This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).
The primary science objective of this project is to gain a global understanding of the Kelvin-Helmholtz Instability (KHI) on Earth's magnetosphere-ionosphere system. In particular the effects of the solar wind parameters and resulting magnetosheath properties on the KHI will be studied. The effects generated by i) KHI and ii) Kinetic-Alfvén waves (KAW). The effects of the magnetosheath properties on ion temperature anisotropies observed within the plasma sheet will also be determined.
The investigation will use several years of Cluster and Themis spacecraft data from low-latitude magnetopause crossings and magnetosheath. Data analysis methods include various variance analysis techniques, transformation to the deHoffman Teller reference frame, Walen relation, multi-spacecraft methods, and a variety of spectral analysis methods. The data analysis results will be compared with 2-D and 3-D high-resolution magnetohydrodynamic (MHD) simulations. The particle dynamics due to KHI will be studied by using test-particles within a 3-D, local MHD code and comparisons with observed ion distribution functions.
The magnetosheath processes will be studied by doing a statistical study of the magnetosheath properties and by utilizing global hybrid (fluid electrons, paritlce ions) simulations. In addition, the MHD-scale KHI will be compared with hybrid and fully kinetic simulations of the instability. The KHI at Mars and Venus will also be studied with these simulations and data from Mars and Venus orbiters will be utilized for comparisons with the simulation results.
The study will address several topics: 1) The statistical study of the occurrence of the KHI at the Earth's magnetosphere and the associated magnetosheath and plasma sheet properties; 2) The influence of the Mach numbers and plasma beta on the plasma transport produced by the KHI; 3) The effects of the KHI and magnetosheath processes and properties on the dawn-dusk asymmetries of the plasma sheet; 4) The coupling of the magnetospheric KHI into the ionosphere; 5) Comparison between MHD, hybrid and kinetic simulations of the KHI; 6) The study of the Kelvin-Helmholtz Instability at Mars and Venus. These topics are of central importance for understanding the global magnetospheric dynamics, cross-scale coupling of space plasmas, and plasma dynamics in the vicinity of non-magnetized planets.
Results of the study will be an important contribution to the goals of the Geospace Environment Modeling (GEM) program. This research fits under several current GEM Focus Groups: Plasma Entry and Transport into and within the Magnetotail; Foreshock, Bow Shock and Magnetosheath; MIC Global Coupling.
The statistical studies will form the core of the Ph.D thesis work of a graduate student in a new Ph.D program in Engineering Physics starting in Fall-2009 at Embry-Riddle Aeronautical University (ERAU). The resulting research papers will be published in refereed scientific journals devoted to space science and plasma science. The project will develop a web site and the student research will be highlighted there. The project will include a public outreach program by organizing a space sciences seminar series at Daytona Beach Museum of Arts and Sciences starting in the Fall of 2009. The study integrates research and education by including undergraduate students in a summer research program. In addition, the PI will develop a graduate course: "Spacecraft Data-Analysis Methods", where students can learn single- and multi-spacecraft data-analysis techniques by utilizing spacecraft data. The ERAU promotes equal opportunities for the underrepresented groups.
