• Atmosphere
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• v.28 no.4
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• pp.457-467
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• 2018

This study investigated the variability of spring (March-May) forest fire risk in Korea for the period 1991~2017 and analyzed its relationship with large-scale climate factors. The Forest Weather Index (FWI) representing the meteorological risk for forest fire occurrences calculated based on observational data and its relationship with large-scale climate factors were analyzed. We performed the empirical orthogonal function (EOF) analysis on the spring FWI. The leading EOF mode of FWI accounting for about 70% of total variability was found to be highly correlated with total number of forest fire occurrences in Korea. The high FWI, forest fire occurrence risk, in Korea, is associated with warmer atmosphere temperature in midwest Eurasia-China-Korea peninsula, cyclonic circulation anomaly in northeastern China-Korea peninsula-northwest pacific, westerly wind anomaly in central China-Korea peninsula, and low humidity in Korea. These are further related with warmer sea surface temperature and enhanced outgoing longwave radiation over Western Pacific, which represents a typical condition for a La $Ni\tilde{n}a$ episode. This suggests that large-scale climate factors over East Asia and ENSO could have a significant influence on the occurrence of spring forest fires in Korea.

• Journal of the Korean Society of Hazard Mitigation
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• v.10 no.3
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• pp.21-29
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• 2010

In this study, characteristics of natural disaster and damage in North Korea are examined by using CRED(Centre for Research on the Epidemiology of Disasters) data from 1980 to 2008. Result shows that most natural disasters are caused by summertime typhoon and floods with typical floods of 1995 and 2007. Also, synoptic weather condition associated with heavy rainfall in North Korea is analyzed by using satellite image and weather chart provided by JMA(Japan Meteorological Agency). The heavy rainfalls associated with flood in North Korea are mainly related to the effect of Changma front, abrupt development of southeastward moving low over Yellow Sea, convective instability at the edge of North Pacific high and passage of weakened tropical cyclone(typhoon).

• Journal of the Korean Solar Energy Society
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• v.31 no.3
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• pp.101-108
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• 2011

This study aims to suggest an energy consumption improvement plan for university buildings through an analysis of energy consumption. Upon a simulation of subject building to interpret energy consumption, it was found that 154.07kWh/$m^2$ of energy is consumpted annually. Improvement of design elements can cut down the energy consumption to 135.61kWh/$m^2$ according to an energy reduction analysis related to envelope performance improvement. Additional improvement of lights and heat exchanger can curtail annual energy consumption to 108.32kWh/$m^2$. Also, an analysis of energy consumption while increasing indoor temperature gradually showed that the two factors are in proportion. $6^{\circ}C$ higher temperature requires over twice of the current energy. Based on this survey result, performance improvement due to building management and envelope elements which influence to building cooling and heating loads can curtail building energy consumption.

• Journal of Korean Society for Atmospheric Environment
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• v.22 no.3
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• pp.297-307
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• 2006

During January $2002{\sim}April\;2004$, hydrogen peroxide ($H_{2}O_{2}$) measurements were performed at the campus of Korea University, which is located in the northeastern part of Seoul. Gas phase hydroperoxide was collected in aqueous solution and separated by HPLC. Concentrations were determined by fluorescence using postcolumn enzyme derivatization. This measurement system was improved to be run automatically from sample collection at every 10 minutes through chemical analysis for data collection. Detection limits of $H_{2}O_{2}$ is $10{\sim}17\;pptv$, and the overall uncertainty of the measurements is better than 8%. Two-year measurements of $H_{2}O_{2}$ show typical seasonal variations. Concentrations of $H_{2}O_{2}$ were higher during $June{\sim}October$ and lower during $January{\sim}February$. Maximum concentration of 1-hour averaged $H_{2}O_{2}$ was 6.5 ppbv, which was observed in August and September. In general $H_{2}O_{2}$ concentrations were well correlated with $O_{3}$ concentrations and largely affected by meteorological factors such as temperature and wind direction.

• Journal of The Korean Society of Agricultural Engineers
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• v.52 no.6
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• pp.135-144
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• 2010

This study was performed to suggest a soil loss reduction skill through estimating soil erosion from a small watershed including each type of sloping agriland by using GEOWEPP model. Experimental watershed at Gangwon province was selected for very typical sloping fields of highland agriculture in Alpine area. Runoff discharge and sediment load, hourly rainfall amount occurred during storm event were gauged, and weather data were obtained from Daegwallyeong meteorological station. The results of GEOWEPP model estimation showed that relative error values for total runoff discharge and sediment load were 3 %, -14.5 % respectively. Based on the result, soil erosion and waterway path map for each hillslope were made to select target hillslope. Several hillslopes of severe soil erosion were analyezed and then the optimal vegetative filter strip construction width and waterway path to plant grass were decided by using GEOWEPP Model.

• Wind and Structures
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• v.24 no.6
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• pp.657-677
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• 2017

This paper discusses some features and conditions that characterize the Zonda wind, focusing particularly on the implications for wind engineering applications. This kind of wind, typical of mountainous regions, is far from being adequately characterized for computational simulations and proper modeling in experimental facilities such as boundary layer wind tunnels. The objective of this article is to report the research works that are being developed on this kind of wind, describing the main obtained results, and also to establish some general guidelines for the proper analysis of the Zonda in the wind engineering context. A classification for the Zonda wind is indicated and different cases of structural and environmental effects are described. Available meteorological data is analyzed from the wind engineering point of view to obtain the Zonda wind gust factors, as well as basic wind speeds relevant for structural design. Some considerations and possible directions for the Zonda wind-tunnel and computational modeling are provided. Gust factor values larger than those used for open terrain were obtained, nevertheless, the basic wind speed values obtained are similar to values presented by the Argentinian Wind Code for three-second gust, principally at Mendoza airport.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.26 no.2
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• pp.96-109
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• 2021

