• Geophysics and Geophysical Exploration
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• v.26 no.4
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• pp.238-267
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• 2023

Studies on Earth's rotation and tide since the 19th century are briefly summarized. The theories of precession, nutation, polar motion, and periodic/secular changes in the rate of rotation are described individually. In addition, a brief review of the Milankovitch theory - the hypothesis of the relationship between the Earth's spin/orbital rotational state and the ice ages - is given. Finally, Earth's tides and their theoretical models are briefly explained. Some detailed technical content is summarized in the appendices.

• 한국지구과학회:학술대회논문집
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• 2010.04a
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• pp.32-33
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• 2010

달의 기조력에 의한 조석현상으로 인하여 지구의 자전속도가 늦어지고, 결과적으로 층상구조를 이루고 있는 지구의 내부는 서로 다른 각속도로 자전한다는 차등자전 개념이 최근에 도입되었다. 지구내부의 각층에서 차등자전이 일어날 경우 각층의 경계면에서는 필연적으로 마찰열과 마찰 정전기가 발생하는 바, 특히 맨틀과 외핵의 경계부분에서 발생하는 마찰전기는 방전과정에서 대규모의 자기장, 즉 지구자기장을 발생시킬 것으로 예측된다. 본 연구에서는 마찰전기를 지속적으로 발생시키는 실험 장치를 개발하고, 고감도 자기센서로 자기장의 변화를 측정하였다. 실험 결과 유의미한 자기장의 변화를 측정하였고, 지구 자기장이 차등자전으로 인한 마찰전기에 의해 발생될 수 있음을 확인하였다.

• 한국지구과학회:학술대회논문집
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• 2005.09a
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• pp.379-394
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• 2005

본 연구자는 우주의 자연원리 가운데서 지구의 자전은 어떠한 힘에 의하여 자전을 하게 되는지? 지구공전은 기존에 알고 있는 태양을 중심으로 공전을 하고 있다는 개념은 공전하는 이치에 맞지 않는 점을 발견하고 새로운 공전원리를 제시하고자 한다. 우주 공간의 여러 현상들 중에서 지구의 자전과 공전운동에 관해 살펴보면 그 요인으로는 운동을 할 수 있는 지구, 지구를 둘러싸고 있는 대기, 지구를 비쳐주는 태양광선이 있다. 이 세 가지 자연현상이 지구 운동의 핵심요소라는 것을 알았다. 태양광선은 지구에 열을 가해주는 역할을 하고 대기는 이 열을 받아서 변화를 일어나게 하여 운동을 한다고 생각한다. 본 연구자의 소견으로 내린 결론의 기저는 ‘대기가 태양열에 의한 팽창과 수축이 대기의 상승기류와 하강기류로 변하여 이 기류의 이동에 따른 마찰력과 압력의 차이가 생겨서 지구가 자전하면서 공전한다고 생각한다.’ 따라서 지구공전운동은 태양을 중심으로 하지 않는다는 점과 지구는 원근법칙(遠近法則)에 의하여 공전을 한다는 점으로 설명할 수 있다.

• Journal of the Korean earth science society
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• v.40 no.3
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• pp.203-211
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• 2019

The two key factors controlling the atmospheric general circulation are the equator-to-pole temperature difference and the Coriolis force driven by Earth's rotation. Although the former's role has been extensively examined, little has been reported about the latter's effect. To better understand the atmospheric general circulation, this study investigates the responses of Hadley Cell (HC) and westerly jet to the rotation faster or slower than the present Earth's rotation rate. It turns out that the HC edge and jet position tend to move equatorward and become weaker with increasing rotation rate. In most cases, the HC edge is quasi-linearly related with the jet position except for the extremely slow or fast rotating cases. The HC edge is more inversely proportional to the root of rotation rate than the rotation rate in the range of 1/8 to 8 times of the current Earth's rotation rate. However, such a relationship does not appear in the relationship between HC strength and jet intensity. This result highlights that while the latitudinal structure of atmospheric general circulation can be, to some extent, scaled with the Earth's rotation rate, overall intensity cannot be simply explained by the Earth's rotation rate.

• Journal of the Korean Society of Earth Science Education
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• v.12 no.3
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• pp.252-260
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• 2019

The purpose of this study is to assist school science class by investigating effective Earth's rotation experiments of districts by school level. The researcher investigated or developed nine experiments for learning Earth's rotation, and conducted and discussed these experiments with 26 elementary school teachers. Each teachers chose an effective Earth's rotation experiment for the district and wrote the reason. As a result, elementary school teachers chose the experiment that is easy to prepare and to do. And elementary school students are interested in the experiments by conducting them on their own. Middle and high school teachers chose more difficult experiments that could be connected with other concepts. University teachers chose effective experiments based on application of knowledge, active exploration, computer literacy, and difficulty.

