages of remote sea surface temperatures and Atlantic tropical cyclone activity mediated by the African monsoon: Remote SST influences Atlantic hurricane. United States. doi:10.1002/2014GL062600.
Taraphdar, Sourav, Leung, L. Ruby, and Hagos, Samson. 2015. "Linkages of remote sea surface temperatures and Atlantic tropical cyclone activity mediated by the African monsoon: Remote SST influences Atlantic hurricane". United States. doi:10.1002/2014GL062600.
title = {Linkages of remote sea surface temperatures and Atlantic tropical cyclone activity mediated by the African monsoon: Remote SST influences Atlantic hurricane},
author = {Taraphdar, Sourav and Leung, L. Ruby and Hagos, Samson},
abstractNote = {},
doi = {10.1002/2014GL062600},
journal = {Geophysical Research Letters},
number = 2,
volume = 42,
place = {United States},
year = 2015,
month = 1

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1002/2014GL062600

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  • 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 show that the NAMED SST is linked to a strengthening of the Saharan heat low and enhancement of moisture and moist static energy in the lower atmosphere 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 developmentmore » region (50W–20E; 10N–20N) of Atlantic TC. By modulating multiple processes associated with the African monsoon, this study demonstrates that warm NAMED SST explains 8% of interannual variability of Atlantic TC frequency. Thus NAME SST may provide useful predictability for Atlantic TC activity on seasonal-to-interannual time scale.« less
  • Analysis of Bay of Bengal tropical cyclone (TC) track data for the month of May during 1980-2013 reveals a meridional dipole in TC intensification: TC intensification rates increased in the northern Bay and decreased in the southern Bay. The dipole was driven by an increase in low-level vorticity and atmospheric humidity in the northern Bay, making the environment more favorable for TC intensification, and enhanced vertical wind shear in the southern Bay, tending to reduce TC development. These environmental changes were associated with a strengthening of the monsoon circulation for the month of May, driven by a La Nin˜a-like shiftmore » in tropical Pacific SSTs andassociated tropical wave dynamics. Analysis of a suite of climate models fromthe CMIP5 archive for the 150-year historical period shows that most models correctly reproduce the link between ENSO and Bay of Bengal TC activity through the monsoon at interannual timescales. Under the RCP 8.5 scenario the same CMIP5 models produce an El Nin˜o like warming trend in the equatorial Pacific, tending to weaken the monsoon circulation. These results suggest« less
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  • Global climate models (GCMs) are routinely relied upon to study the possible impacts of climate change on a wide range of meteorological phenomena, including tropical cyclones (TCs). Previous studies addressed whether GCMs are capable of reproducing observed TC frequency and intensity distributions. This research builds upon earlier studies by examining how well GCMs capture the physically relevant relationship between TC intensity and SST. Specifically, the influence of model resolution on the ability of a GCM to reproduce the sensitivity of simulated TC intensity to SST is examined for the MRI-AGCM (20 km), the GFDL-HiRAM (50 km), the FSU-COAPS (0.94°) model,more » and two versions of the CAM5 (1° and 0.25°). Results indicate that while a 1°C increase in SST corresponds to a 5.5–7.0 m s -1 increase in observed maximum intensity, the same 1°C increase in SST is not associated with a statistically significant increase in simulated TC maximum intensity for any of the models examined. However, it also is shown that the GCMs all capably reproduce the observed sensitivity of potential intensity to SST. The models generate the thermodynamic environment suitable for the development of strong TCs over the correct portions of the Nort h Atlantic basin, but strong simulated TCs do not develop over these areas, even for models that permit Category 5 TCs. This result supports the notion that direct simulation of TC eyewall convection is necessary to accurately represent TC intensity and intensification processes in climate models, although additional explanations are also explored.« less
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