Stratocumulus to cumulus transition in the presence of elevated smoke layers
Stratocumulus to cumulus transition in the presence of elevated smoke layers
复制标题
烟层升高时层积云到积云的转变
DOI：
--
复制
发表时间：
2015
期刊：
影响因子：
--
通讯作者：
A. McComiskey
中科院分区：
文献类型：
--
作者：
T. Yamaguchi;G. Feingold;J. Kazil;A. McComiskey
利用理想大涡模拟研究了在高架吸光烟雾层存在下从层积云到积云的转变。烟雾层位于层积云顶部上方1公里处，在3天的模拟过程中随着云场的变化而变化。模拟结果改变了烟雾产生的热量和烟雾层的水分含量。模拟了无烟的控制情况进行比较。在过渡的第2天，当烟雾仍在云层上方时，烟雾产生的破碎云场比对照情况下更多，这对气溶胶加热强度的依赖性较弱，而对烟雾层中的水蒸气含量的依赖性很强。在夜间恢复并与层积云接触后，烟雾通过加强逆温、限制边界层加深和减少降水相关的破裂来阻碍转变。这种调制延迟了过渡，这可能会使层积云甲板向西延伸，同时对气候强迫产生影响。
The transition from stratocumulus to cumulus clouds in the presence of elevated light‐absorbing smoke layers is investigated with idealized large‐eddy simulations. A smoke layer is placed 1 km above stratocumulus top and evolves with the cloud fields over the course of a 3 day simulation. The simulations presented vary the smoke‐generated heating and the moisture content of the smoke layer. A control case without smoke is simulated for comparison. On day 2 of the transition, when still above cloud, smoke generates a more broken cloud field than the control case, depending weakly on the strength of the aerosol heating but strongly on the water vapor content in the smoke layer. Following nighttime recovery and contact with the stratocumulus, smoke hinders the transition by strengthening the inversion, limiting boundary layer deepening and reducing precipitation‐related breakup. This modulation delays the transition, which may extend the stratocumulus deck westward, with concomitant implications for climate forcing.