DOI: 10.1029/2018JD028504
Scopus记录号: 2-s2.0-85052201254
论文题名: Characterization of the Real Part of Dry Aerosol Refractive Index Over North America From the Surface to 12 km
作者: Aldhaif A.M. ; Stahl C. ; Braun R.A. ; Moghaddam M.A. ; Shingler T. ; Crosbie E. ; Sawamura P. ; Dadashazar H. ; Ziemba L. ; Jimenez J.L. ; Campuzano-Jost P. ; Sorooshian A.
刊名: Journal of Geophysical Research: Atmospheres
ISSN: 2169897X
出版年: 2018
卷: 123, 期: 15 起始页码: 8283
结束页码: 8300
语种: 英语
英文关键词: aerosol
; aerosol optical depth
; DC3
; radiative forcing
; refractive index
; SEAC4RS
英文摘要: This study reports a characterization of the real part of dry particle refractive index (n) at 532 nm based on airborne measurements over the United States, Canada, the Pacific Ocean, and the Gulf of Mexico from the 2012 Deep Convective Clouds and Chemistry (DC3) and 2013 Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC4RS) campaigns. Effective n values are reported, with the limitations and uncertainties discussed. Eight air mass types were identified based on criteria related to gas-phase tracer concentrations, location, and altitude. Average values of n for these air types ranged from 1.50 to 1.53. Values of n for the organic aerosol (OA) fraction (nOA) were calculated using a linear mixing rule for each air mass type, with 1.52 shown to be a good approximation for all OA. Case studies detailing vertical structure revealed that n and nOA increased with altitude, simultaneous with enhancements in the mass fraction of OA. Values of nOA were positively (negatively) correlated with the O:C (H:C) ratio in the absence of biomass burning influence; in contrast, the cumulative data set revealed a slight decrease in nOA as a function of the O:C ratio. The performance of parametric (multiple linear regression) and nonparametric (Gaussian process regression) methods in predicting n based on aerosol composition data is discussed. It is shown that even small perturbations in n values significantly impact aerosol optical depth retrievals, radiative forcing, and optical sizing instruments, emphasizing the importance of further improving the understanding of this important aerosol property. ©2018. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/113265
Appears in Collections: 气候减缓与适应
There are no files associated with this item.
作者单位: Department of Chemical and Environmental Engineering, University of Arizona, Tucson, AZ, United States; Department of Hydrology and Atmospheric Sciences, University of Arizona, Tucson, AZ, United States; Science Systems and Applications, Inc., Hampton, VA, United States; NASA Langley Research Center, Hampton, VA, United States; Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, United States; Department of Chemistry and Biochemistry, University of Colorado, Boulder, CO, United States
Recommended Citation:
Aldhaif A.M.,Stahl C.,Braun R.A.,et al. Characterization of the Real Part of Dry Aerosol Refractive Index Over North America From the Surface to 12 km[J]. Journal of Geophysical Research: Atmospheres,2018-01-01,123(15)