Project Summary

Objectives and Methodology:

This project is motivated by the overarching question: How does mass exchange between the magnetosphere and ionosphere influence the behavior of the integrated system including electrodynamic and inertial linkages? Current understanding of the MI interaction has been derived largely from studies of electrodynamic coupling. This investigation takes a major step in determining how the electrodynamic interaction is influenced by mass exchange and vice versa. The numerical simulation models to be used for this study will challenge the state-of-the-art in treating the constituent regions as a single integrated system. More specifically, the effects of solar wind-magnetospheric dynamics on low-altitude energy deposition, and the effects of ionospheric activity on the magnetosphere including mass and energy transport, will be investigated via simulation of the 1) global multifluid-magnetohydrodynamics of the solar wind-magnetosphere-ionosphere interaction; 2) reduced, compressible multifluid electrodynamics of auroral and polar-cusp flux tubes; and 3) gyrokinetics of collisionless energization and transport in Alfvénic structures and current, vorticity and density layers.

Anticipated scientific innovations include new understanding of the multifluid magnetohydrodynamics of geospace including the effects of variable mass composition; of the impacts of inductive electrodynamics on ionospheric outflows in the cusp and auroral-polar cap boundary regions; and of the wave-particle gyrokinetics of nonlinearly coupled ion sound and shear Alfvén waves. A legacy of the project will be a causal, predictive model for time-variable exchange of mass flux, electron energy flux and Poynting flux between the magnetosphere and ionosphere.

Relevance to NASA Strategic Objectives:

By advancing the state-of-the-art in treating the magnetosphere-ionosphere as a single integrated system, this project directly supports NASA’s 2006 Strategic Plan, strategic sub-goal 3B: Understand the Sun and its effects on Earth and the solar system, including fundamental physical processes of the space environment and the development of capabilities to predict extreme and dynamic conditions in space. It is well-aligned with the current Roadmap for Heliophysics Science and Technology 2005-2035 which recognizes that “the exchange of mass and energy [that couple the inner and outer regimes of geospace] must be understood before predictive capabilities … can be developed.”

Project-Related Publications and Reports (since 2004)

Brizard, A.J., R.E. Denton,  B. Rogers, W. Lotko (2008). Nonlinear finite-Larmor-radius effects in reduced fluid models, Phys. Plasmas 15, 082302, doi:10.1063/1.2965827.

Denton, R.E., B. Rogers, W. Lotko (2007). Reduced MHD equations with coupled Alfvén and sound wave dynamics, Phys. Plasmas 14, 102906, doi:10.1063/1.2786060.

Denton, R.E., B. Rogers, W. Lotko, A.V. Streltsov (2008). Effect of the radial boundary condition on Alfvén wave dynamics in reduced magnetohydrodynamics, Phys. Plasmas 15, 032106, doi:10.1063/1.2898409.

Drake, J., M. Swisdak, K. Schoeffler, B. N. Rogers, S. Kobayashi (2006). Formation of secondary magnetic islands during magnetic reconnection, Geophys. Res. Lett. 33, L13105, doi:10.1029/2006GL025957.

Engebretson, M.J., T.G. Onsager, D.E. Rowland, R.E. Denton, J.L. Posch, C.T. Russell, P.J. Chi, R.L. Arnoldy, B.J. Anderson, H. Fukunishi (2005). On the source of Pc 1-2 waves in the plasma mantle, J. Geophys. Res. 110, A06201, doi:10.1029/2004JA010515.

Ergun, R.E., L. Andersson, Y.-J. Su, D.L. Newman, M.V. Goldman, W. Lotko, C.C. Chaston, C.W. Carlson (2005). Localized parallel electric fields associated with inertial Alfvén waves, Phys. Plasmas 12, 072901, doi:10.1063/1.1924495.

Gagne, J.R. (2005).  Implementation of ionospheric outflow in the LFM global MHD magnetospheric simulation, M.S. Thesis, Dartmouth College.

Keiling, A.., G.K. Parks, J.R. Wygant, J. Dombeck, F.S. Mozer, C.T. Russell, A.V. Streltsov, W. Lotko (2005). Some properties of Alfvén waves: Observations in the tail lobes and the plasma sheet boundary layer, J. Geophys. Res. 110, A10S11, doi:10.1029/2004JA010907.

