Observations of Fog‐Aerosol Interactions Over Central Greenland
Observations of Fog‐Aerosol Interactions Over Central Greenland
复制标题
DOI：
10.1029/2023jd038718
复制
发表时间：
2023-05
期刊：
影响因子：
--
通讯作者：
H. Guy;I. Brooks;David D. Turner;C. Cox;P. Rowe;M. Shupe;V. Walden;Ryan Reynolds Neely
中科院分区：
文献类型：
--
作者：
H. Guy;I. Brooks;David D. Turner;C. Cox;P. Rowe;M. Shupe;V. Walden;Ryan Reynolds Neely
过冷雾可以在格陵兰冰盖表面产生重要的辐射影响，但它们很难被检测到，我们对控制其寿命和辐射特性的因素的了解受到缺乏观测的限制。这项研究表明，下降流长波辐射的光谱分辨测量可以用来产生雾的微物理特性（相位和粒子有效半径）的检索时，雾的可见光深度大于10.25。2019年6月至9月期间，在格陵兰中部的Summit Station，在晴朗的天空下发生了12起雾，其中9起是混合相。平均冰粒（光学等效球）有效半径为24.0 ± 7.8 µm，平均液滴有效半径为14.0 ± 2.7 µm。这些结果与气溶胶粒子数浓度的测量结果相结合，提供了支持以下假设的证据：（a）低表面气溶胶粒子数浓度可以限制雾液体水路径，（B）雾可以通过增强混合来增加近表面气溶胶粒子数浓度，以及（c）静止期的多个雾事件逐渐耗尽近表面气溶胶粒子数浓度。
Supercooled fogs can have an important radiative impact at the surface of the Greenland Ice Sheet, but they are difficult to detect and our understanding of the factors that control their lifetime and radiative properties is limited by a lack of observations. This study demonstrates that spectrally resolved measurements of downwelling longwave radiation can be used to generate retrievals of fog microphysical properties (phase and particle effective radius) when the fog visible optical depth is greater than ∼0.25. For 12 cases of fog under otherwise clear skies between June and September 2019 at Summit Station in central Greenland, nine cases were mixed‐phase. The mean ice particle (optically‐equivalent sphere) effective radius was 24.0 ± 7.8 µm, and the mean liquid droplet effective radius was 14.0 ± 2.7 µm. These results, combined with measurements of aerosol particle number concentrations, provide evidence supporting the hypotheses that (a) low surface aerosol particle number concentrations can limit fog liquid water path, (b) fog can act to increase near‐surface aerosol particle number concentrations through enhanced mixing, and (c) multiple fog events in quiescent periods gradually deplete near‐surface aerosol particle number concentrations.