• Korean Journal of Agricultural and Forest Meteorology
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• v.12 no.1
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• pp.11-22
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• 2010

According to IPCC 4th Assessment Report, concentration of carbon dioxide has been increasing by 30% since Industrial Revolution. Most of IPCC $CO_2$ emission scenarios estimate that the concentration will reach up to double of its present level within 100-year if the current tendency continues. The global warming has resulted in the agro-climate change over the Korean Peninsula as well. Accordingly, it is necessary to understand the future agro-climate induced by the increase of greenhouse gases in terms of the agro-climatic indices in the Korean peninsula. In this study, the future climate is simulated by an atmosphere/ocean/land surface/sea ice coupled general circulation climate model, Pusan National University Coupled General Circulation Model(hereafter, PNU CGCM), and by a regional weather prediction model, Weather Research and Forecasting Model(hereafter, WRF) for the purpose of a dynamical downscaling. The changes of the vegetable period and the crop growth period, defined as the total number of days of a year exceeding daily mean temperature of 5 and 10, respectively, have been analyzed. Our results estimate that the beginning date of vegetable and crop growth periods get earlier by 3.7 and 17 days, respectively, in spring under the $CO_2$-doubled climate. In most of the Korean peninsula, the predicted frost days in spring decrease by 10 days. Climatic production index (CPI), which closely represent the productivity of rice, tends to increase in the double $CO_2$ climate. Thus, it is suggested that the future $CO_2$ doubled climate might be favorable for crops due to the decrease of frost days in spring, and increased temperature and insolation during the heading date as we expect from the increased CPI.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2010.04a
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• pp.238-239
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• 2010

근래, 이산화탄소로 대표되는 온실효과 기체의 증가에 동반하여 대류권의 기온이 정정 상승하는 지구 온난화의 경향이 나타나고 있다. 지구 온난화가 지속되면 해수면온도가 상승하고 그에 따라 해빙 면적의 축소와 해수면 상승이 동반된다. 이와 같은 지구 온난화의 상황이 지속되면 이상기상이 지구상 각지에서 빈발할 것이라는 주장도 제기되고 있다. 이 연구에서는 장기간의 태풍 관련 데이터를 이용하여 지구 온난화와 관련한 태풍의 변화 경향을 분석하였다. 연구 결과 지구 온난화와 더불어 태풍의 발생 수는 감소하고 있으며, 태풍의 세기는 서서히 강화되고 있음을 확인하였다. 그리고 태풍의 이동경로 중에서 정상진로는 증가하는 경향을 보이고 서진형진로는 감소하는 추세를 보이고 있다는 사실을 알았다. 우리나라의 경우는 최근에 들어 통해(또는 일본)를 통과하면서 영향을 미치는 태풍의 수가 증가하는 반면 서해를 통과하는 태풍의 수는 감소하는 경향을 보인다. 그리고 우리나라에 가장 큰 기상재해를 입히는 남해를 통과하는 태풍의 수는 시계열 상 큰 변화를 보이지 않는다.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.274-274
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• 2023

기후변화의 영향으로 겨울철 적설의 양상이 과거와는 많이 달라진 것으로 보인다. 따라서 미래의 적설이 어떤 확률로 발생할 것인지도 과거에 비해 많이 달라질 것으로 예상된다. 하지만 어떤 정도로 달라질 것인지는 정확하게 알 수가 없다. 본 연구에서는 이를 합리적으로 추정하기 위해 일본에서 수행한 대규모 기후 앙상블 모의실험 결과로 생성된 d4PDF(Data for Policy Decision Making for Future Change) 자료 중 적설과 기온 자료를 이용하여 일 최심적설심을 모의하고 연최대치계열을 작성하여 과거의 최심적설심 연최대치분포와 비교하여 분위사상법을 통해 모형의 오차를 보정한 후 미래 지구평균온도 상승 시의 기후모의 결과에 적용함으로써 지구평균온도 상승 정도에 따라 우리나라의 적설양상과 확률적설심이 어떻게 변화할 것인지 추정해 보았다. 연구의 결과는 미래 적설과 관련된 설계와 방재 목적에 참고적으로 활용될 수 있을 것이다.

