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HQ Lunch Science Seminar Series 1 NASA/HQ, 1/28/2008 Introduction, THEMIS overview First THEMIS results from the tail First THEMIS results in the dayside.

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Presentation on theme: "HQ Lunch Science Seminar Series 1 NASA/HQ, 1/28/2008 Introduction, THEMIS overview First THEMIS results from the tail First THEMIS results in the dayside."— Presentation transcript:

1 HQ Lunch Science Seminar Series 1 NASA/HQ, 1/28/2008 Introduction, THEMIS overview First THEMIS results from the tail First THEMIS results in the dayside First THEMIS results in the radiation belts Engaging students and the public Future activities THEMIS First Results and near future

2 HQ Lunch Science Seminar Series 2 NASA/HQ, 1/28/2008 Maximizing Substorm Science on THEMIS: Probe Alignments and Ground Conjunctions Vassilis Angelopoulos, UCLA ESS April 13, 2006 Simulation: J. Raeder, UNH Visualization: Tom Bridgman, GSFC/SVS

3 HQ Lunch Science Seminar Series 3 NASA/HQ, 1/28/2008 T IME H ISTORY OF E VENTS AND M ACROSCALE I NTERACTIONS DURING S UBSTORMS (THEMIS) RESOLVING THE PHYSICS OF ONSET AND EVOLUTION OF SUBSTORMS Principal Investigator Vassilis Angelopoulos, UCLA EPO Lead Laura Peticolas, UCB Mission Operations Manager Manfred Bester, UCB Industrial Partner ATK Space (SWALES Aerospace Inc.) SCIENCE GOALS: Primary: “How do substorms operate?” – One of the oldest and most important questions in Geophysics – A turning point in our understanding of the dynamic magnetosphere First bonus science: “What accelerates storm-time ‘killer’ electrons?” – A significant contribution to space weather science Second bonus science: “What controls efficiency of solar wind – magnetosphere coupling?” – Provides global context of Solar Wind – Magnetosphere interaction

4 HQ Lunch Science Seminar Series 4 NASA/HQ, 1/28/2008 THEMIS’s science and impact THEMIS will answer how substorms operate – Explains how magnetospheres process solar wind energy –Explains how auroras erupt MERCURY: 10 min EARTH: 3.75 hrs JUPITER: days ASTROSPHERE GALACTIC CONFINEMENT SUBSTORM RECURRENCE:

5 HQ Lunch Science Seminar Series 5 NASA/HQ, 1/28/2008 Auroral eruptions and substorms Auroral eruptions… Aurora …are a manifestation of magnetospheric substorms MAGNETOSPHERE SOLAR WIND EQUATORIAL PLANE

6 HQ Lunch Science Seminar Series 6 NASA/HQ, 1/28/2008 THEMIS Mission elements Probe conjunctions along Sun-Earth line recur once per 4 days over North America. Ground based observatories completely cover North American sector; determine auroral breakup within 1-3s … … while THEMIS’s space-based probes determine onset of Current Disruption and Reconnection each within <10s. : Ground Based Observatory

7 HQ Lunch Science Seminar Series 7 NASA/HQ, 1/28/2008 Substorms in THEMIS GBOs Mende et al, GRL 2007

8 HQ Lunch Science Seminar Series 8 NASA/HQ, 1/28/2008 Discovery of the first indicator of onset on the ground: Pulsations “irregular” of type 1, Burst 48-192s 12-48s … … Ground magnetograms…High-pass filtered Downward Current Upward Current Milling et al., GRL, 2008

9 HQ Lunch Science Seminar Series 9 NASA/HQ, 1/28/2008 Mission overview Instrument I&T UCB Mission I&T UCB Encapsulation & launch BGS Operations UCB Probe instruments: ESA: ElectroStatic Analyzer (coIs: Carlson and McFadden) SST: Solid State Telescopes (coI: Larson) FGM: FluxGate Magnetometer (coIs: Glassmeier, Auster & Baumjohann) SCM: SearchCoil Magnetometer (coI: Roux) EFI: Electric Field Instrument (coI: Bonnell) Ground SST ESA EFIa EFIs FGM SCM T spin =3s Release D2925-10 @ CCAS

10 HQ Lunch Science Seminar Series 10 NASA/HQ, 1/28/2008 Launch= 2007-02-17 2007-03-23 2007-06-03 2007-07-15 2007-08-30 2007-12-04 X GSE Y GSE TH-B TH-C TH-D TH-E TH-A P1 P2 P3 P4 P5 First 10 months Angelopoulos, 2008 Space Sci. Rev. Submitted

11 HQ Lunch Science Seminar Series 11 NASA/HQ, 1/28/2008 Tail 1 2008-02-02 Dayside 1 2008-08-08 X GSE Y GSE TH-B TH-C TH-D TH-E TH-A P1 P2 P3 P4 P5 First year baseline orbit Angelopoulos, 2008 Space Sci. Rev. Submitted

12 HQ Lunch Science Seminar Series 12 NASA/HQ, 1/28/2008 Angelopoulos et al., First Results from THEMIS, Space Sci. Reviews, 2008 V ~ 350km/s First light: Nature’s welcome. Substorm captured on March 23, 2007 Speed: 1MLT/min

