Assimilative Mapping of Interhemispheric Polar Ionospheric Electrodynamics

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The Earth's main magnetic field geometry is not similar to that of a bar magnet centered and simply tilted about 11 degrees from the Earth's spin axis. The geomagnetic field has its North Pole located at ~1,200-km of the North Geographic Pole towards Canada, but its South Pole is located about 1,550-km from the South Geographic Pole in Antarctica towards Pacific Ocean. This asymmetry is caused by the non-dipolar nature of the Earth's magnetic field that leads to various hemispherical differences in the interaction of the solar wind plasma flow with the Earth's magnetosphere. Thus the solar wind's energy and momentum are deposited into the polar ionospheres of both the Northern and Southern Polar Regions asymmetrically, causing considerable diversity in different electrodynamic parameters of the polar ionosphere reported in past studies. As new instrumentation techniques are developed, it is important to invest in development of new data assimilation and inverse methods to assure a more complete extraction of geophysical information out of new observations.The magnetosphere-ionosphere coupling is not symmetrical in terms of high-latitude ionospheric convection, field-aligned currents, electromagnetic energy (Poynting) flux, auroral particle precipitation, and upper atmosphere (thermosphere) responses. This study will quantify the degree of instantaneous interhemispheric imbalance of the electromagnetic energy deposition via geomagnetic field-aligned currents and ionospheric convection electric fields, integrating quantification of all these variables into a unified framework. Multiple types of space-based and ground-based observations can be simultaneously analyzed, creating a coherent interhemispheric picture of global ionospheric electrodynamics via the community Assimilative Mapping of Ionospheric Electrodynamics (AMIE) software technique. In the past, the lack of observations in the Southern polar region in comparison with the Northern polar region precluded a comprehensive analysis of interhemispheric ionosphere electrodynamic variables, unless exclusively relying on space-based observations. The recent availability of data from ground-based magnetometers and high frequency (HF) radars in the Southern polar region is changing this situation. The proposed research is timely, using a creative, even transformative approach that takes advantage of new global interhemispheric observations available through the NSF-funded Active Magnetosphere and Polar Electrodynamics Response Experiment (AMPERE), Super Dual Auroral Radar Network (SuperDARN), and SuperMAG database. This will help addressing fundamental questions of geospace research that have eluded conclusive explanation so far. Several electrodynamic variables will be self-consistently analyzed globally in both polar regions via the extensive assimilation of observational data. This study will contribute significantly to the research and development activities at the NOAA Space Weather Prediction Center (SWPC) where a new generation of AMIE mapping of interhemispheric high-latitude electrodynamics may become part of the services provided by SWPC to the U.S. Government agencies that address negative effects of space weather on the nationwide ground- and space-based technological systems. The updated AMIE will also become a common platform for active collaboration among national and international space scientists who study the global transfer of solar wind energy and momentum into the Earth's magnetosphere, ionosphere, and thermosphere. At last, this interesting and important scientific research provides an ideal opportunity for educational experience and training for a graduate student through direct involvement in the study.