• Journal of Environmental Science International
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• v.6 no.6
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• pp.613-628
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• 1997

Diurnal variations of air quality due to the characteristic features of local weather phenomena over Kunsan, Taegu, and Pohang are analyzed using various synoptic wand fields and the characteristics of local weather during the period of 1990 to 1992. The air pollutants analyzed are sulfur dioxide($SO2_$), nitrogen dioxide($NO_2$), and oxidants ($0_3$). The synoptic wind fields estimated at over the 850 hPa geopotential height are divided in terms of four wand directions and two wand speed categories for each season. The synoptic weather conditions are also classified Into two categories depending on the 850 hPa cloud amounts. The present study shows that the $SO_2$ concentration over Kunsan, and Taegu was maximum at the two or three hours after sunrise and second primary was three or flour hours after sunset. On the other hand, Its concentration over Kunsan was malnmum at 1900 LST or 2000 LST The $O_3$ concentration over the three cities shows Its mapdmum In the afternoon when the solar radiation is strong. The $NO_2$ concentration over Kansan shows in reverse proportion to the $O_3$ concentration over the Kunsan.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.10
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• pp.1345-1352
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• 2021

Most of weather radar systems are used to monitor the whole weather situation for the very wide and medium-to-long range area. However, as the likelihood of occurrence of the local weather hazards is increased in recent days, it is very important to detect these wether phenomena with a local weather radar. For this purpose, it is necessary to detect the fast varying low altitude weather conditions and the effect of the ground surface clutter is more evident. Therefore, in this paper, the newly suggested method is explained and analyzed for detection of weather hazards such as the gust and wind shear using the fluctuation of wind velocities and the gradient of wind velocities among range cells. It is shown that the suggested method can be used efficiently in the future for faster detection of weather change through the simple algorithm implementation and also the effect of the ground clutter can be minimized in the detection procedure.

• Communications for Statistical Applications and Methods
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• v.19 no.6
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• pp.849-858
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• 2012

Today, local environmental factors has an influence on our society. Local environmental factors, as well as weather-related natural phenomena, social phenomena are also included. In this paper, numeric factors and categorical factors were analyzed, looking for a local environmental factors affecting the company's sales.Sales model by performing a regression analysis based on this was implemented.Sales model considering the local environment had an accuracy of 88.89%.

• Korean Journal of Agricultural and Forest Meteorology
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• v.10 no.3
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• pp.107-112
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• 2008

"Jeung-Bo-San-Lim-Gyeong-Je" (meaning "Revised Forest Management") has been well recognized as the informative document that introduces scientific knowledge and experiences of Korean ancestors regarding weather and climate. The tradition of Gwan-Cheon-Mang-Gi(i.e., empirical forecasting of short-term weather phenomena based on the status of cloud or sky) has been continuously utilized as a civilian weather forecasting method and even for very short-term weather prediction by operational forecasters these days. This agricultural technology textbook, published during the Great King Youngjo in Chosun-Dynasty, may be regarded as a poorly written document from the modern standpoint. Nonetheless, this study demonstrates that by and large the empirical knowledge contained in the book is indeed science based although their applications are limited to several hours for local forecasts in agricultural practices and daily living. For example, the wisdom of keeping water at an optimum level in a paddy field after sowing to prevent young seedlings from late frost damages was not at all different from the present technique of vinyl covered seedling nursery.

• Journal of the Korean earth science society
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• v.41 no.6
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• pp.575-587
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• 2020

Meteorological phenomena are observed by the Korea Meteorological Administration in a variety of ways (e.g., surface, upper-air, marine, ocean, and aviation). However, there are limits to the meteorological observation of the planetary boundary layer (PBL) that greatly affects human life. In particular, observations using a sonde or aircraft require significant observational costs in economic terms. Therefore, the goal of this study was to measure and analyze the meteorological factors of the vertical distribution of the see-land breeze among local meteorological phenomena using meteorological drones. To investigate the spatial distribution of the see-land breeze, a same integrated meteorological sensor was mounted on each drone at three different points (seaside, bottom of mountain, and mountainside), including the Boseong tall tower (BTT) at the Boseong Standard Weather Observatory (BSWO) in the Boseong region. Vertical profile observations for air temperature, relative humidity, wind direction, wind speed, and air pressure were conducted up to 400 m every 30 minutes from 1100 LST to 1800 LST on August 4, 2018. The spatial characteristics of meteorological phenomena for temperature, relative humidity, and atmospheric pressure were not shown at the four points. Strong winds (~8 m s-1) were observed from the midpoint (~100 m) at strong solar radiation hour, and in the afternoon the wind direction changed from the upper layer at the inland area to the west wind. It is expected that the analysis results of the lower atmospheric layer observed using the meteorological drone may help to improve the weather forecast more accurately.