Lessard, M.R., W. Lotko, J. LaBelle, W. Peria, C.W. Carlson, F. Creutzberg, D.D. Wallis (2007). Ground and satellite observations of the evolution of growth–phase auroral arcs,J. Geophys. Res. 112, A09304, doi:10.1029/2006JA011794.

Lotko, W. (2004). Inductive magnetosphere-ionosphere coupling, J. Atmos. Solar-Terr. Phys. 66/15-16, 1443-1456, doi:10.1016/j.jastp.2004.03.027.

Lotko, W. (2007). The magnetosphere–ionosphere system from the perspective of plasma circulation: A tutorial,  J. Atmos. Sol.-Terr. Phys. 69, 191-211, doi:10.1016/j.jastp.2006.08.011.

Lotko, W., M. Lessard, C.W. Carlson, F.R. Fenrich, W. Peria, R.C. Elphic (2007). Collisionless dissipation in a field line resonance, J. Geophys. Res.

Melanson, P. D., W. Lotko, D. L. Murr, M. Wiltberger, J. G. Lyon (2007). Polar-region distributions of Poynting flux: Global models compared with observations, J. Atmos. Solar-Terr. Phys., submitted.

Melanson, P.D. (2007). Magnetosphere-Ionosphere Coupling: Understanding the Consequences of Energy and Mass Transport in the LFM Global MHD Simulation, M.S. Thesis, Dartmouth College.

Murr, D.L., W.J. Hughes (2007). The coherence between the IMF and high-latitude ionospheric flows: The dayside magnetosphere–ionosphere low-pass filter, J. Atmos. Sol.-Terr. Phys. 69, 223-233, doi:10.1016/j.jastp.2006.07.019.

Pokhotelov, D., W. Lotko, A.V. Streltsov (2004). Simulations of resonant Alfvén waves generated by artificial HF heating of the auroral ionosphere, Ann. Geophys. 22, 2943, doi:1432-0576/ag/2004-22-2943.

Ricci, P., B.N. Rogers, W. Dorland, M. Barnes (2006). Gyrokinetic linear theory of the entropy mode, Phys. Plasmas 13, 062102, doi:10.1063/1.2205830.

Ricci, P., B. Rogers, B. Dorland (2006). Gyrokinetic simulations of particle transport, plasma turbulence and zonal flows in a closed field line geometry, Phys. Rev. Lett. 97, 245001, doi:10.1103/PhysRevLett.97.245001.

Streltsov, A.V. (2007). Narrowing of the discrete auroral arc by the ionosphere, J. Geophys. Res. 112(A10), A10218, doi:10.1029/2007JA012402.

Streltsov, A.V. (2008). Effects of ionospheric heating on feedback-unstable electromagnetic waves, J. Geophys. Res. 113(A9), A09211, doi:10.1029/2008JA013199.

Streltsov, A.V., W. Lotko (2004). Multiscale electrodynamics of the ionosphere-magnetosphere system, J. Geophys. Res. 109, A09214, doi:10.1029/2004JA010457.

Streltsov, A.V., W. Lotko, G.M. Milikh (2005). Simulations of ULF field-aligned currents generated by HF heating of the ionosphere, J. Geophys. Res. 110, A04216, doi:10.1029/2004JA010629.

Streltsov, A.V., W. Lotko (2005). Ultralow-frequency electrodynamics of the magnetosphere-ionosphere interaction,  J. Geophys. Res. 110, A08203, doi:10.1029/2004JA010764.

Streltsov, A.V., G. Marklund (2006).  Divergent electric fields in the downward current channels, J. Geophys. Res. 111, A07204, doi:10.1029/2005JA011196.

Streltsov, A.V., W. Lotko (2007). Coupling between density structures, electromagnetic waves and ionospheric feedback in the auroral zone,  J. Geophys. Res. 113, A05212, doi:10.1029/2007JA012594.

Watts, J., W. Lotko, A.V. Streltsov (2007). Magnetosphere-ionosphere Alfvén resonator, to be submitted to J. Atmos. Sol.-Terr. Phys.

Wiltberger, M.,  R.S. Weigel, W. Lotko, J.A. Fedder (2008). Modeling seasonal variations in auroral particle precipitation in a global scale magnetosphere - ionosphere model, J. Geophys. Res., submitted.

Wiltberger, M., W. Lotko,  J.G. Lyon, P. Damiano (2008). Effect of O+ ionospheric outflow in a multifluid MHD model of the magnetosphere, Geophys. Res. Lett, submitted.