MAC-v1: A new global aerosol climatology for climate studies
MAC-v1: A new global aerosol climatology for climate studies
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DOI：
10.1002/jame.20035
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发表时间：
2013-12-01
影响因子：
6.8
通讯作者：
Stevens, Bjorn
中科院分区：
文献类型：
--
作者：
Kinne, Stefan;O'Donnel, Declan;Stevens, Bjorn
介绍了马克斯-普朗克研究所气溶胶气候学第1版（MAC-v1）。它描述了对流层气溶胶在月时间尺度上的光学特性，并以经纬度1度的空间分辨率覆盖全球。通过提供辐射传输应用所需的太阳（或短波）和地面（或长波）辐射光谱任何波长的气溶胶辐射特性，这套MAC-v1数据集有助于在气候研究中简化和计算高效地表示对流层气溶胶。气溶胶辐射特性的估计提供了总的和人为的气溶胶从工业化前的时间（即，从1860年开始）一直到未来（直到2100年）。气溶胶气候学的核心是合并当前（2000年）条件下气溶胶光学特性的月度统计数据。因此，当地稀疏，但值得信赖的高质量的数据，地面太阳光度计网络合并到完整的背景图所定义的中央数据从全球建模与复杂的气溶胶模块。这种合并产生的全球年度中可见光气溶胶光学厚度（AOD）为0.13，0.07归因于气溶胶尺寸大于1微米的直径和0.06归因于气溶胶尺寸小于1毫米的直径。因此，较大的颗粒吸收较少，与较小尺寸的0.93相比，具有0.98的单次散射散射散射系数（SSA）。一个全球模式的模拟结果被应用到规定的垂直分布，并估计人为的贡献较小尺寸的AOD作为时间的函数，与0.037的值为当前条件。在示范应用中，确定了相关的气溶胶直接辐射效应。在当前条件下，总气溶胶估计会使大气顶部的短波和长波净通量平衡减少约-1.6 W/m（2），其中-0.5 W/m（2）（不确定度为+/-0.2 W/m（2））归因于人类活动。根据过去和预测的气溶胶排放数据，全球人为直接气溶胶影响（即，ToA冷却）目前接近最大值，预计将在2100年下降至约-0.3 W/m（2）。所报告的全球平均数是由相当大的空间和时间变异性决定的。为了更好地传达这种多样性，区域和季节分布的气溶胶光学特性及其辐射效应。在区域尺度上，人为气溶胶直接强迫可以比全球平均值强一个数量级，它可以是任何一种符号。它还表明，在过去的30年中，最大的人为影响已经从美国和欧洲转移到东亚和南亚。
The Max-Planck-Institute Aerosol Climatology version 1 (MAC-v1) is introduced. It describes the optical properties of tropospheric aerosols on monthly timescales and with global coverage at a spatial resolution of 1 degrees in latitude and longitude. By providing aerosol radiative properties for any wavelength of the solar (or shortwave) and of the terrestrial (or longwave) radiation spectrum, as needed in radiative transfer applications, this MAC-v1 data set lends itself to simplified and computationally efficient representations of tropospheric aerosol in climate studies. Estimates of aerosol radiative properties are provided for both total and anthropogenic aerosol in annual time steps from preindustrial times (i.e., starting with year 1860) well into the future (until the year 2100). Central to the aerosol climatology is the merging of monthly statistics of aerosol optical properties for current (year 2000) conditions. Hereby locally sparse but trusted high-quality data by ground-based sun-photometer networks are merged onto complete background maps defined by central data from global modeling with complex aerosol modules. This merging yields 0.13 for the global annual midvisible aerosol optical depth (AOD), with 0.07 attributed to aerosol sizes larger than 1 mu m in diameter and 0.06 of attributed to aerosol sizes smaller than 1 mm in diameter. Hereby larger particles are less absorbing with a single scattering albedo (SSA) of 0.98 compared to 0.93 for smaller sizes. Simulation results of a global model are applied to prescribe the vertical distribution and to estimate anthropogenic contributions to the smaller size AOD as a function of time, with a 0.037 value for current conditions. In a demonstration application, the associated aerosol direct radiative effects are determined. For current conditions, total aerosol is estimated to reduce the combined shortwave and longwave net-flux balance at the top of the atmosphere by about -1.6 W/m(2) from which -0.5 W/m(2) (with an uncertainty of +/- 0.2 W/m(2)) is attributed to anthropogenic activities. Based on past and projected aerosol emission data, the global anthropogenic direct aerosol impact (i.e., ToA cooling) is currently near the maximum and is projected to drop by 2100 to about -0.3 W/m(2). The reported global averages are driven by considerable spatial and temporal variability. To better convey this diversity, regional and seasonal distributions of aerosol optical properties and their radiative effects are presented. On regional scales, the anthropogenic direct aerosol forcing can be an order of magnitude stronger than the global average and it can be of either sign. It is also shown that maximum anthropogenic impacts have shifted during the last 30 years from the U.S. and Europe to eastern and southern Asia.