Evaluation of thermal and dynamic impacts of summer dust aerosols on the Red Sea
File(s)2016JC011911.pdf (2.59 MB)
Published version
Author(s)
Cahill, B
Toumi, R
Stenchikov, G
Osipov, S
Brindley, H
Type
Journal Article
Abstract
The seasonal response of upper ocean processes in the Red Sea to summer-time dust aerosol perturbations is investigated using an uncoupled regional ocean model. We find that the upper limit response is highly sensitive to dust-induced reductions in radiative fluxes. Sea surface cooling of −1°C and −2°C is predicted in the northern and southern regions, respectively. This cooling is associated with a net radiation reduction of −40 W m−2 and −90 W m−2 over the northern and southern regions, respectively. Larger cooling occurs below the mixed layer at 75 m in autumn, −1.2°C (north) and −1.9°C (south). SSTs adjust more rapidly (ca. 30 days) than the subsurface temperatures (seasonal time scales), due to stronger stratification and increased mixed layer stability inhibiting the extent of vertical mixing. The basin average annual heat flux reverses sign and becomes positive, +4.2 W m−2 (as compared to observed estimates −17.3 W m−2) indicating a small gain of heat from the atmosphere. When we consider missing feedbacks from atmospheric processes in our uncoupled experiment, we postulate that the magnitude of cooling and the time scales for adjustment will be much less, and that the annual heat flux will not reverse sign but nevertheless be reduced as a result of dust perturbations. While our study highlights the importance of considering coupled ocean-atmosphere processes on the net surface energy flux in dust perturbation studies, the results of our uncoupled dust experiment still provide an upper limit estimate of the response of the upper ocean to dust-induced radiative forcing perturbations.
Date Issued
2017-02-20
Date Acceptance
2017-01-16
Citation
Journal of Geophysical Research: Oceans, 2017, 122 (2), pp.1325-1346
ISSN
2169-9275
Publisher
American Geophysical Union
Start Page
1325
End Page
1346
Journal / Book Title
Journal of Geophysical Research: Oceans
Volume
122
Issue
2
Copyright Statement
© 2017. American Geophysical Union. All Rights Reserved.
Sponsor
Kaust
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000398063100032&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Grant Number
CRG-1-2012-STE-IMP
Subjects
Science & Technology
Physical Sciences
Oceanography
SEASONAL OVERTURNING CIRCULATION
FRESH-WATER BUDGETS
ARABIAN PENINSULA
BULK PARAMETERIZATION
OPTICAL DEPTH
MODEL
OCEAN
SYSTEM
WINTER
HEAT
Publication Status
Published