Climatic controls on the interannual to decadal variability in Saudi Arabian dust activity: Toward the development of a seasonal dust prediction model

Abstract

The observed climatic controls on springtime and summertime Saudi Arabian dust activities during 1975-2012 are analyzed, leading to development of a seasonal dust prediction model. According to empirical orthogonal function analysis, dust storm frequency exhibits a dominantly homogeneous pattern across Saudi Arabia, with distinct interannual and decadal variability. The previously identified positive trend in remotely sensed aerosol optical depth since 2000 is shown to be a segment of the decadal oscillation in dust activity, according to long-duration station record. Regression and correlation analyses reveal that the interannual variability in Saudi Arabian dust storm frequency is regulated by springtime rainfall across the Arabian Peninsula and summertime Shamal wind intensity. The key drivers of Saudi Arabian dust storm variability are identified. Winter-to-spring La Niña enhances subsequent spring dust activity by decreasing rainfall across the country's primary dust source region, the Rub' al Khali Desert. A relatively cool tropical Indian Ocean favors frequent summer dust storms by producing an anomalously anticyclonic circulation over the central Arabian Peninsula, which enhances the Shamal wind. Decadal variability in Saudi Arabian dust storm frequency is associated with North African rainfall and Sahel vegetation, which regulate African dust emissions and transport to Saudi Arabia. Mediterranean sea surface temperatures (SSTs) also regulate decadal dust variability, likely through their influence on Sahel rainfall and Shamal intensity. Using antecedent-accumulated rainfall over the Arabian Peninsula and North Africa, and Mediterranean SSTs, as low-frequency predictors, and tropical eastern Pacific and tropical Indian Ocean SSTs as high-frequency predictors, Saudi Arabia's seasonal dust activity is well predicted.

Sensitivity of the interannual variability of mineral aerosol simulations to meteorological forcing dataset

“…Previous studies have shown that there are decreases in dust from South America over the 1990-2005 period in some models (Doney et al, 2009), but these are not shown in all the model versions or supported by robust observational data (Doney et al, 2009). Yu et al (2015) show evidence for strong decadal variability in the Saudi Arabian source over a different time period than considered here, with an increase between 2000 and 2015, arguing that a drought in the Fertile Crescent is (Fig. 9), consistent with their results, and correlation between precipitation and dust source in these simulations (Table 7).…”

“…It is well established in the dust literature that meteorology and surface conditions play central roles in driving changes in dust emissions, primarily from changes in precipitation, winds, surface roughness or vegetation cover on daily to interannual to geological timescales (e.g., Westphal et al, 1987;Petit et al, 1999;Marticorena and Bergametti, 1996;Mahowald et al, 2002;Prospero and Lamb, 2003;Engelstadter and Washington, 2007;Engelstaedter et al, 2003;Roe, 2008;McGee et al, 2010;Knippertz and Todd, 2012;Cowie et al, 2013;Yu et al, 2015), and we do not seek to repeat or review that work here. Rather, we address the question of how sensitive our simulation of interannual variability is to the meteorology or, alternatively, the modeling framework used.…”

Identification and Characterization of Dust Source Regions Across North Africa and the Middle East Using MISR Satellite Observations

“…A substantial increase in AOD over the Middle East since the onset of the 21st century has been revealed from various remote-sensing and ground-based observations Klingmüller et al, 2016;Notaro et al, 2015;Yu et al, 2015) and has been reproduced by global aerosol models (Chin et al, 2014). A substantial increase in AOD over the Middle East since the onset of the 21st century has been revealed from various remote-sensing and ground-based observations Klingmüller et al, 2016;Notaro et al, 2015;Yu et al, 2015) and has been reproduced by global aerosol models (Chin et al, 2014).…”

Seasonal variability and synoptic characteristics of dust cases over southwestern Saudi Arabia

“…Meanwhile, decadal variability is regulated by the North African rainfall and the Sahel vegetation (which activates the transport of African dust), in addition to the Mediterranean Sea surface temperatures (which activate the Shamal wind). Furthermore, Yu et al (2015) explain that there is a decreasing amount of rainfall during the winter-to-spring La Niña across the Rub' al Khali Desert, which enhances dust activity, while a relatively cool tropical Indian Ocean produces an anomalously anticyclonic circulation over the central Arabian Peninsula, which enhances the Shamal wind.…”