• 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.

• 한국기후변화학회지
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• 제6권2호
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• pp.87-94
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• 2015

To compare changes in winter temperature over South Korea, 30-year average climate data and climate data of recent 10 years (2014~2014) such as mean temperature, daily maximum temperature and daily minimum temperature were analyzed. Also, we set analysis extreme cold waves frequency related to winter such as freezing days, snow days, days with temperature of below -5, and days with temperature of below -10. This process enabled the comparative analysis of winter temperature changes and extreme cold waves frequency related to winter. This study estimated that winter temperature has gradually increased throughout the last five decades, however, the frequency of extreme weather, such as cold waves has also increased.

• 한국지역사회생활과학회지
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• 제21권4호
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• pp.633-639
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• 2010

This study was carried out to compare human thermoregulatory responses and preferred air temperature by feet immersion between summer and winter in terms of thermal comfort. Five healthy female university students participated in the study as subjects. They experienced feet immersion at $40^{\circ}C$ of water in the climatic chamber of $24^{\circ}C$, 50%RH from 19:30 to 21:00 in the summer and winter, respectively. Rectal temperature gradually decreased and maintained $0.08^{\circ}C$ lower in winter than summer, while mean skin temperature changed $0.4^{\circ}C$ greater in winter than summer(p=0.00). Air temperature selected by each subject for their thermal comfort revealed $0.8^{\circ}C$ higher in summer than winter(p=0.06). The results obtained suggest an increase in human thermoregulation and be used as preliminary data to maintain optimal indoor temperature in summer and winter.

• 한국환경과학회지
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• 제21권12호
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• pp.1425-1433
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• 2012

Water temperature in the eastern part of the Yellow Sea (EYS) during winter (JFM) and summer (JJA) from 1964 to 2009 and Siberian High Pressure Index (SHI) and Arctic Oscillation index (AOI) during winter (JFM) from 1950 to 2011 were used to analyze long-term variation in oceanic and atmospheric conditions and relationship between winter and summer bottom water temperature. Winter water temperature at 0, 30 and 50 m had fluctuated highly till the late of 1980s, but after this it was relatively stable. The long-term trends in winter water temperature at both depths were separated with cold regime and warm regime on the basis of the late 1980s. Winter water temperature at 0m and 50m during warm regime increased about $0.9^{\circ}C$ and $1.1^{\circ}C$ respectively compared to that during cold regime. Fluctuation pattern in winter water temperature matched well with SHI and AOI The SHI had negative correlation with water temperature at 0 m (r=-0.51) and 50 m (r=-0.58). On the other hand, the AO had positive correlation with Winter water temperature at 0 m (r=0.34) and 50 m (r=0.45). Cyclic fluctuation pattern of winter water temperature had a relation with SHI and AO, in particular two to six-year periodicity were dominant from the early of the 1970s to the early of the 1980s. Before the late of 1980s, change pattern in winter water temperature at 0 and 50 m was similar with that in the bottom water temperature during summer, but after this, relationship between two variables was low.

• 대기
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• 제29권5호
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• pp.599-607
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• 2019

The change and periodicity of Korean winter temperature in the period 1979-2018 are investigated. It is shown that the winter temperature is on a long-term rise, with two regime shifts of winter temperature during 40 years. In addition, the decrease in cold days is confirmed along with the rise in temperature. Analysis of the periodicity of daily temperature in winter is carried out by means of power spectral analysis. Of the spectral peaks that are statistically significant, the most frequent detection exists on the time scale between 7 and 8 days. It is found that the number of significant periods have decreased since 2014, particularly no longer existent around the period of 7 day. The longer periods than 7 days gradually increase during 40 years, while the shorter periods show the tendency of decrease but recently rebound. Spectral analysis calculated from high/low-pass filtered daily temperature data also shows similar results.

• Journal of Biosystems Engineering
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• 제30권3호
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• pp.155-160
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• 2005

The objective of this research was to establish a domestically available cooling storage technique by cold-air in winter, using winter cool air ventilation fur determining rough rice cooling method in the storage and dry bin. The rough rice storage characteristics of two test conditions, winter cool-air ventilation storage and ambient temperature storage, were evaluated from January to July 2001, using a storage and dry bin of 300-ton capacity. Results of this research are as follows: Grain temperature was from $-5.1\~-8.5^{\circ}C$ after winter cool-air ventilation, and grain initial temperature for ambient temperature bin storage was $0.3\~1.9^{\circ}C$. Moisture content of rough rice decreased from $0.28\;to\;0.93\%$ and from $1.53\;to\;1.92\%$ to compare with original moisture contents for winter cool-air ventilation, and for ambient temperature bin storage, respectively. Broken ratio of brown rice from winter cool-air ventilation bin increased from $0.16\;to\; 0.92\%$, and brown rice broken ratio was from $2.24\;to\;2.86\%$ for ambient temperature bin storage to compare with initial broken ratio. Hardness of stored rice increased along storage period increase in alt storage methods, and cooling bin storage increased rice hardness of 0.271kgf: this increasing was lower then the other methods from 0.059 to 2.239kgf. Germination rates were decreased approximately 9.03, 3.14 and $3.20\%$ for upper, middle, and bottom of ventilating winter air bin, respectively, and germination rates of 2.70, 3.47 and $4.14\%$ were approximately decreased for upper, middle, and bottom parts of ambient temperature bin storage, respectively.

