1 STEREO Today Status report presented by Janet Luhmann and Peter Schroeder for the ACE/STEREO/WIND/SOHO Workshop 2010 June 8-10, Kennebunkport (Material drawn in part from this year’s STEREO Senior Review presentation by Joe Gurman, Toni Galvin and Bill Thompson-using material provided by the STEREO teams)

1. To Understand the causes and mechanisms of Coronal Mass Ejection (CME) initiation 2. To Characterize the propagation of CMEs through the heliosphere 3. To Discover the mechanisms and sites of energetic particle acceleration in the low corona and the interplanetary medium 4. To Develop a 3D time- dependent model of the solar wind Pre-STEREO SOHO images STEREO Science Goals

SECCHI - Remote Sensing Package of imagers Two White Light Coronagraphs (COR1,COR2)- COR1 explores 1.4 – 4 Rsun. COR2 explores 2 – 15 Rsun Extreme Ultra Violet Imager (EUVI)- Observes chromosphere and inner corona Heliospheric Imager (HI1, HI2)- Observes Coronal Mass Ejections from the Sun to the Earth (12 – 300 Rsun) IMPACT - Samples the distribution of solar wind electrons, the characteristics of the energetic ions and electrons, and magnetic field. Solar Wind Electron Analyzer (SWEA)- Measures ~0-3 keV electrons with wide angle coverage Suprathermal Electron Telescope (STE) -Measures electrons from keV with wide angle coverage Magnetometer Experiment (MAG)- Measures the vector magnetic field at 65,536 nT and 500 nT ranges Solar Energetic Particle Experiment (SEP) Suite (LET,SIT,SEPT,HET) –Measures electrons from MeV –Measures protons from 0.02 – 100 MeV –Measures helium ions from 0.03 – 100 MeV/nucleon –Measures heavier ions form 0.03 – 40 MeV/nucleon PLASTIC - Provides the plasma characteristics of protons, alphas, and heavy ions.including composition SWAVES - in-situ as well as remote sensing instrument. Tracks CME Driven Shocks from the Corona to the Earth. Measures plasma waves. STEREO investigations and measurements

STEREO In-situ Investigation Concept

SECCHI Images from 3 June 2007 VenusEarth Moon (R. Howard image) The multipoint measurements complement the Sun-to-Earth images

Overlap of Views from HI1 and CORs

7 STEREO’s location can be watched at the STEREO Science Center site stereo-ssc.nascom.gov STEREO whereabouts on June 3, 2010

8 Updates The STEREO mission is in extended phase (has had two Senior Reviews) Science Goals Affected by low solar activity (few fast CMEs, SEPs) since launch in October, 2006 Recent work emphasizes ‘quiet’ heliosphere CIR/solar wind sources and structure analyses Multispacecraft studies of small to moderate CMEs Interplanetary magnetic field including shocks and waves and topology

9 SOHO EIT and SECCHI EUVI images (Bill Thompson, at SSC) STEREO is doing its job of giving a whole Sun view

10 MFSC solar website plot- D. Hathaway But solar activity has been very low since launch, retargeting the main STEREO science activities somewhat

11 CME rates follow the sunspot cycle, but still occurred at this solar minimum at rates similar to previous cycle minimum (St. Cyr and Xie)

12 Example of a Multi- spacecraft analysis of a magnetic cloud 2007 November 19 – 21 Interaction of a CIR and a magnetic cloud near the heliospheric current sheet Near-Earth (WIND) data and geomagnetic response

13 Inferred Magnetic cloud magnetic field → Magnetic field maps obtained from Grad-Shafranov reconstructions; from solar E to W: STEREO B, WIND, STEREO A Farrugia et al. 2010, submitted to JASTP (special CME/ICME volume)

14 In 2010 CMEs are getting more frequent and energetic, and SEP events are returning Multi-spacecraft SEP events observed on 2009/12/22, 2010/01/17; 2010/02/07, 08, 12 – when separation was > 130°

Flare at 9:04; Halo CME at 10:33 (C2) Type III No Type III April 3-6, 2010 Shock + ESP event No Shock + ESP event? SWAVES SEPT PLASTIC Wind/WAVES ACE/EPAM ACE/SWEPAM GOES SOHO/LASCO Example: multipoint reconstruction of SEP events (Caltech)

16 Scientific topics addressed, Stream/Corotating Interaction Regions (SIRs and CIRs) and associated energetic particles Mapping/Tracking solar wind and IMF sources, including transient sources of slow solar wind Ion cyclotron and other waves in the solar wind Multipoint CME, ICME and SEP event analyses Modeling of quiet corona, solar wind and transients Energetic neutral atoms from solar events (flares and/or coronal mass ejections) and the magnetosphere Small, impulsive He3 rich SEP events Comet-solar wind interactions

