Large atmospheric shortwave radiative forcing by Mediterranean aerosols derived from simultaneous ground‐based and spaceborne observations and dependence on the aerosol type and single scattering albedo
Large atmospheric shortwave radiative forcing by Mediterranean aerosols derived from simultaneous ground‐based and spaceborne observations and dependence on the aerosol type and single scattering albedo
复制标题
来自同时地基和星载观测的地中海气溶胶造成的大大气短波辐射强迫以及对气溶胶类型和单散射反照率的依赖
DOI：
10.1029/2009jd012697
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发表时间：
2010
影响因子：
--
通讯作者：
D. Meloni
中科院分区：
文献类型：
--
作者：
C. D. Biagio;A. Sarra;D. Meloni
[1]2004-2007年期间在兰佩杜萨岛（地中海中部）的气溶胶光学特性和短波辐照度测量相结合的云和地球辐射能量系统的观测在大气层顶部（TOA）的出射短波通量。利用这些测量结果估算了太阳天顶角（θ）在15° ~ 55°范围内沙漠沙尘（DD）、城市/工业生物质燃烧气溶胶（UI-BB）和混合气溶胶（MA）的地表（FES）、大气顶（FETOA）和大气（FEATM）短波气溶胶强迫效率。在不同的大气层位上的强迫效率是用直接方法得到的，即在固定的θ下，短波净通量对气溶胶光学厚度的导数。在春分点，DD、UI-BB和MA的地面/TOA的日平均强迫效率分别为（−68.9 ± 4.0）/（−45.5 ± 5.4）W m−2、（−59.0 ± 4.3）/（−19.2 ± 3.3）W m−2和（−94.9 ± 5.1）/（−36.2 ± 1.7）W m−2。春分日平均大气辐射强迫对DD、UI-BB和MA的影响分别为（+7.3 ± 2.5）W m−2、（+8.4 ± 1.9）W m−2和（+8.2 ± 1.9）W m−2，表明平均大气强迫几乎与气溶胶类型无关。大气强迫的最大值对于DD可能达到+35 W m−2，对于UI-BB可能达到+23 W m−2，对于MA可能达到+34 W m−2。在415.6和868.7 nm处，计算了MA和25° ≤ θ ≤ 35°的三种单散射散射模式（0.7 ≤ ω < 0.8，0.8 ≤ ω < 0.9和0.9 ≤ ω ≤ 1）的FETOA：FETOA的绝对值随着ω的增加而增加。ω增加0.1，FETOA增加10-20 W m−2。
[1] Aerosol optical properties and shortwave irradiance measurements at the island of Lampedusa (central Mediterranean) during 2004–2007 are combined with Clouds and the Earth's Radiant Energy System observations of the outgoing shortwave flux at the top of the atmosphere (TOA). The measurements are used to estimate the surface (FES), the top of the atmosphere (FETOA), and the atmospheric (FEATM) shortwave aerosol forcing efficiencies for solar zenith angle (θ) between 15° and 55° for desert dust (DD), urban/industrial-biomass burning aerosols (UI-BB), and mixed aerosols (MA). The forcing efficiency at the different atmospheric levels is derived by applying the direct method, that is, as the derivative of the shortwave net flux versus the aerosol optical depth at fixed θ. The diurnal average forcing efficiency at the surface/TOA at the equinox is (−68.9 ± 4.0)/(−45.5 ± 5.4) W m−2 for DD, (−59.0 ± 4.3)/(−19.2 ± 3.3) W m−2 for UI-BB, and (−94.9 ± 5.1)/(−36.2 ± 1.7) W m−2 for MA. The diurnal average atmospheric radiative forcing at the equinox is (+7.3 ± 2.5) W m−2 for DD, (+8.4 ± 1.9) W m−2 for UI-BB, and (+8.2 ± 1.9) W m−2 for MA, suggesting that the mean atmospheric forcing is almost independent of the aerosol type. The largest values of the atmospheric forcing may reach +35 W m−2 for DD, +23 W m−2 for UI-BB, and +34 W m−2 for MA. FETOA is calculated for MA and 25° ≤ θ ≤ 35° for three classes of single scattering albedo (0.7 ≤ ω < 0.8, 0.8 ≤ ω < 0.9, and 0.9 ≤ ω ≤ 1) at 415.6 and 868.7 nm: FETOA increases, in absolute value, for increasing ω. A 0.1 increment in ω determines an increase in FETOA by 10–20 W m−2.