Experimental Space Plasma

Magnetosphere Ion Sources, Acceleration, and Transport

There are two sources for the plasma in the Earth's magnetosphere: the solar wind and the ionosphere. The solar wind is predominantly protons, with a small percentage of alpha particles and high charge state heavy ions, while the ionosphere provides low charge state ions, primarily hydrogen and O+. Although the protons are common to both sources, the heavy ions can be used to differentiate the sources, and to better understand the acceleration mechanisms and transport paths that bring the ions in the the Earth's magnetotail and inner magnetosphere. We are involved in a number of studies using Van Allen Probes, Cluster and Arase data to better understand how the two sources are accelerated and transported within the magnetosphere, and how the ion composition impacts the magnetospheric dynamics.

Recent publications

• Lund, E. J., N. Nowrouzi, L. M. Kistler, X. Cai, and H. U. Frey (2018), On the Role of Ionospheric Ions in Sawtooth Events, Journal of Geophysical Research (Space Physics), 123(1), 665–684, doi:10.1002/2017JA024378.
• Menz, A. M., L. M. Kistler, C. G. Mouikis, H. E. Spence, R. M. Skoug, H. O. Funsten, B. A. Larsen, D. G. Mitchell, and M. Gkioulidou (2017), The role of convection in the buildup of the ring current pressure during the 17 March 2013 storm, Journal of Geophysical Research (Space Physics), 122(1), 475–492, doi:10.1002/2016JA023358.
• Kistler, L. M., C.G. Mouikis, H.E. Spence, A.M. Menz, R.M. Skoug, H.O. Funsten, B.A. Larsen, D.G. Mitchell, M. Gkioulidou, J.R. Wygant, and L.J. Lanzerotti  (2016), The source of O+ in the storm time ring current, Journal of Geophysical Research (Space Physics), 121(6), 5333–5349, doi:10.1002/2015JA022204
• Kistler, L. M. (2016) The Impact of O⁺ on Magnetotail Dynamics, in Magnetosphere-Ionosphere Coupling in the Solar System (eds C. R. Chappell, R. W. Schunk, P. M. Banks, J. L. Burch and R. M. Thorne), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9781119066880.ch.

Inner Magnetosphere Waves

The inner magnetosphere is an active location for wave generation. These waves can impact the magnetospheric dynamics both by accelerating ions or electrons, and through scattering the particles, creating loss.  Wave acceleration is one mechanism responsible for the Van Allen radiation belts. Our groups have been studying the conditions that lead to wave excitation, as well as how the interplay of different particle populations and waves lead to the development of the radiation belts.

Recent Publications

• Saikin, A. A. et al. (2018), Comparing simulated and observed EMIC wave amplitudes using in situ Van Allen Probes' measurements, Journal of Atmospheric and Solar-Terrestrial Physics, 177, 190–201, doi:10.1016/j.jastp.2018.01.024.
• Paulson, K. W., C. W. Smith, M. R. Lessard, R. B. Torbert, C. A. Kletzing, and J. R. Wygant (2017), In situ statistical observations of Pc1 pearl pulsations and unstructured EMIC waves by the Van Allen Probes, Journal of Geophysical Research (Space Physics), 122(1), 105–119, doi:10.1002/2016JA023160.
• Allen, R. C., J.-C. Zhang, L. M. Kistler, H. E. Spence, R. L. Lin, B. Klecker, M. W. Dunlop, M. André, and V. K. Jordanova (2016), A statistical study of EMIC waves observed by Cluster: 2. Associated plasma conditions, Journal of Geophysical Research (Space Physics), 121(7), 6458–6479, doi:10.1002/2016JA022541.

