Collaborative Research: Direct radiative forcing over central Greenland; Assessment of the coupled effect of light absorbing aerosols and snow albedo variability

合作研究：格陵兰岛中部的直接辐射强迫；

• 批准号: 1023227
• 负责人: Michael Bergin
• 金额: $ 21万
• 依托单位: Georgia Tech Research Corporation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-15 至 2013-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1023227&HistoricalAwards=false
• 关键词: Collaborative; Research; Direct; radiative; forcing

The PIs will make key measurements needed to accurately estimate the direct radiative forcing by aerosols over the central Greenland ice sheet. Sampling will take place over a field season that will occur from the spring through fall of 2011. It will include real-time measurements of aerosol physical and optical properties (size distribution, multi-wavelength scattering, σsp, and backscattering, σbsp, coefficients as well as the multi-wavelength absorption coefficient, σap) needed to estimate the aerosol single scattering albedo, ω, and asymmetry parameter, g. Additional measurements of the wavelength-dependent optical depth, τλ, as well as the spectral surface reflectance, Rs will also be made. These data will serve as input to a radiative transfer model that will be used to estimate the direct aerosol radiative forcing at the surface and top of the atmosphere over Greenland. Sources and source regions of the direct radiative forcing will be determined by the chemical composition of the aerosols sampled. It is hypothesized that dust, biomass burning and fossil fuel combustion aerosols often exert a positive direct radiative forcing many times greater than that of anthropogenic greenhouse gases. Additional characterization of snow albedo, which varies occurs on timescales of hours to days, will be made to determine whether it, too, exerts a significant influence on the direct aerosol forcing over Summit. Surface snow grain properties and surface snow chemistry will be determined at high temporal frequency to explore the link between the variability in these properties and the surface albedo.

pi将进行关键测量，以准确估计格陵兰岛中部冰盖上气溶胶的直接辐射强迫。采样将在2011年春季到秋季的一个季节进行。它将包括气溶胶物理和光学特性的实时测量（尺寸分布、多波长散射和后向散射、系数以及多波长吸收系数），这些都是估算气溶胶单次散射反照率所需的。g.波长相关光深度的附加测量，τ&#955；，以及光谱表面反射率，Rs也将被制作。这些数据将作为辐射传输模式的输入，该模式将用于估计格陵兰岛大气表面和顶部的直接气溶胶辐射强迫。直接辐射强迫的源和源区域将由采样的气溶胶的化学成分决定。据推测，粉尘、生物质燃烧和化石燃料燃烧气溶胶经常施加比人为温室气体大许多倍的正直接辐射强迫。积雪反照率在小时到天的时间尺度上发生变化，为了确定它是否也对峰顶的直接气溶胶强迫产生重大影响，将对积雪反照率进行额外的表征。在高时间频率下确定地表雪颗粒特性和地表雪化学，以探索这些特性的变化与地表反照率之间的联系。