NSWP: Improving Quantitative Modeling of High-latitude Electrojet Conductivities during Magnetic Storm and Substorm Time

Trustees Of Boston University, Boston

Investigators

Abstract

The project aims to improve space weather prediction capabilities by developing an accurate model of electrojet conductivity under disturbed conditions. During periods of intense geomagnetic activity, large currents along the magnetic field lines can induce the formation of strong electrojets, plasma instabilities, and turbulence. This turbulence gives rise to intense anomalous electron heating and nonlinear transport which significantly affects the E-region conductivity. Existing ionospheric models do not include these effects. This limits their ability to accurately model magnetic storms and substorms essential for space weather predictions. Accordingly, the objective of this project is to develop an ionospheric-conductance module which will predict nonlinear currents and anomalous electron heating during magnetic storms and substorms. This module will consist of a look-up table and/or analytic expressions which will return the E-region conductivity matrix for a range of altitudes, latitudes, driving electric fields, and plasma and neutral atmospheric conditions. The project will undertake three tasks: (1) quantitative modeling of anomalous electron heating and nonlinear currents; (2) creation of a conductivity database which accounts for turbulent effects; and (3) testing the modified conductivities in existing magnetosphere and ionosphere simulation codes and models. Supercomputer simulations of 3D E-region turbulence combined with modern theoretical analyses will be applied to determine the heating and conductivities. The predictions of electron heating will be validated using incoherent scatter radar and rocket data, while the predicted ionospheric fields and currents will be tested against magnetometer and SuperDarn data. In order to make the results useful and available, they will be incorporated into the Lyon-Fedder-Mobary (LFM) magnetosphere simulation code and the magnetosphere-ionosphere-thermosphere model (CMIT), two codes that are widely used by the magnetosphere/ionosphere community. The results of the upgraded LFM and CMIT will be tested against the unmodified codes and observations. Particular science questions to be addressed are: What is the nonlinear response of the high-latitude ionosphere to strong convection electric fields? Why is the observed storm-time cross-polar-cap potential often smaller than that predicted by existing models? Do the turbulence generated changes in conductivities mostly or fully account for the reason that models fail to account for observations?