Temperature trends in the tropical upper troposphere and lower stratosphere: Connections with sea surface temperatures and implications for water vapor and ozone
Temperature trends in the tropical upper troposphere and lower stratosphere: Connections with sea surface temperatures and implications for water vapor and ozone
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DOI：
10.1002/jgrd.50772
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发表时间：
2013-09-16
影响因子：
4.4
通讯作者：
Hurwitz, M. M.
中科院分区：
文献类型：
--
作者：
Garfinkel, C. I.;Waugh, D. W.;Hurwitz, M. M.
卫星观测和化学-气候模式实验被用来了解热带低平流层温度、水汽和臭氧趋势的纬向结构。近30年来，热带对流层高层增温在印度洋-太平洋暖池附近最强，而西太平洋和中太平洋增温趋势较弱。在平流层下部，这些趋势相反：印度-太平洋暖池的历史降温趋势最强，西太平洋和中太平洋最弱。这些纬向变化比北方冬季的纬向平均响应要强。利用化学-气候模式进行的有针对性的实验表明，海表面温度(以下简称SST)趋势正在驱动对流层上部和平流层下部热带温度趋势的纬向不对称性。印度洋和暖池区的海温变暖导致对流层上层的湿加热增强，进而导致延伸到平流层下部的刺状反应。这种异常环流导致了对流层顶附近臭氧和水汽趋势的纬向结构，从而导致进入平流层的水汽减少。这些微量气体变化对辐射的影响比潮湿加热的直接影响要小。预测的未来海温似乎推动了温度和水汽响应，其纬向结构类似于历史响应。在平流层下部，由于预计未来的海温，水汽和温度的变化与直接由于预计未来的二氧化碳、臭氧和甲烷而产生的变化的强度相似，但略弱。
Satellite observations and chemistry-climate model experiments are used to understand the zonal structure of tropical lower stratospheric temperature, water vapor, and ozone trends. The warming in the tropical upper troposphere over the past 30 years is strongest near the Indo-Pacific warm pool, while the warming trend in the western and central Pacific is much weaker. In the lower stratosphere, these trends are reversed: the historical cooling trend is strongest over the Indo-Pacific warm pool and is weakest in the western and central Pacific. These zonal variations are stronger than the zonal-mean response in boreal winter. Targeted experiments with a chemistry-climate model are used to demonstrate that sea surface temperature (hereafter SST) trends are driving the zonal asymmetry in upper tropospheric and lower stratospheric tropical temperature trends. Warming SSTs in the Indian Ocean and in the warm pool region have led to enhanced moist heating in the upper troposphere, and in turn to a Gill-like response that extends into the lower stratosphere. The anomalous circulation has led to zonal structure in the ozone and water vapor trends near the tropopause, and subsequently to less water vapor entering the stratosphere. The radiative impact of these changes in trace gases is smaller than the direct impact of the moist heating. Projected future SSTs appear to drive a temperature and water vapor response whose zonal structure is similar to the historical response. In the lower stratosphere, the changes in water vapor and temperature due to projected future SSTs are of similar strength to, though slightly weaker than, that due directly to projected future CO2, ozone, and methane.