• 한국수산과학회지
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• 제30권6호
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• pp.974-983
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• 1997

The Okhotsk Sea is unique natural object with climatic peculiarities. The climate of the Okhotsk Sea results from the general distribution of solar radiation during a year, and the characteristics of the atmospheric circulation that varies through a year: In cold half year the main pressure formations are Siberian high and Aleutian low. Asian low centered on Afghanistan dominates over the Asian continent in summer. The North-Pacific sea surface is under effect of permanent North Pacific high. The changes in their position from year to year are very significant. The anticyclonic activity over the Far Eastern Seas is one of the main factors for the formation of weather anomalies over the adjacent territories. The analysis of summer weather characteristics over the coast of Okhotsk and East Sea using the data obtained from Hydrometeorological stations during $1949\~1990$ showed that, to a great extent, distribution of the air temperature depends on thermal state of the Okhotsk Sea and atmospheric circulation over it. We show some relations between weather characteristics and the intensity of atmospheric action center for the North Pacific high in summer when its ridge propagates to Okhotsk Sea. Correlation coefficients between air pressure over the Okhotsk Sea and air temperature for the coastal areas reach up to 0.7. Analysis of the spatial-temporal distribution of main meteorological values over the Okhotsk Sea such as air pressure, and air temperature are also performed.

• 한국해양학회지:바다
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• 제6권4호
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• pp.225-233
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• 2001

본 연구에서는 기후 시스템 내에서의 해빙의 역할을 살펴보고자 열역학적 방식에 의한 해빙 모형을 개발하고 이를 해양대순환 모형인 MOM에 접합한 해양/해빙 접합 모형을 구축하여 수치적 실험을 하였다. 연구에서는 먼저 접합한 모형을 이용하여 해빙의 계절 평균적인 분포를 모사하였다. 또한 해양대순환 모형이 해빙 모형과 접합한 경우와 접합하지 않은 경우를 비교함으로써 대규모 해양 분포에 나타나는 해빙의 역할을 살펴보았다. 또한 모형의 결과를 다른 모형의 결과 및 관측자료와 비교 분석함으로써 해양/해빙 모형 접합 모형의 결과를 검증하였다. 접합 모형은 양반구 고위도에서의 해빙이 계절적 분포를 전체적으로 적절히 모사하였다. 해양대순환 모형이 해빙 모형과 접합한 경우와 그렇지 않은 경우에 대한 비교 연구에서 해빙은 양반구 고위도에서의 해수온과 염분을 유지시켜주는 중요한 역할을 할뿐만 아니라 South Ocean 순환세포와 남반구 순환세포(Southern Hemisphere circulation cell) 및 북대서양 심층수와 관련한 자오 심해 순환과 남극환류 같은 동서류의 순환도 적절히 모사하였다.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2004년도 한국우주과학회보 제13권1호
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• pp.70-70
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• 2004

Lower thermospheric winds are forced primarily by non-uniform solar heating, atmospheric tides and other waves coming from below, and energy and momentum forcing associated with high-latitude magnetosphere-ionosphere coupling, particularly ion drag and Joule heating. To understand the physical processes that control the thermospheric dynamics, we quantify the momentum forces that are mainly responsible for maintaining the high-latitude lower thermospheric wind system and examine the resulting momentum balance with the aid of the Thermosphere-Ionosphere Electrodynamics General Circulation Model (NCAR-TIEGCM) developed by the National Center for Atmospheric Research. (omitted)

• Ocean and Polar Research
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• 제31권4호
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• pp.297-304
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• 2009

We investigated the response of the westerly winds over the Southern Ocean (SO) to glacial boundary conditions for the Last Glacial Maximum using the CCM3 atmospheric general circulation model. In response to glacial boundary conditions, the zonally averaged maximum SO westerly winds weakened 20-35% and were displaced toward the equator by 3-4 degrees. This weakening of the SO westerly winds arose from a substantial increase in mean sea level pressure (MSLP) in the southern part of the SO around Antarctica relative to the northern part. The increase in MSLP around Antarctica is associated with a marked temperature reduction caused by an increase in sea ice cover and ice albedo feedback during the glacial time. The weakened westerly winds in the SO and their equator-ward displacement might play a role in reducing the atmospheric $CO_2$ concentration by reducing upwelling of the carbon rich deep water during the glacial time.

• 한국해안·해양공학회논문집
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• 제36권4호
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• pp.158-166
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• 2024

순환 모델 연구를 위한 수치 방법에서는, 증가하는 온실가스 배출에 대한 해양과 대기의 물리적 반응을 모의하기 위해 다양한 연직 좌표계를 사용한다. 본 연구에서는 해양 및 대기 순환 수치모델에 자주 사용하는 4종류의 연직좌표계, 즉 고도, 일반, 압력, 그리고 무차원 연직좌표계에 대하여 소개한다. 최종적으로, 연직좌표계로 표현된 정수압 방정식, 연직속도, 수평방향 운동방정식, 그리고 연속방정식을 도입하고, 연직좌표계에 대한 장단점을 정리하여, 수치모형 개발 정확성을 도모하였다.

