• Journal of the Korean Geographical Society
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• v.52 no.1
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• pp.1-13
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• 2017

This study aims to identify the warm and cold periods(WP, CP) of November appeared in the daily normals of daily minimum temperature of Seoul for 1941~1970 and 1971~2000 and to investigate synoptic characteristics of the temperature changes of WP and CP. The WP temperatures are increased clearly(p value 0.000), the CP temperatures are also warming but not significant statistically. In WP, there are not apparent trends corresponding the warming of WP temperature, in the Siberian High, Sea Level Pressure(SLP), 925hPa surface wind(U925, V925) around the Korean peninsula. In high period(1972~1979) of WP temperature, there are positive SLP anomaly and anomalous anticyclonic circulation pattern of 925hPa wind field over the Korean peninsula then the winter monsoon is weakened and the WP temperature is ascending. In CP, the Siberian high are weakening, the Hokkaido eastern low are strengthening and the westerlies(U925) over the Korean Peninsula are enlarging. So CP temperature are suppressed in rising trend or shows weak descent.

• The Bulletin of The Korean Astronomical Society
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• v.46 no.1
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• pp.43.3-43.3
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• 2021

10세기부터 18세기까지 한국 역사서에 기록된 38개 흑점과 이와 연관된 것으로 보이는 25개의 적색 오로라를 조사하여 고대 흑점의 지구 영향성을 분석하였다. 고대 관측 시기를 1300년을 기준으로 이전의 온난기와 이후의 냉한기로 나누어 보면, 흑점의 관측 빈도는 두 기간에서 비슷하지만, 오로라는 냉한기에 집중적으로 관측된다. 특이하게도, 크기가 큰 흑점의 경우는 냉한기보다 온난기에서 관측 빈도가 세 배 이상 높다. 또한, 흑점과 관련된 오로라의 강도를 분석해보면 크기가 큰 흑점은 작은 흑점보다 2~3배 이상 지구영향성이 높다는 것을 알 수 있다. 우리는 1185년에 관측된 흑점이 수개월에 걸쳐 여러 차례 관측되었다는 것을 확인하였으며, 그 활동성 면에서 2003년 할로윈 이벤트와 유사했을 것으로 유추하였다. 향후 현대의 흑점 관측 스케치와 국제 흑점수의 관계를 정량화할 수 있다면, 유일하게 한국 역사서에만 찾아볼 수 있는 흑점의 크기 단위는 흑점수와 같이 태양활동의 지표로 사용될 수 있을 것으로 보인다.

• The Bulletin of The Korean Astronomical Society
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• v.46 no.1
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• pp.44.1-44.1
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• 2021

We plan to visit the Apophis, a Potentially Hazardous Asteroid (PHA). Apophis will have an extremely close encounter with the Earth on April, 2029. At the closest position, Apophis approaches 0.1 lunar distances from the Earth. The science goals are 1) mapping the surface of the asteroid before and after the encounter, 2) measuring surface roughness before and after the encounter, and 3) measuring interplanetary space environments such as magnetic field and dust particles. For the science goal, we are planning to employ five instruments for this mission, which are Polarimetric Asteroid Camera (PolACam), Asteroid Terrain Mapping Camera (MapCam), Laser Altimeter, Dust Particle Detector (DPDetector), Magnetometer (Mag). In this presentation, we plan to give a talk on the instruments.

• Proceedings of the Korean Society of Crop Science Conference
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• 2020.06a
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• pp.156-156
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• 2020

• Journal of the Korean Geographical Society
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• v.33 no.2
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• pp.191-208
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• 1998

제주도의 기온온난화가 한라산 고산식물 분포에 미치는 영향에 대한 연구의 하나로 한라산 고산식물 8종의 수평 및 수직 분포역과 생육환경이 조사되었다. 그 결과 희귀하거나 멸종 위기 상태에 있는 고산식물들에 관한 생물지리학적 기초 자료와 정보가 축적되었다. 한라산 고산식물은 분포특성에 따라 8가지 유형으로 분류되며, 그 중 70퍼센트 정도가 한반도의 고산지나 일본열도의 것들과 공통적인 것으로 밝혀졌다. 이들은 빙하기 동안 동북아시아에서 한반도를 거쳐 제주도로 유입되었고, 일부는 일본열도에 전파된 것으로 생각된다. 현재 이들 고산식물은 열악한 기후, 척박한 토질과 지질 그리고 동결과 융해가 반복되는 주빙하성 환경에 적응하여 산정부 일대에 주로 분포한다. 본 연구는 한라산 고산식물의 분포와 과거 및 현재 환경과의 관계에 대한 기초 자료를 구축하여, 한반도의 자연환경 변천사를 파악하고, 기온온난화가 지속될 때 한라산 고산경관과 생태계가 당면할 문제를 파악하고 대안을 제시하는데 필요한 정보를 제공할 것으로 기대된다.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.20 no.2
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• pp.79-82
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• 1984

Seasonal and secular variations of water temperature in Chungmu port were investigated with the data obtained from the Technical Reports(1976~1983) of Hydrographic Office. Monthly and annual range of water temperature were 2 to 8$^{\circ}C$ and 18 to 21$^{\circ}C$, respectively. The coefficients of variance of monthly mean water temperature were 0.015(February, 1976) to 0.208(December, 1980) and their values were smaller in the summer season than in the winter season. The result of harmonic analysis for investigating the seasonal variation of water temperature was T(t)=15.66+8.06 cos(10$^{\circ}$t-233.5)+0.92 cos(20$^{\circ}$t-216). The periods of secular variation were about 2 years and 3 years.

