Polar cap patches and aurora are common in the polar ionosphere where their motion and associated density gradients result in variable disturbances to High Frequency (HF) radio communications, over-the-horizon radar location errors, and disruption and errors to satellite navigation and communication. They are also directly subject to space weather disturbances and link to magnetosphere-ionosphere-thermosphere (M-I-T) coupling processes. However, their formation and evolution under disturbed space weather conditions are poorly understood, and there is no forecasting tool to predict either their formation or evolution. Improved knowledge and modeling efforts of these phenomena are key to making progress toward improved space weather forecasts and correction of global navigation satellite system (GNSS) signals in real-time in the polar cap regions. With the fast development of coverage in the polar regions during recent years from the multiple instruments, such as GNSS ground-based receivers, incoherent scatter radars (ISRs), Super Dual Auroral Radar Network (SuperDARN), and all sky imagers as well as space-based measurements, a wealth of data on the global distributions of plasma and flows, as well as the associated scintillations are now available. This offers an excellent opportunity to study polar cap patches and aurora and to understand in detail the M-I-T coupling processes within a global perspective.

The aim of this proposal is to understand the dynamical processes associated with the polar cap patches and aurora and their impact on M-I-T coupling processes, through coordinated investigations of multiple ground-based and space-based observations (including data from GNSS Receivers, ISRs, SuperDARN, all sky imagers, MMS / THEMIS / Cluster / DMSP / SWARM satellites, etc.). The proposal also will address the impact of polar cap patches and aurora on GNSS navigation and communications, as well as scintillation modeling and forecasts. To enhance our understanding of this basic high-latitude physics, we propose to follow three avenues of investigation: (1) Analysis of observational data taken with ground-based and space-based instruments during ongoing coordinated international high-latitude campaigns; (2) Scientific analysis of the observations; (3) model simulation of important high-latitude effects. The conclusion of this study will lead to a number of papers on the work carried out.

Tasks:

Based on the multiple ground-based and space-based observations as well as theory and simulations experience, we expect to advance our understanding of polar cap patch and aurora formation, evolution and interaction with other regions, specifically;

1) Determine the dominant mechanism for the polar cap patches and aurora forming and exiting the polar cap. Understand the role of the E×B drift for patch transport and mechanism to maintain their high density during its evolution.

2) Understand the relationship between patches/aurora and other types of irregularities (e.g. SED, TOI, SAPS, etc.) and dynamical processes in the auroral and subauroral ionosphere, and how dynamical processes associated with patch/aurora play a role in the M-I-T coupling.

3) Understand the generation mechanism(s) of the scintillations at the edges of polar cap patches/aurora during their formation and evolution. Develop more accurate empirical and/or theoretical models for scintillations in the polar ionosphere to improve the accuracy of the GNSS navigation and HF Radar communications. 

We are confident that our chosen topic will be scientifically productive. The previous experience already opened up new ways of understanding the datasets and resulting in several published papers. Our team includes experts in the observations of GPS TEC/scintillation, ISR, SuperDARN, and all-sky imagers, together with very experienced modelers and space-based expertise. We will identify a small number of priority events (3 or 4 initially) which best address the questions raised above. Our primary aim is to study these events in great detail using multi-point multi-instrument approach and to publish the results of this research in peer-refereed journals.

Team Members:

Young Scientist:

Schedule:

It is proposed to conduct the study over two meetings held at a several month intervals, with the option of a third meeting if required. Before the first meeting, we will identify and select potential events from our recent/ongoing campaigns, collect data sets from multiple instruments, and make preliminary analysis. We propose that the first meeting could be over three-four full days to discuss the initial results of the potential events for in-depth analysis, assign analysis tasks，and identify the most fruitful areas for further coordinated interdisciplinary analysis addressing the proposed questions. The second meeting may require a week to review “homework”, conclude analysis and identify results. A final three-day meeting will be used to ensure the timely completion of publications.

Agenda of the Meetings:

The first meeting was 8-12 May, 2017 taken place at ISSI-BJ in Beijing. The final program can be found here.