• 한국환경과학회지
• /
• 제15권10호
• /
• pp.919-928
• /
• 2006

The present study applied an atmospheric flow field model in Gwangyang-Bay which can predict local sea/land breezes formed in a complex terrain lot the development of a model that can predict short term concentration of air pollution. Estimated values from the conduct of the atmospheric flow field were used to evaluate and compare with observation data of the meteorological stations in Yeosu and the Yeosu airport, and the effect of micrometeorology of surround region by the coastal area reclamation was predicted by using the estimated values, Simulation results, a nighttime is appeared plainly land breezes of the Gwangyang-bay direction according to a mountain wind that formed in the Mt. of Baekwooun, Mt. of Youngchui. Land winds is formed clockwise circulation in the north, clockwise reverse direction in the south with Gangyang-bay as the center. Compared with model and observation value, Temperature is tend to appeared some highly simulation value in the night, observation value in the daytime in two sites all, but it is veil accorded generally, the pattern of one period can know very the similarity. And also, wind speed and wind direction is some appeared the error of observation value and calculation results in crossing time of the land wind and sea land, it can see that reproducibility is generally good, is very appeared the change land wind in the nighttime, the change of sea wind in the daytime. And also, according to change of the utilization coefficient of soil before and after development with Gwangyang-Bay area as the center. Temperature after development was high $0.55\sim0.67^{\circ}C$ in the 14 hoots, also was tend to appear lowly $0.10\sim0.22^{\circ}C$ in the 02 hours, the change of u, v component is comparatively tend to reduced sea wind and land wind, it is affected ascending air current and frictional power of the earth surface according to inequality heating of the generation of earth surface.

• Ocean and Polar Research
• /
• 제25권4호
• /
• pp.503-518
• /
• 2003

This study examines the relationship among temperature, wind, and sea level pressure to understand recent warming in the vicinity of the Antarctic Peninsula. To do this, the surface air temperature, NCEP/NCAR reanalysis wind data and sea level pressure data for the period of 40 years are analyzed. The 40-year surface air temperature data in the Antarctic Peninsula reveals relatively the larger warming trends for autumn and winter than other seasons. The variability of the surface air temperature in this region is compared with that of the regional atmospheric circulation. The surface air temperature is positively correlated with frequency of northwesterlies and negatively correlated with frequency of southeasterlies. This relation is more evident in the northern tip of the Antarctic Peninsula for autumn and winter. The trend analysis of wind frequency in the study area shows increasing and decreasing trends in the frequency of northwesterlies and southeasterlies, respectively, in the northwestern part of the Weddell Sea for autumn and winter. And also it is found that these winds are closely related with decreasing of sea level pressure in the southeastern region of the Antarctic Peninsula. Furthermore from the seasonal variation of sea level pressure in this area, it may be presumed that decreasing of sea level pressure in the southeastern region of the Antarctic Peninsula is related with warming in the vicinity of the Antarctic Peninsula for autumn and winter. Therefore it can be explained that recent warming in the vicinity of the Antarctic Peninsula is caused by positive feedback mechanism, that is, the process that warming in the vicinity of the Antarctic Peninsula can lead to the decrease of sea level pressure in the southeastern region of the Antarctic Peninsula and these pressure decrease in turn lead to the variation of wind direction in northwestern part of Weddell Sea, again the variation of wind direction enhances the warming in the Antarctic Peninsula.

• 한국지구과학회지
• /
• 제41권4호
• /
• pp.356-366
• /
• 2020

The accuracy of satellite-observed sea surface salinity (SSS) was evaluated in comparison with in-situ salinity measurements from ARGO floats and buoys in the seas around the Korean Peninsula, the northwest Pacific, and the global ocean. Differences in satellite SSS and in-situ measurements (SSS errors) indicated characteristic dependences on geolocation, sea surface temperature (SST), and other oceanic and atmospheric conditions. Overall, the root-mean-square (rms) errors of non-averaged SMOS SSSs ranged from approximately 0.8-1.08 psu for each in-situ salinity dataset consisting of ARGO measurements and non-ARGO data from CTD and buoy measurements in both local seas and the ocean. All SMOS SSSs exhibited characteristic negative bias errors at a range of -0.50- -0.10 psu in the global ocean and the northwest Pacific, respectively. Both rms and bias errors increased to 1.07 psu and -0.17 psu, respectively, in the East Sea. An analysis of the SSS errors indicated dependence on the latitude, SST, and wind speed. The differences of SMOS-derived SSSs from in-situ salinity data tended to be amplified at high latitudes (40-60°N) and high sea water salinity. Wind speeds contributed to the underestimation of SMOS salinity with negative bias compared with in-situ salinity measurements. Continuous and extensive validation of satellite-observed salinity in the local seas around Korea should be further investigated for proper use.

• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 2008년도 International Symposium on Remote Sensing
• /
• pp.340-343
• /
• 2008

The Soya Warm Current (SWC) is a coastal boundary current, which flows along the coast of Hokkaido in the Sea of Okhotsk. Seasonal and subinertial variations in the SWC are investigated using data obtained by high-frequency (HF) ocean radars, coastal tide gauges, and a bottom-mounted acoustic Doppler current profiler (ADCP). The HF radars clearly capture the seasonal variations in the surface current fields of the SWC. The velocity of the SWC reaches its maximum, approximately 1 m/s, in the summer, and becomes weaker in the winter. The velocity core is located 20 to 30 km from the coast, and its width is approximately 50 km. The almost same seasonal cycle was repeated in the period from August 2003 to March 2007. In addition to the annual variation, the SWC exhibits subinertial variations with a period from 10-15 days. The surface transport by the SWC shows a significant correlation with the sea level difference between the Sea of Japan and Sea of Okhotsk for both of the seasonal and subinertial variations, indicating that the SWC is driven by the sea level difference between the two seas. Generation mechanism of the subinertial variation is discussed using wind data from the European Centre for Medium-range Weather Forecasts (ECMWF) analyses. The subinertial variations in the SWC are significantly correlated with the meridional wind component over the region. The subinertial variations in the sea level difference and surface current delay from the meridional wind variations for one or two days. Continental shelf waves triggered by the meridional wind on the east coast of Sakhalin and west coast of Hokkaido are considered to be a possible generation mechanism for the subinertial variations in the SWC.

• 대기
• /
• 제29권2호
• /
• pp.115-129
• /
• 2019

Surface winds over the ocean influence not only the climate change through air-sea interactions but the coastal erosion through the changes in wave height and direction. Thus, demands on a reliable projection of future changes in surface winds have been increasing in various fields. For the future projections, climate models have been widely used and, as a priori, their simulations of surface wind are required to be evaluated. In this study, we evaluate the climatological mean surface winds over the Korean Waters simulated by five regional climate models participating in Coordinated Regional Climate Downscaling Experiment (CORDEX) for East Asia (EA), an international regional climate model inter-comparison project. Compared with the ERA-interim reanalysis data, the CORDEX-EA models, except for HadGEM3-RA, produce stronger wind both in summer and winter. The HadGEM3-RA underestimates the wind speed and inadequately simulate the spatial distribution especially in summer. This summer wind error appears to be coincident with mean sea-level pressure in the North Pacific. For wind direction, all of the CORDEX-EA models simulate the well-known seasonal reversal of surface wind similar to the ERA-interim. Our results suggest that especially in summer, large-scale atmospheric circulation, downscaled by regional models with spectral nudging, significantly affect the regional surface wind on its pattern and strength.

• 한국지구과학회지
• /
• 제40권5호
• /
• pp.447-463
• /
• 2019

해상풍은 해양 현상을 이해하고, 지구 온난화에 의한 지구 환경의 변화를 분석하기 위한 필수 요소이다. 전세계 연구 기관은 해상풍을 정확하고 지속적으로 관측하기 위해 산란계(scatterometer)를 개발하여 운영해오고 있으며, 정확도는 풍향이 ${\pm}20^{\circ}$, 풍속이 ${\pm}2m\;s^{-1}$ 안팎이다. 하지만, 산란계의 해상도는 12.5-25.0 km로, 해안선이 복잡하고 섬이 많은 한반도 근해에서는 자료의 결측이 빈번하게 발생하여 활용도가 감소한다. 그에 반해, Synthetic Aperture Radar (SAR, 합성개구레이더)는 마이크로파를 활용하는 전천후 센서로, 1 km 이하의 고해상도 해상풍이 산출이 가능하여 산란계의 단점 보완이 가능하다. 본 연구에서는 일반적으로 활용되는 SAR 자료 기반 해상풍 산출 알고리즘인 Geophysical Model Function (GMF, 지구 물리 모델 함수)를 밴드별로 분류하여 조사하였다. 상대 풍향, 입사각, 풍속에 따른 후방산란계수를 L-band Model (LMOD, L 밴드 모델), C-band Model (CMOD, C 밴드 모델), X-band Model (XMOD, X 밴드 모델)에 적용하여 모의하였고, 각 GMF의 특성을 분석하였다. 이러한 GMF를 SAR 탑재 인공위성 자료에 적용하여 산출한 해상풍의 정확도 검증 연구에 대해 조사하였다. SAR 자료 기반 해상풍의 정확도는 영상 관측 모드, 적용한 GMF의 종류, 정확도 비교 기준 자료, SAR 자료 전처리 방법, 상대 풍향 정보 산출 방법 등에 따라 변하는 것으로 나타났다. 본 연구를 통해 국내 연구자들의 SAR 자료 기반 해상풍 산출 방법에 대한 접근성이 향상되고, 고해상도 해상풍 자료를 활용한 한반도 근해 분석에 이바지할 것으로 기대된다.

