Influence of Internal Climate System Forcing on the Relationship Between North Atlantic Tropical Cyclones and Saharan Dust

Abstract

AbstractThis study explores the role of internal climate system forcing in the relationship between dust and tropical cyclones (TCs). Here internal climate system forcing includes the Atlantic Multidecadal Oscillation (AMO), Atlantic Meridional Mode (AMM), Sahel rainfall, North Atlantic Oscillation (NAO), and El Niño–Southern Oscillation (ENSO). The dust‐TC relationship is evaluated through statistical analyses of 42‐year (1980–2021) reanalysis and observation data sets for TCs and the Saharan dust plume over the North Atlantic. In August, the negative correlation between dust and TCs in the region east of the Florida Peninsula and north of the Caribbean Sea is inhibited by AMO, AMM, and ENSO and promoted by NAO. In September, the positive correlation between dust and TCs in the eastern US and its adjacent ocean is inhibited by Sahel rainfall and promoted by AMO, AMM, and ENSO. In October, the positive correlation between dust and TCs in the southeastern US is promoted by Sahel rainfall and inhibited by AMO, AMM, and ENSO. The leading climate mode influence on the dust‐TC relationship comes from AMO in August and September, and ENSO in October. The dust‐TC relationship in September and October indicates an increase in TC landfalls over the continental US accompanied by a strengthened Saharan dust plume, which further affects the hydrology of the continental US on an interdecadal timescale by reducing land moisture in September and increasing it in October, as determined by the location of TC landfalls, topography, and the impact of climate mode.