Dynamical heating of the polar summer mesopause induced by solar proton events
Dynamical heating of the polar summer mesopause induced by solar proton events
复制标题
太阳质子事件引起的极地夏季中层顶的动态加热
DOI：
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发表时间：
2010
期刊：
影响因子：
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通讯作者：
C. Savigny
中科院分区：
文献类型：
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作者：
E. Becker;C. Savigny
[1]太阳质子事件（SPE）期间和之后观测到的极地夏季中层顶加热被解释为一个大尺度的动力学响应的临时非绝热冷却在夏季极地上方的中间层下部的结果从临时臭氧消耗在SPE。我们的方法是基于时间片的敏感性实验进行机械的大气环流模型。模式响应表明，根据梯度风平衡，极地低层中间层冷却导致异常东风分量。其结果是，由向东传播的重力波（GW）施加的阻力转移到较低的高度与平衡的剩余环流向下移动的串联。在对流层外的夏季中层顶附近，伴随着异常的大尺度动力加热，定性地解释了该区域的正温度响应。的纬向动量和感热收支的定量检查表明，GW阻力响应的部分补偿行星Rossby波的下移，大约三分之二的异常大尺度动态加热周围的中层顶是平衡的变化的直接热效应由于GW，扩散和耗散。
[1] The observed heating of the polar summer mesopause during and after a solar proton event (SPE) is interpreted as a large-scale dynamical response to the temporary diabatic cooling in the lower mesosphere above the summer pole that results from the temporary ozone depletion during an SPE. Our method is based on time slice sensitivity experiments performed with a mechanistic general circulation model. The model response shows that according to the gradient wind balance, the polar lower mesospheric cooling induces an anomalous eastward wind component. As a result, the drag exerted by eastward propagating gravity waves (GWs) shifts to lower altitudes in tandem with a balancing downward shift of the residual circulation. Around the extratropical summer mesopause, this is accompanied by an anomalous large-scale dynamic heating which qualitatively explains the positive temperature response in this region. A quantitative inspection of the zonal momentum and sensible heat budgets reveals that the GW drag response is partly compensated by a downshift of planetary Rossby waves and that about two thirds of the anomalous large-scale dynamic heating around the mesopause is balanced by changes of the direct thermal effects due to GWs, diffusion, and dissipation.