Aerosol optical depth trend over the Middle East

Handle URI:
http://hdl.handle.net/10754/610582
Title:
Aerosol optical depth trend over the Middle East
Authors:
Klingmüller, Klaus; Pozzer, Andrea; Metzger, Swen; Stenchikov, Georgiy L. ( 0000-0001-9033-4925 ) ; Lelieveld, Jos
Abstract:
We use the combined Dark Target/Deep Blue aerosol optical depth (AOD) satellite product of the moderate-resolution imaging spectroradiometer (MODIS) collection 6 to study trends over the Middle East between 2000 and 2015. Our analysis corroborates a previously identified positive AOD trend over large parts of the Middle East during the period 2001 to 2012. We relate the annual AOD to precipitation, soil moisture and surface winds to identify regions where these attributes are directly related to the AOD over Saudi Arabia, Iraq and Iran. Regarding precipitation and soil moisture, a relatively small area in and surrounding Iraq turns out to be of prime importance for the AOD over these countries. Regarding surface wind speed, the African Red Sea coastal area is relevant for the Saudi Arabian AOD. Using multiple linear regression we show that AOD trends and interannual variability can be attributed to soil moisture, precipitation and surface winds, being the main factors controlling the dust cycle. Our results confirm the dust driven AOD trends and variability, supported by a decreasing MODIS-derived Ångström exponent and a decreasing AERONET-derived fine mode fraction that accompany the AOD increase over Saudi Arabia. The positive AOD trend relates to a negative soil moisture trend. As a lower soil moisture translates into enhanced dust emissions, it is not needed to assume growing anthropogenic aerosol and aerosol precursor emissions to explain the observations. Instead, our results suggest that increasing temperature and decreasing relative humidity in the last decade have promoted soil drying, leading to increased dust emissions and AOD; consequently an AOD increase is expected due to climate change.
KAUST Department:
Physical Sciences and Engineering (PSE) Division
Citation:
Aerosol optical depth trend over the Middle East 2016, 16 (8):5063 Atmospheric Chemistry and Physics
Publisher:
Copernicus GmbH
Journal:
Atmospheric Chemistry and Physics
Issue Date:
22-Apr-2016
DOI:
10.5194/acp-16-5063-2016
Type:
Article
ISSN:
1680-7324
Sponsors:
The research reported in this publication has received funding from King Abdullah University of Science and Technology (KAUST). For computer time, the resources of the KAUST Supercomputing Laboratory were used by the KAUST researchers. K. Klingmüller is supported by the KAUST CRG3 grant URF/1/2180-01 Combined Radiative and Air Quality Effects of Anthropogenic Air Pollution and Dust over the Arabian Peninsula.
Additional Links:
http://www.atmos-chem-phys.net/16/5063/2016/
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division

Full metadata record

DC FieldValue Language
dc.contributor.authorKlingmüller, Klausen
dc.contributor.authorPozzer, Andreaen
dc.contributor.authorMetzger, Swenen
dc.contributor.authorStenchikov, Georgiy L.en
dc.contributor.authorLelieveld, Josen
dc.date.accessioned2016-05-23T13:35:48Z-
dc.date.available2016-05-23T13:35:48Z-
dc.date.issued2016-04-22-
dc.identifier.citationAerosol optical depth trend over the Middle East 2016, 16 (8):5063 Atmospheric Chemistry and Physicsen
dc.identifier.issn1680-7324-
dc.identifier.doi10.5194/acp-16-5063-2016-
dc.identifier.urihttp://hdl.handle.net/10754/610582-
dc.description.abstractWe use the combined Dark Target/Deep Blue aerosol optical depth (AOD) satellite product of the moderate-resolution imaging spectroradiometer (MODIS) collection 6 to study trends over the Middle East between 2000 and 2015. Our analysis corroborates a previously identified positive AOD trend over large parts of the Middle East during the period 2001 to 2012. We relate the annual AOD to precipitation, soil moisture and surface winds to identify regions where these attributes are directly related to the AOD over Saudi Arabia, Iraq and Iran. Regarding precipitation and soil moisture, a relatively small area in and surrounding Iraq turns out to be of prime importance for the AOD over these countries. Regarding surface wind speed, the African Red Sea coastal area is relevant for the Saudi Arabian AOD. Using multiple linear regression we show that AOD trends and interannual variability can be attributed to soil moisture, precipitation and surface winds, being the main factors controlling the dust cycle. Our results confirm the dust driven AOD trends and variability, supported by a decreasing MODIS-derived Ångström exponent and a decreasing AERONET-derived fine mode fraction that accompany the AOD increase over Saudi Arabia. The positive AOD trend relates to a negative soil moisture trend. As a lower soil moisture translates into enhanced dust emissions, it is not needed to assume growing anthropogenic aerosol and aerosol precursor emissions to explain the observations. Instead, our results suggest that increasing temperature and decreasing relative humidity in the last decade have promoted soil drying, leading to increased dust emissions and AOD; consequently an AOD increase is expected due to climate change.en
dc.description.sponsorshipThe research reported in this publication has received funding from King Abdullah University of Science and Technology (KAUST). For computer time, the resources of the KAUST Supercomputing Laboratory were used by the KAUST researchers. K. Klingmüller is supported by the KAUST CRG3 grant URF/1/2180-01 Combined Radiative and Air Quality Effects of Anthropogenic Air Pollution and Dust over the Arabian Peninsula.en
dc.language.isoenen
dc.publisherCopernicus GmbHen
dc.relation.urlhttp://www.atmos-chem-phys.net/16/5063/2016/en
dc.rightsThis work is distributed under the Creative Commons Attribution 3.0 License.en
dc.titleAerosol optical depth trend over the Middle Easten
dc.typeArticleen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.identifier.journalAtmospheric Chemistry and Physicsen
dc.eprint.versionPublisher's Version/PDFen
dc.contributor.institutionMax Planck Institute for Chemistry, P.O. Box 3060, 55020 Mainz, Germanyen
dc.contributor.institutionThe Cyprus Institute, P.O. Box 27456, 1645 Nicosia, Cyprusen
dc.contributor.affiliationKing Abdullah University of Science and Technology (KAUST)en
kaust.authorStenchikov, Georgiy L.en
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