Dust transport pathways from the Mesopotamian Marshes

Abstract

The Mesopotamian Marshes, located in southern Iraq and southwestern Iran, represent one of the world’s largest wetland ecosystems. These marshlands have undergone significant degradation primarily due to anthropogenic activities, including extensive dam construction, oil extraction, and political conflicts, transforming vast areas into potential dust sources. This study investigates the wind climatology over the marshes and analyzes the long-range transport pathways of dust originating from the region using forward air-parcel trajectories generated with the HYSPLIT model from 2000 to 2023, with each trajectory calculated over an 8-day period. Through trajectory clustering, we identified four primary transport pathways with distinct seasonal patterns. The dominant pathway (35%) follows the Shamal winds southeastward across the Persian Gulf, particularly active in summer and spring. A second pathway (35%) curves southwestward toward Africa, while a third (19%) moves northeastward toward the Caspian Sea and Kazakhstan during non-summer seasons. The fourth pathway (11%) represents high-altitude transport via mid-tropospheric westerlies, potentially reaching East Asia. Meteorological analysis suggests that dust emission potential is active year-round and is highest during summer. Summer is characterized by high temperatures (seasonal mean of $38.8{}^{\circ }C$), no precipitation, and the highest seasonal mean wind speeds ($5.31m{s}^{-1}$). These findings provide crucial insights into the spatial extent and seasonal variability of dust transport from the Mesopotamian Marshes, demonstrating their far-reaching impact on air quality, ecosystems, and climate in regions as distant as East Asia and North Africa, highlighting the need for targeted conservation to mitigate environmental impacts posed by dust from these degraded wetlands.