• Journal of the Korean Geographical Society
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• v.46 no.4
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• pp.396-412
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• 2011

Multi-proxy analysis was used to produce a high-resolution paleoclimatic record from a thick section of the Holocene alluvial fan deposit in Gatap-ri, Buyeo. According to ${\delta}^{13}C$ analyses, five minor climate fluctuations can be determined. From the stage I to stage VI, climate changes are as follows: cool-dry, warm-humid, cool-dry, warm humid, drier than stage IV, and finally more humid environment than stage V. According to magnetic susceptibility records, four different stages can be identified, among which stage ii shows the highest susceptibility. Stage-i deposit is derived from sediments of back marsh-type wetland. Stage-ii and stage-iii deposits, however, show higher magnetic susceptibility because magnetite-enriched soil from weathered upland was transported to the area to form an alluvial fan deposits. Stage-iv deposit is comparable to the modern plow horizon.

• Journal of the Korean earth science society
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• v.33 no.4
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• pp.320-328
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• 2012

To investigate geomorphic development of alluvial plains and climatic environment change during the late Holocene carbon dating, soil organic carbon analysis and humus analysis of sediments from alluvial plain of Hampyeongcheon basin were performed. The lowest peat layer was formed under warm and humid climates, which is considered to correspond to the Atlantic period in the Holocene. Yellowish brown sandy clay layer was deposited in the natural levee, which we think were deposited in the generally warm and dry climates. The carbon dating age is 1,879-1,532 BC, and this period correspond to the Sub-boreal period in the Holocene. Light brown clay layer is assumed to have been deposited in transitional environment from the natural levee to the back marsh. The climatic environment was warm and humid, which is considered as transitional period from the Sub-boreal to the Sub-Atlantic in the Holocene. Light yellowish brown and light brown clay layer of the upper part are regarded as sediments of the back marsh. Light yellowish brown clay layer was deposited in the cold and dry climates, which is considered to correspond to the Sub-Atlantic period in the Holocene. Light brown clay layer was deposited in the warm and dry climates. The carbon dating age is 211-427 AD, this period corresponds to the Post Roman Warm Period in the Holocene.

• The Korean Journal of Quaternary Research
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• v.25 no.1
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• pp.15-30
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• 2011

Three sediment cores from two different locations (UJ-03 and UJ-12 cores of valley sediment in Paju area, and CL-4 core of wetland sediment in Cheollipo area) along the western Korean Peninsula yield crucial information on the timing and spatial pattern of century-scale climate changes and subsequent surficial responses during the Holocene. In Paju area, the sediments included abundant coarse-grained sediment (coarse sands and pebbles) from 7100 to 5000 cal. yrBP, total organic carbon (TOC) values showed a marked increase from 5000 to 2200 cal. yrBP, several intermittent depositional layers were observed from 2200 cal. yrBP. In Cheollipo area, lake environment developed from 7360 to 5000 cal. yrBP, the deposition of organic materials increased from 5000 to 2600 cal. yrBP, peatland formed from 2600 cal. yrBP. The two patterns of surficial responses to the climate changes through the Holocene are different to each other. This might be due to the dissimilarity in geomorphic conditions. However, the approximate simultaneity of environmental changes in two areas shows that they both can be correlated to the major climate changes. Two areas which have undergone significant changes indicated that the hydrological factors including precipitation and strength of water flow were most responsible for the landscape and geomorphic evolutions. Although the upwards trend in relative sea-level also played a primary role for environmental changes in coastal area (Cheollipo area), detailed studies have still to be undertaken.

• Journal of The Geomorphological Association of Korea
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• v.20 no.4
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• pp.147-163
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• 2013

Gonggeomji, located at the outlet of intermontane basin in the upper reaches of Dong River, is known as being constructed in the late Unified Silla Dynasty. Extensive wetlands were developed before the construction of embankment at Gonggeomji and very compact silty layers were deposited during dry seasons. Paniceae was cultivated on a dry field in the basin during the early Bronze and Iron Ages. Although it is supposed that agricultural activities on a paddy and dry field prevailed during the Three Kingdoms Age, the indicating layer was not found. As the construction of the embankment, Oryza sativa as well as Paniceae were cultivated in the basin at the same time. The climates during the early Bronze are cool and Iron Ages are estimated to be generally warm. From the late Unified Silla Dynasty and middle Goryeo Dynasty when the embankment was constructed, it was still warm, and then, shows alterations between cool and warm conditions. Since the late Goryeo Dynasty, it gradually became cool.