Twenty‐First Century Trends in Mixing Barriers and Eddy Transport in the Lower Stratosphere
Twenty‐First Century Trends in Mixing Barriers and Eddy Transport in the Lower Stratosphere
复制标题
平流层下部混合势垒和涡流传输的二十一世纪趋势
DOI：
10.1029/2020gl089548
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发表时间：
2020
影响因子：
5.2
通讯作者：
A. de la Cámara
中科院分区：
文献类型：
--
作者：
M. Abalos;A. de la Cámara
与平流层示踪剂输送的其他方面相比，平流层下层等熵混合的未来趋势在很大程度上仍未得到探索。本研究考察了在最近的化学-气候模式模拟中有效扩散率（κeff）的趋势，有效扩散率是一种衡量气流产生等熵混合的潜力的指标。结果表明，从秋季到春季，副热带急流上侧翼的κeff显著减少，并随着温室气体的增加而增强。这与更强的涡旋输送形成对比，涡旋输送与该地区波浪阻力的增加有关，在夏季的临界线附近达到峰值。除输运障碍外，示踪剂经向梯度的变化对等熵混合趋势也起着关键作用。预估的臭氧恢复将导致南极极春季和夏季气温升高，并与21世纪末南极极涡减弱和寿命缩短有关。
Future trends in isentropic mixing in the lower stratosphere remain largely unexplored, in contrast with other aspects of stratospheric tracer transport. This study examines trends in effective diffusivity (κeff), a measure of the potential of the flow to produce isentropic mixing, in recent chemistry‐climate model simulations. The results highlight substantial reduction of κeff in the upper flanks of the subtropical jets from fall to spring, which are strengthened in response to greenhouse gas increases. This contrasts with stronger eddy transport, associated with increased wave drag in the region, peaking in summer near the critical lines. The key role of changes in tracer meridional gradients in addition to transport barriers for isentropic mixing trends is evidenced. The projected ozone recovery leads to enhanced κeff in polar austral spring and summer, associated with a weaker and shorter‐lived austral polar vortex by the end of the 21st century.
影响因子：
5.2
作者：
M. Chipperfield;S. Dhomse;R. Hossaini;W. Feng;M. Santee;M. Weber;J. Burrows;J. Wild;D. Loyola-D.-Lo
通讯作者：
M. Chipperfield;S. Dhomse;R. Hossaini;W. Feng;M. Santee;M. Weber;J. Burrows;J. Wild;D. Loyola-D.-Lo