• 통합자연과학논문집
• /
• 제6권1호
• /
• pp.12-15
• /
• 2013

To combine the micro rain radar and microwave radiometer cloud liquid water, we estimate the cloud physical thickness from the difference between the MTSAT-1R cloud top height and cloud base height of visual observation of Daegwallyeong weather station, and the cloud liquid water path of micro rain radar is obtained by multiplying the liquid water content of micro rain radar and the estimated cloud physical thickness. The trend of microwave radiometer liquid water path agrees with that of the micro rain radar during small precipitation. We study these characteristics of micro rain radar and microwave radiometer for small precipitation to obtain the combined cloud water content of micro rain radar and microwave radiometer, constantly operated regardless to the rainfall.

• 한국환경과학회지
• /
• 제27권11호
• /
• pp.983-989
• /
• 2018

The real-time monitoring of surface vegetation is essential for the management of droughts, vegetation growth, and water resources. The availability of land cover maps based on remotely collected data makes the monitoring of surface vegetation easier. The vegetation index in an area is likely to be proportional to meteorological elements there such as air temperature and precipitation. This study investigated relationship between vegetation index based on Moderate Resolution Image Spectroradiometer (MODIS) and ground-measured meteorological elements at the Yongdam catchment station. To do this, 16-day averaged data were used. It was found that the vegetation index is well correlated to air temperature but poorly correlated to precipitation. The study provides some intuition and guidelines for the study of the droughts and ecologies in the future.

• Journal of Positioning, Navigation, and Timing
• /
• 제10권4호
• /
• pp.271-278
• /
• 2021

In this paper, a tropospheric delay error was calculated by using meteorological data collect from weather station and Saastamoinen model, and an empirical variogram of the tropospheric delay in the Korean peninsula was estimated. In order to estimate the empirical variogram of the tropospheric delay according to weather condition, sunny day, rainy day, and typhoon day were selected as analysis days. Analysis results show that a maximum correlation range of the empirical variogram on sunny day was about 560 km because there is overall trend of the tropospheric delay. On the other hand, the maximum correlation range of the empirical variogram on rainy was about 150 km because the regional variation was large. Although there is regional variation when the typhoon exists, there is a trend of the tropospheric delay due to a movement of the typhoon. Therefore, the maximum correlation range of the empirical variogram on typhoon day was about 280 km which is between sunny and rainy day.

• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
• /
• pp.305-308
• /
• 2005

The COMS, Korea's first geostationary multipurpose satellite program will accommodate 3 kind of payloads; Ka-Band communication transponder, GOCI (Geostationary Ocean Color Imager), and MI (Meteorological Imager). MI raw data will be transferred to ground station via L-band link. The ground station will perform image data processing for raw data, generate them into the LRIT/HRIT format, the user dissemination data recommended by the CGMS. The LRIT/HRIT are disseminated via satellite to user stations. This paper shows the COMS LRIT data generation procedure based on COMS LRIT specification and its verification results using the LRIT user station.

• 대한원격탐사학회지
• /
• 제36권6_3호
• /
• pp.1643-1652
• /
• 2020

본 연구에서는 국지예보시스템(LDAPS)과 전산유체역학(CFD) 모델을 접합하여, 부산 중구 광복동에 소재한 건물 밀집 지역의 상세 흐름을 조사하였다. 도시 지역 기상에 대한 보다 현실적인 수치 모의를 위해 기상청이 현업으로 운용하는 LDAPS 결과로부터 기상 요소(풍향, 풍속, 온위)를 추출하여 CFD 모델의 초기·경계장으로 사용하였다. LDAPS로부터 추출한 기상 요소(U, V)는 공간 선형 보간법을 이용하여 CFD 모델의 수평·연직 격자에 맞게 내삽하였고, 공간 선형 보간법을 이용해 내삽한 온위는 CFD 모델의 각 격자점에서 온도로 변환된다. 본 연구에서는 건물 옥상에서 측정한 3차원 초음파 풍향·풍속계에서 측정한 풍속과 풍향을 이용하여 수치 모의 결과를 검증하였다. 대상 기간(2020년 6월 22일) 동안 측정 지점(PKNU-SONIC)에서는 바람이 약하게 나타났고, 새벽 시간에는 북동풍과 북서풍이 불었으며, 주간에는 주로 남동풍이 불었다. LDAPS-CFD 접합 모델은 측정 풍향과 풍속을 유사하게 수치 모의하였다. 07시에는 동북동쪽에서 유입되는 흐름이 지형과 건물에 의해 변화하였고, PKNU-SONIC 지점에서 수치 모의된 풍향(동남동풍)은 측정 풍향과 유사하다. 19시에는 남동쪽에서 유입되는 흐름이 PKNU-SONIC 지점까지 유입되어 측정 풍향과 유사하게 모의하였다.

• 한국대기환경학회지
• /
• 제23권3호
• /
• pp.322-331
• /
• 2007

In this study, we have analyzed $PM_{10}$ concentration measured at Incheon Regional Air Monitoring Network (10 stations) and meteorological data at Incheon Weather Station to investigate factors (i.e. wind direction, wind speed, relative humidity, major meteorological phenomenon, and sea-land breezes existence) influencing $PM_{10}$ concentration in Incheon during 2005. Statistical differences among meteorological factors were assessed by Kruskal-Wallis test or Mann-Whitney U test. The main conditions causing high $PM_{10}$ concentration are summarized below; 1. When westerly wind prevailed (however, $PM_{10}$ decreased when winds were blowing from the east or north). 2. When the winds were calm, owing to accumulation of nearby emissions under stagnant conditions, or when the wind speed is in excess of 6 m/s, which shows the effect of fugitive dust produced by wind erosion. 3. Under the condition of high relative humidity and poor diffusion based on meteorological phenomenon such as fog, mist, and haze. 4. When the Sea-Land breezes existed, which occurred 70 days in Incheon during 2005 and contributed significantly to high $PM_{10}$ concentration in the coastal urban area. In conclusion, we have found that the meteorological factors have influence on $PM_{10}$ concentration in Incheon.

