Space Weather with STEREO

1
Space Weather with STEREO Sun to STEREO (Earth)
Connection Events David Webb ISR, Boston
College Air Force Research Laboratory, Hanscom
AFB, MA With Data Results Provided by Tim
Howard, James Tappin, Bernie Jackson, Mario Bisi,
Russ Howard, Simon Plunkett, Brain Wood, Chris
Davis, Richard Harrison, Yan Li, Ying Lui, Ben
Lynch, Emilia Kilpua, Lan Jian, Janet Luhmann,
Eriksson, Jack Gosling, Nat Gopalswamy, Glenn
Mason and the STEREO SECCHI, PLASTIC, IMPACT and
SMEI experiment teams
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STEREO Space Weather

• My Roles in STEREO Heliospheric Imaging
• -STEREO Space Weather Group Co-Leader
• - LASCO SECCHI Co-I
• - Heliospheric Imagers Co-I
• - Solar Mass Ejection Imager (SMEI) Team Member
• Outline/Notes
• - Recently updated the STEREO Space Weather
  website
• - Added Sun-STEREO Connection Events page to
  website. These are events for which a CME
  observed by one or both S/C hits one of them as
  detected in-situ (also at L1/Earth). Form a
  special class of SWx-type events that provide
  details on ICME propagation and internal
  structure characteristics.
• - Later this year STEREO-B will be at the L5
  point, allowing us to test this position for
  possible a SWx monitor mission with a
  heliospheric imager. View and study CMEs aimed
  Earthward. Also can compare HI views with those
  from SMEI at Earth.
• (ST-B also sees over the east solar limb and,
  eg, can view SEP-producing regions and detect
  them in situ before they hit Earth.)
• - SSC has running diff HI-2 movies from the
  regular data stream on the Beacon browse site.
  These replace the HI-2 Beacon data - too low a
  res. to be useful.

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STEREO Space Weather Group

• Group leaders Dave Webb Doug Biesecker
• Website updated occasionally
• - http//secchi.nrl.navy.mil/spwx/index.php
• - Webmaster is Lynn Simpson of NRL/SECCHI
• Contains background on SWx, SWx-related meetings,
  PI SWx studies, tools/projects, references
  links
• Member list with email addresses
• - Currently have 120 members
• - Contact me to join (david.webb_at_hanscom.af.mil
  ) or request to subscribe at
  http//ares.nrl.navy.mil/cgi-bin/majordomo (?)
• Maintain a list of URLs/links that all PI teams
  can use
• - STEREO CME/event catalog links
• - Feedback please!
• Maintain reference list of key SWx papers
• - Recently updated need feedback!

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STEREO Space Weather Event Pages

• Based on old ISTP Sun-Earth Connection Events
  site
• - http//www-istp.gsfc.nasa.gov/istp/events/
• Contains an event summary, online data, modeling
  links to other data
• Now have two STEREO SWx events
• - December 13-15, 2006
• - May 19-22, 2007
• - Sun-STEREO Connection Events
• Need your feedback on these Event pages
• - Incorporate or link to other STEREO data
• Beacon (NRT quicklook)
• SECCHI SWAVES imagery
• PLASTIC IMPACT in-situ data
• Modeling/simulation results
• - Need more geo inputs!
• - Try to incorporate new events/pages soon
  after events occurrence

