• 한국지구과학회지
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• 제38권3호
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• pp.182-193
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• 2017

A typical snowfall pattern occurs over the east coastal region of the Korean Peninsula, known as the Yeongdong region. The precipitation over the Yeongdong region is influenced by the cold and dry northeasterly wind which advects over warm and moist sea surface of the East Sea of Korea. This study reveals the influence of large-scale factors, affecting local to remote areas, on the mesoscale snowfall system over the Yeongdong region. The National Centers for Environmental Prediction-Department of Energy reanalysis dataset, Extended Reconstructed sea surface temperature, and observed snowfall data are analyzed to reveal the relationship between February snowfall and large-scale factors from 1981 to 2014. The Yeongdong snowfall is associated with the sea level pressure patterns over the Gaema Plateau and North Pacific near the Bering Sea, which is remotely associated to the sea surface temperature (SST) variability over the North Pacific. It is presented that the relationship between the Yeongdong snowfall and large-scale factors is strengthened after 1999 when the central north Pacific has warm anomalous SST. These enhanced relationships explain the atmospheric patterns of recent strong snowfall years (2010, 2011, and 2014). It is suggested that the newly defined index in this study based on related SST variability can be used for a seasonal predictor of the Yeongdong snowfall with 2-month leading.

• 인문언어
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• 제8집
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• pp.265-289
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• 2006

The geographical characteristics of Yeongdong(永同) the southernmost part of the Chungcheongbukdo province, has attracted attention among the academic circle as one of the dialectal contact regions since it adjoins the Gyeongsang and Jeolla dialects. Unlike the local language in Mooju (Jellado dialect) adjacent to the Southwest part, the local language in Yeongdong is quite different from that of Kimcheon (Gyeongsang dialect). More specifically, it is noteworthy that the boundary line of the Gyeongsang dialect is found in this region, which is different from the administrative division. In other words, the local language in Yeongdong is divided into the Chungcheong dialect and the Gyeongsang dialect, and furthermore each dialect region still has the characteristics of the other region's dialect. For example, the phonological structure of Yeongdong Chungcheongdo dialect has very unique characteristics of the fudged dialect, which is seemingly influenced by the Gyeongsang dialect. The present study is to define the bottom boundary line of the southeast area of the Chungcheong dialect by identifying the boundary line between the Gyeongsang dialect and the Chungcheong dialect, and to clarify its specific sound system generated by the contact of these two dialects. For this, the author collected and analyzed data of the local language around Yeongdong and adjacent areas. It was found that Cheongwha-ri, Deokjin-ri, and Sanjeo-ri at Yeongsan-myeon, and Mugeunjeom, Sangga-ri, and Jungga-ri at Yeongdong-eup, among the regions that belongs to Chungcheong dialect within the local language of Yeongdong, show the characteristics of the Gyeongsang dialect. Accordingly, the western areas of these villages become the southeast boundary line of the Chungcheong dialect. Also, the unique phonological characteristics of the Yeongdong Chungcheong dialect is affected by the Gyeongsang dialect, among which "rhythms, y deletion, nasal phoneme deletion, and w deletion" appeared. It is thought to be the unique fudged dialectal phenomenon that appeared only in this region. The research result is expected to be of some help in finding out various aspects of dialectal contacts as well as clarifying the phonological features of the local language in Yeongdong, and thereby contributing to exact divisioning of the Chungcheong dialect.

• 대기
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• 제19권4호
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• pp.345-370
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• 2009

Numerical experiments using the Weather Research and Forecasting (WRF) model were done to identify the role of the mountain ranges in the northern part of the Peninsula (referred as "the northern mountain complex"), in the occurrence of two heavy snowfall events over the Yeongdong region on 7-8 December 2002 and 20-21 January 2008. To this end, control simulations with the topography of the northern mountain complex and other simulations without the topography of the mountain complex were performed. It was revealed that the amount of snowfall over the Yeongdong region from the control simulation much more exceeded that of the simulation without the topography of the mountain complex. This increase of the snowfall amount over the Yeongdong region can be explained as follows: As the upstream flow approached the northern mountain complex, it deflected around the northern mountain complex due to the blocking effect of the mountains with a low Froude number less than ~0.16. This lead to the strengthening of northeasterly over the East Sea and over the Yeongdong region. The strong northeasterly is accompanied with much more snowfall over the Yeongdong region by intensifying air-mass modification over the sea and the orographic effect of the Taeback mountains. Thus, it was concluded that the topography of the northern mountain complex is one of the main factors in determining the distribution and amount of precipitation in the Yeongdong region when there is an expansion of the Siberian High toward the East Sea.

