A quasi-periodic variation of the lower cloud amount induced by atmospheric waves was reproduced in our Venus general circulation model for the first time. This result agrees well with previous 2.3-μm infrared nightside measurements. The cloud amount variation is mainly caused by a temperature fluctuation with a period of ∼5.5 Earth days near the cloud base, which is associated with a Kelvin-like gravity wave with a zonal wavenumber-1 structure. Our result might be able to explain the mechanism of the periodical variation of the brightness in the Venusian low-latitudes shown by the previous 2.3-μm infrared nightside measurements. It is also suggested that the temporal variation of the mass loading due to the temperature fluctuation is related to the abrupt appearance and disappearance of the large cloud particle (Mode 3) and explains the sharp discontinuity of the lower cloud found by the recent Akatsuki and ground-based infrared nightside measurements.

中文翻译：

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金星大气波引起的低赤道云的准周期性变化

我们的金星环流模型首次再现了大气波引起的低云量的准周期性变化。这一结果与先前的2.3-吻合较好μ米红外阴面测量。云量变化主要是由云底附近周期为~5.5个地球日的温度波动引起的，这与具有纬向波数1结构的类开尔文重力波有关。我们的结果或许能够解释之前2.3- μ所显示的金星低纬度地区亮度周期性变化的机制。m 红外夜间测量。还提出由于温度波动引起的质量载荷的时间变化与大云粒子（模式 3）的突然出现和消失有关，并解释了最近 Akatsuki 和地面发现的低层云的急剧不连续性。基于红外夜边测量。