On the Localization Phenomena of Snowfall

[摘要]  The localization phenomena of snowfalls in the winter monsoon season were studied from various points of view, namely cloud physics, laboratory experiment, radar meteorology and the satellite meteorology.  The results of the study are summarized as follows:  1. Snowfalls can occur over the Sea of Japan without any upglide effect by mountains. 2. The localization of snowfalls is produced by the convergence of snow clouds, because falling snow crystals are considered to be transported nearly horizontally by wind. 3. A meso-scale front is formed by two meso-scale air-masses, and a series of mesoscale cyclones is formed along the meso-scale front. 4. The formation mechanism of meso-scale cyclones may be explained by the classical model given by Bjerkness. 5. The orographic effect on the movement of snow clouds is considerably stronger than usually expected. 6. The snowfall is localized on an area where the wind speed is decreasing.  Actual examples of the localization of a result of the orographic effect.

[学科分类] 大气科学