Impacts of interactive dust and its direct radiative forcing on interannual variations of temperature and precipitation in winter over East Asia

Abstract

We used two 150 year preindustrial simulations of the Community Earth System Model, one with interactive dust and the other with prescribed dust, to quantify the impacts of changes in wind during East Asian winter monsoon (EAWM) season on dust emissions, and the resulting consequences for interannual variations of temperature and precipitation over East Asia. The simulated December‐January‐February dust column burden and dust optical depth are lower over northern China in the strongest EAWM years than those of the weakest years by 38.3% and 37.2%, respectively. The decrease in dust over the dust source regions and the downwind region leads to an increase in direct radiative forcing (RF) at the surface by up to 1.5 W m−2. The effects of EAWM‐related variations in surface winds, precipitation, and their effects on dust emissions and wet removal contribute 67% to the total dust‐induced variations of direct RF at the surface and partly offset the cooling that occurs with the EAWM strengthening by heating the surface. The variations of surface air temperature induced by the changes in wind and dust emissions between the strongest and weakest EAWM years (strongest minus weakest) decrease by 0.4–0.6 K from eastern coastal China to Japan, which weakens the impact of EAWM on surface air temperature by 3–18% in these regions. The warming results from the combined effects of changes in direct RF, turbulent heat flux at the surface, and northwesterly wind anomalies that bring cold and dry air from Siberia to these regions. Over eastern coastal China, the variations of large‐scale precipitation induced by the feedback of EAWM‐related changes in wind on dust emissions decrease by 10–30% in winter because of the reduced changes in surface air temperature and the anomalous circulation.

East Asian Monsoon Variability Since the Sixteenth Century

“…The EAWM itself exerts some influence over climate in the SH region. Strong EAWM circulation causes lower dust concentrations over northern China, with subsequent increased surface temperature from solar radiative forcing (Lou et al, ). Similarly, variability attributed to the EAWM resulted in severe snow storms and long‐persisting snowpack over northeast Asia during 2007–2008 (Wu et al, ), which could also have altered surface temperatures and SLP fields in the region.…”

Estimates of African Dust Deposition Along the Trans‐Atlantic Transit Using the Decadelong Record of Aerosol Measurements from CALIOP, MODIS, MISR, and IASI

“…Along the dust's transit across the Atlantic, some is lost into the ocean, on account of cloud and precipitation scavenging (collectively referred to as wet deposition), as well as turbulent diffusion and gravitational settling (collectively referred to as dry deposition). Airborne dust can degrade air quality, perturb the radiation budget, modulate cloud lifecycles and properties, and influence large‐scale circulations and the water cycle (e.g., Kok et al, ; Lou et al, ; Prospero, ; Song et al, ; Yang et al, ; Yuan et al, ). Nutrients associated with the deposited dust have been linked to the biological productivity of marine ecosystems, thus modifying the uptake of atmospheric CO 2 , global biogeochemical cycles, and climate (Jickells et al, ; Mills et al, ; Moore et al, ).…”

Modeling Dust in East Asia by CESM and Sources of Biases

“…East Asia is one of the main sources of atmospheric mineral dust, which accounts for~20% of the global dust emission (Nagashima et al, 2016). Dust aerosol has a significant impact on regional climate of East Asia (Gu et al, 2016;Guo & Yin, 2015;Lou et al, 2017;Sun et al, 2012Sun et al, , 2017Zhang et al, 2009); dust-induced cooling can weaken the East Asia summer monsoon and suppress precipitation (Guo & Yin, 2015;Sun et al, 2012;Sun et al, 2017). It is estimated that 26% of the East Asian dust is transported into the Pacific Ocean (Zhao et al, 2006).…”