Modeling a typical winter-time dust event over the Arabian Peninsula and the Red Sea

Abstract

Abstract. We used WRF-Chem, a regional meteorological model coupled with an aerosol-chemistry component, to simulate various aspects of the dust phenomena over the Arabian Peninsula and Red Sea during a typical winter-time dust event that occurred in January 2009. The model predicted that the total amount of emitted dust was 18.3 Tg for the entire dust outburst period and that the two maximum daily rates were ~2.4 Tg day−1 and ~1.5 Tg day−1, corresponding to two periods with the highest aerosol optical depth that were well captured by ground- and satellite-based observations. The model predicted that the dust plume was thick, extensive, and mixed in a deep boundary layer at an altitude of 3–4 km. Its spatial distribution was modeled to be consistent with typical spatial patterns of dust emissions. We utilized MODIS-Aqua and Solar Village AERONET measurements of the aerosol optical depth (AOD) to evaluate the radiative impact of aerosols. Our results clearly indicated that the presence of dust particles in the atmosphere caused a significant reduction in the amount of solar radiation reaching the surface during the dust event. We also found that dust aerosols have significant impact on the energy and nutrient balances of the Red Sea. Our results showed that the simulated cooling under the dust plume reached 100 W m−2, which could have profound effects on both the sea surface temperature and circulation. Further analysis of dust generation and its spatial and temporal variability is extremely important for future projections and for better understanding of the climate and ecological history of the Red Sea.

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

“…The stations close to the Red Sea had a high number of dust observations during summer and autumn, consistent with the results of Jiang et al (2009); Kalenderski et al (2013) and Klingmüller et al (2016).…”

“…Furthermore, the first modelling study, Miller and Tegen (1998), who examined the effect of dust on radiation, showed that dust aerosols reduce the global average surface radiation by 3 Wm −1 during summer in the northern hemisphere. Balkanski et al (2007) evaluated the annual decrease in global surface net radiation in the range from −1.11 to 0.92 Wm −1 , and this value increased by two orders of magnitude to 2.3 Wm −1 (Kalenderski et al, 2013). In contrast, Jish Prakash et al (2015) simulated the dust event on 18-22 March 2012 and found that most of the dust over the western Arabian Peninsula was deposited in the Red Sea, reaching a maximum of 0.23 Mt day −1 with 1.2 Mt deposited during the event.…”

Impact of atmospheric dust emission schemes on dust production and concentration over the Arabian Peninsula

“…It should be noted that the proportionality constant, c (Eq. 1), of the AFWA simulation was set to a value, representative for the Arabian Peninsula, of 0.4 as suggested by Kalenderski et al (2013). Studies have shown that c can range from 0.4 to 0.65 (Zhao et al 2010;Su and Fung 2015) to accommodate various regions of the world.…”

“…Prakash et al (2015) used the ''online'' meteorological and chemical transport weather research and forecasting/chemistry (WRF-Chem) model to study the effect of dust events in the Arabian Peninsula on radiation fluxes and regional climate characteristics. Using the same model, Kalenderski et al (2013) simulated a typical winter-time dust event over the Arabian Peninsula and the Red Sea and found that the total amount of emitted dust was 18.3 Tg for the entire dust outburst period.…”

“…We cover the Arabian Peninsula with a triple-nested domain configuration with the highest grid resolution over the region of Qatar. We focus on dust emissions and concentrations and unlike previous WRF-Chem applications in this region (Prakash et al 2015;Kalenderski et al 2013) we utilize the two latest dust emission schemes incorporated in the WRF-Chem model; namely (1) the AFWA (Air Force Weather Agency) and (2) the S11 (Shao et al 2011) emission schemes. We finally evaluate the model predictions of PM 10 concentrations with ambient data collected from a monitoring station at Doha, Qatar.…”