Numerical Simulation of Wind Hole Circulation at Ice Valley in Korea Using a Simple 2D Model

[摘要] In this study, numerical simulations of the summertime ice formation at Ice Valley in Korea are conducted using a simple 2D model, which is driven by the observed air temperature. The Ice Valley in Korea is a famous summer resort, as the Natural Monument where natural ice forms in spring, and remains till summer along the slope, and the ice disappears in fall to winter. It is interesting to note that the hotter the outside air is, the larger the ice grows in spring. The mysterious behavior of the summertime ice has been partly explained by a series of numerical experiments in terms of the convection theory, which is explained by the seasonally reversing wind-hole circulations. The numerical model in this study is updated from our former versions considering the new finding by the in situ observations. The result of the simulation is compared with the observations at the Ice Valley in Korea, and Nakayama in Japan.According to the result of the numerical simulation, the summertime wind-hole circulation activates the downward flow when the outside air is getting hot. The downward flow transfers the cold accumulated in the talus during the previous winter toward the outlet of the cold wind hole. As a result, the intensified cold advection grows the ice when the outside air is getting hot. The wind hole circulation appears to be about 17 mm/s in April, and the residence time of the air in the talus is estimated as 2.8 hours for this case. It is shown, that the seasonal reversal of the wind hole circulation is the essential mechanism of the summertime ice at the Ice Valley, acting as a natural thermal filter which effectively accumulates only the winter cold in the talus.

[学科分类] 大气科学