• Journal of Environmental Science International
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• v.23 no.11
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• pp.1889-1907
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• 2014

The characteristics of meteorological conditions related to changes in atmospheric environment on Jeju Island were investigated during recent years (2010-2012). This analysis was performed using the hourly observed data of meteorological variables (air temperature, wind speed and direction) and air pollutants ($O_3$, $PM_{10}$, $SO_2$, $NO_2$, and CO). Out of 5 pollutants, $O_3$ and $PM_{10}$ concentrations have frequently exceeded national environmental standards in the study area during the study period, with relatively higher concentrations than the others. The concentrations of $O_3$ and $PM_{10}$ in 2010 and 2011 were somewhat higher than those in 2012, and their highest concentrations were mostly observed in spring followed by fall. Nighttime $O_3$ concentrations (with relatively high concentration levels) were almost similar to its daytime concentrations, due to less $O_3$ titration by very low NO concentrations in the target area and in part to $O_3$ increase resulting from atmospheric transport processes. The transport effect related to the concentration variations of $O_3$ and $PM_{10}$ was also clarified in correlation between these pollutants and meteorological variables, e.g. the high exceedance frequency of concentration criteria with strong wind speed and the high concentrations with the westerly/northwesterly winds (e.g., transport from the polluted regions of China). The overall results of this study suggest that the changes in atmospheric environment in the study area were likely to be caused by the transport effect (horizontal and vertical) due to the meteorological conditions rather than the contribution of local emission sources.

• Journal of the Korean earth science society
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• v.24 no.6
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• pp.533-548
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• 2003

The prevailing wind phenomenon around Pohang in winter was investigated by using surface and vertical observatory datas and a numerical simulation was carried out to analyse this phenomenon using RAMS. Direction of the prevailing wind was westerly at upper atmosphere. However, near the surface, southwestern wind prevailed in winter. Using the RAMS to simulate a winter wind system numerically, it was found out that this phenomenon was strongly affected by the geographical features such as directions of coastline and low level valley, and distributions of land and sea. To investigate the accuracy of the model results, wind speed, temperature and wind direction of typical continuous southwestern wind occurring days were compared with observation data. Analyzing the characteristics of local circulation system was very hard because of horizontally sparse observation data. But from the result above, a numerical simulation using the RAMS, which satisfies the spatial high resolution, will provide more accurate results.

• Korean Journal of Remote Sensing
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• v.32 no.2
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• pp.185-194
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• 2016

The effect of artificial changes in geographical features on local wind was analyzed at the construction site of bridge and fill-up bank in the southern part of Haui-do. Geographic Information System (GIS) data and Computational Fluid Dynamics (CFD) model were used in this study. Three-dimensional numerical topography based on the GIS data for the target area was constructed for the surface boundary input data of the CFD model. The wind observations at an Automatic Weather Station (AWS) located in Haui-do were used to set-up the model inflows. The seasonal simulations were conducted. The differences in surface wind speed between after and before artificial changes in geographical features were analyzed. The surface wind speed decreases 5 to 20% at the south-western part and below 2% of the spatial average for salt field. There was also marked the effect of artificial changes in geographical features on local wind in the westerly wind case for the target area.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.3
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• pp.359-371
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• 1998

The cold water event near Gampo-Ulgi coast in summers between 1987 and 1994 are studied using sea surface temperature records at the coastal stations, ocean winds measured by SSM/I and AVHRR SST images. The response time of the cold water events by upwelling is less than two days and surface cold water expands up to the Ulleung Island. An analysis of 61 upwelling favorable winds indicates that the surface water temperature drops more than $1^{\circ}C\;in\;80\%$ of the south-westerly wind events. The linear correlation coefficient between wind impulses and the maximum temperature drops is good (0.6). It is found that the major cause of the cold water events is the along-shore wind in summer. The bottom topography and off-shore direction of the East Korean Warm Current by the potential vorticity conservation near Gampo coast also contribute the formation of the cold water along the southeast coast of Korea.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.192-195
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• 2004

Products of gridded surface wind and windstress vectors over the world ocean have been constructed by satellite scatterometer data with highly temporal and spatial resolutions. Even if the ADEOS-II/SeaWinds has supplied surface wind data only for short duration in Apr. to Oct. 2003 to us, it permits us to construct a product with higher resolution together with the Qscat/SeaWinds. In addition to our basic product with its resolution of $1^{\circ}\times1^{\circ}$ in space and daily in time, we try to construct products with $1/2^{\circ}\times1/2^{\circ}$ and semi- and quarter-daily resolution. These products are validated by inter-comparison with in-situ data (TAO and NDBC buoys), and also compared with numerical weather prediction(NWP) ones (NCEP reanalysis). Result reveals that our product has higher reliability in the study area than the NCEP's. For the open ocean regions in the middle and high latitudes where there are no in-situ data, we find that there are clear differences between them. Especially in the southern westerly region of 400-600S, the' wind-stress magnitudes by the NCEP are significantly larger than the others, suggesting that they are overestimated. We also calculate wind-stress curl field that is an important factor for ocean dynamics and focus its spatial character in the northwestern Pacific around Japan. Positive curl areas are found to cover from southwest to northeast in our focus region and almost correspond to the Kuroshio path. It is suggested that the vorticity field in the lower atmosphere is related to the upper oceanic one, and thus an aspect of air-sea interaction process.

