Attributing the decadal variations in springtime East Asian and North American dust emission to regime shifts in extratropical cyclone

Abstract. Dust activities across East Asia and North America have shown decadal variations, mediating radiation budget, air quality, and human health, especially during their peak months of April and May. Using satellite and ground measurements, as along with simulations from a dust emission model, we demonstrate an increase of 3.6 % and 30.1 % in April dust emissions across East Asia and North America, respectively, during the past four decades, in contrast to a 30.6 % and 13.3 % decrease during the last two decades. Meanwhile, both regions show a steady increase in May dust emissions by 28.8 % and 20.0 %, respectively, since the 1980s. Sensitivity experiments attribute both regions’ decadal variations in dust emission primarily to surface wind speed changes; whereas vegetation exerts minimum influence on the regional dust emission variations. Furthermore, these decadal variations in dust initiating wind could largely be attributed to regime shifts in extratropical cyclone (EC), including their duration and intensity. These results highlight the changing frequency and duration of strong winds, especially those associated with EC, in shaping the decadal variations of mid-latitude dust emissions.