• Journal of the Korean Society of Earth Science Education
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• v.13 no.1
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• pp.29-39
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• 2020

In this study, to find out the learning effects and difficulties of role play activities to learn the earth's rotation and the sun's apparent motion, the degree of concept understanding through role play activities, difficulties arising from activities collected by interview, and eye movement during activities are analyzed. 22 fifth graders participated in this study and collected and analyzed experimental behaviors, post-interviews, and eye movement data during the role play of the students. The study found that students could explain the rotation and direction of the Earth through role play activities, but it was difficult to explain the apparent motion of the sun. Since it is difficult to perceive the sun's apparent motion through role play activities, the learning effect of the earth rotation role play activity is low.

• The Bulletin of The Korean Astronomical Society
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• v.35 no.1
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• pp.35.1-35.1
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• 2010

천체는 천구의 북극을 중심으로 지구자전에 의하여 반시계방향으로 일주 운동을 한다. 적도의식 망원경의 최대 장점은 극축이 정확히 맞추어졌다면 접안렌즈 중앙에 적위축 조정으로 정확히 원하는 천체를 위치시키고, 적경축을 지구자전축에 동기 시켜 회전시키면 어떠한 대상이라도 추적이 가능하다. 본 연구에서는 Hardware적으로 적경축 구동을 지구 자전속도에 동기 시키는 제어회로를 설계하였다.

• Journal of the Korean earth science society
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• v.27 no.6
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• pp.591-605
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• 2006

The purpose of this study is to investigate the relationship between lunar and earth rotation, by quantitatively describing the rotation of lunar configuration which is observed during the lunar diurnal motion. Our research suggests that observation of the lunar diurnal motion could be used as a study topic in the earth science courses. The rotation of the lunar configuration is an apparent phenomenon that can be seen when an observer. standing on the ground. looks at the moon as if the lunar dark configuration rotates on the basis of horizontal line. In spite its competence as a study topic because it is observable by naked eyes, there are only few major textbooks that introduce this phenomenon with regard to the earth rotation. Therefore, this study induced the mathematical principle of the lunar rotation in detail and proposed that this could be developed as a scientific inquiry through practical observation. In addition, an analytical proof and qualitative method of explanation of the lunar reverse rotation were also presented.

• Geophysics and Geophysical Exploration
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• v.18 no.3
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• pp.133-142
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• 2015

Displacement of the Earth's surface due to atmospheric loading has been recognized since a century years ago, and its accurate estimation is required in present day geodesy and surveying, particularly in space geodesy. Atmospheric load deformation in continental region can readily be calculated with the given atmospheric pressure field and the load Green's function, and, in near coastal area, approximate model is used for the calculation. The changes in the Earth's atmospheric circulation and the seasonal variation of atmospheric pressure on two hemispheres of the Earth are the each main causes of variation of the Earth's spin angular velocity and polar motion respectively. Wind and atmospheric pressure do the major role in other periodic and non-periodic perturbations of the positions in the Earth's reference frame and variations in the Earth's spin rotational state. In this reviewing study, the developments of related theories and models are summarized along with brief description of phenomena, and the geodetic perturbing effects of a hypothetical typhoon passing Korea are shown as an example. Finally related existing problems and further necessary studies are discussed in general.

• Journal of the Korean earth science society
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• v.25 no.7
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• pp.532-544
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• 2004

The purpose of this study is to analyze the concept concerned with Earth's rotation as passed by tenth graders whose interest in earth's rotation and learning styles were varied. To examine student's interest in the Earth's rotation, 4students (visual-verbal learning style student with much interest, visual learning style student with much interest, visual learning style student with little interest, and verbal learning style student with little interest) were chosen for study. Personal interview was used for this study. To probe students' conception in varied ways, they were allowed to make gesture and draw pictures through data collection process, except for interviews. And the data were analyzed one by one. The result of this study were as follows: First, the student with much interest was faster to answer the questions about Earth's rotation than the one with little interest. Also he comprehended better and was able to explain reasons coherently. Second, there was little difference according to student's learning style. Third, one of the repeated misconception was direction. For thinking that is the right side is the east side, students have misconception that the sun goes from right to left and stars in north sky move clock-wise.