Research Objectives of the FST Team

 

The overarching goal of this Focused Science Topic (FST) team is to advance our understanding of the mid-latitude and equatorial ionospheric-thermospheric dynamics, the generation of ionospheric irregularities, the longitudinal variability of the ionosphere-thermosphere system, and the driving mechanisms for the longitudinal variability. The research objectives of this FST team are to address the following outstanding science issues:

 

1. What are the characteristics of penetration and disturbance dynamo electric fields during magnetic storms?

            Participating PIs: Chaosong Huang, Liying Qian, Qian Wu, Shasha Zou

·       Determine the characteristics of penetration electric fields: Quantitative relationship with the drivers (IMF and magnetospheric energy input) and the local time distribution.

·       Determine the characteristics of disturbance dynamo electric fields: Arrival time at the equator, quantitative correlation with Dst and AE, and local time distribution.

·       Identify the relative importance of penetration, shielding, and disturbance dynamo electric fields in equatorial ionospheric electrodynamics.

 

2. What are the longitudinal variations of ionospheric parameters and the drivers for the longitudinal variations?

            Participating PIs: Phil Anderson, Manbharat Dhadly, Chaosong Huang, Liying Qian, Ludger Scherliess,
Qian Wu, Shasha Zou

·       Determine the longitudinal variations of storm-time plasma density, TEC, EIA, penetration and disturbance dynamo electric fields.

·       Specify the relative roles of atmosphere tides/waves, planetary waves, TAD/TID, and plasma dynamics in generation of longitudinal variability of storm-time plasma distribution, TEC, EIA, and electric fields.

·       Determine the longitudinal variability of low- and mid-latitude neutral winds during geomagnetic quiet and disturbed times

 

3. What are the driving processes for the generation of plasma instabilities, plasma bubbles and structures at middle and low latitudes?

            Participating PIs: Phil Anderson, Liying Qian, Ludger Scherliess, Shasha Zou

·       Determine the impacts of storm onset, PEF/DDEF, and meridional winds on the generation and latitude coverage of equatorial plasma bubbles.

·       Determine the effects of TADs/TIDs on the generation of plasma bubbles and ionospheric structures.

·       Determine the impact of longitudinal variations in the plasma and neutral environment on low-latitude ionospheric irregularities and plasma instabilities.

 

4. What controls the generation and propagation of storm-time large-scale traveling ionospheric and atmospheric disturbances (LSTIDs and LSTADs)?

            Participating PIs: Phil Anderson, Manbharat Dhadly, Chaosong Huang

·       Determine how auroral disturbances generated by magnetospheric forcing drive LSTADs/LSTIDs.

·       Identify how the background conditions control LSTAD/LSTID generation and propagation.

·       Determine the dependence of the propagation and structure of TADs/TIDs on longitude.

 

* Each participating PI represents his/her team including all Co-Is.

 

Research Plan of the FST Team

 

This team will analyze extensive data sets from multiple satellites and ground-based measurements and run first-principles and data-assimilative models to address the above science issues.

 

Models that will be used by this team include: Global Ionosphere Thermosphere Model (GITM), Multiscale Atmosphere-Geospace Environment (MAGE) model, Multimodel Ensemble Prediction System (MEPS), SAMI3, Space Weather Modeling Framework (SWMF), Thermosphere-Ionosphere-Electrodynamics General Circulation Model (TIEGCM), coupled GAMERA-TIEGCM-RCM (GTR) and GAMERA-TIEGCM (GT), The Whole Atmosphere Community Climate Model with thermosphere and ionosphere extension (WACCM-X), etc.

 

Data sets include plasma drift velocities, plasma density and temperature, ion composition, neutral composition and emission, and neutral winds measured by the C/NOFS, DMSP, GOCE, CHAMP, GOLD, TIMED, GRACE, and Swarm satellites; GNSS/TEC data; ionospheric ion density and drift velocities measured by ionospheric radars and digisondes; magnetic fields measured by the AMPERE and global magnetometer network; neutral winds measured by Fabry–Perot interferometer, etc.

 

All team members (PIs and Co-Is) will work individually, interactively, and collaboratively on their individual research projects and on the overall objectives of the FST team. Observational data will be analyzed statistically and also for case studies of selective magnetic storms. Models will be tested and run for different types of geomagnetic storms to compare with data. The outstanding science issues will be addressed through data analysis, model simulations and comparison between model outputs and observations. The combination of expertise of the team members in modeling, observations, and data analysis assures the success of the proposed work.

 

Data collection, processing, and analysis and model test runs, validations, and improvement will continue through all years. The following plan only lists the science issues.

 

Research Plan for Year 1:

·       Identify and select geomagnetic storms for collaborative studies

·       Study the characteristics of penetration and disturbance dynamo electric fields

·       Simulate and examine the ring current effect on the penetrating electric field control over the equatorial vertical ion drift

·       Identify the maximum duration of penetration electric fields

·       Perform statistical analyses of penetration electric fields based on the radar data and derive penetration efficiency as a function of IMF, local time, and season

·       Identify ionospheric disturbance current systems caused by penetration electric fields associated multiple solar wind and magnetospheric processes

·       Determine the characteristics and generation mechanisms of equatorial zonal ion drifts during magnetic storms

·       Initiate year-long specifications for the year 2012 using the ensemble of models to obtain ensemble specifications for the densities, electric field, and neutral wind.

