임실지방의 신적설 예측방법 연구

Abstract

The representative characteristic of the weather in Jeollabuk-do region is heavy snow in winter due to the continental anticyclone expansion. Especially, the winter heavy snow is characterized by the great deviation of snow accumulation as the spots in limited area. This study classifies the heavy snow type in Jeollabuk-do region by the geographical features under the assumptions that the distribution of snowfall which occurs when a cold air passes through the warm oceans is set by the geographical features. With the Noryeong mountains in Jeollabuk-do as the center, the case of the heavy snowfall which falls in the west area more than the east area of the mountain range is classified as the west coast heavy snow type, and the opposite case is classified as the inland heavy snow type. The study regions are Imsil and Jangsu at the east of the Noryeong mountains, and Jeongeup region at the west of the Noryeong mountains among heavy snowfall regions in Jeollabuk-do. We demonstrated the case that maximum depth of fresh snow cover is over 5 cm more than 1 region among Imsil, Jangsu and Jeongeup. Accordindg to that result, the occurrence of heavy snow in Jeollabuk-do is more frequent by 53% compared with that in the west coast region. In case of the west coast heavy snow type, there is the large deviation of fresh snow cover between both regions. Also, it appears that southward advance of cold air in case of the west coast heavy snow type is more outstanding than that of the inland heavy snow type. When the west coast heavy snow type comes, the isobar of the surface pressure pattern is arranged in linear order to north and south with the west coast region in Korea as the center, as cold air penetrates deep from the northern inland region to the central inland region in Korea. At this time, it is concluded that heavy snow falls in Jeongeup region located on windward side of the Noryeong mountains as cold air flows into Jeollabuk-do region from north-northwest. By contrast, in case of the inland heavy snow type, as cold air cannot flow into the north or the central inland and then expands from Hanam region in China to the southern region in Korea, the isobar of the surface pressure pattern tends to incline from northwest to southwest with the Korean west coast as the center and the main wind in Jeollabuk-do region is from the west to the west-northwest. In this case, after the cold air falls snow in Jeongeup region which is the windward side of the Noryeong mountains by the relatively strong wind from the west to the west-northwest than the west coast heavy snow type, passing the Noryeong mountains, the positive vorticity greatly develops once more at the lee side of the mountains. Thus, it seems to be a heavy snowfall in Imsil and Jangsu region. In case of the inland heavy snow type, the deviation of fresh snow cover between the inland and the west coast station is less than the west coast heavy snow type. The difference in the inland heavy snow type is an ut 6cm. The result shows that the snowfall in Jeollabuk-do is greatly affected by the geographical features.