Since terrestrial input plays a major role in coastal primary production, an understanding of land-ocean coupling (LOC) is key to understand coastal ecological changes. In this study, the LOC has been classified into three stages (i.e., the baseflow, plume event and residual flow). In order to characterize its pattern in Nakdong River estuary, multi-platform data were obtained from remote sensing (geostationary ocean color image (GOCI)), in-situ measurement (marine environment information system (MEIS)), on-site measurement (discharge data and meteorological data). The MEIS data were grouped into three stages of LOC using principal component analysis (PCA), and the LOC (2013 ~ 2018) was examined at each stage using multi-platform data. In the Nakdong River estuary, the maximum value of chlorophyll-a (chl-a) was unexpectedly appeared during the plume event. It is assumed that there was no significant increase in turbidity, expected during the typical plume event, together with the weak flushing effect, caused the enhanced phytoplankton growth. Compared with other estuaries, LOC is common in estuaries affected by freshwater inflow, but LOC has different pattern depending on the size of the plume. While estuaries that form small plumes of about 10 km (low freshwater discharge and weak flushing effect) observed high chl-a in the plume event because the phytoplankton can response to the increased nutrient more rapidly. estuaries that form large plumes of more than 100 km est (high freshwater discharge and strong flushing effect) follow the typical LOC pattern conceptualized in this study (high chl-a in the residual flow).

• Journal of Positioning, Navigation, and Timing
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• v.3 no.4
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• pp.131-141
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• 2014

Over the last decade, the Global Navigation Satellite System (GNSS) has been increasingly utilized as a meteorological research tool. The Korea Astronomy and Space Science Institute (KASI) has also been developing a near real-time GNSS precipitable water vapor (PWV) information management system that can produce a precise PWV for the Korean Peninsula region using GNSS data processing and meteorological measurements. The goal of this paper is to evaluate whether the precise point positioning (PPP) strategy will be used as the new data processing strategy of the GNSS-PWV information management system. For this purpose, quality assessment has been performed by means of a comparative analysis of the troposphere zenith total delay (ZTD) estimates from KASI PPP solutions (KPS), KASI network solutions (KNS), and International GNSS Service (IGS) final troposphere products (IFTP) for ten permanent GNSS stations in the Korean Peninsula. The assessment consists largely of two steps: First, the troposphere ZTD of the KNS are compared to those of the IFTP for only DAEJ and SUWN, in which the IFTP are used as the reference. Second, the KPS are compared to the KNS for all ten GNSS stations. In this step, the KNS are used as a new reference rather than the IFTP, because it was proved in the previous step that the KNS can be a suitable reference. As a result, it was found that the ZTD values from both the KPS and the KNS followed the same overall pattern, with an RMS of 5.36 mm. When the average RMS was converted into an error of GNSS-PWV by considering the typical ratio of zenith wet delay and PWV, the GNSS-PWV error met the requirement for PWV accuracy in this application. Therefore, the PPP strategy can be used as a new data processing strategy in the near real-time GNSS-PWV information management system.

• Journal of the Korean earth science society
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• v.33 no.5
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• pp.377-394
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• 2012

To elucidate the mechanism associated with the development of heavy precipitation system, a field experiment was carried out in Jejudo (or Jeju Island) and Marado, Korea from 22 June to 12 July 2006. The synoptic atmospheric conditions were analyzed using the National Centers for Environmental Prediction-National Center for Atmospheric Research's (NCEP/NCAR) reanalyzed data, weather maps, and sounding data. The kinematic characteristics of each precipitation system were investigated by dual Doppler radar analysis. During the field experiment, data of four precipitation events with more than 20 mm rainfall were collected. In F case (frontal precipitation), a typical Changma front was dominant and the observation field was fully saturated. However there was no convective instability near the surface. LF case (low pressure accompanied with Changma front) showed strong convective instability near the surface, while a strong convergence corresponded to the low pressure from China accompanied with Changma front. In FT case (Changma front indirectly influenced by typhoon), the presence of a convective instability indicated the transport of near surface, strong additional moisture from the typhoon 'EWINIAR'. The convergence wind field was ground to be located at a low level. The convective instability was not significant in T case (precipitation of the typhoon 'EWINIAR'), since the typhoon passed through Jejudo and the Changma front was disappeared toward the northeastern region of the Korean peninsula. The kinematic (convergence and divergence) characteristics of wind fields, convective instability, and additional moisture inflow played important roles in the formation and development of heavy precipitation.

• Journal of the Korean Solar Energy Society
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• v.28 no.4
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• pp.17-24
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• 2008

Estimation of typical solar radiation is very important for the calculations concerning many solar applications. But solar radiation measurements are not easily available because of the expensive measuring equipment and techniques required. Accordingly, for regions where no solar radiation is measured, solar radiation need to be estimated using other meteorological data. However, currently in Korea, there is no study on how to do this. In this paper, the global radiation of the six major cities in South Korea where the global radiation is measured using comparatively simple CRM model was calculated compared and analyzed. The comparison between the original coefficient and the site-fitted coefficient for these cities are as follows. Differences between the site-fitted coefficient and the original coefficient for six cities are small. Except for Gwangju, both calculations show strong correlation. In case of Seoul, the $R^2$(coefficient of determination) were 0.747 and 0.749. In case of Busan and Daegu the figures were 0.817, 0.819 and 0.820, 0.821 respectively. For Gwangju, these were 0.618 and 0.622, Thus, the site-fitted coefficients were slightly higher for these four cities. On the other hand, Daejeon and Incheon was reported 0.773, 0.772 and 0.785, 0.783, respectively.