Bibliography

Impacts of Binning Methods on High-Latitude Electrodynamic Forcing: Static Versus Boundary-Oriented Binning Methods

An outstanding issue in the general circulation model simulations for Earth\textquoterights upper atmosphere is the inaccurate estimation of Joule heating, which could be associated with the inaccuracy of empirical models for high-latitude electrodynamic forcing. The binning methods used to develop those empirical models may contribute to the inaccuracy. Traditionally, data are binned through a static binning approach by using fixed geomagnetic coordinates, in which the dynamic nature of the forcing is not considered and therefore the forcing patterns may be significantly smeared. To avoid the smoothing issue, data can be binned according to some physically important boundaries in the high-latitude forcing, that is, through a boundary-oriented binning approach. In this study, we have investigated the sensitivity of high-latitude forcing patterns to the binning methods by applying both static and boundary-oriented binning approaches to the electron precipitation and electric potential data from the Defense Meteorological Satellite Program satellites. For this initial study, we have focused on the moderately strong and dominantly southward interplanetary magnetic field conditions. As compared with the static binning results, the boundary-oriented binning approach can provide a more confined and intense electron precipitation pattern. In addition, the magnitudes of the electric potential and electric field in the boundary-oriented binning results increase near the convection reversal boundary, leading to a ~11\% enhancement of the cross polar cap potential. The forcing patterns obtained from both binning approaches are used to drive the Global Ionosphere and Thermosphere Model to assess the impacts on Joule heating by using different binning patterns. It is found that the hemispheric-integrated Joule heating in the simulation driven by the boundary-oriented binning patterns is 18\% higher than that driven by the static binning patterns.

Zhu, Qingyu; Deng, Yue; Richmond, Arthur; Maute, Astrid; Chen, Yun-Ju; Hairston, Marc; Kilcommons, Liam; Knipp, Delores; Redmon, Robert; Mitchell, Elizabeth;

Published by: Journal of Geophysical Research: Space Physics      Published on: 01/2020

YEAR: 2020     DOI: 10.1029/2019JA027270

Electric field; high latitude; Joule heating; particle precipitation

Global-scale observations and modeling of far-ultraviolet airglow during twilight

The NASA Global‐scale Observations of the Limb and Disk ultraviolet imaging spectrograph performs observations of upper atmosphere airglow from the sunlit disk and limb of the Earth

Solomon, Stanley; Andersson, Laila; Burns, Alan; Eastes, Richard; Martinis, Carlos; McClintock, William; Richmond, Arthur;

Published by: Journal of Geophysical Research: Space Physics      Published on:

YEAR: 2020     DOI: 10.1029/2019JA027645

Development and Validation of the Whole Atmosphere Community Climate Model With Thermosphere and Ionosphere Extension (WACCM-X 2.0)

Key developments have been made to the NCAR Whole Atmosphere Community Climate Model with thermosphere and ionosphere extension (WACCM-X). Among them, the most important are the self-consistent solution of global electrodynamics, and transport of O⁺ in the F-region. Other ionosphere developments include time-dependent solution of electron/ion temperatures, metastable O⁺ chemistry, and high-cadence solar EUV capability. Additional developments of the thermospheric components are improvements to the momentum and energy equation solvers to account for variable mean molecular mass and specific heat, a new divergence damping scheme, and cooling by O(³P) fine structure. Simulations using this new version of WACCM-X (2.0) have been carried out for solar maximum and minimum conditions. Thermospheric composition, density, and temperatures are in general agreement with measurements and empirical models, including the equatorial mass density anomaly and the midnight density maximum. The amplitudes and seasonal variations of atmospheric tides in the mesosphere and lower thermosphere are in good agreement with observations. Although global mean thermospheric densities are comparable with observations of the annual variation, they lack a clear semiannual variation. In the ionosphere, the low-latitude E \texttimes B drifts agree well with observations in their magnitudes, local time dependence, seasonal, and solar activity variations. The prereversal enhancement in the equatorial region, which is associated with ionospheric irregularities, displays patterns of longitudinal and seasonal variation that are similar to observations. Ionospheric density from the model simulations reproduces the equatorial ionosphere anomaly structures and is in general agreement with observations. The model simulations also capture important ionospheric features during storms.

