• Journal of Environmental Science International
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• v.17 no.6
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• pp.591-599
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• 2008

In order to support the development of wind farms in Jejudo, a wind resource database for Jejudo has been established using a meteor-statistical analysis of KIER(Korea Institute of Energy Research) met-mast measurements and KMA(Korea Meteorological Administration) weather data. The analysis included wind statistics, tower shading, an exposure category classification using satellite images, the effect of atmospheric stability on the wind profile exponent, and a correlation matrix of wind speed to gain an understanding of the meteorological correlation between long-term weather observation stations and short-term met-mast measurements. The wind resource database for Jejudo, is to be provided as an add-on to Google $Earth^{TM}$, which is expected to be utilized as a guideline for the selection of an appropriate reference site for long-term correction in the next wind farm development project.

• 한국태양에너지학회:학술대회논문집
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• 2012.03a
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• pp.337-344
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• 2012

Today, the number of super tall buildings are under construction or being planed in Middle East and Asian Countries. For example the burj Khalifa, the tallest building in the world, is completed in 2008 and the height of that is about 800m. Also, Lotte World Tower is under construction in Korea. External environmental conditions such as wind speed, air temperature, humidity and solar radiation around the super tall building differs according to the building height due to the vertical micro climate change. However, the meteorological information used for AC design of building is obtained typically from standard surface meterological station data(~2m above the ground). In this paper the effect of the building envelope on heating and cooling load in super tall building considering the meteorological changes with height was analyzed with simulation method. As results of this research, the guideline to select the building envelop alternatives for super tall building will be suggested in this paper.

• Journal of Wind Energy
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• v.13 no.3
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• pp.43-52
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• 2022

Although wind turbines have obtained type certification according to international standards and are released to the market, they cannot be regarded as design evaluations that consider site characteristics. Therefore, it is necessary to study the site-specific load analysis method based on the meteorological data measured at the candidate site. In this study, site-specific load calculation was performed based on the meteorological data from the Jeju Haengwon mast. Analysis results were compared and analyzed with the results calculated by IEC design Class (IIA). For the fatigue loads at the blade root and tower base, the site-specific condition was lower than the IEC IIA, but in the case of the ultimate load, the site-specific condition showed higher results in some design load cases (DLCs). Selecting a wind turbine suitable for a site through load evaluation considering site conditions can prevent the reduction of operation and maintenance (O&M) costs and the power loss caused by downtime. Finally, it is expected to contribute to the project's levelized cost of energy (LCOE) reduction.

• Journal of the Korean earth science society
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• v.41 no.5
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• pp.459-468
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• 2020

In this study, the selection criteria for the occurrence of sea breezes in the Boseong area during the spring season (March-May) of 2016-2017 were prepared for the analysis of vertical weather characteristics. For this purpose, wind speed values were determined using the measured precipitation, cloud volume, wind direction, the difference between the ground and sea temperature, a wind Profiler at an altitude of 1 km, and numerical model data. The dates of the sea breezes in Boseong were classified according to the selection criteria, and the spatial and temporal characteristics of the sea breezes were identified by analyzing the time and altitude of the sea breeze and the size of the wind speed. Sea breezes occurred 23 out of 183 days (12%), and in Boseong, at least 1.2 out of 10 spring days exhibited sea breezes. Sea winds ranged from 1200 to 1800 LST, mainly from ground to 700 m altitude during the day. In addition, the maximum wind speed averaged 4.9 m s^-1, at an altitude of 40 m at 1600 LST, showing relatively lower values than those in a preceding study. This seems to be owing to the reduction in wind speed due to the complexity of the coastal terrain.

• Journal of Korea Water Resources Association
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• v.46 no.3
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• pp.301-314
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• 2013

Spatial heterogeneous characteristics of solar radiation energy from Climate Change gives rise to energy imbalance in the general ecological system including water resources. To understand energy flow, flux towers are up and running throughout the world. In step with, in domestic major areas, there have been observed using several flux towers. In this study, downward shortwave radiation, downward long wave radiation, and net radiation that take important part in hydro-meteorology and ecology were calculated by proposed physical equations using flux data of the Seolmacheon and Choengmicheon, then, the calculated net radiation and observed net radiation were individually compared and validated. The results confirmed applicability of physical methods for insufficient hydro-meteorological data and possibility for observed data of hydro-meteorological variables.

