Widespread solid particle formation by mountain waves in the Arctic stratosphere
Widespread solid particle formation by mountain waves in the Arctic stratosphere
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北极平流层山波形成广泛的固体颗粒
DOI：
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发表时间：
1999
期刊：
影响因子：
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通讯作者：
S. Eckermann
中科院分区：
文献类型：
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作者：
K. Carslaw;T. Peter;J. Bacmeister;S. Eckermann
利用激光雷达对极地平流层云（PSC）的观测表明，云中通常含有固体颗粒，这些颗粒很可能是硝酸水合物。然而，实验室实验表明，这种水合物颗粒不容易形成在北极天气尺度条件下，这表明固体PSC颗粒应该是相当罕见的。在这里，我们展示了一个模型研究的结果表明，山区引起的中尺度温度扰动可能是在北极硝酸水合物颗粒的一个重要来源。多个北极涡旋轨迹与全球山波预报模式相结合，计算固体颗粒形成的潜力在1994年12月和1995年1月。山波模式被用来计算几千个脊单元的绝热冷却。硝酸水合物颗粒被假定为形成在山波根据几个微物理机制，然后平流使用极地涡旋填充天气轨迹生成固体颗粒发生的地图。计算结果表明，山波可能是一个重要的来源PSC含有固体颗粒的天气尺度上观察到的。特别是，格陵兰岛东海岸、挪威山脉和乌拉尔山脉被发现是固体粒子源，PSC通常被预测在下游数千公里处存活。
Observations of polar stratospheric clouds (PSCs) by lidar show that the clouds often contain solid particles, which are most likely composed of nitric acid hydrates. However, laboratory experiments indicate that such hydrate particles are not easily formed under Arctic synoptic scale conditions, suggesting that solid PSC particles should be rather rare. Here we show results from a model study indicating that mountain-induced mesoscale temperature perturbations may be an important source of nitric acid hydrate particles in the Arctic. Multiple Arctic vortex trajectories were combined with a global mountain wave forecast model to calculate the potential for solid particle formation during December and January 1994/1995. The mountain wave model was used to calculate adiabatic cooling over several thousand ridge elements. Nitric acid hydrate particles were assumed to form in the mountain waves according to several microphysical mechanisms, and were then advected using polar vortex-filling synoptic trajectories to generate maps of solid particle occurrence. The calculations show that mountain waves may be a significant source of PSCs containing solid particles that are observed on the synoptic scale. In particular, the east coast of Greenland, the Norwegian mountains, and the Urals are found to be solid particle sources, with the PSCs often predicted to survive several thousand kilometers downstream.