Liu, Han-Li; Bardeen, Charles; Foster, Benjamin; Lauritzen, Peter; Liu, Jing; Lu, Gang; Marsh, Daniel; Maute, Astrid; McInerney, Joseph; Pedatella, Nicholas; Qian, Liying; Richmond, Arthur; Roble, Raymond; Solomon, Stanley; Vitt, Francis; Wang, Wenbin;

Published by: Journal of Advances in Modeling Earth Systems      Published on: 01/2018

YEAR: 2018     DOI: 10.1002/jame.v10.210.1002/2017MS001232

The Global-Scale Observations of the Limb and Disk (GOLD) Mission

The Earth\textquoterights thermosphere and ionosphere constitute a dynamic system that varies daily in response to energy inputs from above and from below. This system can exhibit a significant response within an hour to changes in those inputs, as plasma and fluid processes compete to control its temperature, composition, and structure. Within this system, short wavelength solar radiation and charged particles from the magnetosphere deposit energy, and waves propagating from the lower atmosphere dissipate. Understanding the global-scale response of the thermosphere-ionosphere (T-I) system to these drivers is essential to advancing our physical understanding of coupling between the space environment and the Earth\textquoterights atmosphere. Previous missions have successfully determined how the \textquotedblleftclimate\textquotedblright of the T-I system responds. The Global-scale Observations of the Limb and Disk (GOLD) mission will determine how the \textquotedblleftweather\textquotedblright of the T-I responds, taking the next step in understanding the coupling between the space environment and the Earth\textquoterights atmosphere. Operating in geostationary orbit, the GOLD imaging spectrograph will measure the Earth\textquoterights emissions from 132 to 162 nm. These measurements will be used image two critical variables\textemdashthermospheric temperature and composition, near 160 km\textemdashon the dayside disk at half-hour time scales. At night they will be used to image the evolution of the low latitude ionosphere in the same regions that were observed earlier during the day. Due to the geostationary orbit being used the mission observes the same hemisphere repeatedly, allowing the unambiguous separation of spatial and temporal variability over the Americas.

Eastes, R.; McClintock, W.; Burns, A.; Anderson, D.; Andersson, L.; Codrescu, M.; Correira, J.; Daniell, R.; England, S.; Evans, J.; Harvey, J.; Krywonos, A.; Lumpe, J.; Richmond, A.; Rusch, D.; Siegmund, O.; Solomon, S.; Strickland, D.; Woods, T.; Aksnes, A.; Budzien, S.; Dymond, K.; Eparvier, F.; Martinis, C.; Oberheide, J.;

Published by: Space Science Reviews      Published on: 10/2017

YEAR: 2017     DOI: 10.1007/s11214-017-0392-2

High-latitude energy input and its impact on the thermosphere

This paper presents a quantitative assessment of high-latitude energy input and its partitioning in the polar cap by synthesizing various space and ground-based observations during the 17 January 2005 geomagnetic storm. It was found that Joule heating is the primary form of magnetospheric energy input, especially during active times when the hemispheric-integrated Joule heating can be an order of magnitude larger than the hemispheric-integrated auroral power. Most of magnetospheric energy is dissipated in the auroral zone rather than in the polar cap. On average, only about 22\textendash25\% of the total hemispheric energy input is dissipated into the polar cap region bordered by the convection reversal boundary (CRB) and the poleward auroral flux boundary (FXB). The impact of high-latitude energy input was also investigated to unveil the causal relationship between Joule heating and the formation of polar cap mass density anomalies. Our numerical simulation demonstrated that thermosphere dynamics readily redistributes composition, temperature, and mass through upwelling and atmospheric gravity waves. The polar cap mass density anomalies observed by the CHAMP satellite during the storm were largely a result of large-scale atmospheric gravity waves. Therefore, an increase in local thermospheric mass density does not necessarily mean there is direct energy input.