Reconnection

The reconnection of magnetic field lines is one of the fundamental processes that controls the coupling between the magnetosphere and interplanetary space. The Cluster mission, with four spacecraft in a tetrahedon with variable spacing gives an ion-scale view of reconnection. The Magnetospheric Multiscale Mission, with four much more closely spaced spacecraft, combined with high time resolution, has allowed the structure of the reconnection region to be measured at the electron scales. At UNH, studies have involved determining the structure of the electron diffusion region and the dissipation that occurs, studies of magnetic structures that result from reconnection, and the effects of heavy ions and cold dense plasma on reconnection.

Recent Publications

• Alm, L., et al. (2018), Differing Properties of Two Ion-Scale Magnetopause Flux Ropes,, 123(1), 114–131, doi:10.1002/2017JA024525.
• Torbert, R. B. et al. (2017), Structure and Dissipation Characteristics of an Electron Diffusion Region Observed by MMS During a Rapid, Normal-Incidence Magnetopause Crossing, Journal of Geophysical Research (Space Physics), 122(1), 11–, doi:10.1002/2017JA024579.
• Torbert, R.B. et al. (2016), Estimates of terms in Ohm's law during an encounter with an electron diffusion region,, 43(1), 5918–5925, doi:10.1002/2016GL069553.
• Liu, Y. H., C. G. Mouikis, L. M. Kistler, S. Wang, V. Roytershteyn, and H. Karimabadi (2015), The heavy ion diffusion region in magnetic reconnection in the Earth's magnetotail, Journal of Geophysical Research (Space Physics), 120(5), 3535–3551, doi:10.1002/2015JA020982.
• Wang, S., L. M. Kistler, C. G. Mouikis, and S. M. Petrinec (2015), Dependence of the dayside magnetopause reconnection rate on local conditions, Journal of Geophysical Research (Space Physics), 120(8), 6386–6408, doi:10.1002/2015JA021524.

Magnetosphere-Ionosphere Research

Scientists in the Magnetosphere-Ionosphere Research Laboratory focus on the development of instrumentation for ground-based, rocket-based, and satellite observations of space physics phenomena and analysis of the resulting observations.

Ionosphere-thermosphere Coupling

The Space Science Center conducts a robust research program into the science of the ionosphere-thermosphere (and mesosphere) system within the larger geospace system. The IT (or ITM) system occupies the lower reaches of geospace, spanning altitudes of about 80 km to 1000 km. In this region, comingled gases in the neutral and plasma states are tightly coupled by various physical and chemical processes. In fact, the origin of the plasma component is the neutral gas component, primarily through the ionizing action of solar radiation. As a highly structured and variable medium, the processes that dominate in a given location vary greatly, as phenomena originating in other elements of geospace and the lower atmosphere impact the system. The Center’s research program into this science seeks to advance understanding of how the system behaves, with a focus on the impacts of coupling between its charged and neutral constituents.