• Journal of the Korean Society for Marine Environment & Energy
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• v.10 no.1
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• pp.59-65
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• 2007

Rapid variation of coastal ecosystem in the East Sea of Korea, such as fishery resource variation and subtropical chang of bentic flora, accordong to the global warming are actually noticed. In this study we try to identify the characterics of water mass existing in this coastal area and to consider the variation of their physical and chemical properties using data of temperature, salinity and dissolved oxygen obtained by National Fisheries Research & Development Institute from 1960 to 2005. The temperature of all water mass rise during last 45 years; the rise of North Korea Cold Water temperature (about $2.33^{\circ}C$) is 1.5 times higher than that of Tsushima warm water (about $1.6^{\circ}C$), and the temperature rise of Tsushima Surface Water, directly affected by climate chang is $2.57^{\circ}C$, higher than the atmospheric temperature rise during same period, indicating that subtropical change makes progress more rapidly in the coastal marine ecosystem than in the land ecosystem. Otherwise, the salinity in the surface water decrease $0.29\%_{\circ}$ during last 45 years due to the rising trend of rainfall with atmospheric temperature. The dissolved oxygen concentration in the all water mass make a decreasing trend. Specially for the North Korea Cold Water, the dissolved oxygen concentration diminish 0.021 mg/l per year and the decrease in the East Sea Proper Water indicate a change of inner water circulation system.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.22 no.5
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• pp.316-325
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• 2010

Harmonic analyses are carried out in order to obtain the major frequency components of the air temperature (AT) and surface water temperature (SWT) data monitored in the Middle Area of the Yellow Sea (Yellow Sea monitoring buoy). The analysis shows the annual and semi-annual components are predominant and the higher frequency components are relatively weak with contribution to the short fluctuations, i.e. below $0.2{\sim}0.5^{\circ}C$, in the AT and SWT. The standard deviation of the AT residual is 2.4 times larger than that of the SWT residual and the occurrence frequency distributions of the AT and SWT residual components are both closely fitted to a normal-distribution function. The variation pattern on the AT-SWT plane forms the clear continuous hysteresis loop in anti-clockwise direction which is composed of the AT-SWT rising period, AT-SWT falling period, and the constant SWT period in winter season.

• Journal of Bio-Environment Control
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• v.27 no.3
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• pp.269-275
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• 2018

In order to establish the criterion for analyzing outdoor weather conditions in the greenhouse heating and cooling system design, we analyzed heating and cooling design outdoor temperatures by the annual percentile method and compared with design outdoor temperatures by the existing seasonal percentile method. In the annual percentile method, 0.4%, 1% and 2% of the total 8,760 hours per year are presented as cooling design outdoor temperatures and 99.6% and 99% as heating design outdoor temperatures. When the annual percentile method was adopted, heating design outdoor temperatures increased by 6.7 to 9.6% compared with the seasonal percentile method, and cooling design outdoor temperatures decreased by 0.6 to 1.1%. The maximum heating load in the same greenhouse condition decreased by 3.0 to 3.6% when the annual percentile method was adopted, but the effect on the maximum cooling load was insignificant. Therefore, it is necessary to consider the change of heating design outdoor temperatures to the annual percentile method, but it is not necessary to change the cooling design outdoor temperatures since there is little difference between the two methods.

• Journal of the Korean association of regional geographers
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• v.4 no.2
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• pp.151-164
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• 1998

I analyzed the correlation between El-Nino phenomenon and our country's temperature and precipitation laying the stress on the anomaly, and the result of this analysis is as follows: (1) The extraction of the occurrences of El-Nino at the place of sea surface around Nino.3 which was known as the sea area under observation for El-Nino reveals that there are 9 years (1969, 1970, 1973, 1977, 1987, 1992, 1995, 1998) when the temperature anomaly in January is more than 1.0 during the period of research years ($1969{\sim}1998$). (2) The tendency of change of sea surface temperature around Nino.3 and that of our country are about the same, but the anomaly of Pusan and Inchon was much greater than that of Jangki in the East Coast. (3) The anomaly of sea surface temperature around Nino.3 and that of the ground temperature showed the similar changing tendency, the temperature of our country has something to do with that of sea surface as the correlation of ground temperature with the temperature of sea surface showed 0.31. Anomaly warm winter has something to do with El-Nino because the temperature of our country was high when El-Nino phenomenon appeared. (4) As for the precipitation, we can see that it has generally increased after 1989 when the phenomenon of warm climate was intense than before that year. But as we study the change of anomaly, the precipitation has less correlation in comparison with the ground temperature. The precipitation in 1973, 1983 and 1987 which were El-Nino years was correlated with El-Nino. While the change of sea surface temperature has showed a tendency of plus(+)increase since 1990, the precipitation has showed a tendency of minus (-)decrease. Therefore it seems that the temperature of sea surface has little correlation with the amount of rainfall.

