Transcript Grouping the surface activity(1)

•Correlation between halo coronal mass ejections
and solar surface activity (G.Zhou et al. 2003)
•Three-dimensional flux rope model for coronal mass
ejections based on a loss of equilibrium (Roussev et
al. 2003)
•（時間があったら）簡単に研究紹介
太陽雑誌会 （５月１２日）
宮腰剛広
Introduction
•Statistical Study of the relation between
halo coronal mass ejections and solar surface
activity
•With LASCO & EIT (main)
Goes, MDI, BBSO, SXT, and etc.
•The events of 1997 – 2001
(sub)
Sampling the frontside CMEs (1)
•after March 1997 to 2001
•Firstly, we obtain all the halo CMEs whose angular
widths are greater than 130 degree. We find 519 such
halo CMEs.
•Secondary, with EIT movies and EIT running difference
(RD) movies to check whether these halo CMEs have
counterparts on the visible solar disk. Here two criteria
are used to identify frontside halo CMEs.
1. the surface activity starts in the time window TM-30 --TM+30 min
2. the position of solar surface activity (with EIT) is under
the span of the associating CME
Sampling the frontside CMEs (2)
PSSA
If a CME's SRPA is within the range of the CME's span, the
second criterion is satisfied.
•If a CME is associated with such surface activity which
satisfies the above two criteria, we identify the CME as
frontside one.
197 events
Grouping the surface activity(1)
•we only take two primary forms of solar activity, the
flares and filament eruptions, into account
about Flares
•To identify associated flares, (with EIT & SPIDR)
If a flare seen in EIT images takes place within the
duration of a X-ray burst and their position difference
is within the range of -5 --- +5 degree in both the latitude
and longitude, we regard the two sets of observations
as the same event
•With regard to the events not listed in X-ray flare
categories, If (increased intensity / background
intensity) > 50%, we classify it as a flare
Grouping the surface activity(2)
about Filament Eruptions
•We adopt two criteria in identifying a filament eruption.
1. dark and/or bright plasma ejecta, which is an empirical
criterion proposed by Subramanian & Dere (2001)
2. appearance of two flaring ribbons and post-flare loops,
which is suggested by this paper.
•we only group the solar surface activity into the
following three categories:
A(a)-Flares with obvious filament eruptions
A(b)-Flares which may have been preceded by filament
eruptions but cannot be confirmed by the available
data base;
B-Filament eruptions with too little brightening to be
termed flares.
Grouping the surface activity(3)
• about symmetry,
If the difference between SRPA and CPA or PA
(to 360 degree halo CMEs) of a CME is not greater
than 20, we define the event as symmetric, or else
it is asymmetric.
Example (1)
2001 Jan 20 CME
A typical example of A(a)
•start time: near 18:36 UT
•average speed : 839 km/s
•Fig 2B : BBSO H-alpha
a filament lay in the AR9313
at 08:04 UT before the initial
CME time
•Fig 2C : MDI
•Fig 2DEF : EIT (M1.2 flare)
D) bright and dark ejecta
E) two ribbons
F) post flare loops
 this is eruptive flare
•PA --- 64 deg, SRPA --- 100 deg,
 asymmetric event
Example (2)
2001 Apr 6 CME
A typical example of A(b)
•start time: near 18:54 UT
•average speed : 1270 km/s
•Fig 3C : H-alpha
filament exists
•Fig 3DEF : EIT (X5.6 flare)
E) running difference
 propagating dimming
•we cannot ascertain whether the
filament erupted
•PA --- 147 deg, SRPA --- 115 deg,
 asymmetric event
Example (3)
2000 May 8 CME
A typical example of B
•start time: near 12:48 UT
•average speed : 465 km/s
•Fig 4B : BBSO H-alpha
•Fig 4C : MDI
•Fig 4DEF : EIT
development of filament eruption
no corresponding Goes X-ray flare
•CPA --- 216 deg, SRPA --- 210 deg,
 symmetric event
Statistical results(1)
•Table 2
•Most of these events except for 32 events in Category A(a)
and A(b) have flare records in GOES X ray.
Those 32 events whose intensity increase are greater than
50%, as defined in Sect. 2.3, were also regarded as flare
events.
•Filament eruption : EIT, BBSO, HAFB, HSOS, etc.
•at least 94.4% are associated with filament eruption
Statistical results(2)
•Table 3
•The other 322 CMEs are not all from the backside.
There are two reasons for us to exclude these 322 CMEs.
1.Some CMEs with high cadence EIT data are excluded because no associated
activity was observed on the visible disk. Those CMEs may not include frontside
ones,
2.the others with low cadence or no EIT data that are excluded may include some
frontside ones.
only two conditions exist, frontside and backside, thus half of the CME
events should belong to the frontside, that is to say, 259 CMEs are possible. We find
76% (197/259) CMEs to be associated with surface activity, which is higher than that
of most previous statistical results.
•among 141 CMEs associated with GOES X-ray flares, 83 CME
initiations are seen to precede flare onset, while the other 58 are
the opposite
Concluding remarks
•173(88%) associated with flares, 187(94%) with filament
eruptions
•79% whose source regions are inside active regions, 21%
outside
•about 50 % symmetric
•Three-dimensional flux rope model for coronal
mass ejections based on a loss of equilibrium
The model of the
(Roussev et al. 2003)
Titov & Demoulin (1999)
•two point magnetic charges buried at a
depth z = -d below the surface and
ｌocated at x = ±L.
•long line current, I0, that coincides with
the x-axis and also lies below the
photosphere at depth d
•unstable if the large radius, R, of the flux
rope exceeds root 2L, where L is half the
distance between the background
sources ±q.
•force-free limit, gas is hydrostatic
(photosphere – transition – corona)
•ideal MHD, BATS-R-US method,
with AMR (about 7M mesh)
initial condition
color : magnetic fields intensity
•boundary: highly conducting (z=0)
outflow side (x,y)
open (z=zmax)
Fig.2
The velocity of the O-point is decelerated
(not escape case)
Fig.3
t=35 min. (isosurface shows current density)
magnetic fields exists outerby I, so the flux rope cannnot
escape but stop
The most plausible explanation of this structure is that there is
an interchange reconnection between the highly twisted field lines
of the flux rope and the overlying closed field lines from the ±q
sources. As a result of this process, the newly created closed field
lines connect the two flux regions.
about 17% of magnetic energy is converted
into thermal and kinetic energy (t=19)
これから花山でやりたいと思っていること
•理論、数値シミュレーション
リコネクション（田沼）
CME(Chen 
塩田、宮腰、、、）
活動域構造、
ジェット （宮腰）
対流層磁場（磯部）
個々のオブジェクトについて理解を深化させるとともに、
各現象間のつながりを、数値シミュレーションを武器に、理論的に
明らかにする
（ダイナモ) → 対流層 → 光球彩層、黒点 → 活動域コロナ
→ 磁気エネルギー解放 → 太陽面爆発現象
→ 大規模磁場構造へ影響 → CME → 宇宙天気予報
（マンパワー、技術力、利用可能な計算機資源、等の総合力において、
我々のグループは世界でもトップ集団の中にいるのでは？）
これから花山でやりたいと思っていること
•データ解析
１９９２年９月６日 （NOAA ７２７０） のフレアの解析
ようこう ＋ 飛騨DST
（宮腰、田沼、成影、柴田、..........)
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