전남서해안지방 기온특성

Abstract

Nowadays torrential rains, reduced rainfall days, increased amount of precipitation are thought by quite common atmospheric phenomena which are related to the green house effects. The amount of water vapor in atmosphere is subject to temperature. That is, temperature change is an important contributing factor to the change of amount of precipitation. The temperature is most sensitive meteorological element which is affected by topography, the condition of sky, direction of wind, speed of wind and humidity and the affect is comprehensive, not selective, which means if a precise condition of sky or a precise precipitation can not be forecasted, a precise temperature can not be forecasted either. The temperature difference between two consecutive days was checked from 2001 to 2005, and grouped by 4℃ difference and 6℃ difference. There were 417 cases in 4℃ difference group and among 295 days of the highest temperature difference, the period from January to April have more than 30 days a month. Among 122 days of the lowest temperature, January and November had 20 days a month. The feature of the highest temperature is that temperature fluctuation is sharpest in the winter and spring when the change of barometer is big because of the expansion of cP and a regular influence of migratory anticyclone, and July, which has the highest number of rainfall days, has the lowest number 9. The reason why the temperature fluctuates the most between January and April is the winter weather pattern of three cold days and four warm days, and a great shaking of temperature field due to frequent passing through troughs of spring air mass from the influence of Siberia air mass. As for the lowest temperature, the period from June to September has less than five days a month and there was not a single case which had a temperature difference of over 4℃ in June and so the temperature difference from June to September was not remarkable. The number of days which had two types of difference a day was 39 and the number of days when the highest temperature and lowest temperature both went up was 10, and the number of days when the highest temperature went down and the lowest temperature went up was 6, and the number of days when the highest temperature and the lowest temperature both went down was 23. The months without two types of difference was June, July, September. August had 2 days with two types of change which made 5% in summer, and 33 days between November and April which made 85%. The days when the highest temperature and the lowest temperature went down and the days without two types of change between November and April were due to the cold advection influenced by Siberia anti-cyclone. In November 8 days were checked, the highest number of days a month, which was due to a strong Siberia anti-cyclone. As for the difference of the condition of sky between two consecutive days, there were 14 cases of two clear days, 23 cases of clear first day and the second day in the same order, 26 cases of cloudy first day and second day in the same order, and 35 cases of rainy first day rainy and second day which showed the influence of rain to temperature change. In 98 cases, the temperature difference between the first day and the second day was over 6℃. Among 67 days when the highest temperature difference was 6℃, there were over eight days a month between January and April and in November. The reason was similar to the case of 4℃ difference and apart from July, there were twice a year but less than five days between May and September. Among 31 days when the lowest temperature difference is higher than 6℃, only January, March and November had more than five days a month. There was none between June and October which indicated the lowest temperature change was not remarkable in that period. The cases in the 4℃ difference group were classified as (+) deviation and (-) deviation by the order of atmospheric phenomena, and as migratory anti-cyclone, continental anticyclone, stationary front, typhoon by the pattern of barometer. Under the influence of a migratory anticyclone, (-) deviations were 3, (+) deviations were 19 which seemed to have some relation to seasonal change from winter to spring. Under the influence of continental anticyclone, there were 14 (-) deviations and 14 (+) deviations. In spite of the influence a continental anticyclone, there was (+) deviation of over 4℃ which makes the weather forecast in the western Cheonnam difficult. When a cold front moves over the northern part of Korea, (-) deviations are eight and (+) deviations are 12. The temperature goes up if the cold front doesn't exert its influence down to the western Cheonnam. A stationary front usually forms over southern part of Korea, and the temperature goes down due to the drop of temperature from rain and contraction of mT, and the temperature goes up due to expansion of mT and a change mP. With typhoon type, (-) deviations and (+) deviations are 3 respectively.