• 대기
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• 제22권2호
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• pp.187-197
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• 2012

This study investigates the relationship between the Korean temperature and the atmospheric circulation such as Arctic Oscillation, Siberian High and Aleutian Low during the winter (December-January) for the period of 1970-2011. It is found that all indices to represent aforementioned circulations are significantly correlated with Korean winter temperature for the period of 1970 - 2011. There are marked contrasts in such relationship, however, before and after the mid-1980s when a significant regime shift of Korean winter temperature occurred. While Korean winter temperature has a close relationship with Arctic Oscillation after the mid-1980s, its relationship with Siberian High and Aleutian Low is weakened. The composite analysis between a positive and negative phase of Arctic Oscillation before and after the mid-1980s is conducted to examine a recent strengthening of Arctic Oscillation-Korean winter temperature relationship. It is found that the structural changes of low-level wind and the geopotential height at 500 hPa between the two phases of Arctic Oscillation are more effective to influence Korean winter temperature after the mid-1980s. This may induce a close relationship between the Korean winter temperature variability and Arctic Oscillation after the mid-1980s compared to before the mid-1980s.

• 대기
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• 제24권2호
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• pp.131-140
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• 2014

The "Barents Oscillation (BO)", first designated by Paul Skeie (2000), is an anomalous recurring atmospheric circulation pattern of high relevance for the climate of the Nordic Seas and Siberia, which is defined as the second Emperical Orthogonal Function (EOF) of monthly winter sea level pressure (SLP) anomalies, where the leading EOF is the Arctic Oscillation (AO). BO, however, did not attracted much interest. In recent two decades, variability of BO tends to increase. In this study, we analyzed the spatio-temporal structures of Atmospheric internal modes such as Arctic Oscillation (AO) and Barents Oscillation (BO) and examined how these are related with Arctic warming in recent decade. We identified various aspects of BO, not dealt in Skeie (2000), such as upper-level circulation and surface characteristics for extended period including recent decade and examined link with other surface variables such as sea-ice and sea surface temperature. From the results, it was shown that the BO showed more regionally confined spatial pattern compared to AO and has intensified during recent decade. The regional dipolelar structure centered at Barents sea and Siberia was revealed in both sea-level pressure and 500 hPa geopotential height. Also, BO showed a stronger link (correlation) with sea-ice and sea surface temperature especially over Barents-Kara seas suggesting it is playing an important role for recent Arctic amplification. BO also showed high correlation with Ural Blocking Index (UBI), which measures seasonal activity of Ural blocking. Since Ural blocking is known as a major component of Eurasian winter monsoon and can be linked to extreme weathers, we suggest deeper understanding of BO can provide a missing link between recent Arctic amplification and increase in extreme weathers in midlatitude in recent decades.

• 해양환경안전학회지
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• 제25권3호
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• pp.328-333
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• 2019

During the winter of 2017/2018, significantly low water temperatures were detected around the western and southern coasts of Korea (WSCK). In this period, sea surface temperature (SST) in the Korea Waters was about $2^{\circ}C$ lower than mean temperature. Using the real-time observation system, we analyzed the temporal variation of SST during this period around the western and southern coasts. Low water temperature usually manifested over a period of about 10 ~ 20 days. The daily Arctic oscillation index was also similarly detectable with the variation of SST. From the cross-correlation function, we compared two periodic variations, which were SST around the WSCK and the Arctic oscillation index. The cross correlation coefficients between both variations were approximately 0.3 ~ 0.4. The time lag of the two time series was about 6 to 7 days. Therefore, significantly low water temperatures during winter in the Korean coastal areas usually became detectable 6 to 7 days after the negative peak of Arctic oscillation.

