Modulations of aerosol impacts on cloud microphysics induced by the warm Kuroshio Current under the East Asian winter monsoon
Modulations of aerosol impacts on cloud microphysics induced by the warm Kuroshio Current under the East Asian winter monsoon
复制标题
东亚冬季风下黑潮暖流对气溶胶对云微物理影响的调节
DOI：
10.1002/2016jd025375
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
T. Y. Nakajima
中科院分区：
文献类型：
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作者：
M. Koike;N. Asano;H. Nakamura;S. Sakai;T. M. Nagao;T. Y. Nakajima
在我们以前的飞机观测中，揭示了沿黑潮的高海表温度（SST）对北太平洋西部气溶胶-云相互作用的可能影响。云滴数浓度（Nc）随着近地表静态稳定性（NSS）的降低而增加，NSS在局地被评价为海温与地表气温（SAT）之间的差值。为了探索这种温暖海温影响的时空范围，本研究分析了中分辨率成像光谱仪（MODIS）卫星测量估计的ncv值。对比海温- SAT高、低日的局地ncc值，发现东海南部黑潮一带的海温- SAT值显著增加（可达1.8倍），在冬季亚洲大陆季风性冷空气流出的影响下，海温- SAT值特别高（可达8 K）。这种冷气流破坏了大气边界层的稳定，导致发育良好的混合层内的上升气流速度增强，从而导致更大的nc。季风性西北风也从亚洲大陆带来了大量的人为气溶胶，这些气溶胶首先会增加。这些结果表明，同样的云微物理调制可以发生在其他温暖的西部边界流上，包括墨西哥湾流，在受污染的凉爽大陆气流下。还讨论了影响云液态水路径的可能性。
In our previous aircraft observations, the possible influence of high sea surface temperature (SST) along the Kuroshio Current on aerosol‐cloud interactions over the western North Pacific was revealed. The cloud droplet number concentration (Nc) was found to increase with decreasing near‐surface static stability (NSS), which was evaluated locally as the difference between the SST and surface air temperature (SAT). To explore the spatial and temporal extent to which this warm SST influence can be operative, the present study analyzedNcvalues estimated from Moderate Resolution Imaging Spectroradiometer (MODIS) satellite measurements. The comparison of the localNcvalues between the high and low SST − SAT days revealed a marked increase inNc(up to a factor of 1.8) along the Kuroshio Current in the southern East China Sea, where particularly high SST − SAT values (up to 8 K) were observed in winter under monsoonal cold air outflows from the Asian Continent. This cold airflow destabilizes the atmospheric boundary layer, which leads to enhanced updraft velocities within the well‐developed mixed layer and thus greaterNc. The monsoonal northwesterlies also bring a large amount of anthropogenic aerosols from the Asian continent that increaseNcin the first place. These results suggest that the same modulations of cloud microphysics can occur over other warm western boundary currents, including the Gulf Stream, under polluted cool continental airflows. Possibilities of influencing the cloud liquid water path are also discussed.