气候变化领域集成服务门户(CCPortal): Black carbon-induced snow albedo reduction over the Tibetan Plateau: uncertainties from snow grain shape and aerosol-snow mixing state based on an updated SNICAR model

CCPortal

DOI	10.5194/acp-18-11507-2018
	Black carbon-induced snow albedo reduction over the Tibetan Plateau: uncertainties from snow grain shape and aerosol-snow mixing state based on an updated SNICAR model
	He, Cenlin; Flanner, Mark G.; Chen, Fei; Barlage, Michael; Liou, Kuo-Nan; Kang, Shichang; Ming, Jing; Qian, Yun
发表日期	2018
ISSN	1680-7316
EISSN	1680-7324
卷号	18 期号:15
英文摘要	We implement a set of new parameterizations into the widely used Snow, Ice, and Aerosol Radiative (SNICAR) model to account for effects of snow grain shape (spherical vs. nonspherical) and black carbon (BC)-snow mixing state (external vs. internal). We find that nonspherical snow grains lead to higher pure albedo but weaker BC-induced albedo reductions relative to spherical snow grains, while BC-snow internal mixing significantly enhances albedo reductions relative to external mixing. The combination of snow nonsphericity and internal mixing suggests an important interactive effect on BC-induced albedo reduction. Comparisons with observations of clean and BC-contaminated snow albedo show that model simulations accounting for both snow nonsphericity and BC-snow internal mixing perform better than those using the common assumption of spherical snow grains and external mixing. We further apply the updated SNICAR model with comprehensive in situ measurements of BC concentrations in the Tibetan Plateau snow-pack to quantify the present-day (2000-2015) BC-induced snow albedo effects from a regional and seasonal perspective. The BC concentrations show distinct and substantial sub-regional and seasonal variations, with higher values in the non-monsoon season and low altitudes. As a result, the BC-induced regional mean snow albedo reductions and surface radiative effects vary by up to an order of magnitude across different sub-regions and seasons, with values of 0.7-30.7 and 1.4-58.4Wm 2 for BC externally mixed with fresh and aged snow spheres, respectively. The BC radiative effects are further complicated by uncertainty in snow grain shape and BC-snow mixing state. BC-snow internal mixing enhances the mean albedo effects over the plateau by 30-60% relative to external mixing, while nonspherical snow grains decrease the mean albedo effects by up to 31% relative to spherical grains. Based on this study, extensive measurements and improved model characterization of snow grain shape and aerosol-snow mixing state are urgently needed in order to precisely evaluate BC-snow albedo effects.
学科领域	Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences
语种	英语
WOS研究方向	Environmental Sciences ; Meteorology & Atmospheric Sciences
来源期刊	ATMOSPHERIC CHEMISTRY AND PHYSICS
来源机构	中国科学院西北生态环境资源研究院
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/111950
作者单位	Natl Ctr Atmospher Res, Adv Study Program, POB 3000, Boulder, CO 80307 USA
推荐引用方式 GB/T 7714	He, Cenlin,Flanner, Mark G.,Chen, Fei,et al. Black carbon-induced snow albedo reduction over the Tibetan Plateau: uncertainties from snow grain shape and aerosol-snow mixing state based on an updated SNICAR model[J]. 中国科学院西北生态环境资源研究院,2018,18(15).
APA	He, Cenlin.,Flanner, Mark G..,Chen, Fei.,Barlage, Michael.,Liou, Kuo-Nan.,...&Qian, Yun.(2018).Black carbon-induced snow albedo reduction over the Tibetan Plateau: uncertainties from snow grain shape and aerosol-snow mixing state based on an updated SNICAR model.ATMOSPHERIC CHEMISTRY AND PHYSICS,18(15).
MLA	He, Cenlin,et al."Black carbon-induced snow albedo reduction over the Tibetan Plateau: uncertainties from snow grain shape and aerosol-snow mixing state based on an updated SNICAR model".ATMOSPHERIC CHEMISTRY AND PHYSICS 18.15(2018).