1. On the Cause of Solar Differential Rotation Ling-Hsiao Lyu Institute of Space Science, National Central University 呂凌霄 中央大學太空科學研究所 太陽差動自轉的成因

2. Motivation of this study: To answer the toughest question in lectures of space physics

3. Example of a lecture in space physics Solar Cycle and Sun-Earth Connection

4. 磁暴時，難得一見之紅綠相間的極光 （Ｏ 2 → Ｏ＋Ｏ）

5. 太空梭上所拍攝到的極光

6. 極光什麼時候會出現？ 高緯地區，極光橢圓圈內的地方，每天晚上（尤其 是午夜前），如果天空晴朗，一定可以看到極光。 非常劇烈的極光活動，通常發生在太陽閃焰之後的 一兩天內，這段時間裡，全球地表的磁場也發生大 幅變動，故稱為磁暴！ 二十世紀初科學家就發現：【極光出現頻率】、 【磁暴出現頻率】、與【太陽黑子個數多寡】， 三者之間關係密切。

7. What is Sunspots? 太陽黑子 Sunspots on White Light Solar Image

8. Close View of Sunspots

9. 11-years Solar Cycle Based on Sunspot Number

10. Butterfly Diagram of Sunspot Distribution

12. 22-years Solar Cycle Based on Leading Sunspot Magnetic Polarity

13. Solar Differential Rotation --> Solar Dynamo (  -effects,  -effects) -->22-years Magnetic Solar Cycle

14. T: Differential rotation is the major cause of solar cycle! S: What is the cause of solar differential rotation? T: (mmm~~~~~~) It is an observational result! *@#%! Tough question!

15. 太陽黑子數目與強磁暴之間的相關性 太陽外部磁偶極方向朝南期間

16. 二十世紀末二十一世紀初科學家發現： 【太陽日冕物質拋射】與【太陽風速大小】 是造成【磁暴】與【絢麗極光】的主因。 太陽日冕物質拋射則與日珥噴發息息相關！ 什麼是日冕？ 什麼是日珥？ 什麼是太陽風？

17. 日冕與日冕洞的可見光影像 Corona & Coronal Hole in White Light Image

18. White-light solar image during solar maximum

19. White-light solar image during solar minimum

21. Magnetic Field Distribution in Corona and Coronal Hole regions

22. 用不同波長的Ｘ光與紫外光 觀測太陽圓盤上的 日冕與日冕洞的分布 CORONAL HOLE DISTRIBUTION ON SOLAR DISK in Hard X-ray, Soft X-ray, & EUV images

23. Hard X-ray image

24. Soft X-ray image

25. EUV image

26. Ulysses observation of solar wind speed(1991-1998)

27. It is believed that … observed large-amplitude Alfven waves are responsible for solar wind acceleration in the polar coronal hole region. High speed solar wind can lead to magnetic storm or substorm! S: What is the energy source of these large-amplitude Alfven waves? T: mm~~~, Let’s move on to next slide. (another tough question!)

28. 日珥 Solar Prominences

30. 日珥噴發 Prominence Eruption

32. 當日珥出現在太陽光盤上時被稱為暗紋 Prominences on the solar disk is called Filaments

33. Filaments on sloar disk

34. Filaments & Prominences

35. Magnetic field configuration near a filament Q: What process leads to formation of filaments? Q: What cause eruption of a prominence? A:mm~~, this is an ongoing research subject! There are many theoretical models trying to explain formation and eruption of prominence! ~~ another tough question!

36. 日珥噴發 Prominence Eruption 太陽閃焰 Solar Flares 日冕物質拋射 Coronal Mass Ejections (CMEs)

37. 太陽閃焰 (solar flare )[ 耀斑 ] 閃焰發生前的觀測照片 閃焰發生時的觀測照片

38. 日珥噴發伴隨著太陽閃焰

39. 日冕物質拋射（ CME ） 如果噴發方向對著地球，而且攜帶著南向磁場， 可造成地球磁暴

42. CME (Coronal Mass Ejection)