Recent Progresses and Problems in the Study of the East Asian Summer Monsoon

Rong-Hui Huang,Sung-Euii Moon(문승의),Baek-Jo Kim(김백조),Chan-Soo Yoo(류찬수) 한국기상학회 1997 Asia-Pacific Journal of Atmospheric Sciences Vol.33 No.4

광주지방 부유분진의 농도변화

柳贊洙,金銀貞 조선대학교 기초과학연구소 1996 自然科學硏究 Vol.19 No.1

This study analyzes the diurnal, seasonal and annual variations of TSP in Kwangju and investigates the relation of TSP to air temperature and to RH. The data used in this study are observed from Meteorological Office and Environmental Bureau in Kwangju and the period of observation was from Jan. 1, 1991 to Dec. 31, 1993. The diurnal variation of TSP shows two vibration curves and the diurnal means are 67.9㎍/㎥. The time the diurnal maximum value is shown is 10:00 A.M. and that diurnal minimum value is shown is 06:00 A.M. The diurnal range is 55.9㎍/㎥. In this diurnal variation of TSP by season, the concentration is high in winter, spring, autumn and summer in order. The annual variation of TSP shows one vibration curve, the maximum value in April and the minimum one in August. The annual range is 43.6㎍/㎥. As a result of the regression analysis for examining the relations of TSP to air temperature and to RH, a regular polynomial regression expression is made on time series. TSP has a great significance in the diurnal variation with air temperature, but it has a little significance in the annual variation. TSP and RH have a significance in the diurnal and annual variation and show the inverse propertion with them.

대기와 해수의 온도변화 및 주기분석

류찬수 조선대학교 기초과학연구소 1990 自然科學硏究 Vol.13 No.1

This paper is to analyse the period and variation of the temperature of the atmosphere and sea water with respect to seven observation stations selected on the southern, eastern and western coasts of Korea. The results are as follows; Sea water temperature changed more slowly then atmosphere temperature, and it is smaller in relation to the amplitude(A). It shows that the correlationship was very strong because the correlation coefficient between atmosphere and sea water temperature appeared very close to (A). The regression equation of atmosphere and sea water temperature can be expressed as Ti=a_1+a_1cos Di+b_1sin Di. The time gap that shows the minimum temperature of atmosphere and sea water was much longer than that of their maximum temperatures, and it was the longest at the northern observation stations. The minimum temperature of sea water occurred earlier than that of atmosphere in Kunsan. The amplitude of sea water temperature on the eastern coast was much smaller than that on western and southern coasts. The maximum temperature of sea water in Wolmido was higher than that of atmosphere, and the minimum temperature of atmosphere in Kunsan was higher than that of sea water. To interprete the particular phenomena above the autocorrelationship according to the oceanity and the continentality was worked out so that the only correlation coefficient between oceanity and minimum temperature of sea water showed 0.93, and that between others was below 0.3. Therefore, it must be interpreted in relation to other factors.

都市地域의 濕度變化 特性 : 서울과 광주를 중심으로 in Seoul and Kwangju

柳贊洙,崔盟淑 조선대학교 기초과학연구소 1996 自然科學硏究 Vol.19 No.1

This paper is a study on the characteristics of RH variation in the urban area (in Seoul and Kwnagju). air temperature, RH and precipitation are meteorological elements observed from January 1, 1991 through December 31, 1991. The research contents of this study are distribution of variance, regression equation, annual variation, seasonal variation, diurnal variation and Dry Index. The results are as follows : Correlation coefficient of air temperature and RH is -0.91, and regression equation is RH=115-0.31T. Variation of RH has one annual cycle, which shows low RH period (spring and autumn) two times a year. It is shown that RH of urban area is lower on an annual average mean 2∼5.5% than that of surrounding area. Distribution of seasonal RH is in the order of winter>summer>spring>autumn. The order of seasonal RH difference between urban and surrounding area is autumn>spring>summer>winter. The paper shows that during one day RH at night is higher than that in daytime, and the order of RH difference between day and night is spring>autumn>summer (winter)>winter(summer). It is observed that during one day the highest RH occurs at sunrise time and the lowest, at 3 p.m. The distribution of Dry Index and RH are nearly similar.

光州地方의 日平均氣溫 算出에 관한 硏究

柳贊洙 조선대학교 기초과학연구소 1994 自然科學硏究 Vol.17 No.1

The purpose of this study is to examine the variation of daily mean air temperature observed in the Kwangju area and the validity of the computation me-thods currently in use. The data use in this study is hourly observed using a thermograph at the Kwangju observatory. The period of observation was from 1:00 A.M.January 1,1981 to 24:00 P.M December 31,1990. As for the methods used in the study, the characteristics of the diurnal variation were analyzed by Fourier series. The daily mean air temperature was compared with present method according to the observation methods of 2,3,4,6 and 8 times. The most approximate method was found when the difference was calcu-lated for both daily mean air temperature and standard deviation. The results obtained using this formula were then compared with daily mean air temper-atuere used at present. From the results of this study it was learned that the diurnal variation of air temperature lost same quality as in the case of calculating daily mean air temperature due to the distinct difference of the monthly phase angle and amplitude. The greater the number og observation, the less difference, in daily mean air temperature. The difference approximated much closer to the actual daily mean tem-perature than does the current method of when the air temperature was observed at 2:00 and 9:00 A.M, at 2:00 and 9:00 P.M. The daily mean air temperature of the present method was + 0.3 oC higher than the actual daily mean air temperature. The formula for correcting this deviation is as follows. Tm = 0.996 Tp + 0.555 (oC, r ≡ 1, annual mean temperature). If the variation of air temperature is irregular, there is no periodicity and continuity and the width of variation is large. In the case of four observation, the difference in actual daily mean air temperature is large because the ref-lection of daily mean air temperature is small, comparing irregularity of variations. Therefore it may be assumed that, with the least number of observations, we must determine daily mean air temperature by six observations or so in order to decrease the difference of actual daily mean air temperature. However, due to the fact that the observation time of the weather is determined by W.M.0. it is thought that, to achieve more standardization, methods of calcula- ting this must be revised by region and month and utilize method of determining daily mean air temperature which was used in this study rather than method currently in use.