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http//secchi.nrl.navy.mil/spwx/
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Sun-Earth/STEREO Connection Events   - 2006 Dec.
13-15 Two X-flares/CMEs near sun center
ICME/flux rope/SEPs at Earth. Only true STEREO
(Earth) space weather event. Mewaldt, Liu, etc.
See http//secchi.nrl.navy.mil/spwx/index.php?p20
061213event   - 2007 May 19-22 Two events near
Sun center observed with Hinode and STEREO. 3D
views of fil. eruptions and loops. Flux rope at
STEREO and Earth. Radio obs. Liewer, Liu,
Mewaldt, Cohen, Pick, etc. See http//secchi.nrl.n
avy.mil/spwx/index.php?p20070519event ___________
__________________________________________________
_____________________________________ - 2007
Nov. 14-18 3 events, including one from Sun
center obs. by LASCO, SECCHI, SMEI. 3D modeling
and heliospheric density structure. Tim Howard,
Jackson, Webb, Huttenen, Li, Lynch.   -2008 Feb.
4-8 Wood et al., ApJ, 2008. Weak surface eruption
on Feb. 4, with interaction with ST-B and ACE and
effects at ST-A on Feb. 8.   - 2008 April 26.
Event near sun center had a fast CME and EUV
wave seen by SECCHI on both ST-A and B, and also
detected in-situ by ACE and ST-B. 3D shape
modeling, velocity, etc. This was during the WHI
period and is part of that study. Wood, Kunkel,
Plunkett, Chen (fitting Chen's FR model),
etc.   - 2008 May 17 Another Sun-STEREO
interaction event. Wood et al., SP STEREO
issue.    - 2008 June 26 CME to WNW in both CORs
on June 2, with main interaction, a mag. cloud,
on June 6 at ST-B. Minor effects at ACE. Li et
al. Also Wood. - 2008 Dec. 12-16 Small density
enh. in SMEI on Dec. 15. Arrives at L1 on Dec.
16, 0800. Well obs. by STEREOs.   - 2009 Feb.
13-18 ST-B disk center event. EUVI sigmoid,
wave, double dimming COR2A EL CME GOES B2 2
hr. LDE. Possibly a small MC at ST-B mid-Feb. 18.
Nothing before. Freeland movie at
http//www.lmsal.com/solarsoft/secchi/event_movie
s/gev_20090213_0535/scc_euvi_movie_pair_gev_200902
13_0535_diff_f. html Freeland, Webb, etc.   -
2009 March 18-21 No clear source obs. by LASCO
March 18, 03, streamer blowout partial halo
NE-NW. COR2B NW limb. Seen in HIA Bs to N.
SMEI Broad arc in Cam 2 on 21st, and SMEI aurora
1100. Small storm, peak Kp3. Increase in ACE
B, etc on 20-21 Slight increase at ST-B, 21.
Poss. Weak CIR?
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ICME events in 2007 and 2008

• List and results by Yan Li (UCB), Ben Lynch
  (UCB), Emilia Kilpua (Finland), Lan Jian (UCLA),
  Vicki Toy (UCB), Janet Luhmann (UCB)
• STEREO ICMEs are selected using STEREO level2
  data archived at UCLA http//aten.igpp.ucla.edu/fo
  rms/stereo/ascii_PLASTIC_1m_new.html
• ACE ICMEs are from level2 data at the ACE science
  center site http//www.srl.caltech.edu/ACE/ASC/
• Highlighted rows in the two tables indicate good
  Magnetic Clouds. 2008 table is preliminary and
  incomplete.
• STEREO list of ICMEs, Stream Interaction regions,
  and IP Shocks at
• http//www-ssc.igpp.ucla.edu/forms/stereo/stereo_
  level_3.html

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ICME (shock and ejecta) dates, times and
duration2007
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ICME (shock and ejecta) dates, times and
duration2008
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15-19 November 2007 CME

• The most likely parental CME was a slow partial
  halo CME on Nov. 15 with speed 125km/s and
  angular width 200.
• No activity (flare, dimming, etc) in low corona
  in association with the slow CME. No significant
  magnetic region on photosphere.
• Howard Tappin (Space Sci. Rev., submitted,
  2009)
• - Event observed by LASCO, SMEI and both
  STEREOs. Also detected by ACE and STEREO in-situ
  and caused a small geomagnetic storm at Earth.
• - Two limb CMEs were launched the day before
  and the day after this halo event. Discussed by
  Howard Tappin Sol. Phys., 252, p373, 2008.
• High speed solar wind stream compressed the rear
  boundary of the MC.
• From WSA model based on MWO daily updated
  synoptic map, the ambient solar wind during the
  few days around the ICME interval is from the
  southern coronal hole extension within positive B
  field on the photosphere, and the predicted solar
  wind speed should be around 600km/s.

