Investigation of the relative fine and coarse mode aerosol loadings and properties in the Southern Arabian Gulf region

Abstract

The aerosol chemistry environment of the Arabian Gulf region is extraordinarily complex, with high concentrations of dust aerosols from surrounding deserts mixed with anthropogenic aerosols originating from a large petrochemical industry and pockets of highly urbanized areas. Despite the high levels of aerosols experienced by this region, little research has been done to explore the chemical composition of both the anthropogenic and mineral dust portion of the aerosol burden. The intensive portion of the United Arab Emirates Unified Aerosol Experiment (UAE 2), conducted during August and September 2004 was designed in part to resolve the aerosol chemistry through the use of multiple size-segregated aerosol samplers. The coarse mode mass (derived by subtracting the PM 2.5 aerosol mass from the PM 10 mass) is largely dust at 76% ± 7% of the total coarse mode mass, but is significantly impacted by anthropogenic pollution, primarily sulfate and nitrate. The PM 2.5 aerosol mass also contains a large dust burden, at 38% ± 26%, but the anthropogenic component dominates. The total aerosol burden has significant impact not only on the atmosphere, but also the local population, as the air quality levels for both the PM 10 and PM 2.5 aerosol masses reached unhealthy levels for 24% of the days sampled.

Characterization of the atmospheric circulation near the Empty Quarter Desert during major weather events

“…This is consistent with the fact that dust is the prevailing aerosol type in the UAE, and dust emissions are more frequent in the warmer months (Nelli et al, 2021b). As shown in a dedicated field campaign, in coastal UAE dust and sulfates dominate over sea salt, with the latter playing a minor role in the regional aerosol chemistry (Kaku et al, 2016) due to low wind speed over the southern Arabian Gulf preventing the uplift of a significant amount of sea salt aerosols. Even though the 10-m and 60-m wind speeds are larger in the cold season (Figures 4A,B) and the winter Shamal winds are stronger than their summertime counterparts, as noted by Yu et al (2016), in the Arabian Peninsula summertime Shamal events occur more frequently and are more closely related to dust activities in the region (Bou Karam Francis et al, 2017).…”

Aerosol meteorology and Philippine receptor observations of Maritime Continent aerosol emissions for the 2012 7SEAS southwest monsoon intensive study

“…To track overall smoke or pollution transport, we utilize the AERONET operational 500 nm daily averaged fine-mode AOT derived from Level 2.0 Spectral Deconvolution Algorithm (SDA) Version 4.1 (O'Neill et al, 2003). Use of the SDA allows us to track fine-mode particles such as from biomass burning or anthropogenic sources (Kaku et al, 2015) while at the same time removing the influence of thin cirrus contamination which can be large in this region (Chew et al, 2011).…”

The First Characterization of Fog Microphysics in the United Arab Emirates, an Arid Region on the Arabian Peninsula

“…The DSD is, in part, dependent on the type of CCN available, as demonstrated by Martin et al (1994). A mix of aerosol sizes is expected at this site, as sulfates and sea-salt have been reported in the literature (Kaku et al, 2016). However, bimodal distributions would then be expected during fog onset according to Kohler theory where larger CCN (i.e., sea salt) are activated at lower super saturations.…”