Polar lows: The development of baroclinic disturbances in cold air outbreaks
Polar lows: The development of baroclinic disturbances in cold air outbreaks
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极地低压：冷空气爆发时斜压扰动的发展
DOI：
10.1002/qj.49710042604
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发表时间：
1974
影响因子：
8.9
通讯作者：
DA Mansfield
中科院分区：
文献类型：
--
作者：
DA Mansfield
在东北大西洋上空的冷空气爆发中，小扰动的形成是由于斜压不稳定造成的。对两个扰动的实例研究表明，它们的生长速率、波长和相速度与斜压理论的预测非常接近。表面摩擦被证明有非常重要的影响；强烈的地面风增强了摩擦，严重降低了生长速度。来自海面的加热也降低了生长速度。得出的结论是，这些低气压只有在地面风较轻且气流不平行于海面等温线的情况下才会发展，从而解释了它们与冷空气爆发相比的罕见性，并为预测它们的发展提供了更多的判别标准。
The formation of small disturbances in cold air outbreaks over the north‐east Atlantic is shown to be due to baroclinic instability. A case study of two such disturbances shows their growth rate, wavelength and phase speed to be very close to the predictions of the baroclinic theory. Surface friction is shown to have a very important effect; strong surface winds enhancing the friction and severely reducing the growth rate. Heating from the sea surface also reduces the growth rate. It is concluded that these lows will develop only when the surface winds are light and where the air flow is not parallel to sea‐surface isotherms, thus explaining their rarity compared to that of cold air outbreaks and providing more discriminating criteria for forecasting their development.