Lu, G.; Richmond, A.; Lühr, H.; Paxton, L.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 07/2016

YEAR: 2016     DOI: 10.1002/2015JA022294

Electrodynamics of the equatorial evening ionosphere: 2. Conductivity influences on convection, current, and electrodynamic energy flow

We analyze how the evening equatorial plasma vortex and the prereversal enhancement (PRE) of the vertical drift are influenced by the distributions of conductivity in the E and F regions in relation to the wind, through numerical simulations with the thermosphere-ionosphere-electrodynamics general circulation model coupled with the global ionosphere-plasmasphere model. The nightside electric potential satisfies an approximate minimization principle that unifies the connection of the horizontal and vertical components of plasma convection to the wind and conductivity distributions. The relative roles of E and F region conductivities on the convection and current closure are clarified. Evening time F region zonal winds at latitudes that encompass the equatorial ionization anomaly (EIA) region provide the main energy source to drive the convection, including the PRE. The E region helps regulate both the meridional and the zonal convection through drag on the meridional convection associated with Cowling current. For large nighttime E region conductivities, additional drag on the zonal convection comes from the Pedersen conductance. The minimization principle favors meridional plasma inflow to the EIA region from lower rather than higher magnetic apex heights, so long as the E region Cowling conductance is not too large. This upward/poleward inflow maximizes on field lines that traverse the lower F layer near the equatorward edge of the EIA region, producing a PRE with maximum vertical velocity within the equatorial F layer.

Richmond, A.; Fang, T.-W.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 03/2015

YEAR: 2015     DOI: 10.1002/2014JA020935

equatorial ionosphere convection; night-time ionization; pre-reversal enhancement

The NCAR TIE-GCM: A community model of the coupled thermosphere/ionosphere system

Qian, Liying; Burns, Alan; Emery, Barbara; Foster, Benjamin; Lu, Gang; Maute, Astrid; Richmond, Arthur; Roble, Raymond; Solomon, Stanley; Wang, Wenbin;

Published by: Modeling the Ionosphere-Thermosphere System      Published on:

YEAR: 2014     DOI:

Forcing the TIEGCM model with Birkeland currents from the Active Magnetosphere and Planetary Electrodynamics Response Experiment

Marsal, S.; Richmond, A.; Maute, A.; Anderson, B.;

Published by: Journal of Geophysical Research      Published on: Jan-01-2012

YEAR: 2012     DOI: 10.1029/2011JA017416

Assimilation of FORMOSAT-3/COSMIC electron density profiles into a coupled thermosphere/ionosphere model using ensemble Kalman filtering

This paper presents our effort to assimilate FORMOSAT-3/COSMIC (F3/C) GPS Occultation Experiment (GOX) observations into the National Center for Atmospheric Research (NCAR) Thermosphere Ionosphere Electrodynamics General Circulation Model (TIE-GCM) by means of ensemble Kalman filtering (EnKF). The F3/C electron density profiles (EDPs) uniformly distributed around the globe which provide an excellent opportunity to monitor the ionospheric electron density structure. The NCAR TIE-GCM simulates the Earth\textquoterights thermosphere and ionosphere by using self-consistent solutions for the coupled nonlinear equations of hydrodynamics, neutral and ion chemistry, and electrodynamics. The F3/C EDP are combined with the TIE-GCM simulations by EnKF algorithms implemented in the NCAR Data Assimilation Research Testbed (DART) open-source community facility to compute the expected value of electron density, which is \textquoteleftthe best\textquoteright estimate of the current ionospheric state. Assimilation analyses obtained with real F3/C electron density profiles are compared with independent ground-based observations as well as the F3/C profiles themselves. The comparison shows the improvement of the primary ionospheric parameters, such as NmF2 and hmF2. Nevertheless, some unrealistic signatures appearing in the results and high rejection rates of observations due to the applied outlier threshold and quality control are found in the assimilation experiments. This paper further discusses the limitations of the model and the impact of ensemble member creation approaches on the assimilation results, and proposes possible methods to avoid these problems for future work.