• 대기
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• 제23권3호
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• pp.245-264
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• 2013

Heavy rain over the Gangwon region has distinct characteristics in the temporal and spatial distribution of rainfall, most of which are concentrated on a very short period of time and either part of Yeongdong and Yeongseo regions. According to its regional distribution, heavy rain events over the Gangwon region may be classified into Yeongdong and Yeongseo heavy rain in which rainfalls of more than 110 mm $(6 hrs)^{-1}$ (heavy rain warning) have been observed in at least one of the weather stations over only Yeongdong or Yeongseo region, but over the other region the rainfalls are less than 70 mm $(6 hrs)^{-1}$ (heavy rain advisory). To differentiate between Yeongdong and Yeongseo heavy rain, 9 cases for Yeongdong heavy rain and 8 cases for Yeongseo heavy rain are examined on their synoptic and mesoscale environments using some meteorological parameters and ingredients. In addition, 8 cases are examined in which heavy rain warning or advisory are issued in both Yeongdong and Yeongseo regions. The cases for each heavy rain type have shown largely similar features in some meteorological parameters and ingredients. Based on an ingredient analysis, there are three common and basic ingredients for the three heavy rain types: instability, moisture, and lift. However, it is found that the distinct and important process producing strong upward vertical motions may discriminate among three heavy rain types very well. Yeongdong heavy rain is characterized by strong orographic lifting, Yeongseo heavy rain by high instability (high CAPE), and heavy rain over both regions by strong synoptic-scale ascent (strong 850 hPa Q-Vector convergence, diagnostics for ascent). These ingredients and diagnostics for the ingredients can be used to forecasting the potential for regional heavy rain. And also by knowing which of ingredients is important for each heavy rain type, forecasters can concentrate on only a few ingredients from numerous diagnostic and prognostic products for forecasting heavy rain events.

• 대기
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• 제31권4호
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• pp.433-443
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• 2021

The wind speed and wind direction in Yeongdong are one of the crucial meteorological factors for forecasting snowfall in this area. To improve the snowfall forecast in Yeongdong region, Yeongdong Extreme Snowfall-Windstorm Experiment, YES-WEX was designed. We examined the wind field variation simulated with Local Data Assimilation and Prediction System (LDAPS) using observed wind field during YES-WEX period. The simulated wind speed was overestimated over the East Sea and especially 2 to 4 times in the coastal line. The vertical wind in Yeongdong region, which is a crucial factor in the snowfall forecast, was not well simulated at the low level (850 hPa~1000 hPa) until 12 hours before the forecast. The snowfall distribution was also not accurately simulated. Three hours after the snowfall on the East Sea coast was observed, the snowfall was simulated. To improve the forecast accuracy of snowfall in Yeongdong region, it is important to understand the weather conditions using the observed and simulated data. In the future, data in the northern part of the East Sea and the mountain slope of Taebaek observed from the meteorological aircraft, ship, and drone would help in understanding the snowfall phenomenon and improving forecasts.

• 대기
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• 제29권3호
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• pp.325-342
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• 2019

Precipitation and no-precipitation events under the influence of the Siberian high pressure system in Yeondong region, were analysed and classified as four types [obvious precipitation event (OP) type, obvious no-precipitation event (ON) type, ambiguous precipitation event (AP) type and ambiguous no-precipitation event (AN) type], according to the easiness in determining whether to have precipitation or not in Yeongdong region, to help in improving the forecast skill. Concerning the synoptic pressure pattern, for OP type, the ridge of Siberian high extends from Lake Baikal toward Northeast China, and there is a northerly wind upstream of the northern mountain complex (located near the Korean-Chinese border). On the other hand, for ON type, the ridge of Siberian high extends southeastward from Lake Baikal, and there is a westerly wind upstream of the northern mountain complex. The pressure pattern of AP type was similar to the OP type and that of AN type was also similar to ON type. Thus it was difficult to differentiate AP type and OP type and AN type and ON type based on the synoptic pressure pattern only. The four types were determined by U (wind speed normal to the Taebaek mountains) and Froude number (FN). That is, for OP type, average FN and U at Yeongdong coast are ~2.0 and ${\sim}6m\;s^{-1}$, and those at Yeongseo region are 0.0 and $0.1m\;s^{-1}$, respectively. On the contrary, for ON type, average FN and U at Yeongdong coast are 0.0 and $0.2m\;s^{-1}$, and those at Yeongseo region are ~1.0 and ${\sim}4m\;s^{-1}$, respectively. For AP type, average FN and U at Yeongdong coast are ~1.0 and ${\sim}4m\;s^{-1}$, and those at Yeongseo region are 0.0 and $0.2m\;s^{-1}$, whereas for AN type, average FN and U at Yeongdong coast are 0.1 and $0.6m\;s^{-1}$ and those at Yeongseo region are ~1.0 and ${\sim}3m\;s^{-1}$, respectively. Based on the result, a schematic diagram for each type was suggested.

