Evaluation of thermal and dynamic impacts of summer dust aerosols on the Red Sea

Handle URI:
http://hdl.handle.net/10754/623273
Title:
Evaluation of thermal and dynamic impacts of summer dust aerosols on the Red Sea
Authors:
Cahill, Bronwyn ( 0000-0002-3237-706X ) ; Toumi, Ralf; Stenchikov, Georgiy L. ( 0000-0001-9033-4925 ) ; Osipov, Sergey; Brindley, Helen
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.
KAUST Department:
Physical Sciences and Engineering (PSE) Division
Citation:
Cahill B, Toumi R, Stenchikov G, Osipov S, Brindley H (2017) Evaluation of thermal and dynamic impacts of summer dust aerosols on the Red Sea. Journal of Geophysical Research: Oceans 122: 1325–1346. Available: http://dx.doi.org/10.1002/2016jc011911.
Publisher:
Wiley-Blackwell
Journal:
Journal of Geophysical Research: Oceans
Issue Date:
16-Jan-2017
DOI:
10.1002/2016jc011911
Type:
Article
ISSN:
2169-9275
Sponsors:
We would like to thank Ron Miller and an anonymous reviewer who provided tremendous insight and exceptionally constructive comments during the preparation of this publication. The research reported in this publication was supported by the King Abdullah University of Science and Technology (KAUST) in Thuwal, Saudi Arabia, by the Natural Environment Research Council and by the BP Environmental Technology Program. The computer resources were partially provided by the KAUST Supercomputing Laboratory. Output of the ROMS simulations used in our analysis is available from Space and Atmospheric Physics, Imperial College London. Contact Bronwyn Cahill (bronwyn.cahill@io-warnemuende.de) or Ralf Toumi (r.toumi@imperial.ac.uk) for further information.
Additional Links:
http://onlinelibrary.wiley.com/doi/10.1002/2016JC011911/full
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division

Full metadata record

DC FieldValue Language
dc.contributor.authorCahill, Bronwynen
dc.contributor.authorToumi, Ralfen
dc.contributor.authorStenchikov, Georgiy L.en
dc.contributor.authorOsipov, Sergeyen
dc.contributor.authorBrindley, Helenen
dc.date.accessioned2017-04-25T05:48:39Z-
dc.date.available2017-04-25T05:48:39Z-
dc.date.issued2017-01-16en
dc.identifier.citationCahill B, Toumi R, Stenchikov G, Osipov S, Brindley H (2017) Evaluation of thermal and dynamic impacts of summer dust aerosols on the Red Sea. Journal of Geophysical Research: Oceans 122: 1325–1346. Available: http://dx.doi.org/10.1002/2016jc011911.en
dc.identifier.issn2169-9275en
dc.identifier.doi10.1002/2016jc011911en
dc.identifier.urihttp://hdl.handle.net/10754/623273-
dc.description.abstractThe 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.en
dc.description.sponsorshipWe would like to thank Ron Miller and an anonymous reviewer who provided tremendous insight and exceptionally constructive comments during the preparation of this publication. The research reported in this publication was supported by the King Abdullah University of Science and Technology (KAUST) in Thuwal, Saudi Arabia, by the Natural Environment Research Council and by the BP Environmental Technology Program. The computer resources were partially provided by the KAUST Supercomputing Laboratory. Output of the ROMS simulations used in our analysis is available from Space and Atmospheric Physics, Imperial College London. Contact Bronwyn Cahill (bronwyn.cahill@io-warnemuende.de) or Ralf Toumi (r.toumi@imperial.ac.uk) for further information.en
dc.publisherWiley-Blackwellen
dc.relation.urlhttp://onlinelibrary.wiley.com/doi/10.1002/2016JC011911/fullen
dc.rightsArchived with thanks to Journal of Geophysical Research: Oceansen
dc.titleEvaluation of thermal and dynamic impacts of summer dust aerosols on the Red Seaen
dc.typeArticleen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.identifier.journalJournal of Geophysical Research: Oceansen
dc.eprint.versionPublisher's Version/PDFen
dc.contributor.institutionSpace and Atmospheric Physics; Imperial College London; London SW7 2AZ UKen
kaust.authorStenchikov, Georgiy L.en
kaust.authorOsipov, Sergeyen
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