호남 서해안지방과 영동지방의 강설 특성에 관한 비교 연구

柳贊洙,鄭炳玉 조선대학교 기초과학연구소 1996 自然科學硏究 Vol.19 No.1

This paper aims to describe the characteristics of snowfall between Youngdong region and west seaside district at Honam region in Korea. Snowfall datas for Gojin, Kangnung and Samchok where located in Youngdong region and Kwangju, Kunsan and Magilsan adjacent to Sosan where located in west seaside district at Honam region. For this study, it was investigated secular variation of snowy days and snowfall, the monthly occurrence frequency of snowy days and snowfall, and pressure pattern governing snowfall at two regions. Especially, for the cases study of heavy snowfall day, it was investigated mixing ratio field by using the upper air data, which composed of 33 stations and nephanalysis by using GMS picture data. The results were summarized as follows ; 1) Annual mean occurrence frequency of snowy days were about 32.1days in west seaside district at Honam region and 20.0days in Youngdong region, respectively. The order of monthly occurrence frequency of snowy days and snowfall were Jan., Dec., Feb. and Mar. in west seaside district at Honam region, and Feb., Mar., Jan. Dec., in Youngdong region, respectively. The secular variation(1980-1990) of snowy days and snowfall showed increasing trend. 2) The pressure patterns governing snowfall in Honam region were classified broadly into three types ; 1. cP dominant type, 2. Through or Low dominant type 3. Cut-off High type. The pressure pattern which had the most occurrence frequency of snowy days and snowfall was cP dominant type. And the pressure patterns governing snowfall in Youngdong region were classified broadly into two types ; 1. cP dominant type, 2. NE air flow type. The pressure pattern which had the most occurrence frequency of snowy days was NE air flow type, which the most snowfall was cP dominat type. 3) On the heavy snowfall day, the moisture layer existed below 850hPa in west seaside district at Honam region and below 700hPa in Youngdong region, respectively. 4) In the mixing ratio field on the heavy snowfall day, the moisture tongue existed at both SFC and 850hPa level in case of heavy snowy day of Youngdong region and the meridional gradient of mixing ratio at SFC at South region in west seaside district at Honam region.

朝鮮大學校 天文臺 設置를 위한 基礎資料 調査와 YZ Cassiopeiae의 光電觀測

金永成,柳贊洙 조선대학교 기초과학연구소 1988 自然科學硏究 Vol.11 No.1

This paper indicate the best sites for setting up an Chosun univesity observatory by studing topography, geology, and the climatological elements. In the survey of the topography. Traffic condition, photographical condition, elevation surveys are examined. In the survey of the geology. Bed rocks and its developments are examined. In the survey of the climatology. Observational records of the climatological standard stations and auxiliary stations in the studied areas are examined. Is survey elements are mean air temperature, precipitation, maximum wind speed, humidity, duration of sunshine, foggy days, cloudy days clear days, etc. In the results. Songhak mountain Kwangsan-gu, Kwangju is more suitable. The eclipsing nature of YZ Cassiopeiae(HD 4161, mag. 5.59, Sp.A2, α= OO^h 39^m, δ=+74˚ 26' 1900) was discovered by Stebbins(1924). A total of 1628 Photoelectric observation(814-yellow 814-blue) is made from 1983 to 1987, at Yonsei university observatory. Almost complete light curve which coincide to previous authors are grain. Astrophysical computing data of YZ Cas are coincide with another paper.

Acid rain in Kwangju , Korea(Precipitation intensity and persistent time)

Yoo, Chan Soo 한국환경과학회 1996 한국환경과학회지 Vol.5 No.5

The analyzed results of observed precipitation and its pH in Kwangju for 262 days from Jan. 1, 1991 to Dec. 31, 1995 are as follows. The annual mean pH was 5.7, and the monthly mean pH values of January-May and November were less than 5.6 in Kwangju. The ratio of acid rain for these periods was about 48.1 %, almost half that of the total observed days. In March, the pH was 5.4 and the ratio of acid precipitation was 69%, an especially serious situation. In the spring, the pH value was 5.5 thus weak acidic. The pH of precipitation tended to decrease with greater precipitation. The relation between persistent time and pH of precipitation is variable, but if the persistent time is long, the pH is constant and low. It is fortunate that there is an increasing trend of pH in interannual variation, but it is thought important that the amplitude of variation of pH in 1995 was high and the pH value was 4.1 in October and November. Because heavy and persistent precipitation effects the accumulation of acidity, more concern about acid rain is needed.