Increasing Arctic dust suppresses the reduction of ice nucleation in the Arctic lower troposphere by warming

Abstract

Ice nucleating particles (INPs) affect the cloud radiative budget in the rapidly warming Arctic by changing the cloud liquid/ice phase balance. Dust emitted in the Arctic (Arctic dust) has been suggested to be a major contributor to INPs in the Arctic lower troposphere. However, how Arctic dust and its impacts on ice nucleation change with Arctic warming has not been explored. Here we find that the simulated dust emission flux in the Arctic (>60°N) in global model simulations increases by 20% from 1981–1990 to 2011–2020. This increase weakens the sensitivity of ice nucleation in Arctic lower tropospheric clouds to warming by 40% compared to the case without considering Arctic dust emission increases. Our results demonstrate a better understanding of the counterbalancing feedbacks of Arctic dust (i.e., increasing emissions and decreasing ice nucleation efficiency) is needed for more accurate estimates of changes in ice nucleation in the rapidly changing Arctic climate.