SH51B-01 INVITED 

Pickup Helium in the Inner Heliosphere: an Overview

* Klecker, B (berndt.klecker@mpe.mpg.de), Max-Planck Institut für extraterrestrische Physik, Giessenbachstrasse, Garching, 85748, Germany Galvin, A B), EOS and Department of Physics, University of New Hampshire, Durham, NH 03824, United States Kucharek, H), EOS and Department of Physics, University of New Hampshire, Durham, NH 03824, United States Kistler, L M), EOS and Department of Physics, University of New Hampshire, Durham, NH 03824, United States Popecki, M A), EOS and Department of Physics, University of New Hampshire, Durham, NH 03824, United States Mouikis, C), EOS and Department of Physics, University of New Hampshire, Durham, NH 03824, United States Farrugia, C), EOS and Department of Physics, University of New Hampshire, Durham, NH 03824, United States Möbius, E), EOS and Department of Physics, University of New Hampshire, Durham, NH 03824, United States Lee, M A), EOS and Department of Physics, University of New Hampshire, Durham, NH 03824, United States Ellis, L), EOS and Department of Physics, University of New Hampshire, Durham, NH 03824, United States Simunac, K), EOS and Department of Physics, University of New Hampshire, Durham, NH 03824, United States Singer, K), EOS and Department of Physics, University of New Hampshire, Durham, NH 03824, United States Blush, L M), Physikalisches Institut, University of Bern, Bern, 3012, Switzerland Bochsler, P), Physikalisches Institut, University of Bern, Bern, 3012, Switzerland Wurz, P), Physikalisches Institut, University of Bern, Bern, 3012, Switzerland Daoudi, H), Physikalisches Institut, University of Bern, Bern, 3012, Switzerland Giammanco, C), Physikalisches Institut, University of Bern, Bern, 3012, Switzerland Karrer, R), Physikalisches Institut, University of Bern, Bern, 3012, Switzerland Opitz, A (b), Physikalisches Institut, University of Bern, Bern, 3012, Switzerland Wimmer-Schweingruber, R F), Institute for Experimental and Applied Physics, University of Kiel, Kiel, 24098, Germany Koeten, M), Institute for Experimental and Applied Physics, University of Kiel, Kiel, 24098, Germany Hilchenbach, M), Max-Planck-Institut für Sonnensystemforschung, Max-Planck-Str. 2, Katlenburg-Lindau, 37191, Germany Thompson, B), NASA, Goddard Space Flight Center, Greenbelt, MD 20771, United States Acuna, M), NASA, Goddard Space Flight Center, Greenbelt, MD 20771, United States Luhman, J), Space Sciences Laboratory, University of California, Berkeley, CA 94720, United States

The CELIAS experiment onboard SOHO and the two Plasma and Suprathermal Ion Composition (PLASTIC) experiments onboard STEREO-A/B provide measurements of velocity, mass and ionic charge of solar wind ions and of suprathermal particles up to energies of 80 keV/e (PLASTIC) and 600 keV/e (CELIAS), respectively. Thus both the SOHO and STEREO instrumentation covers the energy range of the pickup He particle population of interstellar origin that is accelerated to suprathermal energies at interplanetary shocks and corotating interaction regions (CIRs). ACE and SOHO observations showed a large variability of both the pickup He source and the flux of suprathermal particles that so far could not be satisfactorily explained. In this overview we will summarize recent pickup He observations with ACE and SOHO at 1 AU, present first results of pickup He in CIRs obtained with STEREO, and discuss open questions that can be tackled in the near future with the new constellation of several spacecraft in the inner heliosphere.

SH51B-02 

Observations of Suprathermal Power Law Tails with ACE, Ulysses, MESSENGER, and Voyager

* Gloeckler, G (gglo@umich.edu), University of Michigan, Atmospheric, Oceanic and Space Sciences 2455 Hayward St., Ann Arbor, MI 48109-2143, United States Fisk, L A (lafisk@umich.edu), University of Michigan, Atmospheric, Oceanic and Space Sciences 2455 Hayward St., Ann Arbor, MI 48109-2143, United States

Observations of ubiquitous, suprathermal power law tails with the unique spectral index of –5 on the velocity distributions of solar wind and pickup ions raise important questions and have far reaching consequences. The question of how these tails are formed during quiet times, when no shocks are present, was previously addressed and is briefly reviewed here. One consequence of the existence of these tails during quiet times is that sufficiently energetic particles are always readily available for further acceleration by shocks. To study the evolution of suprathermal tails over a large range of heliocentric distances, we will use proton spectra measured with ACE, Ulysses and Voyager during quiet times as well as upstream and downstream of quasi-stationary and traveling shocks. To look for the first time at suprathermal tails at distances closer to the Sun than 1 AU, we will present our preliminary results from the FIPS instrument on the Mercury MESSENGER Mission. Applying thermodynamic constraints on non-adiabatic heating of upstream particles by a shock, we obtain the downstream –5 power law spectra that are observed and derive an expression for the tail pressure jump across the shock.

