This proposal is in the broad area of "heliosphere", and in the science area "5. Heliospheric plasma processes, turbulence, waves, composition." science goals and objectives: we propose a three-year…

This is a $447,928.44 research grant awarded by NASA to the University of Delaware to employ advanced global multi-temperature magnetohydrodynamic (MHD) simulation to study fundamental problems of heating and acceleration of the solar corona and solar wind plasma. The research aims to understand how turbulence affects the properties of the solar wind, while also providing data to support upcoming Parker Solar Probe and Solar Orbiter missions. The three-year project will refine the MHD model to include turbulence transport, eddy viscosity, and separate energy equations for electrons and protons. No set-aside was used for this grant award.

This proposal is in the broad area of "heliosphere", and in the science area "5. Heliospheric plasma processes, turbulence, waves, composition." science goals and objectives: we propose a three-year project to employ advanced global multi-temperature MHD simulation to study important fundamental problems of heating and acceleration of the solar corona and the solar wind plasma, while also examining a set of problems relating to prediction and context for upcoming parker solar probe and solar orbiter missions. The model, which is under continual testing and further refinement, allows self-consistent study of both large-scale structure and turbulence in the three dimensional region from the coronal base to the distant solar wind (within the termination shock). The most recent versions include turbulence transport, eddy viscosity, and turbulent resistivity as well as separate energy equations for protons and electrons, with no artificial heat functions required. Exploiting these capabilities, an overarching goal is to understand how turbulence changes the properties of the solar wind plasma, including effects on heating and large-scale structure, while also providing data for energetic particle transport models. In the proposed operating version, an expanded turbulence transport model, and turbulent heating model, will be included throughout the system, including the sub-alfvenic coronal region near the sun. All refinements to the global model will be tested against available coronal and inner heliospheric observations. The framework is driven either by (OBSERVED) representative solar magnetograms or by a tilted-dipole approximation to specify boundary conditions at the coronal base. We will apply the model to study the heating and acceleration of the solar corona and solar wind plasma emphasizing its threedimensional properties, including embedded turbulence and solar cycle variations. We will verify the simulation results for flow speed, temperature, density, etc., against spacecraft data from parker solar probe, solar orbiter, ACE, wind, ulysses, and voyager for all phases of solar activity cycle. As we move toward improved ways to incorporate magnetogram data as input, while also calibrating against 1AU data, the model will be of increasing value to the parker solar probe mission. We expect to be able to provide predictions, and context simulations to aid in interpretation of the data, connecting single point in-situ observations to regional and global interplanetary dynamics. Methodology: the proposed study is based on an MHD model ten years in development, expanded to include plasma and magnetic field variables, and fully merged with turbulence transport equations. The coupled system involved RE-derivation and augmentation of the MHD equations themselves, after applying a reynolds averaging procedures that separates resolved and unresolved (FLUCTUATING) fields, leading to new coupling terms such as reynolds stresses. These couplings are modeled using smagorinsky-type eddy viscosity and resistivity terms. Analogous models for heat conduction and heat deposition due to turbulence are also employed, allowing the modeled turbulence cascade to convert fluctuation energy into heat. The solar wind plasma will be treated as a mixture of CO-moving electrons, solar wind protons, and (outside 0.3 AU). Interstellar pickup protons with separate energy equations for all the species. A PH.D. Student will be involved. Relevance to the decadal survey goals: the proposed research is relevant to the two decadal survey goals: (1) "determine the origins of the sun's activity and predict the variations in the space environment," and (4) "discover and characterize fundamental processes that occur both within the heliosphere and throughout the universe."