Aerosol's optical and physical characteristics and direct radiative forcing during a shamal dust storm, a case study

Abstract

Abstract. Dust aerosols are analyzed for their optical and physical properties during an episode of a dust storm that blew over Kuwait on 26 March 2003 when the military Operation Iraqi Freedom was in full swing. The intensity of the dust storm was such that it left a thick suspension of dust throughout the following day, 27 March. The synoptic sequence leading to the dust storm and the associated wind fields are discussed. Ground-based measurements of aerosol optical thickness reached 3.617 and 4.17 on 26 and 27 March respectively while the Ångstrom coefficient, α 870/440 , dropped to −0.0234 and −0.0318. Particulate matter concentration of 10 µm diameter or less, PM 10 , peaked at 4800 µg m −3 during dust storm hours of 26 March. Moderate Resolution Imaging Spectroradiometer (MODIS) retrieved aerosol optical depth (AOD) by Deep Blue algorithm and Total Ozone Mapping Spectrometer (TOMS) aerosol index (AI) exhibited high values. Latitude-longitude maps of AOD and AI were used to deduce source regions of dust transport over Kuwait. The vertical profile of the dust layer was simulated using the SKIRON atmospheric model. Instantaneous net direct radiative forcing is calculated at top of atmosphere (TOA) and surface level. The thick dust layer of 26 March resulted in cooling the TOA by −60 Wm −2 and surface level by −175 Wm −2 for a surface albedo of 0.35. Slightly higher values were obtained for 27 March due to the increase in aerosol optical thickness. Radiative heating/cooling rates in the shortwave and longwave bands were also examined. Shortwave heating rate reached a maximum value of 2 K day −1 between 3 and 5 km, dropped to 1.5 K day −1 at 6 km and diminished at 8 km. Longwave radiation initially heated the lower atmosphere by a maximum value of 0.2 K day −1 at surface level, declined sharply at increasing altitude and diminished at 4 km. Above 4 km longwave radiation started to cool the atmosphere slightly reaching a maximum rate of −0.1 K day −1 at 6 km.

Investigation of aerosol optical, physical, and radiative characteristics of a severe dust storm observed over UAE

“…Different parts of the Middle East, especially the United Arab Emirates (UAE) are affected by dust storms (horizontal visibility lies between 0 and 1 km) for almost 30% of the time during various seasons. The frequency of occurrence of dust storms peaks during the premonsoon season (March-May) when dust aerosols are transported by southwesterly winds from the arid and semi-arid regions around the Arabian Peninsula (Ackerman & Cox, 1982;Middleton, 1986;Aher, Pawar, Gupta, & Devara, 2014;Prakash, Stenchikov, Kalenderski, Osipov, & Bangalath, 2015;Saeed, Al-Dashti, & Spyron, 2014).…”

Shamals and climate variability in the Northern Arabian/Persian Gulf from 1973 to 2012

“…Based on the above, we are led to suggest that environmental changes in desert morphology, possibly related to 'Operation Iraqi Freedom' in 2003, may have lead to the observed increase in DU in 2003. Furthermore, a case study by Saeed et al (2014) during 'Operation Iraqi Freedom' suggested an increase in dust storm intensity in the N Gulf as a result of military activity. 40°N 36°N 32°N 28°N 24°N 20°N 30°E 36°E 42°E 48°E 54°E 30°E 36°E 42°E 48°E 54°E 30°E 36°E 42°E 48°E …”

Mobile Aerosol Measurement in the Eastern Mediterranean - A Utilization of Portable Instruments

“…So far, the aerosol research has been focused on aerosol optical properties (Elminir, 2005;El-Metwally and Alfaro 2013), airborne dust (monitoring, source region, and transport) (Satheesh et al, 2006;El-Askary and Kafatos, 2008;Reid et al, 2008;El-Askary et al, 2009;Dada et al, 2013;Alam et al, 2014;Gherboudj and Ghedira, 2014;Saeed et al, 2014;Basha et al, 2015), transport of anthropogenic aerosols (e.g., Kuwait: impacts of 1991 oil fire plumes in Kuwait) (Lowenthal et al, 1992;Daum et al, 1993;Herring et al, 1996;Rudich 2003;Tazaki et al, 2004;Bonazza et al, 2007), chemical analysis and gaseous pollution (Shaka' and Saliba, 2004;Kouyoumdjian and Saliba, 2006;Saliba et al, 2007;Mahmoud et al, 2008;El-Araby et al, 2011;Dobrzhinsky et al, 2012;Boman et al, 2013;Daher et al, 2013;Engelbrecht and Jayanty, 2013;Hassan et al, 2013;Waked et al, 2013a, b;Jafar et al, 2014;Roumie et al, 2015), and particulate matter (PM) (Saliba et al, 2010;Khodeir et al, 2012;Habeebullah, 2013;Munir et al, 2013a, b;Rushdi et al, 2013;Shaltout et al, 2013;Alghamdi et al, 2014a, b;Hussein et al, 2014a;…”