SH51B-03 

Inner-heliosphere SMEI observations and their comparison with multi-point in-situ measurements

* Jackson, B V (bvjackson@ucsd.edu), Center for Astrophysics and Space Sciences, University of California, San Diego, 9500 Gilman Drive #0424, La Jolla, CA 92093-0424, United States Bisi, M M (mmbisi@ucsd.edu), Center for Astrophysics and Space Sciences, University of California, San Diego, 9500 Gilman Drive #0424, La Jolla, CA 92093-0424, United States Hick, P P (pphick@ucsd.edu), Center for Astrophysics and Space Sciences, University of California, San Diego, 9500 Gilman Drive #0424, La Jolla, CA 92093-0424, United States Buffington, A (abuffington@ucsd.edu), Center for Astrophysics and Space Sciences, University of California, San Diego, 9500 Gilman Drive #0424, La Jolla, CA 92093-0424, United States Clover, J M (jclover@ucsd.edu), Center for Astrophysics and Space Sciences, University of California, San Diego, 9500 Gilman Drive #0424, La Jolla, CA 92093-0424, United States Feynman, J (Joan.Feynman@jpl.nasa.gov), Jet Propulsion Laboratory, M/8 169-506 4800 Oak Grove Dr., Pasadena, CA 91109, United States

Solar Mass Ejection Imager (SMEI) observations of the inner heliosphere have been carried out on a routine basis since shortly after its launch on January 6, 2003. By employing a kinematic model of the solar wind, we reconstruct three-dimensional (3D) solar wind structures from multiple observing lines of sight through the outward-flowing solar wind. This model allows us to extract solar wind densities from the SMEI white-light observations and to compare these to multi-point in situ "ground truth" solar wind measurements from instruments aboard the Ulysses, STEREO, ACE, and Wind spacecraft. This facilitates improvements to our 3D reconstruction technique by comparing these reconstructions at multiple points in the inner-heliosphere. Our observations show heliospheric structures globally, and because of this, our reconstructions provide us with a better understanding of the structure and dynamics of the interplanetary environment around each spacecraft, and how these structures are connected back to the Sun. http://smei.ucsd.edu/

SH51B-04 

In-situ and Numerical Modeling Prospects for Multipoint ICME Observations Featuring the 22 May 2007 STEREO Event

* Lynch, B J (blynch@ssl.berkeley.edu), Space Sciences Laboratory, Univ. of California, Berkeley 7 Gauss Way, Berkeley, CA 94270, United States Li, Y (yanli@ssl.berkeley.edu), Space Sciences Laboratory, Univ. of California, Berkeley 7 Gauss Way, Berkeley, CA 94270, United States Huttunen, K E (huttunen@ssl.berkeley.edu), Space Sciences Laboratory, Univ. of California, Berkeley 7 Gauss Way, Berkeley, CA 94270, United States Antiochos, S K (antiochos@nrl.navy.mil), E. O. Hulburt Center for Space Research, Naval Research Laboratory 4555 Overlook Ave. SW, Washington, DC 20375, United States DeVore, C R (devore@lcp.nrl.navy.mil), Laboratory for Computational Physics and Fluid Dynamics, Naval Research Laboratory 4555 Overlook Ave. SW, Washington, DC 20375, United States Luhmann, J G (jgluhman@ssl.berkeley.edu), Space Sciences Laboratory, Univ. of California, Berkeley 7 Gauss Way, Berkeley, CA 94270, United States

We will present recent 3D MHD simulation results of eruptive flux-rope formation via the magnetic breakout mechanism to provide a theoretical/modeling context for multipoint in-situ observations. Many generic observational CME properties are reproduced by this idealized eruption as it propagates through the low corona (~10 R_\odot). Recently, STEREO observed a "classic" flux-rope ICME on 22 May 2007 with different in- situ field and plasma signatures seen at each spacecraft. The same event was also seen by WIND and ACE, arriving at L1 arriving a few hours before either STEREO A or B. We will describe a preliminary analysis of the large-scale heliospheric structure of the ICME flux-rope utilizing the linear, force-free cylinder model fits to the in- situ magnetic field rotations in order to determine the ICME's relative simplicity and/or consistency with the standard Magnetic Cloud cartoon picture. A comparison between the data, the derived in-situ cylinder orientations at three spacecraft, and the CME large-scale magnetic structure inferred from the MHD simulation results in the low corona show a reasonable qualitative agreement. BJL would like to acknowledge support from NSF ATM-0621725 as a SHINE Postdoc, and thank the STEREO, WIND and ACE teams for making their data readily available.

