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
Motivation of this study: To answer the toughest question in lectures of space physics
Example of a lecture in space physics Solar Cycle and Sun-Earth Connection
磁暴時，難得一見之紅綠相間的極光 （Ｏ 2 → Ｏ＋Ｏ）
太空梭上所拍攝到的極光
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。
What is Sunspots? 太陽黑子 Sunspots on White Light Solar Image
Close View of Sunspots
11-years Solar Cycle Based on Sunspot Number
Butterfly Diagram of Sunspot Distribution
22-years Solar Cycle Based on Leading Sunspot Magnetic Polarity
Solar Differential Rotation --> Solar Dynamo ( -effects, -effects) -->22-years Magnetic Solar Cycle
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!
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
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？
日冕與日冕洞的可見光影像 Corona & Coronal Hole in White Light Image
White-light solar image during solar maximum
White-light solar image during solar minimum
Magnetic Field Distribution in Corona and Coronal Hole regions
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
Hard X-ray image
Soft X-ray image
EUV image
Ulysses observation of solar wind speed( )
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!)
日珥 Solar Prominences
日珥噴發 Prominence Eruption
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
Filaments on sloar disk
Filaments & Prominences
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!
日珥噴發 Prominence Eruption 太陽閃焰 Solar Flares 日冕物質拋射 Coronal Mass Ejections (CMEs)
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
日珥噴發伴隨著太陽閃焰
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
CME (Coronal Mass Ejection)