·       Initiate investigation of quiet-time longitudinal variability in the plasma densities, electric fields and neutral winds using the ensemble of model runs.

·       Determine the effect of atmospheric wave/tide propagation from below on ionospheric electrodynamics

·       Ascertain the importance of magnetosphere-ionosphere-thermosphere coupling on the low and middle latitude electrodynamics in quiet-times

·       Analyze the effects of storm-time high-latitude drivers on equatorial ionization anomaly and plasma bubble dynamics in the low and equatorial regions

·       Develop analysis tools for identifying LSTID/LSTAD in TEC and satellite data

·       Use multiple numerical models to perform simulations for selected LSTID/LSTAD cases

 

Research Plan for Year 2:

·       Use observational data and model simulations to determine the propagation delay of disturbance winds to the equatorial region after the storm onset

·       Use observational data and model simulations to determine the quantitative relationship of disturbance dynamo electric fields with the storm strength (Dst and AE)

·       Use DMSP satellite data, AMPERE data and model simulation to determine the evolution and local time variation of shielding electric fields

·       Identify the relative importance of penetration, shielding, and disturbance dynamo electric fields in storm-time equatorial ionospheric electrodynamics

·       Simulate global ionospheric electric fields with WACCM-X and MAGE to analyze the longitudinal variations of electric fields and plasma drifts at middle and low latitudes

·       Use the GTR and GT model simulations to quantify the effects of subauroral polarization streams (SAPS) on equatorial vertical ion drift

·       Calculate the growth rate of the Rayleigh-Taylor instability

·       Study the dynamics in the global and inner magnetosphere models that are responsible for the high-latitude driver changes and the subsequent RT growth rate

·       Run coupled models for more team events with super EPB events

·       Use observational data and model simulations to identify the generation mechanisms (drivers) and characteristics of storm-time LSTIDs/LSTADs

·       Initiate investigation of storm time longitudinal variability in the plasma densities, electric fields and neutral winds using the ensemble of model runs

 

Research Plan for Year 3:

·       Adjust the eddy diffusion at the GTR lower boundary to match the mid- and low- latitude ionospheric density and dynamo effect on the equatorial vertical ion drift.

·       Determine the local time distribution of penetration electric fields and the dependence of the local time distribution on IMF

·       Determine the local time distribution of disturbance dynamo electric fields and the dependence of the local time distribution on the storm intensity

·       Study the impacts of storm onset, penetration and disturbance dynamo electric fields, and meridional winds on the generation of equatorial plasma bubbles

·       Study the evolution of equatorial plasma bubbles under different conditions and the mechanisms/drivers for plasma bubble extension to middle latitudes

·       Determine the effects of TADs/TIDs on the generation of plasma bubbles and ionospheric structures.

·       Study the role of background conditions in assisting or desisting the horizontal propagation of high-latitude LSTADs/LSTIDs to equatorial latitudes

·       Determine the relationship between equatorial plasma bubble and TIDs/TADs.

·       Investigate effects of longitudinal difference in the neutral wind and plasma drift on plasma distribution using our ensemble of data assimilation runs

·       Adjust the eddy diffusion at the GTR lower boundary to match the mid- and low- latitude ionospheric density and dynamo effect on the equatorial vertical ion drift.

 

Research Plan for Year 4:

·       Adjust the TIEGCM lower boundary condition in the GTR model to match the longitudinal variations in the simulated equatorial ionospheric vertical ion drift

·       Investigate longitudinal variability of storm time neutral winds and their relation with electric fields

·       Identify the longitudinal variations of storm-time penetration electric fields and determine the mechanism for the longitudinal variations

·       Identify the longitudinal variations of storm-time disturbance dynamo electric fields and determine the mechanism for the longitudinal variations

·        Determine the effects of the longitudinal variations of storm-time penetration and disturbance dynamo electric fields on the generation of equatorial plasma bubbles

·       Determine the effects of large-scale TIDs/TADs on the longitudinal variations of penetration and disturbance dynamo electric fields

·       Perform new simulations and compare the results of simulation studies with and without high-latitude forcing to isolate the LSTAD/LSTID associated middle and equatorial latitude variability

·       Perform a statistical analysis on the characteristics of LSTADs/LSTIDs

·       Combine all of our storm-time measurements and generate a cohesive specification of the response of the mid and low latitude ionosphere to storms

·       Continue investigation into plasma instabilities

·       Perform additional storm study that arise during the project period if needed

 

Output of the FST Team

 

·       All PIs and Co-Is will present their research progress and results in team meetings, and the team meeting presentations will be posted in the team website.

·       All PIs and Co-Is will give presentations of their research in national and international conferences (such as CEDAR, AGU Fall Meetings, COSPAR, etc.).

·       Research results of individual projects will be published in peer-reviewed journals, and published papers will be posted in the team website.