• Journal of Environmental Science International
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• v.2 no.3
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• pp.179-191
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• 1993

This paper aims to know the characteristics of occurrence of the anomaly level and variability of the monthly precipitation in Kyeongnam, Korea. For this study, it was investigated 주e distribution of the annual and cont비y mean precipitation, the precipitation variability and its annual change, and the characteristics of occurrence of the anomaly level in Kyeongnam area the results were summarized as follows : 1) she mean of annual total precipitation averaged over Kyeongnam area is 1433.3mm. I'he spatial distribution of the annual total precipitation shows that in Kyeongnam area, the high rainfall area locates in the southwest area and south coast and the low rainfall area in an inland area. 2) Monthly mean precipitation in llyeongnam area was the highest in July(266.4mm) 각lowed by August(238.0mm), June(210.2mm) in descending order. In summer season, rainfall was concentrated and accounted for 49.9 percent of the annual total precipitation. Because convergence of the warm and humid southwest current which was influenced by Changma and typhoon took place well in this area. 3) The patterns of annual change of precipitaion variability can be divided into two types; One is a coast type and the other an inland type. The variability of precipitation generally appears low in spring and summer season and high in autumn and winter season. This is in accord with the large and small of precipitation. 4) The high frequency of anomaly level was N( Normal)-level and the next was LN( Low Informal) -level and 25(Extremely Subnormal)-level was not appeared in all stations. The occurrence frequency of N level was high in high rainfall area and distinguish성 in spring and summer season but the low rainfall area was not. hey Words : anomaly level, variability, precipitation, coast type, inland type.

• Korean Journal of Remote Sensing
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• v.32 no.3
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• pp.331-337
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• 2016

Water vapor is main absorption factor of outgoing longwave radiation. So, it is essential to monitoring the changes in the amount of water vapor and to understanding the causes of such changes. In this study, we monitor temporal variability of Total Precipitable Water (TPW) which observed by satellite. Among climate variables, precipitation play an important part to analyze temporal variability of water vapor because it is produced by water vapor. And El $Ni{\tilde{n}}o$ is one of climate variables which appear regularly in comparison with the others. Through them, we analyze relationship between temporal variability of TPW and climate variable. In this study, we analyzed long-term change of TPW from Moderate-Resolution Imaging Spectroadiometer (MODIS) data and change of precipitation in middle area of Korea peninsula quantitatively. After these analysis, we compared relation of TPW and precipitation with El $Ni{\tilde{n}}o$. The aim of study is to research El $Ni{\tilde{n}}o$ has an impact on TPW and precipitation change in middle area of Korea peninsula. First of all, we calculated TPW and precipitation from time series analysis quantitatively, and anomaly analysis is performed to analyze their correlation. As a result, TPW and precipitation has correlation mostly but the part had inverse correlation was found. This was compared with El $Ni{\tilde{n}}o$ of anomaly results. As a result, TPW and precipitation had inverse correlation after El $Ni{\tilde{n}}o$ occurred. It was found that El $Ni{\tilde{n}}o$ have a decisive effect on change of TPW and precipitation.

• Atmosphere
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• v.22 no.4
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• pp.449-454
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• 2012

This study presents the long-term variability of spring precipitation over the Korean peninsula. It is found that the significant interdecadal change in the spring precipitation has occurred around year 1991. Over the Korean peninsula the precipitation for the post-1991 period increased by about 30 mm per year in CMAP and station-measured data compared to the precipitation prior to year 1991. Due to an increased baroclinicity during the later period, the low-level negative pressure anomaly has developed with its center over northern Japan. Korea is situated at the western end of the negative pressure anomaly, receiving moisture from westerly winds and producing more precipitation. Also, we estimate the change in the near future (years 2020~2040) spring precipitation using six best performing Coupled Model Intercomparison Project 3 (CMIP3) models. These best model ensemble mean shows that spring precipitation is anticipated to increase by about 4% due to the strengthened westerlies accompanied by the northwestern enhancement of the North Pacific subtropical high.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.992-996
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• 2008