SH51B-05 

Solar effects at Earth as observed by the STEREO Heliospheric Imagers

Rouillard, A (alexisrouillard@yahoo.co.uk), University of Southampton, School of Physics and Astronomy Highfield, Southampton, Han SO171BJ, United Kingdom Davis, C J (C.J.Davis@rl.ac.uk), Rutherford Appleford Laboratory, Chilton, Didcot, Ox OX110QX, United Kingdom Harrison, R A (R.A.Harrison@rl.ac.uk), Rutherford Appleford Laboratory, Chilton, Didcot, Ox OX110QX, United Kingdom Davies, J A (J.A.Davies@rl.ac.uk), Rutherford Appleford Laboratory, Chilton, Didcot, Ox OX110QX, United Kingdom * Bewsher, D (D.Bewsher@rl.ac.uk), Rutherford Appleford Laboratory, Chilton, Didcot, Ox OX110QX, United Kingdom Crothers, S R (S.R.Crothers@rl.ac.uk), Rutherford Appleford Laboratory, Chilton, Didcot, Ox OX110QX, United Kingdom Eyles, C J (C.J.Eyles@rl.ac.uk), Rutherford Appleford Laboratory, Chilton, Didcot, Ox OX110QX, United Kingdom

The twin STEREO spacecraft each carry a Heliospheric Imager. These wide angle cameras have provided the first ever observations of Earth directed events from a position outside the Sun-Earth line. We present combined observations taken with the instruments onboard STEREO, SOHO and ACE spacecraft as we track the progress of material through the heliosphere. At Earth, the impact of the solar wind on the Earth's atmosphere is tracked by the Cluster satellites and EISCAT radars. http://www.stereo.rl.ac.uk

SH51B-06 

Multipoint Validation of a Global 3D MHD Model for the Solar Corona and Inner Heliosphere

* Cohen, O (oferc@umich.edu), CSEM-University of Michigan, 2455 Hayward St., Ann Arbor, MI 48105, United States Sokolov, I V (igorsok@umich.edu), CSEM-University of Michigan, 2455 Hayward St., Ann Arbor, MI 48105, United States Roussev, I I (iroussev@ifa.hawaii.edu), IFA-University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822, United States Gombosi, T I (tamas@umich.edu), CSEM-University of Michigan, 2455 Hayward St., Ann Arbor, MI 48105, United States

We present a long-term validation of a global, 3D MHD model for the solar corona and the solar wind. The model is driven by high resolution MDI magnetograms and is constrained by the empirical Wang-Sheeley-Arge (WSA) model. The model provides a three-dimensional steady-state structure of the heliosphere between the Sun and the Earth for a particular Carrington Rotation. We use the model to obtain the large-scale context for the information we collect from multipoint spacecraft observations and large-scale remote sensing imagine of the solar corona and the heliosphere. For the long-term validation of the model, we compare the result with ACE data and the available STEREO data.

SH51B-07 

A comprehensive view of the 13 December 2006 CME: From the Sun to the outer heliosphere

* Liu, Y (liuxying@ssl.berkeley.edu), Space Sciences Laboratory, University of California, Berkeley, 7 Gauss Way, Berkeley, CA 94720, United States Luhmann, J (jgluhman@ssl.berkeley.edu), Space Sciences Laboratory, University of California, Berkeley, 7 Gauss Way, Berkeley, CA 94720, United States Li, Y (yanli@ssl.berkeley.edu), Space Sciences Laboratory, University of California, Berkeley, 7 Gauss Way, Berkeley, CA 94720, United States Lin, R (rlin@ssl.berkeley.edu), Space Sciences Laboratory, University of California, Berkeley, 7 Gauss Way, Berkeley, CA 94720, United States Bale, S (bale@ssl.berkeley.edu), Space Sciences Laboratory, University of California, Berkeley, 7 Gauss Way, Berkeley, CA 94720, United States Acuna, M H (mha@lepmom.gsfc.nasa.gov), NASA/GSFC, Code 695, NASA/GSFC, Code 695, Greenbelt, MD 20771, United States Russell, C T (ctrussel@igpp.ucla.edu), IGPP, University of California, Los Angeles, University of California, Los Angeles, Los Angeles, CA 90095, United States Sauvaud, J (sauvaud@cesr.fr), CESR/CRNS, 9 Avenue du Colonel Roche, Toulouse, 31029, France Galvin, A B (toni.galvin@unh.edu), University of New Hampshire, Durham, University of New Hampshire, Durham, Durham, NH 03824, United States

The first biggest CME in the Stereo era, which occurred on 13 December 2006, is studied in terms of its solar source and heliospheric consequences. The CME appears as a halo event in LASCO coronagraph images and hits the Stereo and ACE spacecraft as a magnetic cloud (MC) preceded by a shock; the shock is also observed at Ulysses which is more than 100 degrees apart from the 1 AU spacecraft in heliocentric longitude, indicative of a large longitudinal extent of the shock. The interplanetary structure of the CME is reconstructed using the Grad- Shafranov technique combined with a minimum variance analysis in an effort to connect with the solar source. Particle acceleration, radio wave emissions and plasma instabilities associated with the shock are investigated by examining the shock geometry and magnetic fluctuations in the sheath region of the MC. We also propagate the in situ measurements at 1 AU to the outer heliosphere using an MHD model in order to compare with Ulysses observations and assess the consequences at large distances.

Author(s) (2007), Title, Eos Trans. AGU, 88(52), Fall Meet. Suppl., Abstract #####-##.