Determination of the Global Conductance Pattern and its Influence on the Dynamics of Geospace


Executive Summary


Text Box: Figure 1 – Ionospheric conductivity plays an es…hroughout the magnetosphere-ionosphere-thermosphere system.

Recent work has shown that in order to fully understand the dynamic behavior of geospace we must treat the ionosphere and magnetosphere as a fully coupled system. A key aspect in regulating the response of this coupled system is the ionospheric conductivity. It plays an essential role in the closure of field-aligned currents from the magnetosphere and energy deposition in the ionosphere and thermosphere.   Direct global measurement of the ionospheric conductance distribution is extraordinarily difficult, so there are major important gaps in our understanding of phenomena that involve this critical system component.  The combination of global ground-based and low altitude measurements of magnetic perturbations along with measurements of ionospheric electric drifts allows the full reconstruction of ionospheric electrodynamics, including both the Hall and Pedersen conductance. Key measurements in this reconstruction include inference of field-aligned currents from AMPERE, the derivation of ionospheric equivalent currents from ground magnetometer data such as that provided by SuperMAG, and the measurement of the ionospheric convection from the network of SuperDARN radars.  Extensive networks of all-sky imagers, photometers, spectrographs, and riometers enable inferring the regional conductance structure that can be compared with the results of our global reconstruction. Together with recent advances in global modeling these observational capabilities can lead to major breakthroughs in our understanding of how the magnetosphere-ionosphere-thermosphere system operates as a whole.  In particular, we can address numerous fundamental questions including the global conductance distribution’s role in regulating the state of magnetospheric evolution, polar cap saturation, and connections between Joule heating and ionospheric outflow.


Our outstanding international team conducting this investigation includes scientists from around the world with expertise covering all aspects of the research in our proposal.  The focused efforts of this team will lead to significant advances in understanding how the global pattern of conductance affects the evolution of the magnetosphere-ionosphere-thermosphere system.  In addition to advancing conductance models used within global simulations we plan to publish a major research paper with the entire team as coauthors.


Team Leader: Michael Wiltberger (United States – NCAR/HAO)

Team Members:  Olaf Amm (Finland – FMI)

                               Eric Donovan (Canada – University of Calgary)

                  Jesper Gjerloev (United States – JHU/APL)

                             William Lotko (United States – Dartmouth College)

                               Viacheslav Merkin (United States – JHU/APL)

                               Steve Milan (United Kingdom – University of Leicester)

                               Colin Waters (Australia – University of Newcastle)



Full Team Proposal

Can be download from here.


Schedule – Sep 2013 to Oct 2014

In Person Meeting 1 – Jan 27 – Jan 31


            Meeting Presentations - Team Members Only 

In Person Meeting 2 – TBD – Likely Mar-Apr 2014

            Agenda TBD

In Person Meeting 3 – TBD – Likely Sep 2014

            Agenda TBD


Team Publications

None at this time