Decoupling the Influence of Climate Change and Natural Variability on the Middle Eastern Shamal Wind

The Middle Eastern Shamal, a prominent north-northwesterly wind, plays a crucial role in the Arabian Peninsula's climate and environment. Originating from the interaction between a semipermanent anticyclone over northern Saudi Arabia and a cyclone over southern Iran, it influences regional climate. The Shamal is essential in transporting dust and pollutants from the Tigris-Euphrates to the Persian Gulf, affecting air quality, health, and travel. Its potential as a renewable energy source also highlights its importance for the region's future energy strategies.

However, understanding the time series of the Shamal wind is a complex task, owing to the intertwined influences of natural climate variability and human-induced climate change. While climate change is a critical factor, natural variability driven by internal climate modes like the Atlantic Multidecadal Oscillation (AMO), Pacific Decadal Oscillation (PDO), and North Atlantic Oscillation (NAO) also significantly influences these winds. These oscillations, operating over multidecadal scales, alongside the overarching trend of climate change, form a complex web affecting the regional climate. 

This study addresses the challenge of decoupling the impacts of climate change and natural climate variability on the Shamal wind. Our analysis employs Empirical Mode Decomposition (EMD), a relatively new approach that allows us to decouple the influence of various internal climate modes from that of anthropogenic climate change. This method surpasses traditional techniques by avoiding assumptions of linearity and stationarity. The study utilizes ERA5 reanalysis data to analyze summer and winter Shamal winds.

Preliminary findings indicate that internal climate modes like the AMO are equally significant as climate change in influencing Shamal wind in the past. This insight is crucial for more accurate projections and predictions of future Shamal wind behavior, benefiting the Middle East's environmental management, health, and renewable energy sectors.