Parametric uncertainty effects on aerosol radiative forcing
Parametric uncertainty effects on aerosol radiative forcing
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DOI：
10.1029/2009gl039050
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发表时间：
2009-08-13
影响因子：
5.2
通讯作者：
von Storch, J. -S.
中科院分区：
文献类型：
--
作者：
Haerter, J. O.;Roeckner, E.;von Storch, J. -S.
在已知的辐射强迫中，气专委第四次评估报告估计，气溶胶辐射强迫具有最大范围的不确定性，范围从-1.8至-0.3 W/m(2)。政府间气候变化专门委员会的估计主要集中在结构性不确定性上，包括气溶胶来源的不确定性。在这里，我们研究了在最先进的大气环流模式(GCM)中由于参数不确定性而引起的硫酸盐气溶胶辐射强迫的不确定性。通过对模式中7个云参数的摄动，进行了数值试验。我们发现，这些参数中的单个参数的不确定度可达0.5W/m(2)，而这些参数组合的不确定度可达1W/m(2)以上。这些数字应与2000年的硫酸盐气溶胶强迫-1.9W/m(2)进行比较，后者是使用参数的缺省值获得的。这种不确定性是由于云的光学性质对气溶胶浓度的高度敏感性造成的，这种敏感性可以通过改变云参数设置来放大。引用：Haerter，J.O.，E.Roeckner，L.Tomassini和J.-S.von Storch(2009)，参数不确定性对气溶胶辐射强迫的影响，地球物理。莱特，36，L15707，DOI：10.1029/2009GL039050。
Among the known radiative forcings, the fourth IPCC assessment report estimates the aerosol radiative forcing to harbor the widest range of uncertainty extending from -1.8 to -0.3 W/m(2). The IPCC estimates focus mainly on structural uncertainties, including uncertainties in aerosol sources. Here, we study the uncertainty of the sulfate aerosol radiative forcing due to parametric uncertainty in a state-of-the-art general circulation model (GCM). Numerical experiments were carried out by perturbing seven cloud parameters in the model. We find that the uncertainty due to a single one of these parameters can be as large as 0.5 W/m(2), and the uncertainty due to combinations of these parameters can reach more than 1 W/m(2). These numbers should be compared with the sulfate aerosol forcing of -1.9 W/m(2) for the year 2000, obtained using the default values of the parameters. The uncertainty results from a high sensitivity of cloud optical properties to aerosol concentrations, which can be amplified by changing cloud parameter setting. Citation: Haerter, J. O., E. Roeckner, L. Tomassini, and J.- S. von Storch (2009), Parametric uncertainty effects on aerosol radiative forcing, Geophys. Res. Lett., 36, L15707, doi:10.1029/2009GL039050.