Saharan dust regulates hurricane rainfall

The research shows a previously unknown relationship between hurricane rainfall and Saharan dust plumes.

Previous studies have found that Saharan dust transport may decline dramatically in the coming decades and hurricane rainfall will likely increase due to human-caused climate change.

Uncertainty remains around the questions of how climate change will affect outflows of dust from the Sahara and how much more rainfall we should expect from future hurricanes.

It has been reported that Saharan dust tends to suppress the formation of tropical cyclones via a cooling effect on SST that consequently cuts the energy supply for TCs. This phenomenon was evident during the peak of European air pollution in the 1970s and 1980s, which is believed to have amplified the Sahel dust emissions due to the prevalent drought conditions.

Another study has highlighted a close association between the North Atlantic's dust and considerable spatial shifts in factors such as zonal wind shear, midlevel moisture, and SST. However, they found a minimal correlation between dust optical depth and the Atlantic's accumulated cyclone energy.

In a nutshell, there is no consensus on the sign of the dust effect on TCR, and it remains uncertain what is the relative importance of dust effect compared to the other meteorological factors.

In this research, we first derive a long-term record of TCR, which is defined as the average tropical cyclone rain rate within 600 km of each TC position, and then aim to: develop an ML model capable of predicting TCR variabilities across the Atlantic Ocean using environmental forcing variables; pinpoint the most influential environmental forcing variables within the ML model and explore their interactions; and specifically, elucidate the role of Saharan dust in TCR. This will be achieved by contrasting various ML models with and without the dust variable and interpreting their physical significance through the lens of ML interpretability techniques. 

https://wattsupwiththat.com/2024/07/26/saharan-dust-regulates-hurricane-rainfall/