• 대기
• /
• 제29권4호
• /
• pp.343-353
• /
• 2019

The seasonal climatology of atmospheric rivers (ARs) and their effects on the seasonal precipitation and temperature in Korea are examined using the AR chronology obtained by a methodology based on the vertically integrated water vapor transport (IVT) in conjunction with a fine-scale gridded analysis of station precipitation and temperature. ARs are found to affect Korea most heavily in the warm season with minimal impacts in winter. This contrasts the AR effects in the western North America and the Western Europe that are affected most in winters. Significant portions of precipitation in Korea are associated with AR landfalls for all seasons; over 35% (25%) of the summer (winter) rainfall in the southern part of the Korean peninsula. The percentage of AR precipitation over Korea decreases rapidly towards the north. AR landfalls are also associated with heavier-than-normal precipitation events for all seasons. AR landfalls are associated with above-normal temperatures in Korea; the warm anomalies increase towards the north. The warm anomalies during AR landfalls are primarily related to the reduction in cold episodes as the AR landfalls in Korea are accompanied by anomalous southerlies/southwesterlies.

• 대기
• /
• 제24권2호
• /
• pp.159-171
• /
• 2014

This study investigated the temporal and spatial characteristics of summertime (June-August) precipitation over Korean peninsula, using Korea Meteorological Administration (KMA)is Automated Synoptic Observing System (ASOS) data for the period of 1973-2010 and Automatic Weather System (AWS) data for the period of 1998-2010.The authors looked through climatological features of the summertime precipitation, then examined the degree of locality of the precipitation, and probable precipitation amount and its return period of 100 years (i.e., an extreme precipitation event). The amount of monthly total precipitation showed increasing trends for all the summer months during the investigated 38-year period. In particular, the increasing trends were more significant for the months of July and August. The increasing trend of July was seen to be more attributable to the increase of precipitation intensity than that of frequency, while the increasing trend of August was seen to be played more importantly by the increase of the precipitation frequency. The e-folding distance, which is calculated using the correlation of the precipitation at the reference station with those at all other stations, revealed that it is August that has the highest locality of hourly precipitation, indicating higher potential of localized heavy rainfall in August compared to other summer months. More localized precipitation was observed over the western parts of the Korean peninsula where terrain is relatively smooth. Using the 38-years long series of maximum daily and hourly precipitation as input for FARD2006 (Frequency Analysis of Rainfall Data Program 2006), it was revealed that precipitation events with either 360 mm $day^{-1}$ or 80 mm $h^{-1}$ can occur with the return period of 100 years over the Korean Peninsula.

• 대기
• /
• 제32권3호
• /
• pp.179-189
• /
• 2022

The purpose of this study is to build and evaluate a high-resolution (50 m) KMAPP (Korea Meteorological Administration Post Processing) reflecting building data. KMAPP uses LDAPS (Local Data Assimilation and Prediction System) data to detail ground wind speed through surface roughness and elevation corrections. During the detailing process, we improved the vegetation roughness data to reflect the impact of city buildings. AWS (Automatic Weather Station) data from a total of 48 locations in the metropolitan area including Seoul in 2019 were used as the observation data used for verification. Sensitivity analysis was conducted by dividing the experiment according to the method of improving the vegetation roughness length. KMAPP has been shown to improve the tendency of LDAPS to over simulate surface wind speeds. Compared to LDAPS, Root Mean Square Error (RMSE) is improved by approximately 23% and Mean Bias Error (MBE) by about 47%. However, there is an error in the roughness length around the Han River or the coastline. Accordingly, the surface roughness length was improved in KMAPP and the building information was reflected. In the sensitivity experiment of improved KMAPP, RMSE was further improved to 6% and MBE to 3%. This study shows that high-resolution KMAPP reflecting building information can improve wind speed accuracy in urban areas.

• 한국관개배수논문집
• /
• 제19권1호
• /
• pp.87-96
• /
• 2012

Information of local solar radiation is essential for many field, including water resources management, crop yield estimation, crop growth model, solar energy systems and irrigation and drainage design. Unfortunately, solar radiation measurements are not easily available due to the cost and maintenance and calibration requirements of the measuring equipment and station. Therefore, it is important to elaborate methods to estimate the solar radiation based on readily available meteorological data. In this study, two empirical equations are employed to estimate daily solar radiation using Cheongju Regional Meteorological Office data. Two scenarios are considered: (a) sunshine duration data are available for a given location, or (b) only daily cloudiness index records exist. Simple linear regression with daily sunshine duration and cloudiness index as the dependent variable accounted for 91% and 80%, respectively of the variation of solar radiation(H) at 2011. Daily global solar radiation is highly correlated with sunshine duration. In order to indicate the performance of the models, the statistical test methods of the mean bias error(MBE), root mean square error(RMSE) and correlation coefficient(r) are used. Sunshine duration and cloudiness index can be easily and reliably measured and data are widely available.