Wu Lianghai, Hasekamp Otto, van Diedenhoven Bastiaan, Cairns Brian, Yorks John E, Chowdhary Jacek
SRON Netherlands Institute for Space Research, Sorbonnelaan 2, 3584 CA Utrecht, the Netherlands.
Columbia University, Center for Climate System Research, 2880 Broadway, New York, NY 10025, USA.
Geophys Res Lett. 2016 Aug 28;43(16):8783-8790. doi: 10.1002/2016GL069848. Epub 2016 Aug 11.
We demonstrate that multi-angle polarization measurements in the near-UV and blue part of the spectrum are very well suited for passive remote sensing of aerosol layer height. For this purpose we use simulated measurements with different set-ups (different wavelength ranges, with and without polarization, different polarimetric accuracies) as well as airborne measurements from the Research Scanning Polarimeter (RSP) obtained over the continental USA. We find good agreement of the retrieved aerosol layer height from RSP with measurements from the Cloud Physics Lidar (CPL) showing a mean absolute difference of less than 1 km. Furthermore, we found that the information on aerosol layer height is provided for large part by the multi-angle polarization measurements with high accuracy rather than the multi-angle intensity measurements. The information on aerosol layer height is significantly decreased when the shortest RSP wavelength (410 nm) is excluded from the retrieval and is virtually absent when 550 nm is used as shortest wavelength.
我们证明，在光谱的近紫外和蓝光部分进行多角度偏振测量非常适合于气溶胶层高度的被动遥感。为此，我们使用了不同设置（不同波长范围、有偏振和无偏振、不同偏振精度）的模拟测量以及在美国大陆上空通过研究扫描偏振计（RSP）获得的机载测量数据。我们发现，从RSP反演得到的气溶胶层高度与云物理激光雷达（CPL）的测量结果吻合良好，平均绝对差值小于1千米。此外，我们发现，气溶胶层高度的信息很大程度上是由高精度的多角度偏振测量提供的，而不是多角度强度测量。当反演中排除RSP最短波长（410纳米）时，气溶胶层高度的信息显著减少，而当使用550纳米作为最短波长时，该信息几乎不存在。