13 HQ Lunch Science Seminar Series 13 NASA/HQ, 1/28/2008 THEMIS Detail For ULF waves also see: Keiling et al., GRL, 2008

14 HQ Lunch Science Seminar Series 14 NASA/HQ, 1/28/2008 Remote sensing establishes motion 1000 km V ~ 70km/s Z Y D B A

15 HQ Lunch Science Seminar Series 15 NASA/HQ, 1/28/2008 FAC B By X Z Y Assuming an outward plasma sheet expansion (evidenced by the |Bx| reduction - interpreted as a diamagnetic effect) the FAC is a pair of oppositely directed current sheets, embeded in an overall outward current sheet. This is consistent with THEMIS being at the westward edge of the WTS. B sc Reconstruction of Field Aligned Currents

16 HQ Lunch Science Seminar Series 16 NASA/HQ, 1/28/2008 Strangeway et al. GRL, 2008 observe same signatures on FAST

17 HQ Lunch Science Seminar Series 17 NASA/HQ, 1/28/2008 Timing For further details on timing see: Wenlon Liu et al., GRL, 2008 For event simulation see: Raeder et al., SSR, 2008

18 HQ Lunch Science Seminar Series 18 NASA/HQ, 1/28/2008 Westward expansion speed on the ground ~ 1 MLT hrs/min Maps to 10R E as 200-300km/s westward Westward observed speed in space (D - E) is ~250km/s Consistent with mapping the speed from the ground up Hot boundary motion near onset location is an outward expansion Obtained using remote sensing and finite gyroradius techniques Summary: First Observations of Westward Traveling Surge in Space Similar papers establish the nature of substorm expansion in space: Zhang, H. et al., GRL, 2008 [February 28, 2007 substorm; FGM only] Donovan, H., et al., GRL, 2008 [March 13, 2007 substorm; TH-A ESA] Conclusions on March 23 event

19 HQ Lunch Science Seminar Series 19 NASA/HQ, 1/28/2008 Dusk MP Sphere Sheath -,+ THEMIS at the dayside: First ever detection of a detached flux rope Details, see: Sibeck et al., GRL, 2008

20 HQ Lunch Science Seminar Series 20 NASA/HQ, 1/28/2008 THEMIS at the dayside: Discovery of remote signatures of flux ropes BNBN PTPT See Liu J., GRL, 2008 Remote signatures of flux ropes: Field compression; velocity inside opposes sheath flow! Trains of flux ropes suggest high reconnection rate. TH-B N M L B TH-C TH-D TH-E TH-A TH-B, C, D, E, A VL,M,NVL,M,N VL,M,NVL,M,N VL,M,NVL,M,N VL,M,NVL,M,N VL,M,NVL,M,N

21 HQ Lunch Science Seminar Series 21 NASA/HQ, 1/28/2008 THEMIS at the dayside: Significance of the apparent preponderance of flux ropes Courtesy: N. Omidi, Solana Scientific If dissipated in high latitude cusp they add to wave accelerated electrons, and ion outflows at the cusp. If dissipated at the low latitude boundary, they add to wave acceleration of electrons and ion outflows on field lines along the auroral oval. Courtesy: X.J. Jia, UCLA

22 HQ Lunch Science Seminar Series 22 NASA/HQ, 1/28/2008 THEMIS first direct observation of the birth of the storm-time ring current Ions Electrons Dst storm index TH-B TH-D TH-B TH-D TH-B See Wang C. P., et al, GRL, 2008 Ions penetrate deep into the inner magnetosphere, and remain after storm. Electrons also come close to Earth, but decay fast after storm recovery.

23 HQ Lunch Science Seminar Series 23 NASA/HQ, 1/28/2008 THEMIS tracks, for the first time, a Solar Wind shock, and the substorm it triggered. Keika, K. GRL, 2008. THEMIS data quality and availability is revitalizing coordination amongst all available space assets in the panoply of Heliophysics.

24 HQ Lunch Science Seminar Series 24 NASA/HQ, 1/28/2008 THEMIS observations: GRL, JGR and media presentations 40 Fall AGU presentations Numerous topical conferences Media coverage

25 HQ Lunch Science Seminar Series 25 NASA/HQ, 1/28/2008 Inspiring Yound Minds Reaching out to K-12 classes in rural America The Jim Lehrer show: http://www.pbs.org/newshour/bb/science/jan- june07/themis_05-16.html

26 HQ Lunch Science Seminar Series 26 NASA/HQ, 1/28/2008 Data availability, community participation. Maximize discourse and discovery.

27 HQ Lunch Science Seminar Series 27 NASA/HQ, 1/28/2008 Discoveries to date –In Tail/Substorms First signature of substorm onset on the ground: Pi1B waves First measurements of the Westward Traveling Surge in space First observations of shock propagation through magnetosphere, triggered substorm –In Dayside First observations of detached flux ropes Discovery of remote signatures of magnetic reconnection First in-situ observations of the onset of hot flow anomalies First direct observations of microphysics of asymmetric reconnection –In Inner Magnetosphere First observations of the birth of the ring current Outlook –Constellation in excellent state –Tail conjunctions have started, quality optimal in late February, early March, 2008 –Repeat again from different perspective in 2009 Long Term –Preparing Senior Review proposal (FY09-12) –Will build on successes of prime mission The fun has only just started! Summary


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