• 한국수자원학회논문집
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• 제51권12호
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• pp.1247-1260
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• 2018

본 연구에서는 북극진동이 우리나라에 미치는 영향을 파악하고자 북극진동지수(AOI)와 북태평양에서 발생한 태풍의 개수 및 우리나라에 영향을 준 태풍의 개수, 또한 장마기간 중 총강수량 및 장마기간 중 강수일수와의 교차상관분석을 시도하였다. AOI 자료는 월단위 형태로 존재하나 교차 상관 분석에는 1월을 중심으로 한 평균 자료와 봄, 여름, 가을, 겨울의 계절자료를 이용하였다. 장마 특성 및 태풍 특성 자료는 모두 연 단위자료이다. 본 연구에서는 AOI 및 태풍, 장마 자료의 가용성을 고려하여 1961년에서 2016년 사이의 자료를 이용하였다. 본 연구에서의 결과를 종합해 보면, 북극진동은 우리나라의 장마 특성에 약한 수준이나 유의하게 영향을 미치고 있음을 확인할 수 있었다. 그러나 그 정도는 전체기간에 대해 일정하지 않으며 시기에 따라 크게 다른 것으로 나타난다. 예를 들어, 최근 10년간 북극진동이 장마에 미친 영향은 교차상관계수로 0.8 이상이다. 그러나 그 전 30년간은 통계학적으로 유의한 영향은 없었다. 이와는 반대로 북극진동이 우리나라에 영향을 준 태풍의 개수에 미치는 영향은 전체적으로는 유의하지 않은 것으로 나타난다. 공교롭게도 부분적으로 보면 이 역시 기간에 따라 유의한 영향과 유의하지 않은 영향이 반복적으로 교차하는 모습을 보인다. 즉, 기간에 따라 북극진동의 영향은 비정상적으로 크게 변동하는 모습을 보인다. 또한, 북극진동이 우리나라의 장마와 태풍에 미치는 영향이 과거 1960년대에서 2000년대까지 서로 교차되는 특성을 보여 왔다는 점에 주목할 필요가 있다. 그러나 공교롭게도 2010년대에 들어서면서 장마에의 영향과 태풍에의 영향이 둘 다 증가하는 형태로 바뀐 것으로 보인다.

• 대한지리학회지
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• 제44권6호
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• pp.675-690
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• 2009

본 연구에서는 우리나라에 출현하는 황사에 영향을 미치는 요인을 파악하기 위하여, 우리나라의 황사 출현일수와 대기순환지수인 북극진동지수, 남극진동지수와 유라시아 대륙 적설면적과의 관계를 분석하였다. 우리나라의 황사 출현일수는 1980년대 중반 이후 증가하고 있는 경향이다. 월별로는 4월에 황사 출현일수가 집중되었고 전반기의 3.2일에서 후반기의 5.1일로 1.9일 증가하였다. 황사 출현일수와 겨울철 북극진동지수 및 남극진동지수와는 정적인 관계가 있었다. 이는 겨울철 북극진동지수와 남극진동지수가 양의 값일 때 황사 출현일수가 증가한다고 할 수 있다. 황사 출현일수와 유라시아 대륙 적설면적과는 부적인 관계가 있었다. 이는 유라시아에 적설면적이 감소하면 황사 출현일수가 증가한다고 할 수 있다.

• 한국지구과학회지
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• 제40권1호
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• pp.1-8
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• 2019

Although recent reports suggest that the negative correlation between the Arctic Oscillation (AO) and the East Asian winter monsoon (EAWM) has been strengthened, it is not clear whether this intermittent relationship is an intrinsic oscillation in the climate system. We investigate the oscillating behavior of the AO-EAWM relationship at decadal time scales using the long-term (500-yr) climate model simulation. The results show that ice cover over the East Siberian Seas is responsible for the change in the coupling strength between AO and EAWM. We found that increased ice cover over these seas strengthens the AO-EAWM linkage, subsequently enhancing cold advection over the East Asia due to anomalous northerly flow via a weakened jet stream. Thus, this strengthened relationship favors more frequent occurrences of cold surges in the EAWM region. Results also indicate that the oscillating relationship between AO and EAWM is a natural variability without anthropogenic drivers, which may help us understand the AO-EAWM linkage under climate change.