Lee, I.; Matsuo, T.; Richmond, A.; Liu, J; Wang, W.; Lin, C.; Anderson, J.; Chen, M.;

Published by: Journal of Geophysical Research      Published on: 10/2012

YEAR: 2012     DOI: 10.1029/2012JA017700

data assimilation; ensemble Kalman filter; FORMOSAT-3/COSMIC; Ionosphere

Parameterization of the ion convection and the auroral oval in the NCAR thermospheric general circulation models

Emery, B; Roble, Raymond; Ridley, Cicely; Richmond, Arthur; Knipp, Delores; Crowley, Geoff; Evans, David; Rich, Frederick; Maeda, Sawako;

Published by: NCAR Tech. Note NCAR/TN-491+ STR      Published on:

YEAR: 2012     DOI:

Modeling Density Variation in the Thermosphere

when this function is imposed at the lower boundary of the TIEGCM, neutral density variation consistent with satellite drag data, and O/N2 consistent with measurements by TIMED/GUVI

Richmond, Arthur;

Published by:       Published on:

YEAR: 2011     DOI:

Effects of high-latitude ionospheric electric field variability on global thermospheric Joule heating and mechanical energy transfer rate

Effects of high-latitude ionospheric electric field variability on the Joule heating and mechanical energy transfer rate are investigated by incorporating realistic spatial and temporal characteristics of electric field variability derived from observations into the forcing of a thermosphere ionosphere electrodynamic general circulation model. First, the characteristics of subgrid-scale variability are examined from a spectral analysis of Dynamic Explorer-2 (DE-2) plasma drift measurements. The analysis reveals that the subgrid-scale electric field varies with magnetic latitude, magnetic local time, interplanetary magnetic field (IMF), and season in a manner distinct from that of the resolved-scale electric field and of the climatological electric field. The subgrid-scale electric field varies strongly with season, and its magnitude averaged over the polar region does not depend on IMF. On the other hand, the resolved-scale electric field depends less on season but more on IMF. Second, the spatial-temporal structure of resolved-scale electric fields are characterized from various electromagnetic observations taken during the storm period of January 10–11, 1997, using a space-time covariance model derived from the DE-2 observations. Finally, the modeling results show that the amount of Joule heating and mechanical energy transfer rate in the thermosphere is significantly altered by taking into account the electric field variability and its space-time structure. Additional electromagnetic energy due to the electric field variability dissipates in the ionosphere almost exclusively as Joule heating if the variability has no spatial and temporal correlation. However, the spatially and temporally correlated electric field variability has seasonally dependent effects on the mechanical energy transfer rate.

Matsuo, Tomoko; Richmond, Arthur;

Published by: Journal of Geophysical Research: Space Physics      Published on:

YEAR: 2008     DOI: https://doi.org/10.1029/2007JA012993

Joule heating rate; mechanical energy transfer rate; electric field variability

Effects of high-latitude ionospheric electric field variability on global thermospheric Joule heating and mechanical energy transfer rate

Effects of high-latitude ionospheric electric field variability on the Joule heating and mechanical energy transfer rate are investigated by incorporating realistic spatial and temporal characteristics of electric field variability derived from observations into the forcing of a thermosphere ionosphere electrodynamic general circulation model. First, the characteristics of subgrid-scale variability are examined from a spectral analysis of Dynamic Explorer-2 (DE-2) plasma drift measurements. The analysis reveals that the subgrid-scale electric field varies with magnetic latitude, magnetic local time, interplanetary magnetic field (IMF), and season in a manner distinct from that of the resolved-scale electric field and of the climatological electric field. The subgrid-scale electric field varies strongly with season, and its magnitude averaged over the polar region does not depend on IMF. On the other hand, the resolved-scale electric field depends less on season but more on IMF. Second, the spatial-temporal structure of resolved-scale electric fields are characterized from various electromagnetic observations taken during the storm period of January 10–11, 1997, using a space-time covariance model derived from the DE-2 observations. Finally, the modeling results show that the amount of Joule heating and mechanical energy transfer rate in the thermosphere is significantly altered by taking into account the electric field variability and its space-time structure. Additional electromagnetic energy due to the electric field variability dissipates in the ionosphere almost exclusively as Joule heating if the variability has no spatial and temporal correlation. However, the spatially and temporally correlated electric field variability has seasonally dependent effects on the mechanical energy transfer rate.