• Journal of the Korean Institute of Landscape Architecture
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• v.30 no.3
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• pp.25-34
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• 2002

The purpose of this paper is to discuss the function of microclimate amelioration of urban trees regarding the environmental benefits of street trees in summer, focusing on the heat pollution-urban heat island, tropical climate day's phenomenon and air pollution. We measured the diurnal variation of air/ground temperatures and humidity within the vegetation canopy with the meteorological tower observation system. Summertime air temperatures within the vegetation canopy layer were 1-2$^{\circ}C$ cooler than in places with no vegetation. Due to lack of evaporation, the ground surface temperatures of footpaths were, at a midafternoon maximum, 8$^{\circ}C$ hotter than those under trees. This means that heat flows from a place with no vegetation to a vegetation canopy layer during the daytime. The heat is consumed as a evaporation latent heat. These results suggest that the extension of vegetation canopy bring about a more pleasant urban climate. Diurnal variation of air/ground temperatures and humidity within the vegetation canopy were measured with the meteorological tower observation system. According to the findings, summertime air temperatures under a vegetation canopy layer were 1-2$^{\circ}C$ cooler than places with no vegetation. Due mainly to lack of evaporation the ground surface temperature of footpaths were up to 8$^{\circ}C$ hotter than under trees during mid-afternoon. This means that heat flows from a place where there is no vegetation to another place where there is a vegetation canopy layer during the daytime. Through the energy redistribution analysis, we ascertain that the major part of solar radiation reaching the vegetation cover is consumed as a evaporation latent heat. This result suggests that the expansion of vegetation cover creates a more pleasant urban climate through the cooling effect in summer. Vegetation plays an important role because of its special properties with energy balance. Depended on their evapotranspiration, vegetation cover and water surfaces diminish the peaks of temperature during the day. The skill to make the best use of the vegetation effect in urban areas is a very important planning device to optimize urban climate. Numerical simulation study to examine the vegetation effects on urban climate will be published in our next research paper.

• Journal of Environmental Science International
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• v.7 no.3
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• pp.335-348
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• 1998

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 Und speeds at Gulup-Do are analyzed and discussed with those at four inland meteorological stations. The vertical profiles of wind vector, ortho- gonality(Ω), and shear obtained from the pibal obsenrations are also presented to examine the change of wand 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 mow 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 lay- ers and non-cloud layers. The maximum Und shear Is appeared at the bel각t where the varlauon of wand direction Induced by the passage of synoptic-scale pressure system Is accompanied with the In- crease of Und 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 wand direction is showed to be at around 2km.

• Journal of the Korean Geophysical Society
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• v.8 no.4
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• pp.201-205
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• 2005

Turbulent fluxes of heat, water vapor, and CO2 have been measured since August, 2003 at Dasan Station (78o 55’ N, 11o50’E) in the Arctic. These data can allow us to better understand the interactions between the Polar ecosystems and the atmosphere together with those at King Sejong Station in the Antarctic. Due to the buildings and measurement platforms around the flux tower, it is required to evaluate how they influence measured flux data. By using one-year turbulence statistics data and footprint model, flux footprint climatology was analyzed together with data availability. The upwind distance of source area ranged from 150 to 300 m, where the buildings and measurement platforms existed. However, flow distortion due to them may be not a major factor to reduce the data availability significantly. Based on, the dominant wind direction of SW and footprint climatology, the location of flux tower is considered suitable for flux measurement.

• Wind and Structures
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• v.15 no.1
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• pp.1-15
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• 2012

High-resolution wind data were acquired from a 100-m high offshore tower during the passage of Typhoon Hagupit in September, 2008. The meteorological tower was equipped with an ultrasonic anemometer and a number of cup anemometers at heights between 10 and 100 m. Wind characteristics of the strong typhoon, such as mean wind speed and wind direction, turbulence intensity, turbulence integral length scale, gust factor and power spectra of wind velocity, vertical profiles of mean wind speed were investigated in detail based on the wind data recorded during the strong typhoon. The measured results revealed that the wind characteristics in different stages during the typhoon varied remarkably. Through comparison with non-typhoon wind measurements, the phenomena of enhanced levels of turbulence intensity, gust factors, turbulence integral length scale and spectral magnitudes in typhoon boundary layer were observed. The monitored data and analysis results are expected to be useful for the wind-resistant design of offshore structures and buildings on seashores in typhoon-prone regions.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.6B
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• pp.541-549
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• 2010

While the number of rainy days is decreasing, the mean annual precipitation is increasing due to abnormal climate changes caused by the global warming in Korea. Owing to the biased-concentration of rainfall during specific short terms, not only flood but also drought becomes more and more serious. From the literature, it is easily found that previous studies about flood have been intensively conducted. However, previous studies about drought have been performed rarely. This study conducted the comparison between two representative drought indexes calculated from soil moisture and precipitation. Study area was Haenam-gun, Jeollanam-do in Korea. Soil Moisture Index(SMI) was calculated from soil moisture data while the Standardized Precipitation Index(SPI) and the Palmer Drought Severity Index(PDSI) were calculated from meteorological data. All monthly data utilized in this study were observed at the KoFlux Tower. After the comparative analysis, three indexes showed similar tendency. Therefore, it is thought that the drought index using soil moisture measured at the KoFlux Tower is reasonable, which is because the soil moisture is immediately affected by all the meteorological factors.