A numerical experiment on the nocturnal low level jet over the Kanto Plain
A numerical experiment on the nocturnal low level jet over the Kanto Plain
复制标题
关东平原夜间低空急流的数值试验
DOI：
10.2151/jmsj1965.61.6_848
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发表时间：
1983
影响因子：
3.1
通讯作者：
S. Arakawa
中科院分区：
文献类型：
--
作者：
F. Kimura;S. Arakawa
本文用三维局地风数值模式模拟了夜间出现在关东平原东南部的低空急流。计算结果与观测到的急流的水平和垂直分布相吻合。急流的日变化与观测基本一致。但日变化幅度较小，最大风速出现的时间比观测值早几个小时。从一些额外的数值实验，例如，在不考虑地面热力作用的情况下，日本中部山脉对大尺度风的机械作用是低空急流形成的主要因素。山脉的热力作用使低空急流增强，并产生日变化。湍流应力对急流的日变化也有重要影响，但由大尺度风场和应力日变化引起的惯性振荡不可能是急流形成的主要因素。
The nocturnal low level jet, which appears over the southeastern part of the Kanto Plain, is simulated using a three-dimensional numerical model of the local winds. The results agree well with observations of the horizontal and vertical distribuitons of the jet. The diurnal variation of the jet generally agrees with the observation. However, the amplitude of the diurnal variation is a little smaller and the maximum wind velocity appears a few hours earlier than the observation. From some additional numerical experiments, e.g., without the thermal effect of the ground, it is found that the primary factor of the low level jet formation is the mechanical effect of the mountains in central Japan upon the large scale wind. The thermal effect of the mountains enhances the low level jet and produces a diurnal variation. The turbulent stress is also important to the diurnal variation of the jet, but the inertia oscillation, which is generated by the large scale wind and the diurnal variation of the stress, is unlikely to be a primary factor of the jet formation.