17 Scientific topics addressed, (continued) CMEs without solar surface source signatures Reconnection in the solar wind Interplanetary shocks structure and evolution Interplanetary dust distribution and impacts Imaging stream interaction regions seen in-situ Coronal loops and dimmings- multiperspective studies Anomalous cosmic ray gradients Upstream (of bow shock) particle events Planetary space weather applications Quadrature space weather forecasting applications

18 Publications Update 2009 Solar Physics special issue appeared JASTP special volume, Three Dimensional Aspects of CMEs, Their Source Regions, and Interplanetary Manifestations ( Mierla, Srivastava, and Rodriguez, eds.) –due out by end of this year Upcoming Solar Physics special issue on Whole Heliosphere Interval (WHI)

STEREO Science Supporting Resources are Many SSC provides Beacon images, plots, and access and/or links to data files (beacon and processed) Investigator sites provide these plus much additional information: e.g. synoptic maps from imagers, movie makers, space weather information, links to instrument papers, etc. Modeling sites provide results that can be used to connect what is seen in the images and at 1 AU (e.g. solar wind source mapping)

Space Weather Website includes events (D. Webb)

Example: GONG-based PFSS coronal field models and EUV image comparisons from SECCHI EUVI and SOHO EIT (GONG website images below show open field regions and HSB)

22 These models can also be used to map solar wind/IMF sources (WSA model results-NSWPC website)

23 Proposed Science, FY11 - FY14 Senior Review proposal lists 19 specific scientific objectives, all tied to the rise of solar activity cycle 24, including: angular distribution and dependencies of SEP events solar cycle modulation of anomalous cosmic rays reaching the ecliptic plane Radio probing of the heliosphere before and after ICME passage 23

To be aware of: Telemetry rates will be changing At Senior Review Ahead was operating at 360 kbps, and Behind at 240 kbps. Ahead switched to 240 kbps on April 26. Switch to 160 kbps on 2010 September 13 on both spacecraft. Switch to 120 kbps on Behind: 2010 Nov 15, Ahead: Apr 11 Switch to 96 kbps in 2011 September for both spacecraft Currently planning for switch to 30 kbps in 2012 August STEREO on 01 April 2011 (left) and 2012 (right)

STEREO In Situ Data Access

Overview: Several Points of Entry STEREO Science Center archives all primary instrument data. It also provides the real- time space weather beacon data, images and plots: PI sites provide access to primary instrument data, some higher order data products, plots/browsers and lots of associated information about the instruments and the data : IMPACT: PLASTIC: S/WAVES: Co-I sites provide additional tools, browsers and data in different formats (for example, ASCII): UCLA: MAG data, “Level 2” (merged MAG and PLASTIC), “Level 3” (event lists): ssc.igpp.ucla.edu/ssc/stereo/ ssc.igpp.ucla.edu/ssc/stereo/ Caltech: SEP suite browsers and data: Toulouse: SWEA PAD and (limited) moments data: Kiel: SEPT browser: CDAWeb serves a great deal of data and more is on the way: The Virtual Heliospheric Observatory (VHO) likewise serves some STEREO data and more is also in the pipeline:

STEREO Science Center:

IMPACT Investigation Site:

PLASTIC Investigation Site:

S/WAVES Investigation Site:

IMPACT Server at UCLA STEREO IMPACT L1 Magnetometer Data (1 Hz, 8 Hz, 32 Hz) Earth orbit in GSM (Nov 7, 2006 – Oct 31, 2008) Heliocentric orbit in RTN or spacecraft coordinates (Nov 7, 2006 – Mar 31, 2010) Correlative: Wind/ACE mag data in RTN (1m, 1s) Plots and ASCII data L2 Merged Magnetometer and PLASTIC Plasma Data (1 hour, 10 min, 1 min) STA (Feb 15, 2007 – Feb 28, 2010) and STB (Mar 1, 2007-Feb 28, 2010) Parameters: Vp, Np, Tp, entropy, beta, total pressure, Br, Bt, Bn, B, cone angle, clock angle, Br/B, Bt/B, Bn/B, spacecraft location Plots and ASCII data L3 Event Lists (ICMEs, CIRs, Shocks) Updated to Oct 31, 2009 ICME parameters: start and stop time, maxima of total pressure, magnetic field, and solar wind speed, declining speed, group, and comments SIR parameters: start and stop time, interface time, maxima of total pressure, magnetic field, proton number density, minimum and maximum solar wind speed Shock parameters (using 8-Hz data): time, field ratio, shock normal angle, beta, Mach number, availability of 32-Hz data, forward/reverse shock

IMPACT/SEP Suite Site:

IMPACT/SEPT kiel.de/stereo/browseplots/