• 한국제4기학회지
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• 제33권1_2호
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• pp.37-48
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• 2021

한파는 겨울철 동아시아 지역의 대표적인 위험 기상 현상으로, 시베리아 고기압에 지배적인 영향을 받으며, 북극 지역의 기압장이 일정 주기로 강약을 되풀이하는 북극진동의 위상과도 밀접한 관련이 있다. 또한, 한반도-일본 동쪽 해상에서 발달하는 저기압은 해수면 온도에 민감하고 한파발생 시 한반도로 유입되는 한랭 이류의 강화에 중요한 역할을 한다. 본 연구에서는 겨울철 동아시아 한파의 대규모 배경장에 영향을 미치는 북극진동과 저기압과 관련된 급격한 기온 변화에 기여하는 동아시아 해안 지역의 해수면 온도를 분석하였다. 분석을 위해 49년(1969/70-2017/18) 동안 한반도 5개의 관측소에서 측정된 일 평균기온 중 하위 3%에 해당하는 날을 한파 사례로 선택하였다. 북극진동이 음의 위상일 때, 동아시아 지역에 위치한 기압골이 강해지며 극 지역의 한랭한 공기 유입이 강화되어 한파가 빈번하게 발생함을 확인하였다. 또한, 동아시아 주변의 해수면 온도가 평균보다 높은 경우 대기와 해양의 온도 및 습도 차이로 인해 현열 및 잠열 방출이 강화되며, 종관 저기압이 더 강하게 발달하여 기온이 빠르게 하강하는 극심한 한파가 발생할 가능성을 보였다.

• 대기
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• 제12권2호
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• pp.8-9
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• 2002

• 한국제4기학회지
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• 제33권1_2호
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• pp.25-35
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• 2021

In this study, we identified characteristics of heatwaves on the Korean Peninsula and related atmospheric circulation patterns using data on the daily maximum temperature (TMX) and reanalysis data for the past 42 years (1979-2020) and analyzed their connection to the Arctic oscillation (AO). The heatwave on the Korean Peninsula showed to be stronger and more frequent in the 2000s. The recent strong and frequent heatwaves on the Korean Peninsula are mainly affected by abnormal high-pressure over the Korean Peninsula on the middle/upper-level atmosphere and the strengthening of the North Pacific high pressure. Interestingly, composite difference of sea level pressure showed very similar results to the positive AO pattern. The correlation coefficients between the summertime AO and the TMX and HWD of the Korean Peninsula were 0.407 and 0.437, respectively, which showed a statistical significance in 1%, and showed a clear relationship with the abnormal high-pressure over the Korean Peninsula and the strengthening of the North Pacific high pressure. In addition, in the positive AO phase, the TMX and HWD of the Korean peninsula were approximately 30.1 ℃ and 14.6 days, which were about 1.2 ℃ and 8.8 days higher than in the negative AO phase, respectively. As a result of the 15-year moving average correlation analysis, the relationship between the heatwave and AO on the Korean Peninsula has increased significantly since 2003, and the linear relationship between them has become more apparent. Moreover, after the 2000s, when the relationship developed, AO had more strongly induced the atmospheric circulation pattern to be more favorable to the occurrence of heatwaves in the Korean Peninsula. This study implies that understanding the AO, which is the large-scale variability in the Northern Hemisphere, and the Arctic-mid latitude teleconnection, can improve the performance of global climate models and help predict the seasonality of the summer heatwave on the Korean Peninsula.

• 대기
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• 제20권4호
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• pp.387-398
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• 2010

This study shows that frequency of tropical cyclone (TC) around Korea in summer (June-September) has positive relation with Arctic Oscillation (AO) in the preceding April. In a positive AO phase, each of anomalous cyclone and anomalous anticyclone is developed in low latitude and middle latitude regions of East Asia from the preceding April to summer. As a result, while anomalous southeasterly around Korea serves as a steering flow that TCs move toward this area is strengthened, northwesterly that reinforced in southeastern area of East Asia plays a role in preventing TCs from moving toward this area. In addition, due to this distribution of pressure systems developed in this AO phase, TCs tend to occur, move and recurve in further northeastern region in the western North Pacific than TCs in a negative AO phase. On the contrary, TCs in a negative AO phase mainly move westward toward southern China or Indochina Peninsula from Philippines. Eventually, intensity of TCs is weaker than those in a positive AO phase due to the terrain effect caused by high passage frequency of TCs in mainland China.