1. Science goals and objectives: the overarching science goal of this proposal is to determine how ions are transported across the low-latitude boundary layer on the flanks of the magnetosphere, and…

This is a research grant awarded by the National Aeronautics and Space Administration (NASA) Shared Services Center to Lockheed Martin Corporation to determine how ions are transported across the low-latitude boundary layer on the flanks of the Earth's magnetosphere. The $523,693.31 grant supports the Magnetospheric Multiscale (MMS) mission goals of understanding the interactions between the solar wind and the Earth's magnetosphere. The research will analyze data from the MMS and THEMIS spacecraft to study how the transport of plasma differs between the dawn and dusk flanks of the magnetosphere. Additional space-based and ground-based assets may be utilized to provide contextual information. The grant does not have a set-aside designation and is scheduled for completion by August 10, 2023.

1. Science goals and objectives: the overarching science goal of this proposal is to determine how ions are transported across the low-latitude boundary layer on the flanks of the magnetosphere, and whether there are systematic differences between dawn and dusk. The magnetospheric flanks are the location of a range of transient phenomena including kelvin-helmholtz instabilities (KHI), flux transfer events, and solar wind discontinuities that can affect ION transport. The development of these processes depends on the local conditions including polarity of the vorticity (for KHI), fluctuations in the magnetosheath, and the plasma mass density (and hence the ION composition). Because the local conditions may differ on the dawn and dusk side, the transport may also differ. Specific science questions to be answered in order to achieve the science goal of this investigation are: 1) how much transport of plasma is there across the dawn and dusk flanks, 2) how does the transport vary with ION species?, and 3) how do local conditions and processes affect the transport? 2. Listing of mission data to be used in this investigation: MMS FPI moments and distribution functions MMS hpca moments and distribution functions MMS EIS energetic plasma observations MMS FGM magnetic field observations themis iesa moments and distribution functions themis FGM magnetic field observations 3. Listing of data analysis methodology and models and simulations: during march-april 2016, the MMS spacecraft were on the dawnside flank with an apogee of ~12 RE, while the themis spacecraft (with similar apogees) sampled the duskside flank. Approximately six months earlier, and six months later, the dawn/dusk configuration is reversed. To answer the first two questions, the changes in the energy spectra across the low latitude boundary layer at dawn and dusk will be determined. The ION composition measurements from MMS hpca and EIS will be used to show how these changes depend on ION species. While themis only has all-ION measurements, the changes in the spectra from magnetosheath-like to magnetosphere-like can still be determined. By using both the simultaneous measurements on the dawn and dusk flanks, and the two phases (MMS at dawn, themis dusk, and vice versa) the differences in transport between dawn and dusk for the major species can be determined. To answer the third question, two types of studies will be performed. First, the measurements will be sorted by local parameters to determine what conditions favor particular transient phenomenon. Second, the data will be sorted by the type of transient phenomena observed to determine how the transport varies due to the different processes. Comparing the results from these studies at dawn and dusk will resolve our overall question. Additional space and ground-based assets (e.g., cluster, all-sky imagers, etc.) may be used when available to provide additional contextual information when favorably located during the time intervals of study. 4. Relevance of the proposed problem: this proposal directly supports the goals of the MMS mission of understanding the interactions between the solar wind and magnetosphere via the transfer of plasma across the magnetopause. This proposal also directly addresses goal #2 of the heliophysics decadal survey: determine the dynamics and coupling of earths magnetosphere, ionosphere, and atmosphere and their response to solar and terrestrial inputs. IT specifically addresses swmi goal 2: "identify the controlling factors that determine the dominant sources of magnetospheric plasma, and goal 3: "understand how plasmas interact within the magnetosphere and its boundaries."