In this study, changes in precipitation across South Korea during snow seasons (November-April) and their potential are examined. Current (1973/74-2006/07) and future (2081-2100) time series of snow indices including snow season, snow-to-precipitation ratio, and snow impossible day are extracted from observed snow and precipitation data for 61 weather stations as well as observed and modeled daily temperature data. Analyses of linear trends reveal that snow seasons have shortened by 3-13 days/decade; that the snow-to-precipitation ratio (the percentage of snow days relative to precipitation days) has decreased by 4-8 %/decade. These changes are associated with pronounced formations of a positive pressure anomaly core over East Asia during the positive Arctic Oscillation winter years since the late 1980s. A snow-temperature statistical model demonstrates that the warming due to the positive core winter intensifies changes from snow to rain at the rate of $4.7cm/^{\circ}C$. The high pressure anomaly pattern has also contributed to decreases of air-sea thermal gradient which are associated with the reduction of snow could formation. Modeled data predict that a fingerprint of wintertime global warming causing changes from snow to rain will continue to be observed over the 21st century.

• Korean Journal of Remote Sensing
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• v.32 no.2
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• pp.195-200
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• 2016

Water vapor leading various scale of atmospheric circulation and accounting for about 60% of the naturally occurring warming effect is important climate variables. Using the Total Precipitable Water (TPW) from Moderate Resolution Imaging Spectroradiometer (MODIS) operating on both Terra and Aqua, we study long-term Variation of TPW and define relationship among TPW and climatic parameters such as temperature and precipitation to quantitatively demonstrate the impact on climate change over East Asia focusing on the Korea peninsula. In this study, we used linear regression analysis to detect the correlation of TPW and temperature/precipitation and harmonic analysis to analyze changeable aspects of periodic characteristics. A result of analysis using linear regression analysis between TPW and climate elements, TPW shows a high determination coefficient ($R^2$) with temperature and precipitation (determination coefficient between TPW and temperature: 0.94, determination coefficient between TPW anomaly and temperature anomaly: 0.8, determination coefficient between TPW and precipitation: 0.73, determination coefficient between TPW anomaly and precipitation anomaly: 0.69). A result of harmonic analysis of TPW and precipitation of two-year to five-year cycle, amplitude contribution ratio of 3.5-year cycle are much higher and two phases are similar in 3.5-year cycle.

• Journal of Navigation and Port Research
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• v.40 no.5
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• pp.271-278
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• 2016

Localized atmospheric conditions between multi-reference stations can bring the tropospheric delay irregularity that becomes an error terms affecting positioning accuracy in network RTK environment. Imbalanced network error can affect the network solutions and it can corrupt the entire network solution and degrade the correction accuracy. If an anomaly could be detected before the correction message was generated, it is possible to eliminate the anomalous satellite that can cause degradation of the network solution during the tropospheric delay anomaly. An atmospheric grid that consists of four meteorological stations was used to detect an inhomogeneous weather conditions and tropospheric anomaly applied AWSs (automatic weather stations) meteorological data. The threshold of anomaly detection algorithm was determined based on the statistical weather data of AWSs for 5 years in an atmospheric grid. From the analytic results of anomaly detection algorithm it showed that the proposed algorithm can detect an anomalous satellite with an anomaly flag generation caused tropospheric delay anomaly during localized atmospheric conditions between stations. It was shown that the different precipitation condition between stations is the main factor affecting tropospheric anomalies.

• Journal of the Korean Geographical Society
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• v.38 no.5
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• pp.659-666
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• 2003

This study is a comparative analysis on the variabilities of spring precipitation and atmospheric circulations of 500hPa surfaces between dry years and wet years over the Korean Peninsula. The distribution of variabilities of precipitation in spring are different from month to month. In March, the pattern is west-high and east-low, in April, north-high and south-low, in May, east-high and west-low respectively. In the distribution of 500hPa geopotential height anomaly, dry years of March show west-high and east-low pattern in that negative anomaly zones are formed around the Korean Peninsula and western coast of the northern Pacific Ocean, and positive anomaly zones are formed in the inland of East Asia centered on Siberia. Consequently, the Korean Peninsula and neighboring regions experience dry season when the zonal flows are strong with the positive anomaly zones of zonal components. On the contrary in the wet years the westerlies are weak since the pattern is east-high and west-low in which the positive anomaly zones are formed over the Korean Peninsula centered on the Aleutian Islands and western coast of the northern Pacific Ocean and the negative anomaly zones are formed in the inland of East Asia centered on Tibet Plateau and Siberia. The dry years of April and May show north-high and south-low patterns in that negative anomaly zones are found from the center of the northern Pacific Ocean to the eastern coast of East Asia, and the positive anomaly zones are found in the center of East Asia extending from Aleutian Islands to Tibet Plateau. On the contrary, in the wet years the patterns show south-high and north-low. This study identified not only that there are contrary atmospheric circulation patterms between dry years and wet years over Korean Peninsua in spring, but also there are different atmosphric circulation patterns between early and late spring.

