Quantifying the range of the dust direct radiative effect due to source mineralogy uncertainty

作者：Longlei Li, N. M. Mahowald, Ron L. Miller, Carlos Pérez García‐Pando, Martina Klose, Douglas Stephen Hamilton, Marı́a Gonçalves Ageitos, Paul A. Ginoux, Yves J. Balkanski, Robert O. Green, О. В. Калашникова, Jasper F. Kok, Vincenzo Obiso, David J. Paynter, David Ray Thompson · 发表于：Atmospheric chemistry and physics · 年份：2021 · DOI：10.5194/acp-21-3973-2021 · 被引用次数：144 · 研究领域：Atmospheric chemistry and aerosols、Atmospheric aerosols and clouds、Atmospheric Ozone and Climate

The large uncertainty in the mineral dust direct radiative effect (DRE) hinders projections of future climate change due to anthropogenic activity. Resolving modeled dust mineral speciation allows for spatially and temporally varying refractive indices consistent with dust aerosol composition. Here, for the first time, we quantify the range in dust DRE at the top of the atmosphere (TOA) due to current uncertainties in the surface soil mineralogical content using a dust mineral-resolving climate model. We propagate observed uncertainties in soil mineral abundances from two soil mineralogy atlases along with the optical properties of each mineral into the DRE and compare the resultant range with other sources of uncertainty across six climate models. The shortwave DRE responds region-specifically to the dust burden depending on the mineral speciation and underlying shortwave surface albedo: positively when the regionally averaged annual surface albedo is larger than 0.28 and negatively otherwise. Among all minerals examined, the shortwave TOA DRE and single scattering albedo at the 0.44–0.63 µm band are most sensitive to the fractional contribution of iron oxides to the total dust composition. The global net (shortwave plus longwave) TOA DRE is estimated to be within −0.23 to +0.35 W m −2 . Approximately 97 % of this range relates to uncertainty in the soil abundance of iron oxides. Representing iron oxide with solely hematite optical properties leads to an overestimation of sh...