The characteristics of the basic statistics and steadiness of wind and the monthly normality test of surface wind distribution are investigated by using the observed wind data compiled from 10m meteorological observation tower at Seocheon district, where is located in the western coastal region of Korea, during the period from Feb. 7, 1996 to Feb. 7 1997. The northerly is appeared to be even in August and Sepember due to the influences of local circulation such as land and sea breeze. The correlation coefficients(γuv) between two wind components are seemed to be positive during the in the period of from June to September and negative from October to April, respectively. The constancy of wind is high in winter and low in summer. It is evident that the modal values of S decrease and their maximum values shifts to lower values with increasing sampling time. It is found from monthly normality test based on the skewness and the excess of kurtosis coefficients that the distribution of zonal wind component is normal in spring and meridional one is normal in late summer and early autumn.

The intensive meteorological observations including pibal balloon at Ungcheon, airsonde and 10m meteorological tower observations at Gulup-Do, where are located in the western coastal region, are taken to investigate the characteristics of the upper and lower atmospheric structure and the local circulation pattern during the period of 17 to 22 September 1996. The diurnal variations of weather elements(i.e, air temperature, humidity, pressure, and wind speed) at Gulup-Do are analyzed and discussed with those at four inland meteorological stations. The vertical profiles of wind vector, orthogonality(Ω), and shear obtained from the pibal observations are also presented to examine the change of wind structure according to the synoptic-scale pressure system`s movement. The diurnal temperature changes at Gulup-Do are more sensitive than that of inland meteorological stations in case of the inflow of southwesterlies but are not dominant due to the ocean effect under the influence of relatively cold northerlies. A well defined mixed layer is developed from the 500m to the maximum 1700m with a significant capping inversion layer on the top of it. It can be found from the vertical profiles of wind vector that the wind become generally strong at the interface heights between cloud layers and non-cloud layers. The maximum wind shear is appeared at the height where the variation of wind direction induced by the passage of synoptic-scale pressure system is accompanied with the increase of wind speed. Based on the wind orthogonality, the change of wind direction with height is more complicated in cloudy day than in clear day. In case of a fair weather, the change of wind direction is showed to be at around 2㎞

One-dimensional thermodynamic mixed layer model to simulate variations of meteorological variables within the planetary boundary layer has been developed in this study. This model consists of 2 prognostic equations, which can predict the variations of potential temperature and mixing ratio and several diagnostic equations. Physics within the surface and mixed layers has been considered seperately in the model. For the variations of the model, its result has been analysed and compared with observated data over the Dukyang Bay for one day, July 23, 1992. The simulated height of mixed layer is comparable to the observation and the variations of temperature and mixing ratio in the mixed layer are also reasonably simulated. Those imply that the model responds appropriately with given boundary conditions in spite of its simplified assumptions applied to the model and insufficient boundary and initial conditions.

The characteristics on the transtion probabilities and periodicity for the daily precipitation occurrence in Korean peninsula are investigated by applying the Markov chain properties to daily precipitation occurrence. In order to examine the responses of Markov Chain properties to the applied period and their magnitudes, three cases (Case A: 1956∼1985 at 14 stations, Case B: 1965∼1994 at 14 stations, and Case C: 1985∼1994 at 63 stations) are considered in this study. The transition probabilities from wet day to wet day for all cases are about 0.50 and in summer, especially July, are higher. In addition, considering them in each station we can find that they are the highest at Ullung-do and lowest at Inchon for all cases. The annual equilibrium probabilities of a wet day appear 0.31 in Case A, 0.30 Case B, and 0.29 Case C, respectively. This may explain that as the data-period used becomes shorter, the higher the equilibrium probability is. The seasonal distributions of equilibrium probabilities are appeared the lowest(0.23∼0.28) in winter and the highest(more than 0.39) in spring and monthly in July and in October, repectively. The annual mean wet duration for all cases is 2.04 days in Case A, 1.99 Case B, and 1.89 Case C, repectively. The weather cycle obtained from the annual mean wet and dry duration is 6.54∼6.59 days, which are closely associated with the movement of synoptic systems. And the statistical tests show that the transitions of daily precipitation occurrence for all cases may have two-state first Markov chain property, being the stationarity in time and heterogeneity in space.