M3-I2 Session 1 - Mag Effects
Notes by Vince Eccles and the M3-I2 session leaders. Barbara Giles moderated the session.
Rick Chappell of Vanderbilt University reminds the GEM community of the slow paradigm shift towards the ionosphere as the dominant source of magnetospheric plasma. In the 1960s the solar wind plasma was viewed as the dominant source. The earth's polar wind of ionospheric outflow was identified in the 1970s and there was a substantial increase in observations of O+, H+, and He+ outflow in the 1980s. The main magnetosphere models and theoretical studies did not account for the shift to the new paradigm described in observations until the late 1990s. In the 2000s the new paradigm begins to take hold as there is a move towards multiple species MHD models and towards coupling with polar wind outflow models. A Chapman Conference and book on describing the effects of ionospheric outflow on the whole magnetosphere system is due out soon. Continued studies on the effects in the different regions (tail dynamics & substorms, ring current, plasma sheet) is needed to complete the community's full shift to the new perspective of the ionosphere-magnetosphere system. Additionally, kinetic ion studies are needed to follow the history of injected ions to understand the processes of populating the different regions and the energization of these ion populations.
Dan Welling (U of Michigan) states the primary result of the coupling ionospheric outflow models and MHD magnetosphere models: Outflow Really Matters! A number of effects observed are (1) dayside reconnection rate influenced by cold plasma presence, (2) polar cap potential is reduced (or limited) with increased presence of O+, (3) the magnetosphere tail is stretched, (4) fast outflows generally escape through the tail but slow populations 'hang around' to increase their relative importance, (5) source location and composition of the outflow matter, (6) O+ cusp outflow can cause storms and subsequent substorm auroral outflow can drive sawtooth substorms (7) ring current calculations are improved with better H+/O+ composition in the ring current region. The coupled ionosphere - magnetosphere behavior needs to be studied in greater detail because the magnetosphere affects the ionosphere, affects the magnetosphere, affects the ionosphere, affects ...
Barbara Giles of GSFC/NASA presented a survey of the Magnetospheric Multiscale (MMS) Mission. The instruments are providing wonderful data for science study opportunities. Data can be explored on https://lasp.colorado.edu/mms/sdc/public/ website. One quick observation from the FPI is that H+, He+, O+ species are seen in the Warm Plasma Cloak.
Matina Gkioulidou of APL Johns Hopkins University presented Van Allen Probe ring current observations. O+ outflow at 300 eV seen during storm period with multiple bands of energy in the O+ outflow. Additional O+ outflow observed in the post midnight sector begging the question of source region: Joule heating or aurora?
Naritoshi Kitamura of ISAS/JAXA first stated that the Geotail mission is now extended to 2019. Dr. Kitamura presented MMS FPI data showing O+ 1000 eV beam and H+ 100 eV beams in the tail lobe in nightside region. Dayside shows no O+ beams but H+ beams are structured between 100 to 1000 eV.
Jonathan Krall of NRL presented SAMI3 model results of the plasmapause. The dawn side plasmapause is most evident in the model results. Rick Chappell commented that the drift of plasma from noon to nightside generally produces this steepening on the dawn side. The SAMI3 results may be capturing this effect.
Chris Mouikis of U. of New Hampshire presented a Dst epoch study of outflow for isolated moderate storms. The epochs were divided by Pre-storm, main phase, early recovery and late recovery. Magnetic local time & latitude dial plots of H+ outflow and O+ outflow demonstrated clear trends through the storm epochs. This is an excellent study to be used as a benchmark for ionospheric outflow model results.
Lynn Kistler of U. of New Hampshire has gathered multi-satellite, multi-instrument studies of a storm with sawtooth oscillations to produce a morphology of the sawtooth storms. LANL was used for sawtooth identification, ACE for solar wind drivers, CLUSTER for plasma sheet O+ presence, FAST for auroral outflow, IMAGE for auroral morphology. The storm of October 1, 2001 was used because of its nice sawtooth structure during the period of multi-satellite observations. Dr. Kistler presence an early conclusion that the 1st observed sawtooth sub-storm may be connected to auroral outflow from the previous substorm (10 eV O+ outflow observed in nightside). The next sawtooth substorm seemed to be connected to cusp outflow.
Barbara Giles seeded the discussion with questions on how the community should proceed given the excellent data now arriving.
Bill Peterson requested input from the community on ePoP observation scheduling. What local times and energy distribution of ion outflow are most useful to the community? He awaits your requests!
Dan Welling put forward that magnetosphere models need a minimum of three fluids: H+ from solar wind , H+ from earth ionosphere, and O+ from earth ionosphere.