• 한국해안해양공학회:학술대회논문집
• /
• 한국해안해양공학회 1995년도 정기학술강연회 발표논문 초록집
• /
• pp.20-25
• /
• 1995

Surface wind field over an ocean plays a very important role not only to generate wind-driven current, but also to control heat exchange between ocean and atmosphere. However, the surface wind-field used for the ocean circulation and heat exchange is usually estimated by indirect methods because of lack of observed wind data and incomplete spatial coverage. (omitted)

• Journal of the korean society of oceanography
• /
• 제38권2호
• /
• pp.60-67
• /
• 2003

Typhoon Rusa passed over the East China Sea and crossed over the Korea Peninsula on August 31, 2002. The core of the typhoon passed directly over a data buoy mooring site at ($127^{\circ}45'E,\;34^{\circ}25'\;N$) and several ARGOS-tracked drifters capable of measuring salinity. Peak hourly mean wind speed reached 28 m/s at the mooring site and wind pattern in the East China Sea changed from southerly wind to northwesterly wind after the typhoon passage. Two or three days before the typhoon tile drifter displacement changed significantly and the region-wide circulation pattern changed from a northeastward current to a westward current one week after the typhoon had passed. The surface water in the East China Sea was cooled to about $4^{\circ}C$ under the typhoon core and a general cooling occurred in most of the East China Sea with the exception of the Chinese coast. The salinity as observed by the drifters in the East China Sea increased about 2 psu but the near-shore water along the Korean coast observed by the mooring was freshened about 3 psu. The freshening of near-shore water was caused by an intrusion of off-shore water rather than local freshening by typhoon precipitation.

• Ocean and Polar Research
• /
• 제31권1호
• /
• pp.11-29
• /
• 2009

Variability of sea surface temperature (SST) in the Japan/East Sea (JES) was studied using complex empirical orthogonal function (CEOF) analysis. Two daily data sets were analyzed: (1) New Generation 0.05o-gridded SST from Tohoku University, Japan (July 2002-July 2006), and (2) 0.25o-gridded SST from the Japan Meteorological Agency (October 1993-November 2006). Linkages with wind stress curl were revealed using 6-h 1o-gridded surface zonal and meridional winds from ancillary data of the Sea- WiFS Project, a special National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) product (1998-2005). SST anomalies (SSTA) were obtained by removing the seasonal signal, estimated as the leading mode of the CEOF decomposition of the original SST. Leading CEOF modes of residual SSTA obtained from both data sets were consistent with each other and were characterized by annual, semiannual, and quasi-biennial time scales estimated with 95% statistical significance. The Semiannual Mode lagged 2 months behind the increased occurrence of the anticyclonic (AC) wind stress curl over the JES. Links to dynamic processes were investigated by numerical simulations using an oceanic model. The suggested dynamic forcings of SSTA are the inflow of subtropical water into the JES through the Korea Strait, divergence in the surface layer induced by Ekman suction, meridional shifts of the Subarctic Front in the western JES, AC eddy formation, and wind-driven strengthening/weakening of large-scale currents. Events of west-east SSTA movement were identified in July-September. The SSTA moved from the northeastern JES towards the continental coast along the path of the westward branch of the Tsushima Current at a speed consistent with the advective scale.

• 한국환경과학회지
• /
• 제24권12호
• /
• pp.1657-1671
• /
• 2015

In this study, the wind direction and the wind speed of the nearest temperature observations point of the National Weather Service was analyzed in order to investigate the rapid rise and drop of water temperature in the East Coast appeared after passing of the 2015 typhoon No. 9 and 11. Then the figures were simulated and analyzed using the WRF(weather research and forecast) model to investigate in more detailed path of the typhoon as well as the changes in the wind field. The results were as follows. A sudden drop of water temperature was confirmed due to upwelling on the East coast when ninth typhoon Chanhom is transformed from tropical cyclones into extra tropical cyclone, then kept moving eastwards from Pyongyang forming a strong southerly wind after 13th and this phenomenon lasted for two days. The high SST(sea surface temperature) is confirmed due to a strong northerly wind by 11th typhoon Nangka. This strong wind directly affected the east coast for three days causing the Ekman effect which transported high offshore surface waters to the coast. The downwelling occurred causing an accumulation of high temperature surface water. As a results, the SST of 15m and 25m rose to that of 5m.