Recent Publications

• Observations of spatial variations in O/N2 during an auroral substorm using the multichannel downlooking camera on the VISIONS rocket, J. H. Hecht, J. H. Clemmons, M. G. Conde, D. L. Hampton, R. G. Michell, D. E. Rowland, R. F. Pfaff, and R.L. Walterscheid, J. Geophys. Res., 123, 7089-7105, doi:10.1029/2018JA025288, 2018.
• High-resolution modeling of the cusp density anomaly: Response to particle and Joule heating under typical conditions, Douglas G. Brinkman, Richard L. Walterscheid, James H. Clemmons, and James. H. Hecht, J. Geophys. Res., 121, 2645-2661, doi:10.1002/2015JA021658, 2016.
• LAICE cubesat mission for gravity wave studies, John Westerhoff, Gregory Earle, Rebecca Bishop, Gary R. Swenson, Sharon Vadas, James Clemmons, Ryan Davidson, Lucy Fanelli, Chad Fish, Vidur Garg, Alex Ghosh, Bindu B. Jagannatha, Erik Kroeker, Peter Marquis, Daniel Martin, Stephen Noel, Cameron Orr, and Robert Robertson, Adv. Space Res., 56, 1413-1427, doi:10.1016/j.asr.2015.06.036, 2015.
• Rapid, highly-structured meridional winds and their modulation by non-migrating tides: Measurements from the Streak mission, J. H. Clemmons, R. L. Walterscheid, A. B. Christensen, and R. L. Bishop, J. Geophys. Res., 118, 866-877, doi:10.1029/2012JA017661, 2013.
• A multi-year (2002-2006) climatology of O/N2 in the lower thermosphere from TIMED GUVI and ground-based photometer observations, J. H. Hecht, T. Mulligan, J. T. Correira, J. H. Clemmons, D. J. Strickland, R. L. Walterscheid, and M. G. Conde, J. Geophys. Res., 117, A03302, doi:10.1029/2011JA017146, 2012.
• High-latitude E region ionosphere-thermosphere coupling: A comparative study using in situ and incoherent scatter radar observations, J. K. Burchill, J. H. Clemmons, D. J. Knudsen, M. Larsen, M. J. Nicolls, R. F. Pfaff, D. Rowland, and L. Sangalli, J. Geophys. Res., 117, A02301, doi:10.1029/2011JA017175, 2012.
• The ionization gauge investigation for the Streak mission, J. H. Clemmons, L. M. Friesen, N. Katz, M. Ben-Ami, Y. Dotan, and R. L. Bishop, Space Sci. Rev., 145, 263-283, doi:10.1007/s11214-009-9489-6, 2009.
• Thermospheric density in the Earth's magnetic cusp as observed by the Streak mission, J. H. Clemmons, J. H. Hecht, D. R. Salem, and D. J. Strickland,  Geophys. Res. Lett., 35, L24103, doi:10.1029/2008GL035972, 2008.

Magnetospheric Multiscale Mission

Launched March 15, 2015

The Magnetospheric Multiscale Mission is a NASA Solar-Terrestrial Probes Mission designed to study how the sun's and Earth's magnetic fields connect and disconnect, in a process called "reconnection". Our researchers at the University of New Hampshire plays two key roles in the mission. First, we are the overall lead for the FIELDS instrument suite, the suite of instruments that measured the electric and magnetic fields. We are also the lead for the Electron Drift Instrument (EDI), one of the instruments in the FIELDS suite. EDI measures the electric field by emitting a beam of electrons, and tracking its return, and has flown on the Equator-S, Cluster and now the MMS missions.

Van Allen Probes

Launched August 30, 2012

Van Allen Probes is a NASA mission designed to study the dynamics of the inner mnagnetosphere, particularly the Van Allen Radiation Belts. It consists of two identical spacecraft well instrumented to cover electrons from ~20 eV up to 10 MeV, and ions from 20 eV to 75 MeV, as well as measuring the magnetic and electric fields.

UNH has two roles in the Van Allen Probes mission. UNH is the lead for the Energetic Particle and Thermal Plasma (ECT) Suite, and for the Central Data Processing Unit (CDPU) for the EMFISIS instrument suite.

Cluster

Launched July 16 and August 9, 2000

Cluster is a European Space Agency mission designed to study magnetospheric dynamics by separating spatial and temporal varations through the use of four identifical spacecraft, designed to be in a tretrahedron configuraton during key locations in the orbit. UNH participated in two instruments: We built the time-of-flight section for the Composition Distribution Function analizer (CODIF) part of the Cluster Ion Spectometer (CIS) instrument package, and we participated in and are the lead for the Electron Drift Instrument (EDI). 

Mechanisms of Energetic Mass Ejection - eXplorer

The Mechanisms of Energetic Mass Ejection - eXplorer (MEME-X) is a mission concept to map the processes that control the outflow of mass through the upper atomosphere to space.  The mission concept is one of five selected for  competitive Phase-A studies. If selected, UNH will contribute instruments that measure ion and electron fluxes, as well as the neutral thermospheric density.  UNH will also contribute a student experiment to the mission.