• Journal of Environmental Science International
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• v.24 no.3
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• pp.291-302
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• 2015

The seasonal variations of sea surface winds and significant wave heights were investigated using the data observed from the marine meteorological buoys (nine stations) and Automatic Weather Stations (AWSs) in lighthouse (nine stations) around the Korean Peninsula during 2010~2012. In summer, the prevailing sea surface winds over the East/West Sea and the South Sea were northerly/southerly and easterly/westerly winds due to both of southeast monsoon and the shape of Korean Peninsula. On the other hand, the strong northerly winds has been observed at most stations near Korean marginal seas under northwest monsoon in winter. However, the sea surface winds at some stations (e.g. Galmaeyeo, Haesuseo in the West Sea) have different characteristics due to topographic effects such as island or coastal line. The significant wave heights are the highest in winter and the lowest in summer at most stations. In case of some lighthouse AWSs surrounded by islands (e.g. Haesuseo, Seosudo) or close to coast (e.g. Gangan, Jigwido), very low significant wave heights (below 0.5 m) with low correlations between sea surface wind speeds and significant wave heights were observed.

• Journal of the Korean earth science society
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• v.33 no.3
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• pp.233-241
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• 2012

Based on the observation of the microwave radiometers at Cheongju, Hapcheon and Daegwallyeong in Korea, the precipitable water vapor and liquid water path have been analyzed for spatio-temporal characteristics. The observed datas have been validated by comparing precipitable water vapor between the microwave radiometer and the radiosonde near the sites. It resulted in the correlation coefficient of more than 0.8 in all three sites. For three regions, the precipitable water vapor shows similar seasonal variation and diurnal cycle, and that amount of precipitable water vapor increases from around 1000 LST and has a maximum value at 1900 LST. On the other hand, the liquid water path of microwave radiometer has regional differences for its seasonal variation, which seems to be caused by the geographical characteristics including the frequent fog and clouds in Daegwallyeong, a high mountain region (834 m from sea level), almost flat land in Chengju, and Sobaek Mountains in Hapcheon that blocks the westerly clouds.

• Journal of Environmental Science International
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• v.20 no.6
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• pp.737-753
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• 2011

The typical characteristics of seasonal winds were studied around the Pohang using two-stage (average linkage then k-means) clustering technique based on u- and v-component wind at 850 hpa from 2004 to 2006 (obtained the Pohang station) and a high-resolution (0.5 km grid for the finest domain) WRF-UCM model along with an up-to-date detailed land use data during the most predominant pattern in each season. The clustering analysis identified statistically distinct wind patterns (7, 4, 5, and 3 clusters) representing each spring, summer, fall, and winter. During the spring, the prevailed pattern (80 days) showed weak upper northwesterly flow and late sea-breeze. Especially at night, land-breeze developed along the shoreline was converged around Yeongil Bay. The representative pattern (92 days) in summer was weak upper southerly flow and intensified sea-breeze combined with sea surface wind. In addition, convergence zone between the large scale background flow and well-developed land-breeze was transported around inland (industrial and residential areas). The predominant wind distribution (94 days) in fall was similar to that of spring showing weak upper-level flow and distinct sea-land breeze circulation. On the other hand, the wind pattern (117 days) of high frequency in winter showed upper northwesterly and surface westerly flows, which was no change in daily wind direction.

• Journal of the Korean Geophysical Society
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• v.9 no.4
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• pp.397-408
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• 2006

Due to the temporal and spatial variability of the warming at and near the Antarctic Peninsular, it is required to better understand local climate at the issued region. The purpose of the study are to characterize surface radiation, air temperature and wind direction and investigate their relations at the King Sejong Station near the Antarctic Peninsular during last three and half years. While the study site was a weak radiative energy sink (positive net radiation) with annual mean of 15-20 Wm-2, it played a role as a strong sink in summer (December to January) with mean of 85 Wm-2, a magnitude that was significantly larger than those at other surface covered with snow or ice in Antarctica. Monthly averaged air temperature ranged from -7.7-2.8oC and the variations of monthly averaged air temperature showed the distinct differences with year. Northwesterly, westerly and easterly were dominant and the variability of air temperature could be explained by the variability of the frequency of wind direction with cold easterly and warm northwesterly/northerly to some degree, which in turn influenced radiation budget through albedo in summer.

• Journal of Environmental Impact Assessment
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• v.16 no.5
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• pp.351-361
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• 2007

To evaluate dominant synoptic classes which affect on $PM_{10}$ concentration in Seoul, 64 synoptic classes are classified from four seasons, 850hPa geopotential wind and lower level stability Index. In this study, we used air monitoring and meteorological data in Seoul for five years from 2001 to 2005. The results indicate that the highest occurrence frequency of synoptic class is under a strong westerly geopotential wind and stable lower atmosphere in spring. The highest $PM_{10}$ concentration of synoptic class is associated with a weak geopotential wind speed and high lower level stability. In that class, not only $PM_{10}$ but $SO_2$, $NO_2$ and CO concentrations are also higher than other classes. The analysis of spacial distribution of $PM_{10}$ concentration in each class are indicate that the influence of synoptic class are similar in the Metropolitan area in Korea. But $PM_{10}$ concentration in some areas in Kyoung-Gi are more higher than in Seoul. The relationship between $PM_{10}$ concentration and Meteorological indicator (relative humidity, temperature, surface wind speed) under same synoptic class is more correlative in Winter than other season.