• Atmosphere
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• v.29 no.2
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• pp.183-196
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• 2019

High-quality and high-resolution meteorological information is essential to reduce damages due to disastrous weather phenomena such as flash flood, strong wind, and heat/cold waves. There are many meteorological observation stations operated by Korea Meteorological Administration (KMA) in Seoul Metropolitan Area (SMA). Nonetheless, they are still not enough to represent small-scale weather phenomena like convective storm cells due to its poor resolution, especially over urban areas with high-rise buildings and complex land use. In this study, feasibilities to use additional pre-existing networks (e.g., operated by local government and private company) are tested by investigating the effects of network density on the gridded horizontal distribution of two meteorological variables (temperature and precipitation). Two heat wave event days and two precipitation events are chosen, respectively. And the automatic weather station (AWS) networks operated by KMA, local-government, and SKTechX in Incheon area are used. It is found that as network density increases, correlation coefficients between the interpolated values with a horizontal resolution of 350 m and observed data also become large. The range of correlation coefficients with respect to the network density shows large in nighttime rather than in daytime for temperature. While, the range does not depend on the time of day, but on the precipitation type and horizontal distribution of convection cells. This study suggests that temperature and precipitation sensors should be added at points with large horizontal inhomogeneity of land use or topography to represent the horizontal features with a resolution higher than 350 m.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.11
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• pp.1492-1499
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• 2020

A weather radar system generally shows the weather phenomena related with rainfall and wind velocity. These systems are usually very helpful to monitor the relatively high altitude weather situation for the wide and long range area. However, since the weather hazards due to the strong hail and heavy rainfall occurring locally are observed frequently in recent days, it is important to detect these wether phenomena. For this purpose, it is necessary to detect the fast varying low altitude weather conditions. In this environment, the effect of surface clutter is more evident and the antenna dwell time is much shorter. Therefore, the conventional Doppler spectrum estimation method may cause serious problems. In this paper, the AR(autoregressive) Doppler spectrum estimation methods were applied to solve these problems and the results were analyzed. Applied methods show that improved Doppler spectra can be obtained comparing with the conventional FFT(Fast Fourier Transform) method.

• Journal of Korea Multimedia Society
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• v.16 no.11
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• pp.1239-1249
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• 2013

According to development of weather radar, researches about observation, analysis or forecast of weather phenomena such as tornado, flash-flood etc. were encouraged by reducing frequency interferences, transmission noises, attenuations of radar signal. In contrast, there is a growing interest in the visualization and expression methods for weather radar data but weather radar manufacturers or the organs of government for weather are just busy interpreting expressed weather images projected on GIS. We propose an effective high definition weather radar information visualization method able to apply various GIS platforms to observe and take actions against rapid local weather changes effectively. In this paper, first we change information acquired from weather radar to raster or vector type high definition data structures using specific algorithms. And then, we quadrate our processed raster/vector type weather data with various GIS platforms accurately to make observers can recognize and check weather situations over exact geographical positions and elevations intuitively. Experimental results verify that our method make observers can recognize and analyze weather changes, tornados, local downpours or flash floods accurately by analyzing high definition weather radar data combined with GIS platform including detailed target locations and elevations.

• Journal of Korea Water Resources Association
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• v.41 no.10
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• pp.1023-1034
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• 2008

The size and frequency of the natural disaster related to the severe storms are increased for recent decades in all over the globe. The damage from natural disasters such as typhoon, storm and local severe rainfall is very serious in Korea since they are concentrated on summer season. These phenomena will be more frequent in the future because of the impact of climate change related to increment of $CO_2$ concentration and the global warming. To reduce the damage from severe storms, a short-range precipitation forecasting model using a weather radar was developed. The study was conducted as following four tasks: conversion three-dimensional radar data to two-dimensional CAPPI(Constant Altitude Plan Position Indicator) efficiently, prediction of motion direction and velocity of a weather system, estimation of two-dimensional rainfall using operational calibration. Results demonstrated that two-dimensional estimation using weather radar is useful to analyze the spatial characteristics of local storms. If the precipitation forecasting system is linked to the flood prediction system, it should contribute the flood management and the mitigation of flood damages.

• Journal of the Korean Association of Geographic Information Studies
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• v.20 no.2
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• pp.75-88
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• 2017

This study analyzed wind flows based on spatial and geomorphological characteristics of Daegu Metropolitan City. A three-stage analysis was performed, starting with a comparison of meteorological relationships between local wind direction (synoptic wind) and local wind flow. In the second stage the study area was subdivided into districts and suburban districts to analyze the relative change of local wind flow. In stage three, the formation of wind corridor for local wind flow, wind flow for the entire urban space, and spatial relationships between flows were verified comparatively using KLAM_21. Three results are notable, the first of which is a low correlation between synoptic wind of a region, and local wind, flow in terms of meteorology. Secondly, observations of local wind flow at five downtown districts and two suburban districts showed that there were diverse wind directions at each measurement point. This indicates that the spatial and geomorphological characteristics of areas neighboring the measurement points could affect the local wind flow. Thirdly, verifying the results analyzed using KLAM_21, compared to Atomatic Weather System(AWS) measurement data, confirmed the reliability of the numerical modelling analysis. It was determined that local wind flow in a city performs a spatial function and role in ameliorating the urban heat island phenomena. This indicates that, when an urban planning project is designed, the urban heat island phenomena could be ameliorated effectively and sustainably if local wind flow caused by immediate spatial and geomorphological characteristics is confirmed systematically and techniques are intentionally applied to connect the flows spatially within areas where urban heat islands occur.