Diurnally Forced Tropical Tropospheric Circulation over South America
Diurnally Forced Tropical Tropospheric Circulation over South America
复制标题
南美洲上空的昼夜强迫热带对流层环流
DOI：
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发表时间：
1987
期刊：
影响因子：
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通讯作者：
V. Kousky
中科院分区：
文献类型：
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作者：
P. Dias;J. P. Bonatti;V. Kousky
摘要利用赤道β平面上的线性化浅水模式，研究了日变化热力强迫对热带环流的影响。的质量和流场被解释为一个内部模式与等效深度的顺序为250米。这是热带典型积云加热廓线激发的最佳垂直模态。亚马逊源的水平尺度的昼夜强迫分区约40%的输入能量的慢模式。快模式被捕获的临界纬度贡献显着的发散场，这散发出的源区域的振荡。源处的辐散场与强迫大致同相;涡度场滞后强迫约10小时。模式的结果与500毫巴水平的垂直运动，来自国家气象中心的分析，显示出类似的模式传播振荡。因此，建议将日F…
Abstract The impact of diurnally varying thermal forcing on the tropical circulation is studied with a linearized shallow water model on an equatorial beta plane. The mass and flow fields are interpreted as an internal mode with equivalent depth of the order of 250 m. This is the preferred vertical mode excited by typical cumulus heating profiles in the tropics. The diurnal forcing with the horizontal scale of the Amazon source partitions approximately 40% of the input energy to slow modes. The fast modes are trapped by the critical latitudes contributing significantly to oscillations in the divergence field, which emanate out of the source region. The divergence field at the source is approximately in phase with the forcing; the vorticity field lags the forcing by approximately 10 hours. A comparison of the model results with the 500 mb level vertical motion, derived from the National Meteorological Center analysis, shows a similar pattern of propagating oscillations. It is suggested that the diurnally f...