The broadband surface albedo of snow can greatly be reduced by the deposition of light-absorbing impurities, such as black carbon on or near its surface. Such a reduction increases the absorption of solar radiation and may initiate or accelerate snowmelt and snow albedo feedback. Coincident measurements of both black carbon concentration and broadband snow albedo may be difficult to obtain in field studies; however, using the relationship developed in this simple model sensitivity study, black carbon mass densities deposited can be estimated from changes in measured broadband snow albedo, and vice versa. Here, the relationship between the areal mass density of black carbon found near the snow surface to the amount of albedo reduction was investigated using the popular snow radiative transfer model Snow, Ice, and Aerosol Radiation (SNICAR). We found this relationship to be linear for realistic amounts of black carbon mass concentrations, such as those found in snow at remote locations. We applied this relationship to measurements of broadband albedo in the Chilean Andes to estimate how vehicular emissions contributed to black carbon (BC) deposition that was previously unquantified.

中文翻译：

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雪地表面反照率对黑碳的敏感性：辐射转移模型

雪的宽带表面反照率可通过吸收光的杂质（例如黑碳）在其表面或其附近沉积而大大减少。这种减少会增加对太阳辐射的吸收，并可能启动或加速融雪和积雪反照率的反馈。在野外研究中可能难以同时获得黑碳浓度和宽带雪反照率的同时测量值。但是，使用在此简单的模型敏感性研究中建立的关系，可以根据测得的宽带雪反照率的变化来估算沉积的黑碳质量密度，反之亦然。在这里，使用流行的雪辐射传输模型“雪，冰和气溶胶辐射”（SNICAR），研究了在雪表面附近发现的黑碳的单位质量密度与反照率减少量之间的关系。我们发现这种关系对于现实的黑碳质量浓度（例如在偏远地区的雪中发现的浓度）是线性的。我们将此关系应用于智利安第斯山脉的宽带反照率测量中，以估计车辆排放如何导致了以前未量化的黑碳（BC）沉积。