초록 ▼

첫째, 과거 1000년 정도의 기간에 존재하는 한국과 중국의 오로라와 흑점관측 기록을 분석하고, 이 결과를 지구 대기 중 방사선 동위원소 ${}^{14}C$와 ${}^{10}Be$의 변화와 비교하였다. 이를 통해 태양 활동과 지구 대기권 반응에 대한 장주기적 상관관계를 고찰하였다. 둘째, 태양 활동의 감소기에 주로 나타나는 coronal high-speed stream에 대해 지구 자기권 반응을 여러 관점에서 연구하였다. 주로, 서브스톰 발생과의 상관관계, 상대론적 전자 플럭스의 증감과 관련된

첫째, 과거 1000년 정도의 기간에 존재하는 한국과 중국의 오로라와 흑점관측 기록을 분석하고, 이 결과를 지구 대기 중 방사선 동위원소 ${}^{14}C$와 ${}^{10}Be$의 변화와 비교하였다. 이를 통해 태양 활동과 지구 대기권 반응에 대한 장주기적 상관관계를 고찰하였다. 둘째, 태양 활동의 감소기에 주로 나타나는 coronal high-speed stream에 대해 지구 자기권 반응을 여러 관점에서 연구하였다. 주로, 서브스톰 발생과의 상관관계, 상대론적 전자 플럭스의 증감과 관련된 현상을 다루었다.

Abstract ▼

The deep minima in the solar activity, so called "great minima" or "grand minima", occurred several times during the last 1000 years. Such prolonged periods of inactivity, corresponding to unusual cold weather on the Earth, are confirmed by past solar activity recorded in sunspot and auroral observa

The deep minima in the solar activity, so called "great minima" or "grand minima", occurred several times during the last 1000 years. Such prolonged periods of inactivity, corresponding to unusual cold weather on the Earth, are confirmed by past solar activity recorded in sunspot and auroral observations or tree rings and ice cores. However, these records show that such deep minima are a fairly common aspect of solar behavior in a long-term point of view, and can be expected to occur again in the future. Therefore, we have examined on the features of great minima during the last 1000 years, using the sunspot and auroral records of ancient Korea and China, and the cosmogenic isotopes. These ancient historical records exhibit clearly the existence of great minima and the auroral records are much more frequent than sunspot throughout the whole period including the great minima. The great minima appeared in these historical data are consistent with those from the data of 14C which shows the overall trend that galactic cosmic ray flux increased during the period of great minima and decreased between them. Lastly, ancient sunspot and auroral data indicate that the Sporer minimum occurred in 1410-1510, implying the duration of which is ~100 years, consistent with the results by previous reports.
We have also studied interactions between coronal high-speed streams, which occur most frequently during solar declining phase, and the earth`s magnetosphere. First, substorms occur repetitively during high-speed streams, and we find that energy input as estimated from the Akasofu epsilon parameter ranges from $10^{13}J$ to $10^{15}J$. This rather wide energy range seems to imply that energy storage above some "unknown" critical level may not be a necessary factor for a substorm to occur if there is a solar wind trigger. Also, we have examined on whistler wave data in order to see its statistical relation with substorm occurrences. The wave is known to be responsible for relativistic electron acceleration. We found that for many substorms, the wave intensifies ~20-30 min prior to each substorm onset and decays away after onset. This implies that the wave is intensified by electrons transported by enhanced convection during the substorm growth phase. The relativistic electron flux increases during high-speed streams, but usually preceded by a dropout. We find that this dropout is consistent with an increase of the solar wind dynamic pressure which pushes the magnetopause inward. We have developed a Guiding center tracing code in order to compute electron for various solar wind conditions.

목차 Contents

• 표지...1
• 제출문...2
• 요약문...3
• SUMMARY...5
• 목차...8
• 제 1 장 연구개발과제의 개요...9
• 제 1 절...9
• 제 2 절...9
• 제 2 장 국내외 기술개발 현황...10
• 제 3 장 연구개발수행 내용 및 결과...11
• 제 1 절...11
• 제 2 절...14
• 제 4 장 연구개발목표 달성도 및 관련분야에의 기여도...24
• 제 5 장 연구개발결과의 활용계획...25
• 제 6 장 연구개발과정에서 수집한 해외과학기술정보...26
• 제 7 장 참고문헌...27