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Results
Event 3 15-20 November, 2007
The CME Component
Coronagraph (LASCO) Parameters Onset
DateTime Speed Central PA PA Width 15 Nov.
2007 1850 UT 200 km/s 280 200


15
12
15-20 November 2008 ICME Component
a) SMEI 19 Nov.
b) HI-2A 19 Nov.
c) HI-2B 19-20 Nov.
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19 November 2007 Magnetic Cloud
Shk STB STA
41
STA
STB
STEREO data of November 2007
ICME
2250
2230
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19 November 2007 Force-free flux rope fit
SUN
Y
X
Two views show the approximate orientations of
the the force-free fluxrope (Lynch et al.,
2003) Magnetic Cloud (MC) at ST-B, ACE, and
ST-A. The fluxrope (all left-handed) are
consistent with a CME structure/fluxrope having
the axis parallel with the ecliptic plane with
a longitudinal extend at the same scale with
the STEREO separation 41.
STB
?
STA
ACE
Z
Y
STB
ACE
STA
Lat. 156.0 81.1
162.4 Lon. -22.2 -4.7
4.9 Rho -0.70 0.39
-0.72 left-handed
left-handed left-handed
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Reconnection Exhausts Associated with an
ICME/Cloud-Driven Disturbance Eriksson et al., ST
SWG, Feb. 2009
Field Shear Angle 15
3-s plasma data
Exhaust
92-ms field data
11 exhausts in a 1.5-day interval. 5 exhausts
within the cloud and 1 at trailing edge. 3 of
cloud exhausts occurred at local field shear
angles lt 18!
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SMEI 3D Reconstruction of Nov. 2007 Event
Note linear structure - ST-A Density flows
ST-B Earth
Courtesy B. Jackson, UCSD
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Tappin-Howard 3D Model Results
The ICME Component
Converging parameters Shell Speed Central
Central Latitude Longitude
Latitude Longitude Width Width 480 km/s
9N 15E 108 84


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18
Output Visualization of Model

Sun
STEREO-A
Earth

STEREO-B
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From the perspective of the Ulysses spacecraft
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Height Speed Plots
15-20 November 2007
ST-B Shock
ACE Shock
SMEI HI Model
ST-A Shocks
LASCO COR Data
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20
Ecliptic plane projection of 3D model
reconstruction a) Event near ST-B Earth on 19
November
b) Event near ST-A on 20 November
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4-8 February 2008 CME Wood et al., ApJ, 2009
Ecliptic plane schematic showing ST-A, Earth
ST-B and SECCHI views. Purple arcs are estimated
extent of CME at 1 AU.
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4 February 2008 CME EUVI rd movie
(Wood et al, ApJ (2009)
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4 February CME COR2s
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4-5 February CME HI-1s
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5-10 February CME HI-2s
(Wood et al, ApJ (2009)

• This movie demonstrates that the in situ
  instruments on STEREO-B (particularly PLASTIC) do
  see a particle response to the CME and CIR fronts
  seen by HI2-A crossing the position of STEREO-B.
• HI2-B sees faint, fast, broad fronts pass through
  the foreground at this time.
• SOHO/CELIAS sees the CME, but before the visible
  HI2-A front reaches SOHOs position.
• STEREO-A/PLASTIC sees the CIR, but not the CME,
  providing an upper limit to the CMEs angular
  extent.

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6-16 February CME In-situ Data
CME detected at ST-B, weakly at ACE/SOHO, and not
at ST-A. Note CIR observed in time sequence at
ST-B, L1, then ST-A.
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Feb. 2008 CME Model Distance Speed
Two methods used to convert elongation to
distance Green Point P Red
Fixed-F Velocities computed from
distance pairs.
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2 - 6 June 2008 CME

• The parent CME observed by imagers on ST-A as a
  east-limb 3-part CME, a halo CME by ST-B and
  east-limb CME by LASCO. Slow CME lt300 km/s.
  3-part CME also seen in ST-A HI (helispheric
  imager) images.
• No obvious activity (flare, dimming, etc.) in low
  corona associated with CME. Photospheric
  magnetograms show a very quiet disk with no
  active region.
• A magnetic cloud observed in-situ at ST-B on 6
  June 2008 The ambient solar wind around the MC
  was slightly gt400km/s, with no high speed stream
  encounters.
• GONG PFSS model shows the coronal field with a
  section of highly inclined coronal streamer belt
  and HSC.