• Journal of the Korean earth science society
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• v.30 no.3
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• pp.282-293
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• 2009

This study examines the effects of the Madden-Julian oscillation (MJO) or the Intraseasonal Oscillation (ISO) on precipitation, temperature and circulation anomalies over East Asia according to the eight different MJO phases during the winter and summer seasons. A nonlinear response appears the wintertime precipitation pattern during the phase of 3 (where the MJO center is located over the Eastern Indian Ocean) and 8 (where the MJO center is located over the Western Hemisphere) over the Korean Peninsula. That is, for these phases, the positive precipitation anomalies appear for the MJO intensity less than 2 standard deviations while the negative precipitation anomalies appear in the case of the MJO intensity greater than 2 standard deviations. The negative precipitation anomaly in the latter case is duandard d stronger anomalous anticyclone formed over the Korean Peninsula and cold and dry advection by northerly winds. The response of precipitation and circulation to the boreal summer ISO is also investigated.

• Journal of the Korean association of regional geographers
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• v.2 no.2
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• pp.93-102
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• 1996

The Korean Peninsula is located on the east coast of monsoon Asia of the midlatitude, where the Pacific polar front moves. As a result variations of spatial and temporal distribution of precipitation occur. A great variation of precipitation during the summer months created frequent droughts and floods. The purpose of this study is to identify distributional characteristics and to analyze synopic characteristics of summer droughts in Korea. The research methods used are ; (1) to identify droughts based on the anomaly of monthly precipitation during summer of 1994. (2) to analyze correlations between drought and weather systems by using the calender of rain days. (3) to compare a synoptic mechanism of summer droughts with that of typical normal summer. The characteristics of summer droughts of 1994 may be summarized as follows ; 1) While most regions were affected by the droughts some regions displayed specific characteristics. The southern part of the Korean Peninsula was severely affected during the month of June. August droughts severely affected east part of the Sobek Mountains, thus showing that the droughts of June and August are highly localized. 2) In the pressure anomaly of surface field. the positive anomaly appears in June around Korean Peninsula, but in July when all parts of the South Korea were under severe droughts, the anomaly changes and becomes negative. 3) Extracyclones occurred less frequently in the summer of 1994. Those that did occur were located in areas far off the Korean Peninsula having little consequences on the drought patterns. 4) The trough of westerly wave at 500hPa height patterns in June is located far from the eastern sea of Korean Peninsula, but in July and August Korean Peninsula belongs to ridge of westerly wave. 5) In June the positive height anomaly at 500hPa surface appears zonally from Siberia to the western Parts of North Pacific Ocean, and in July and August, the strong positive anomaly appears around Korean Peninsula. As a result the zonal index of westerlies at during each month of summer in Korean sector has a large value, which in turn implies that drought will prevails when zonal flow is strong.

• International Union of Geodesy and Geophysics Korean Journal of Geophysical Research
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• v.26 no.1
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• pp.31-41
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• 1998

The climatic characteristics of summer in 1998 are analyzed with the weather observational data and the upper air observational data. The temperature of that period is lower than that of normal years and the precipitation is larger. Due to the heavy rainfall which started at July 31, rain pured down compared to normal years and the maximum precipitation recorded at the many observational stations, particularly in Seoul, Kyunggi-Do region and mountanious districts like Taegwallyong, Mt. Sokri and Mt. Chiri. The patterns of general circulations in 1982/98 and 1997/98 are compared each other and are analyzed. The anomaly patterns of stream functions on winter in two El Nio years are simialr. The counterclockwise circulation occurred near the date line and the clockwise circulation was appeared near the Hwanam region and Alaska. These patterns are opposite to those of La Nia year, 1988/89. And the anomaly patterns of 500hPa geopotential height in summer are similar, too. The low temperature and much rain were dominated in summer of 1997/98. These phenomena is similar to the existing results of research, that temperature is low and precipitation is large in summer of El Nio years.