Global direct radiative forcing due to multicomponent anthropogenic and natural aerosols

Abstract

Abstract. Global simulations of the composition of and direct forcing due to aerosols containing natural and/or anthropogenic sulfate, nitrate, chloride, carbonate, ammonium, sodium, calcium, magnesium, potassium, black carbon, organic matter, silica, ferrous oxide, and aluminum oxide were carried out. Chloride and natural sulfate were found to be the most important natural aerosol constituents in the atmosphere in terms of solar plus thermal-infrared forcing. Sea spray was the most important natural aerosol type, indicating that it should be accounted for in weather and climate calculations. Ammonium was found to have a positive direct forcing, since it reduces water uptake in sulfate-containing solutions; thus, anthropogenic ammonium contributes to global warming. The magnitudes of ammonium and nitrate forcing were smaller than those of chloride or sulfate forcing. When organics were divided into three groups with different assumed UV absorption characteristics, total aerosol direct forcing at the tropopause increased by about +0.

Direct Surface Tension Measurements of Individual Sub-Micrometer Particles Using Atomic Force Microscopy

“…As NaCl is one of the most abundant electrolyte salts present in SSA, it was chosen as the first model system. 2,8,28 A representative three-dimensional (3D) AFM height image of solid NaCl particle at ∼20% RH is shown ( Figure 3A); NaBr has similar prism-shape crystalline morphology. AFM surface tension data of NaCl were taken from Morris et al; however, the range of RH probed was limited from 80% to 87% RH ( Figure 3B) due to high deliquescent point of NaCl at ∼75% RH.…”

Aerosol distribution over Europe: a model evaluation study with detailed aerosol microphysics

“…Sectional aerosol models used in 3-D studies (e.g. Jacobson, 2001, Gong et al, 2003 reach generally a higher accuracy compared with the modal approach (Zhang et al, 1999) but are computationally more demanding. We have chosen the modal aerosol microphysical approach of M7 (Vignati et al, 2004) to extend the regional online climate-chemistry/aerosol model REMOTE (Langmann, 2000;.…”

Monitoring the transport of biomass burning emissions in South America

“…Modeling efforts of Jacobson [10] and Sato et al [11] have suggested that the blackcarbon radiative forcing could balance the cooling effects of the global anthropogenic sulfate emissions. The direct global radiative forcing of the black-carbon is estimated to be 0.55 Wm -2 , corresponding to 1/3 of the CO 2 forcing.…”