• 대기
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• 제19권2호
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• pp.155-168
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• 2009

Characteristics of seasonal mean diurnal temperature range (DTR) and their causes over South Korea are investigated using the 60 stations data of Korea Meteorological Administration from 1976 to 2005. In general, the seasonal mean DTR is greatest during spring (in inland area) and least during summer (urban and coastal area). The spatial and seasonal variations of DTR are closely linked with the land surface conditions (especially vegetation activity and soil moisture) and atmospheric conditions (cloud amount, precipitation, local circulation). The seasonal mean DTR shows a decreasing trend at the major urban areas and at the north-eastern part of South Korea. Whereas, it shows an increasing trend at the central area of the southern part. Decreasing and increasing trends of DTR are more significant during summer and fall, and during spring and winter. The decrease (increase) of DTR is mainly caused by the stronger increase of daily minimum (maximum) temperature than daily maximum (minimum) temperature. The negative effects of precipitation and cloud amount on the DTR are greater during spring and at the inland area than during winter and at the coastal area. And the effect of daytime precipitation on the DTR is greater than that of nighttime precipitation.

• 대기
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• 제26권4호
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• pp.523-540
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• 2016

The effects of satellite observations on large-scale atmospheric circulations in the reanalysis data are investigated by comparing the latest Japanese Meteorological Association's reanalysis data (JRA-55) and its family data, JRA-55 Conventional (JRA-55C). The latter is identical to the former except that satellite observations are excluded during the data assimilation process. Only conventional datasets are assimilated in JRA-55C. A simple comparison revealed a considerable difference in temperature and zonal wind fields in both the stratosphere and troposphere. Such differences are particularly large in the Southern Hemisphere and whole stratosphere where conventional ground-based measurements are limited. The effects of satellite observations on the zonal-mean tropospheric circulations are further examined in terms of the Hadley cell, eddy-driven jet, and mid-latitude storm tracks. In both hemispheres, JRA-55C exhibits slightly weaker and narrower Hadley cell than JRA-55. This is consistent with a weaker diabatic heating in JRA-55C. The eddy-driven jet shows a small difference in its latitudinal location only in the Southern Hemisphere. Likewise, while the Northern-Hemisphere storm tracks are quantitatively similar in the two datasets, Southern-Hemisphere storm tracks are relatively weaker in JRA-55C than in JRA-55. Their difference is comparable to the uncertainty between reanalysis datasets, indicating that satellite data assimilation could yield significant corrections in the zonal-mean circulation in the Southern Hemisphere.

• 한국대기환경학회지
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• 제19권6호
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• pp.733-743
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• 2003

The flow field in multiple fluid sphere systems was studied analytically. The expanded zero vorticity cell model based on Kuwabara's theory (1959) was applied and the effects of gas slippage at the collecting surface were considered. Also, the solid sphere system was extended to fluid sphere including the effects of the induced internal circulation inside the liquid droplet spheres or gas bubble systems. As a result, the obtained analytic solution was converged to the existing solutions for flow field around solid and bubble sphere systems with proper boundary conditions. Based on the resolved flow field, the terminal velocity around the collecting fluid spheres was obtained. Subsequently, this study evaluated the most general solution for flow field around the multiple fluid sphere systems. The obtained flow field in multiple fluid sphere could be used as a fundamental consideration of wet scrubber design and devices for removing particles by fluid-fluid interactions.

• 대기
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• 제20권1호
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• pp.49-61
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• 2010

Atmospheric aerosols play a crucial role for changing climate, resulting in a wide range of uncertainty for future climate prediction. In this paper we review current international research status and trend of climate-related aerosol science. There have been carried out a number of campaigns (including ACE-Asia, TRACE-P, ABC, and so on) and special experiments with some modeling studies over Korea, East Asia, and the Northwestern Pacific to characterize the various properties (physical, chemical, optical, and radiative) of Asian aerosols and evaluate their climate forcing impacts. But some parts of the aerosol research may need to be improved, advanced, or newly launched. Especially, a chemical transport model (CTM) embedded by a general circulation model (GCM) should be developed by the national scientific community with a high research priority, actively collaborating with international community in order to estimate direct and indirect global radiative forcing due to anthropogenic and natural aerosols.

• 한국환경과학회지
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• 제7권1호
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• pp.27-35
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• 1998

The present study intends to investigate the transient response of an atmosphere /ocean general circulation model to a gradual Increase of atmospheric carbon dioxide. To detect the climatic change of the for 1% $CO_2$ run with increasing $CO_2$ and the control run with fried $CO_2$ are compared. From response of the surface air temperature due to the gradual increase of atmospheric carbon dioxide is slowly increased with latitudes and is clearly larger over continents than oceans. The annual goffal mean temperature is continuously increased with 0.03552 per one year with strong SIN ratio and distinguished from the natural variability The time dependent response of the gradual increasing $CO_2$ has the strong seasonal variability with small change In summer and large change in winter, and the strong regional In the Asian and the American continents. It has been suggested that the direct and the feedback processes in the climate systems should be investigated by the detailed sensitivity runs to get the meaninguul estimate of the $CO_2$ forced variability.