• Proceedings of the KAIS Fall Conference
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• 2009.05a
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• pp.825-828
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• 2009

기후변화는 기상재해뿐만 아니라 지속적인 해수면 상승의 원인이 되고 있으며, 자연 생태계화 인간의 사회, 경제시스템 전반에 걸쳐 영향을 미치고 있으며, 건설분야도 이와 무관하지 않다. 특히 기후변화는 해수면 상승으로 이어져 사회기반시설인 항구, 연안도로, 철도, 빌딩 등과 연안산업인 석유 및 석유화학공장, 그리고 서비스업인 관광에 대한 위협으로 나타나고 있다. 이러한 해수면 상승은 토지 및 건물의 재산 가치 하락과 해수면 상승에 따른 보호비용 증대, 구조물의 급속한 노후화에 따른 유지관리비용의 증가뿐만 아니라 정치적 제도적 불안 및 사회동요 등을 유발할 수 있다. 우리나라의 경우, 지난 100년간 6대 도시 평균기온이 약 $1.5^{\circ}C$ 상승하였으며, 해수면(제주기준)은 40년간 22cm가 상승하였다. 특히 제주의 경우 매년 5mm씩의 해수면 상승을 보이고 있으며 이는 전 지구 해수면 상승률보다 3배 높은 수치이다. 본 연구는 해수면의 상승에 따른 건설분야의 영향을 분석하기 위한 선도적인 연구로서, 연구의 범위를 제주지역에 국한하였으며, 해수면 상승에 따른 영향 지역을 추출하고, 영향 지역 내 건설시설물 정보를 추출하기 위한 절차를 규명하였다. 본 연구 결과는 유지보수 및 시설물 이설에 따른 공사비 산출의 근거가 될 뿐만 아니라 관련 예산 확보에 대한 근거 자료로 활용될 수 있을 것이다. 향후 관련 지역의 유지보수 및 이설 공사비 정보의 추출 및 DB 구축을 통해 연안 건설 시설물의 이설에 따른 공사비를 예측할 수 있을 것이다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.6
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• pp.2237-2244
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• 2013

In this study, physics based K-DRUM(K-water Distributed RUnoff Model) using GIS spatial hydrologic data as input data was developed to account for the temperature variation according to the altitude change considering snow melt and cover. The model was applied for Pakistan Kunhar River Basin($2,500km^2$) to calculate long-term discharge considering snow melt and cover. Time series analysis of the temperature and rainfall data reveals that temperature and rainfall of the river basin differs significantly according to altitude change compared to domestic basin. Thus, applying temperature and altitude lapse rate during generate input data generation. As a result, calculated discharge shows good agreement with observed ones considering snow melt and accumulation characteristic which has the difference of 4,000 meter elevation above sea level. In addition, the simulated discharge strongly showed snow melting effect associated with temperature rise during the summer season.

• Journal of Astronomy and Space Sciences
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• v.25 no.4
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• pp.395-404
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• 2008

We explore the linkage between the long term variability of the Sun and earth's climate change by analysing periodicities of time series of solar proxies and global temperature anomalies. We apply the power spectral estimation method named as the periodgram to solar proxies and global temperature anomalies. We also decompose global temperature anomalies and reconstructed total solar irradiance into each local variability components by applying the EMD (Empirical Mode Decomposition) and MODWT MRA (Maximal Overlap Discrete Wavelet Multi Resolution Analysis). Powers for solar proxies at low frequencies are lower than those of high frequencies. On the other hand, powers for temperature anomalies show the other way. We fail to decompose components which having lager than 40 year variabilities from EMD, but both residuals are well decomposed respectively. We determine solar induced components from the time series of temperature anomalies and obtain 39% solar contribution on the recent global warming. We discuss the climate system can be approximated with the second order differential equation since the climate sensitivity can only determine the output amplitude of the signal.