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지구 자전속도에 따른 해들리 순환과 제트의 반응

The Response of Hadley Cell and Jet Stream to Earth's Rotation Rate

  • 조종혁 (서울대학교 물리천문학부) ;
  • 김서연 (서울대학교 지구환경과학부) ;
  • 손석우 (서울대학교 지구환경과학부)
  • Cho, Chonghyuk (School of physics and astronomy, Seoul National University) ;
  • Kim, Seo-Yeon (School of Earth and Environmental Sciences, Seoul National University) ;
  • Son, Seok-Woo (School of Earth and Environmental Sciences, Seoul National University)
  • 투고 : 2019.02.07
  • 심사 : 2019.05.31
  • 발행 : 2019.06.30

초록

대기 대순환을 결정하는 주요 인자로는 남북방향 온도 경도와, 지구 자전으로 인한 코리올리 힘이 있다. 남북방향 온도 경도에 따른 경압성 차이로 인한 대기 대순환의 변화는 지금까지 많이 연구되어 왔으나, 자전속도에 따른 대기 대순환의 반응은 크게 연구되어 오지 않았다. 때문에 본 연구에서는 현 지구보다 느리거나 빠른 자전속도 범위를 모두 포괄하여 이에 따른 해들리 순환과 제트의 변화를 확인하였다. 이 연구에서 우리는 지구의 자전속도가 빨라질수록 해들리 순환 경계와 제트의 위치가 적도에 가까워지고, 제트와 해들리 순환의 세기가 약해진다는 것을 발견하였다. 해들리 순환 경계와 제트의 위치는 자전속도가 매우 빠르거나 느린 경우를 제외하면 준선형적인 관계를 가졌다. 특히, 해들리 순환 경계는 자전속도가 현재보다 1/8에서 8배의 자전속도 범위에서 자전속도보다 그 제곱근에 더 잘 반비례하는 경향성을 보였다. 단, 이러한 자전속도에 따른 변화는 해들리 순환 세기와 제트의 세기에 대해서는 뚜렷하지 않았다. 이는 대기 대순환의 위치 구조 변화는 지구 자전속도와 관련이 큰 반면, 세기의 변화는 자전속도로 설명되지 않음을 의미한다.

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.

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참고문헌

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