Convection in Conditionally Unstable Atmosphere
Convection in Conditionally Unstable Atmosphere
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条件不稳定大气中的对流
DOI：
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发表时间：
1961
期刊：
影响因子：
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通讯作者：
H. Kuo
中科院分区：
文献类型：
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作者：
H. Kuo
分析表明，如果层结在无限大范围内对上升运动是不稳定的，而对下降运动是稳定的，并引入各种尺度的随机小扰动，则最终演化的扰动将具有积云的尺度。下降区的稳定层结使临界失稳率增大，上升区变窄，使下降运动范围扩大，使上升区中心相距更远。从理论分析中估计的距离与从卫星观测中获得的距离一致。得到了圆对称扰动的各种扰动量的分布。它们与热带风暴的相应分布有许多相似之处。由于成熟热带风暴的主要能量来源是凝结潜热，因此很容易将这些大规模扰动的形成直接归因于条件不稳定空气中的对流。但分析表明，要将不稳定层结能量的释放引导到大尺度环流中，还需要一些组织机制。DOI：10.1111/j.2153-3490.1961.tb00107.x
The analysis has shown that if the stratification is unstable for ascending motion over an infinite area and stable for descending motion, and small random perturbations of various scales are introduced, the final disturbance evolved will have the dimension of a cumulus cloud. The stable stratification in the descending region has the effect of increasing the critical lapse-rate and narrowing the ascending region and making the descending motion widespread, so that the centers of the ascending regions are further apart. The distance estimated from the theoretical analysis agrees favorably with those obtained from satellite observations. The distributions of the various perturbation quantities pertaining to a circular symmetrical disturbance have been obtained. They show many resemblances to the corresponding distributions in tropical storms. Since the main source of energy of the mature tropical storms is the latent heat of condensation, it is really tempting to attribute the formation of these large-scale disturbances directly to convection in conditionally unstable air. However, the analysis shows that some organizing mechanisms are needed in order to channel the release of the energy of unstable stratification into a large scale circulation. DOI: 10.1111/j.2153-3490.1961.tb00107.x