• 대기
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• 제33권5호
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• pp.505-517
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• 2023

This study investigates the impacts of carbon neutrality and air quality control policies on near-term climate change in East Asia, by examining three Shared Socioeconomic Pathways (SSPs) scenarios from five climate models. Specifically, low carbon and strong air quality control scenario (SSP1-1.9), high carbon and weak air quality control scenario (SSP3-7.0), and high carbon and strong air quality control scenario (SSP3-7.0-lowNTCF) are compared. For these scenarios, the near-term climate (2045-2054 average) changes are evaluated for surface air temperature (SAT), hot temperature extreme intensity (TXx), and hot temperature extreme frequency (TX90p). In all three scenarios, SAT, TXx, and TX90p are projected to increase in East Asia, while carbon neutrality reduces the increasing rate of SAT and hot temperature extremes. Air quality control strengthens the warming rate. These opposed mitigation effects are robustly forced in all model simulations. Nonetheless, the impact of carbon neutrality overcomes the impact of air quality control. These results suggest that fast carbon neutrality, more effective than an air quality control policy, is necessary to slowdown future warming trend in East Asia.

• 대기
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• 제31권2호
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• pp.199-214
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• 2021

A record-breaking high surface air temperature of 41.0℃ was observed on 1 August 2018 at Hongcheon, South Korea. In this study, to quantitatively determine the formation mechanism of this extremely high surface air temperature, particularly considering the contributions of the foehn and the foehnlike wind, observational data from Korea Meteorological Administration (KMA) and the Weather Research and Forecasting (WRF) model were utilized. In the backward trajectory analysis, trajectories of 100 air parcels were released from the surface over Hongcheon at 1600 LST on 1 August 2018. Among them, the 47 trajectories (38 trajectories) are tracked back above (below) heights of 1.4 km above mean sea level at 0900 LST 31 July 2018 and are defined as upper (lower) routes. Lagrangian energy budget analysis shows that for the upper routes, adiabatic heating (11.886 × 10³ J kg^-1) accounts for about 77% of the increase in the thermal energy transfer to the air parcels, while the rest (23%) is diabatic heating (3.650 × 10³ J kg^-1). On the other hand, for the lower routes, adiabatic heating (6.111 × 10³ J kg^-1) accounts for about 49% of the increase, the rest (51%) being diabatic heating (6.295 × 10³ J kg^-1). Even though the contribution of the diabatic heating to the increase in the air temperature rather varies according to the routes, the contribution of the diabatic heating should be considered. The diabatic heating is caused by direct heating associated with surface sensible heat flux and heating associated with the turbulent mixing. This mechanism is the Type 4 foehn described in Takane and Kusaka (2011). It is concluded that Type 4 foehn wind occurs and plays an important role in the extreme event on 1 August 2018.

• 한국환경과학회지
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• 제26권9호
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• pp.1023-1029
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• 2017

We studied the distribution of air temperature using the high density urban climate observation network data of Daegu. The observation system was established in February 2013. We used a total of 38 air temperature observation points (23 thermometers and 18 AWSs). From the distribution of monthly averaged air temperatures, air temperatures at the center of Daegu were higher than in the suburbs. The daily minimum air temperature was more than or equal to $25^{\circ}C$ and the daily maximum air temperature was more than or equal to $35^{\circ}C$ at the elementary school near the center of Daegu. Also, we compared the time elements, which are characterized by the diurnal variation of surface air temperature. The warming and cooling rates in rural areas were faster than in urban areas. This is mainly due to the difference in surface heat capacity. These results indicate the influence of urbanization on the formation of the daily minimum temperature in Daegu.

• 대기
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• 제24권3호
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• pp.379-390
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• 2014

This study explores the long-term trends of surface air temperatures in 11 KMA stations over the period of 1960~2012. Both linear and nonlinear trends are examined for the $95^{th}$, $50^{th}$, and $5^{th}$ percentiles of daily maximum ($T_{max}$) and minimum temperatures ($T_{min}$) by using quantile regression method. It is found that in most stations linear trends of $T_{max}$ and $T_{min}$ are generally stronger in winter than in summer, and warming trend of the $5^{th}$ percentile temperature (cold extreme) is stronger than that of the $95^{th}$ percentile temperature (warm extreme) in both seasons. The nonlinear trends, which are evaluated by the second order polynomial fitting, show a strong nonlinearity in winter. Specifically, winter temperatures have increased until 2000s but slightly decreased afterward in all percentiles. This contrasts with the $95^{th}$ and $50^{th}$ percentiles of summer $T_{min}$ that show a decreasing trend until 1980s then an increasing trend. While this result is consistent with a seasonal dependence of the recent global warming hiatus, most of the nonlinear trends are statistically insignificant, making a quantitative attribution of nonlinear temperature trends challenging.