• 대기
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• 제22권1호
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• pp.57-71
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• 2012

Influences of orographic and ocean effect, which depend on the detailed geographic characteristics, upon winter time (December-February) precipitation in the Yeongdong region are investigated. Most of precipitation events in the Yeongdong region during the wintertime are associated with moist northeasterly (coming from the northeast direction) winds and also the spatial distribution of precipitation shows a great difference between Mountain area (Daegwallyeong) and Coastal area (Gangneung). The linear correlation coefficient between the meteorological variables obtained from NCEP/NCAR Reanalysis Data and precipitation amount for each precipitation type is calculated. Mountain type precipitation is dominated by northeasterly wind speed of the low level (1000 hPa and 925 hPa) and characterized with more precipitation in mountain area than coastal area. However, Coastal type precipitation is affected by temperature difference between ocean and atmosphere, and characterized with more precipitation in coastal area than mountain area. The results are summarized as follows; In the case of mountain type precipitation, the correlation coefficient between wind speed at 1000 hPa (925 hPa) and precipitation amount at Daegwallyeong is 0.60 (0.61). The correlation is statistical significant at 1% level. In the case of coastal type precipitation, the correlation coefficient of temperature difference between ocean and 925 hPa (850 hPa) over the East sea area and precipitation amount at Gangneung is 0.33 (0.34). As for the mountain type precipitation, a detailed analysis was conducted in order to verify the relationship between precipitation amount at Daegwallyeong and low level wind speed data from wind profiler in Gangneung and Buoy in the East Sea. The results also show the similar behavior. This result indicates that mountain type precipitation in the Yeongdong region is closely related with easterly wind speed. Thus, the statistical analysis of the few selected meteorological variables can be a good indicator to estimate the precipitation totals in the Yeongdong region in winter time.

• 대기
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• 제24권3호
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• pp.343-364
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• 2014

This study presents local and synoptic conditions associated with extreme heavy snowfall events in the Yeongdong region, as well as the temporal and spatial variability of these conditions. During the last 12 years (2001~2012), 3 extreme snowfall events occurred in the Yeongdong region, which recorded daily snowfall greater than 50 cm, respectively. In these events, one of the noticeable features is the occurrence of heavy hourly snowfall greater than 10 cm. It was reported from satellite analysis that these heavy snowfall may be closely related to mesoscale convective clouds. In this paper the 3 extreme events are examined on their synoptic environments associated with the developments of mesoscale convective system using numerical model output. These 3 events all occurred in strongly forced synoptic environments where 500 and 300 hPa troughs and 500 hPa thermal troughs were evident. From the analysis of diagnostic variables, it was found in all 3 events that absolute vorticity and cold air advection were dominant in the Yeongdong region and its surrounding sea at upper levels, especially at around 500 hPa (absolute vorticity: $20{\sim}60{\times}10^{-5}s^{-1}$, cold air advection: $-10{\sim}-20^{\circ}C$ $12hr^{-1}$). Moreover, the spatial distributions of cold advection showed mostly the shape of a narrow band along the eastern coast of Korea. These features of absolute vorticity and cold advection at 500 hPa were sustained for about 10 hours before the occurrence of maximum hourly snowfall.

• 대기
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• 제16권2호
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• pp.125-139
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• 2006

Precipitation forecasts from MM5 have been verified for the period 1989-2001 over Yeongdong region to show a tendency of model forecast. We select 57 events which are related with the heavy snowfall in Yeongdong region. They are classified into three precipitation types; mountain type, cold-coastal type, and warm type. The threat score (TS), the probability of detection (POD), and the false-alarm rate (FAR) are computed for categorical verification and the mean squared error (MSE) is also computed for scalar accuracy measures. In the case of POD, warm, mountain, and cold-coastal precipitation type are 0.71, 0.69, and 0.55 in turn, respectively. In aspect of quantitative verification, mountain and cold-coastal type are relatively well matched between forecasts and observations, while for warm type MM5 tends to overestimate precipitation. There are 12 events for the POD below 0.2, mountain, cold-coastal, warm type are 2, 7, 3 events, respectively. Most of their precipitation are distributed over the East Sea nearby Yeongdong region. These events are also shown when there are no or very weak easterlies in the lower troposphere. Even in the case that we use high resolution sea surface temperature (about 18 km) for the boundary condition, there are not much changes in the wind direction to compare that with low resolution sea surface temperature (about 100 km).

• 한국지구과학회지
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• 제44권2호
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• pp.119-134
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• 2023

본 연구는 2021년 3월 1일부터 2일까지 영동지역에 강설이 발생했던 사례의 종관적, 열역학적, 역학적 특성을 분석한 것이다. 분석에 사용한 자료는 AWS 관측자료, 지상일기도, ERA5 재분석 자료, 레윈존데, 천리안 2A 위성 자료, WISSDOM 자료 등이다. 사례 기간 영동지역 4개소에서 관측된 적설은 10 cm 이상으로 나타났으며, 북강릉(37.4 cm)에서는 가장 많은 적설을 보였다. 종관 분석결과, 동해상 및 영동지역 주변으로 중·상층 대기의 매우 차고 건조한 대기와 상대적으로 따뜻한 하층 대기의 온도 차이로 대류 불안정이 형성되어 북강릉 지역으로 대류운의 발달과 함께 강설이 나타났다. 특히 열역학적 및 운동학적 연직 분석에서, 하층에서 온위의 연직 경도에 의한 강한 바람과 한랭이류에 의한 대류 불안정이 영동지역의 강설 발생에 큰 역할을 한 것으로 판단된다. 이러한 결과는 레윈존데의 연직 분석에서도 확인할 수 있었다.