Stratocumulus Cloud Clearings and Notable Thermodynamic and Aerosol Contrasts across the Clear–Cloudy Interface
Stratocumulus Cloud Clearings and Notable Thermodynamic and Aerosol Contrasts across the Clear–Cloudy Interface
复制标题
层积云清除以及晴云界面上显着的热力学和气溶胶对比
DOI：
--
复制
发表时间：
2016
期刊：
影响因子：
--
通讯作者：
Seinfeld
中科院分区：
文献类型：
--
作者：
E. Crosbie;Zhen Wang;A. Sorooshian;Patrick;Y.;Chuang;Jill;S.;Craven;Roy;K.;Woods;Richard;C.;Flagan;John;H.;Seinfeld
在加州海岸附近的水域进行的三次研究飞行的数据被用来调查不同大小的层积云云甲板和空地之间的边界。大型空地表现出一个昼夜周期与增长在白天和夜间收缩和一个多天的生命周期，可以包括增长和衰减之间的振荡，而一个小的沿海清除被观察到局部局限于一个subdailyear寿命。在这三种情况下，云下气溶胶特征在晴-多云边界的两侧是相似的，而气象特性表现出微妙的，但重要的梯度，这意味着动力学，而不是微物理学，是清除特性的主要驱动力。在一次飞行过程中，在多个层次上跨越云边界的断面，突出了云边缘附近热力学性质的微尺度（~1公里）结构的重要性，这表明与对流涡尺度相当的长度尺度上的动态强迫可能会影响大尺度的清除特征。这些结果对海洋边界层云的建模和观测研究具有一定的意义，特别是在气溶胶-云的相互作用和层积云净空演变的变率尺度方面。
Data from three research flights, conducted over water near the California coast, are used to investigate the boundary between stratocumulus cloud decks and clearings of different sizes. Large clearings exhibit a diurnal cycle with growth during the day and contraction overnight and a multiday life cycle that can include oscillations between growth and decay, whereas a small coastal clearing was observed to be locally confined with a subdiurnal lifetime. Subcloud aerosol characteristics are similar on both sides of the clear–cloudy boundary in the three cases, while meteorological properties exhibit subtle, yet important, gradients, implying that dynamics, and not microphysics, is the primary driver for the clearing characteristics. Transects, made at multiple levels across the cloud boundary during one flight, highlight the importance of microscale (~1 km) structure in thermodynamic properties near the cloud edge, suggesting that dynamic forcing at length scales comparable to the convective eddy scale may be influential to the larger-scale characteristics of the clearing. These results have implications for modeling and observational studies of marine boundary layer clouds, especially in relation to aerosol–cloud interactions and scales of variability responsible for the evolution of stratocumulus clearings.