• 한국습지학회지
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• 제20권4호
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• pp.338-344
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• 2018

본 연구에서는 기후변화에 따른 극한 강우의 비정상성을 반영하기 위하여 GEV 분포의 3개 매개변수 중 위치매개변수를 공변량으로 적용하여, 지표면 기온(Surface air temperature, SAT) 및 이슬점 온도(Dew point temperature, DPT)을 고려한 비정상성 빈도해석이 실시된다. 부산 지점이 연구대상지점으로 선정되었으며, 5월부터 10월까지의 월 최대 일강수량을 이용하여 분석을 수행하였다. GEV 분포의 위치 매개변수를 위한 가장 적절한 공변량(기온과 이슬점 온도) 함수를 선택하기 위하여 다양한 모델을 구성하였으며, 구성된 모델 중 AIC(Akaike Information Criterion)가 가장 작은 모델을 최적 모델로 선정하였다. 분석 결과, exp(DPT)가 공변량인 비정상성 GEV 분포가 가장 적합한 것으로 나타났다. 선택된 모델을 이용하여 기후변화 시나리오에 따른 확률강우량의 영향을 분석하였으며, 부산지점의 경우 미래 이슬점 온도가 증가함에 따라 확률강우량이 증가할 가능성이 매우 높음을 살펴볼 수 있었다.

• 한국기후변화학회지
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• 제5권4호
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• pp.323-329
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• 2014

Since the terrain of Korea is complex, micro- as well as meso-climate variability is extreme by locations in Korea. In particular, air temperature of agricultural fields is influenced by topographic features of the surroundings making accurate interpolation of regional meteorological data from point-measured data. This study was carried out to compare spatial interpolation methods to estimate air temperature in agricultural fields surrounded by rugged terrains in South Korea. Four spatial interpolation methods including Inverse Distance Weighting (IDW), Spline, Ordinary Kriging (with the temperature lapse rate) and Cokriging were tested to estimate monthly air temperature of unobserved stations. Monthly measured data sets (minimum and maximum air temperature) from 588 automatic weather system(AWS) locations in South Korea were used to generate the gridded air temperature surface. As the result, temperature lapse rate improved accuracy of all of interpolation methods, especially, spline showed the lowest RMSE of spatial interpolation methods in both maximum and minimum air temperature estimation.

• 해양환경안전학회지
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• 제27권6호
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• pp.701-707
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• 2021

본 연구에서는 강한 한파가 발생했던 2018년과 온난 한파가 발생했던 2019년의 기온에 따른 수온의 반응 및 지연시간과 북풍계열 바람 빈도와의 상관관계를 분석하였다. 사용된 시간 자료는 국립수산과학원에서 제공하는 7개 지점 해역별 수온자료와 수온관측소 인근 7개 지점 AWS 기온자료를 이용하였다. 관측되지 못한 자료는 내삽법으로 근사값을 계산하였고, FIR Filter를 이용하여 자료의 주기성을 파악하였다. 그 결과, 강한 한파가 발생했던 2018년은 북풍계열 바람을 통해 차가운 공기가 남하하면서 기온을 하강시켜 전 해역에 저수온을 유발한 반면 온난 한파가 발생했던 2019년은 평년 수준의 기온으로 하강하였지만 수온은 크게 변화하지 않았다. 강한 한파가 발생했던 2018년 기온 하강에 따른 수온의 지연시간은 평균 14시간으로 0.7 이상의 높은 상관성을 나타냈고 온난 한파가 발생했던 2019년은 평균 지연시간이 20시간으로 0.44-0.67 사이의 상관성을 보였다. 본 연구를 통해 해역별로 기온 하강에 따른 표층수온의 반응을 해석하였고 지연시간을 파악함으로써 양식생물의 피해를 최소화하고 한파 피해의 신속한 대응에 기여할 수 것으로 기대한다.

