Short circuit of water vapor and polluted air to the global stratosphere by convective transport over the Tibetan Plateau
Short circuit of water vapor and polluted air to the global stratosphere by convective transport over the Tibetan Plateau
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DOI：
10.1073/pnas.0601584103
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发表时间：
2006-04-11
影响因子：
11.1
通讯作者：
Wu, DL
中科院分区：
文献类型：
--
作者：
Fu, R;Hu, YL;Wu, DL
在北半球夏季，进入全球热带平流层的水汽和CO大部分通过亚洲季风/青藏高原（TP）地区输送。研究表明，这种输送主要是通过南亚季风区的热带对流或中国南方的热带外对流进行的。通过使用测量从新的美国国家航空航天局的光环微波临边探测器，沿着从水和热带降雨测量使命卫星的观测，我们确定，TP提供了跨对流层顶运输在这一地区的主要途径。对流层湿对流驱动的地面加热的TIP是更深，更多的水蒸气，CO和冰在对流层顶比季风区。更温暖的对流层顶温度和较慢的失败，较小的卷云粒子在不饱和的环境空气中的对流层顶也允许更多的水蒸气进入平流层较低的TP，有效地短路了缓慢上升的水蒸气在整个寒冷的热带对流层顶的季风区。在亚洲季风/TP地区上空的高水汽和高CO的空气主要在TP上空进入平流层低层，然后被输送到亚洲季风区，并分散到全球平流层环流的大尺度上升运动中。因此，全球平流层的水合作用可能对TP上方对流的变化特别敏感。
During boreal summer, much of the water vapor and CO entering the global tropical stratosphere is transported over the Asian monsoon/Tibetan Plateau (TP) region. Studies have suggested that most of this transport is carried out either by tropical convection over the South Asian monsoon region or by extratropical convection over southern China. By using measurements from the newly available National Aeronautics and Space Administration Aura Microwave Limb Sounder, along with observations from the Aqua and Tropical Rainfall-Measuring Mission satellites, we establish that the TP provides the main pathway for cross-tropopause transport in this region. Tropospheric moist convection driven by elevated surface heating over the TIP is deeper and detrains more water vapor, CO, and ice at the tropopause than over the monsoon area. Warmer tropopause temperatures and slower-failing, smaller cirrus cloud particles in less saturated ambient air at the tropopause also allow more water vapor to travel into the lower stratosphere over the TP, effectively short-circuiting the slower ascent of water vapor across the cold tropical tropopause over the monsoon area. Air that is high in water vapor and CO over the Asian monsoon/TP region enters the lower stratosphere primarily over the TP, and it is then transported toward the Asian monsoon area and disperses into the large-scale upward motion of the global stratospheric circulation. Thus, hydration of the global stratosphere could be especially sensitive to changes of convection over the TP.