...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Geophysical Research. Biogeosciences >VERTICAL PROFILES, AEROSOL MICROPHYSICS, AND OPTICAL CLOSURE DURING THE ATLANTIC STRATOCUMULUS TRANSITION EXPERIMENT - MEASURED AND MODELED COLUMN OPTICAL PROPERTIES
【24h】

VERTICAL PROFILES, AEROSOL MICROPHYSICS, AND OPTICAL CLOSURE DURING THE ATLANTIC STRATOCUMULUS TRANSITION EXPERIMENT - MEASURED AND MODELED COLUMN OPTICAL PROPERTIES

机译：大西洋纹状体过渡实验中的垂直剖面，气溶胶微物理和光学关闭-测量和建模的柱光学特性

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

During the Atlantic Stratocumulus Transition Experiment (ASTEX) in June 1992, two descents in cloud-free regions allowed comparison of the change in aerosol optical depth as determined by an onboard total-direct-diffuse radiometer (TDDR) to the change calculated from measured size-resolved aerosol microphysics and chemistry. Both profiles included a pollution haze layer from Europe, but the second also included the effect of a Saharan dust layer above the haze. The separate contributions of supermicrometer (coarse) and submicrometer (fine) aerosol were determined, and thermal analysis of the pollution haze indicated that the fine aerosol was composed primarily of a sulfate/water mixture with a refractory sootlike core. The soot core increased the calculated extinction by about 10% in the most polluted drier layer relative to a pure sulfate aerosol but had significantly less effect at higher humidities. A 3-km descent through a boundary layer air mass dominated by pollutant aerosol with relative humidities (RH) 10-77% yielded a close agreement between the measured and calculated aerosol optical depths (550 nm) of 0.160 (+/-0.07) and 0.157 (+/-0.034), respectively. During descent the aerosol mass scattering coefficient per unit sulfate mass (inferred) varied from about 5 to 16 m(2) g(-1) and was primarily dependent upon ambient RH. However, the total scattering coefficient per total fine mass was far less variable at about 4 +/-0.7 m(2) g(-1). A subsequent descent through a Saharan dust layer located above the pollution aerosol layer revealed that both layers contributed similarly to aerosol optical depth. The scattering per unit mass of the coarse aged dust was estimated at 1.1 +/- 0.2 m(2) g(-1). The large difference (50%) in measured and calculated optical depth for the dust layer exceeded estimated measurement uncertainty (12%). This is attributed to inadequate data on the spatial variability of the aerosol field within the descent region, a critical factor in any validation of this type. Both cases demonstrate that surface measurements may be a poor indicator of the characteristics and concentration of the aerosol column. [References: 29]
机译：在1992年6月的大西洋层积云过渡实验（ASTEX）期间，在无云区域的两次下降使得可以将由机载总直接扩散辐射计（TDDR）确定的气溶胶光学深度变化与从实测尺寸计算得出的变化进行比较-解决了气溶胶的微观物理和化学问题。这两个剖面都包括来自欧洲的污染雾霾层，但第二个剖面还包括雾霾上方撒哈拉尘埃层的影响。确定了超细（粗）气雾剂和亚细（细）气雾剂的单独贡献，对污染霾的热分析表明，细气雾剂主要由具有耐火烟尘状核的硫酸盐/水混合物组成。相对于纯硫酸盐气溶胶，烟灰芯在最受污染的干燥剂层中将计算的消光度提高了约10％，但在较高湿度下的消光作用却明显不足。通过边界层空气团下降3公里，该边界层由相对湿度（RH）为10-77％的污染物气溶胶主导，在实测和计算的气溶胶光学深度（550 nm）为0.160（+/- 0.07）和分别为0.157（+/- 0.034）。在下降期间，每单位硫酸盐质量（推断）的气溶胶质量散射系数在大约5到16 m（2）g（-1）之间变化，并且主要取决于环境RH。但是，每总精细质量的总散射系数变化很小，约为4 +/- 0.7 m（2）g（-1）。随后通过位于污染气溶胶层上方的撒哈拉尘埃层的下降表明，这两个层对气溶胶光学深度的贡献相似。每单位质量的粗老化灰尘的散射估计为1.1 +/- 0.2 m（2）g（-1）。灰尘层的测量和计算光学深度的较大差异（50％）超过了估计的测量不确定度（12％）。这归因于关于下降区域内气溶胶场的空间变异性的数据不足，这是这种类型验证中的关键因素。两种情况都表明，表面测量可能无法很好地指示气雾剂色谱柱的特性和浓度。 [参考：29]

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号