• 대기
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• 제25권3호
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• pp.461-472
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• 2015

The sudden stratospheric warming (SSW), which is characterized by an abrupt increase of polar stratospheric temperature by several tens of degrees in a week, has been known to affect tropospheric weather and climate on sub-seasonal time scale in the boreal winter. Such downward coupling has been often examined in North Atlantic and Europe, but rarely examined in East Asia. In this study, by applying the two definitions of SSW to the reanalysis data, the possible impacts of the SSW events on the surface air temperature (SAT) and tropospheric circulation in East Asia are analyzed. It is found that Eurasian continent, including Siberia and the Northeast Asia, tends to experience anomalously cold SAT for up to sixty days after the SSW events. The resulting SAT anomalies largely resemble those associated with negative Artic Oscillation. However, over East Asia, SSW-related SAT change is weak and not statistically significant. Only during the extreme SSW events when the downward coupling between the stratosphere and troposphere is strong, East Asia exhibits significantly cold SAT anomalies. This relationship is presented by grouping SSW events into those followed by cold SAT anomalies over East Asia and those by warm anomalies for varying threshold values of the SSW events.

• 한국제4기학회:학술대회논문집
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• 한국제4기학회 2004년도 하계학술대회
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• pp.29-29
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• 2004

Long term observational analysis by climatologists has confirmedthat the global warming is no longer a topic of debate among scientists andpolicy makers. According to the report of IPCC-2001 (Intergovernmental Panelon Climate Change), the global mean surface air temperature is increasinggradually. The reported increase of mean temperature is by 0.6 degree in the end of twentieth century. This could represent severe threat for propertylosses especially due to increase in the number of extreme weather arising out of global warming. period of model integration from 2001 to 2100 using output of ECHAM4/HOPE-G of Max Planet Institute of Meteorology (MPI) for IPCC SRES (Special Report on Emission Scenarios). The main results of this study indicate increase of surface air temperature by 6.20C and precipitation by 2.6% over Korea in the end of 21st century. Simulation results also show that there is increase in daily maximum and minimum temperatures while decrease in diurnal temperature range (DTR). DTR changes are diminished mainly due to relatively rapid increase of daily minimum temperature than that of daily maximumtemperature. It has been observed that increase in precipitation amount anddecrease in the number of rainy days lead to increase of pre precipitationintensity.

• 대한지리학회지
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• 제50권1호
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• pp.1-21
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• 2015

본 연구에서는 지난 40년 동안(1973~2012)의 우리나라 기상청 산하 61개 지점 일기온 자료와 NCEP/NCAR 재분석 자료를 바탕으로 우리나라 지역별 겨울철 극한저온현상 발생 시 동아시아 영역의 종관 기후 패턴의 특징을 밝히고자 하였다. 일최고기온과 일최저기온 하위 10 퍼센타일 기준으로 정의된 겨울철 극한저온현상은 주로 겨울철 전반기(12월 초순~1월 중순)에 2~7일 간격으로 우리나라 전역 또는 주요 산맥 기준 동서지역으로 구분되어 발생함을 알 수 있다. 해수면기압과 바람벡터 등의 지상 종관 자료 합성장 분석에 따르면 총 13개로 구분되는 우리나라 겨울철 극한저온현상 발생 공간 패턴은 산맥뿐만 아니라 시베리아 고기압과 알류샨 저기압의 상대적인 확장 범위와 강도와 밀접한 관련성이 있음을 알 수 있다. 대류권 중층(500 hPa) 종관기후도 분석에 따르면, 블러킹 형태의 저기압이 상층 찬 공기를 고위도 지역에서 한반도로 이류시킬 때 우리나라에 겨울철 극한저온현상이 발생하기에 적합한 조건이 형성됨을 알 수 있다. 이러한 결과들은 지역규모 이상의 동아시아 겨울철 극한저온현상 예보를 향상시키기 위해 시베리아 고기압, 알류샨 저기압, 상층 블러킹 등의 종관 기후 요소를 모니터링하는 것이 중요함을 가리킨다.