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6 June 2008
55
0.13AU
STEREO data of JUNE 2008
shk
MC
June 2008
06/06 1530 13h5m
MC
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6 June 2008 Force-free flux rope fit
SUN
Y
X
Two views show the approximate orientations of
the the force-free flux rope (Lynch et al.,
2003) Magnetic Cloud (MC) at STB. The flux rope
based on STB data is right handed, and has its
axis highly inclined to the ecliptic plane. ACE
likely crossed the edge of the MC.
STB
STA
ACE
Z
Y
STB
ACE
STA
Lat. 298.4 Lon. 54.3 Rho -0.34 Righthanded
likely encounter Waiting for Level 2 data
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2008 April 26-29 CME Arcade, dimming, EIT
wave, type II (m), halo CME ST-B LASCO- Near
Sun-center for ST-B EarthSmall SEP at ST- B
on 26 April MC at ST-B on 29 April A WHI
Event, but just after official period.
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ST-B Shock/MC ST-A
Nothing ST-B SEP ST
A Nothing
26 April
29 April
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SMEI 3D Reconstruction of 29 April 2008 Event
Density flows at ST-B Earth
Courtesy B. Jackson, UCSD
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12 December 2008 CME Davis et al., JGR (2009)
Ecliptic plane schematic showing ST-B, Earth
ST-A and HI views.
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EUVI Prominence Eruption - 12 Dec. 2008
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December 2008 CME HIs in-situ obs.

• Assoc. with N eruptive prominence
• Earth directed seen at ACE
• Dotted lines are at the times when structure
  boundaries in HI2 crosses the LOS to ACE
• Only modestly geoeffective Kp3 for 1 day
• CME core may have passed to north
• Davis et al (2009)

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SMEI 3D Reconstruction of Dec. 2008 Event
Courtesy B. Jackson, UCSD
38
13 February 2009 CME SC in ST-B, possible small
in-situ MC at ST-B EUVI-B (left) COR-2A (right)
movies
Sam Freeland movies at http//www.lmsal.com/solar
soft/secchi/event_movies/gev_20090213_0535/scc_euv
i_movie_pair_gev_20090213_0535_diff_f.html
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14-15 February 2009 CME HI-1A (left) HI-2A
(right) movies
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17-18 February 2009 In-situ IMF
Plasma Possible ejecta/magnetic cloud?
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Brief Word on CIRs Space Weather

• Stream Interactions regions, whether recurrent
  (corotating) or not, can be geoeffective.
• - Compression of IMF (and plasma) can lead to
  enhanced B, and Bs, fields.
• - Turner et al., JASTP (2009) Mag storms driven
  by CIRs deposit more energy in ring current and
  ionosphere than expected from their input
  energy. Are more geoeffecient ratio of energy
  deposited to energy input is greater than for
  CMEs. Also, Borovsky Denton, JGR (2006).
• Have had some strong CIRs since STEREO launch
• - A two-stream recurrent structure since
  late-2007.
• Can now observe IP density enhancements assoc.
  with CIRs
• - HIs Sheeley et al., ApJ (2008) Rouillard et
  al., GRL (2008)
• - HIs SMEI Tappin Howard, Solar Phys.
  (2009)
• Important to detect coornal hole sources track
  CIRs
• - Use ST-B solar obs. initial detection of CIR
  in-situ for Earth prediction
• - L5 pathfinder period

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• Phase of CIR
• recurrent CIRs show origin at same or nearby
  coronal holes
• more complex pattern in early 2007
• gives way to 2 steam per rotation pattern from
  later 2007 through 2008
• single feature seen in more recent data
• G. Mason et al., SWG, Feb. 09

Fig. 2 Day of Bartels rotation for each CIR in
Table 1 vs. the time of the CIR at ACE (year).
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CIR Geometry and Detection Tracking
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CIR Observed by SMEI HIs in late Nov. 2008
Source coronal hole SOHO EIT on 22 Nov. 2008.
Circles show projected locations of 3 S/C
STEREO locations at central meridian.
45
CIR Observed in HIs J-plots HI-1 and HI-2
image. Left HI-A right HI-B
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THE END