• 한국농공학회논문집
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• 제47권6호
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• pp.73-82
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• 2005

This study was performed to evaluate the need for heating wastewater to enhance treatment efficiency of organic matter (BOD, SS) during cold winter in newly developed Absorbent Biofilter System (ABS) which was established in the Suwon Campus of the Seoul National University. Treatments consisted of non-heating (2000 year) and heating(2001, 2002 year), and sampled data were analyzed during cold winter period as well as post winter period to investigate the influence of heating after winter season. Even the average air temperature showed only $0.4^{\circ}C$ difference between two experimental years, the difference in the average effluent temperature during cold winter period between heating and non-heating experiment was approximately $11^{\circ}C$. The average effluent concentration of organic matter in non-heating treatment exceeded the Korean standards for water quality of discharged effluent in riparian area (BOD and SS 10 mg/L); however, the standards were met in case of heating treatment during both winter and post winter period. Therefore, the need fur heating wastewater during cold winter season in ABS was justified. On the other hand, there was no improvement of treatment efficiency in T-N and T-p, but we observed the more activated nitrification as increasing the wastewater temperature. Because the average underground temperature was $5^{\circ}C$ higher than the average air temperature during cold winter period, we recommend that the ABS can be established in the underground rather than on-ground for saving the heating cost.

• 한국지역지리학회지
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• 제12권4호
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• pp.461-474
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• 2006

우리나라의 여름과 겨울철의 이상기온 출현 분포 특성을 분석한 후 여름과 겨울철의 월별 이상기온 출현 빈도에 의하여 한반도 이상기온 지역을 5개로 구분하였다. 여름철 이상고온의 출현 빈도가 다른 이상기온 지역보다 2배 이상 높은 제 I지역(중부 동안), 겨울철 이상고온 출현은 낮고 이상저온 출현은 높은 제 II지역(경기 서안과 중부 내륙 북부), 다른 지역과 달리 여름과 겨울철 이상기온의 출현이 특정 계절에 집중되지 않는 제 III지역(중 남부의 서부), 여름철 이상고온의 출현 빈도가 가장 낮고 겨울철 이상고온의 출현도 비교적 적은 제 IV지역(산지와 남부 및 남해안 동부), 겨울철 이상고온 빈도가 가장 높은 제 V지역(소백산맥/노령산맥 이남과 남해안 서부 및 제주도)이다.

• 한국농림기상학회지
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• 제2권3호
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• pp.95-102
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• 2000

근래의 '춥지 않은 겨울'현상의 연속출현으로 가을 보리의 재배지역의 북상에 따른 재배면적 확대를 논의 할 만하다. 최근('74∼'98년)의 가을보리재배기간(10∼5월)의 기상변화를 살펴보고 '87년을 기준으로 '춥지 않은 겨울현상'을 보인 13년('87∼'99년) 그전 13년('74∼'86년)의 가을보리 재배기간의 기상을 평년('61∼'90년)기상과 비교ㆍ분석한 결과는 다음과 같다. 1. 최근 25년 동안 가을보리재배기간의 평균기온은 1.02℃ 증가하였으며, 평균기온의 상승은 최저기온보다 최고기온의 상승이 더 크게 기여하였다. 2. 가을보리재배기간의 연도별 강수량은 최근 25년 동안 전국평균이 513.3 ㎜ 이었으며.'74년 이후 감소하다가 '92년 이후로는 다시 증가하는 경향이었으며, 일조시간은 농촌지역만 조금 적어지는 경향이고 다른 지역들은 조금씩 증가하는 경향을 보였다. 3. '춥지 않은 겨울' 현상을 보인 최근 13년의 가을보리재배기간의 기온은 평년보다 높았으며 특히 1∼2월의 기온이 많이 상승하였다 반면에 '87년을 기준으로 그전 13년의 기온은 평년과 비슷하거나 다소 낮은 경향을 보였다. 4. '춥지 않은 겨울'현상을 보인 최근 13년의 가을 보리재배기간의 강수량은 평년과 전반적으로 비슷하였으나, 4월의 강수량이 전국적으로 평년보다 26㎜정도 적었다. 반면에 일조시간은 전반적으로 평년보다 적었다 그러나, '87년을 기준으로 그전 13년의 강수량과 일조시간은 대체로 평년과 비슷하였다. 5. 가을보리의 안전재배선의 기준이 되는 월동기(1∼2월)의 기온상승으로 가을보리안전재배의 북상이 전망된다.

• 대한지리학회지
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• 제41권1호
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• pp.94-105
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• 2006

본 연구에서는 우리나라의 여름과 겨울철의 이상기온 출현 빈도의 변화와 그에 영향을 미치는 요인과의 관계를 파악하고자 하였다. 우리나라의 대부분 관측 지점에서는 여름철 이상고온 출현 빈도의 증가와 겨울철 이상저온 출현 빈도의 감소 경향이 뚜렷하다. 이러한 이상기온 출현 빈도의 변화는 대기 순환 지수 중 겨울철 이상기온 출현에 영향을 미치는 겨울 몬순 지수와 시베리아 고기압 강도 지수 및 북극 진동 지수, 그리고 여름철 이상저온 출현에 영향을 미치는 오호츠크해 고기압 강도 지수와 북태평양 지수 등의 변화 경향과 유사하다. 이 지수들은 이상기온의 변화에 영향을 미치는 요인 중 최근의 지구 온난화 경향을 반영하며 우리나라 전 지역의 이상기온 출현 빈도와 관계가 뚜렷하다.