Matsuo, Tomoko; Richmond, Arthur;

Published by: Journal of Geophysical Research: Space Physics      Published on:

YEAR: 2008     DOI: https://doi.org/10.1029/2007JA012993

Joule heating rate; mechanical energy transfer rate; electric field variability

High Latitude Thermosphere-Ionosphere Variability During the Solar Minimum IPY Period

Crowley, G; Curtis, N; Richmond, A; Carlson, H; van Eyken, T;

Published by:       Published on:

YEAR: 2008     DOI:

A data-model comparative study of ionospheric positive storm phase in the midlatitude F region

Lu, G; Goncharenko, LP; Coster, AJ; Richmond, AD; Roble, RG; Aponte, N; Paxton, LJ;

Published by:       Published on:

YEAR: 2008     DOI:

Modeling storm-time electrodynamics of the low-latitude ionosphere–thermosphere system: Can long lasting disturbance electric fields be accounted for?

Storm-time ionospheric disturbance electric fields are studied for two large geomagnetic storms, March 31, 2001 and April 17–18, 2002, by comparing low-latitude observations of ionospheric plasma drifts with results from numerical simulations based on a combination of first-principles models. The simulation machinery combines the Rice convection model (RCM), used to calculate inner magnetospheric electric fields, and the coupled thermosphere ionosphere plasmasphere electrodynamics (CTIPe) model, driven, in part, by RCM-computed electric fields. Comparison of model results with measured or estimated low-latitude vertical drift velocities (zonal electric fields) shows that the coupled model is capable of reproducing measurements under a variety of conditions. In particular, our model results suggest, from theoretical grounds, a possibility of long-lasting penetration of magnetospheric electric fields to low latitudes during prolonged periods of enhanced convection associated with southward-directed interplanetary magnetic field, although the model probably overestimates the magnitude and duration of such penetration during extremely disturbed conditions. During periods of moderate disturbance, we found surprisingly good overall agreement between model predictions and data, with penetration electric fields accounting for early main phase changes and oscillations in low-latitude vertical drift, while the disturbance dynamo mechanism becomes increasingly important later in the modeled events. Discrepancies between the model results and the observations indicate some of the difficulties in validating these combined numerical models, and the limitations of the available experimental data.

Maruyama, Naomi; Sazykin, Stanislav; Spiro, Robert; Anderson, David; Anghel, Adela; Wolf, Richard; Toffoletto, Frank; Fuller-Rowell, Timothy; Codrescu, Mihail; Richmond, Arthur; Millward, George;

Published by: Journal of Atmospheric and Solar-Terrestrial Physics      Published on:

YEAR: 2007     DOI: https://doi.org/10.1016/j.jastp.2006.08.020

Magnetosphere–ionosphere–thermosphere coupling; Ionospheric electrodynamics; low-latitude ionosphere; Penetration electric fields; disturbance dynamo electric fields; Numerical modeling

The effects of mid and low latitude electric fields upon the ionosphere and magnetosphere

Garner, TW; Crowley, G; Richmond, A; Roble, RG;

Published by:       Published on:

YEAR: 2006     DOI:

Large-scale variations of the low-latitude ionosphere during the October\textendashNovember 2003 superstorm: Observational results

Lin, C.; Richmond, A.D.; Liu, J.Y.; Yeh, H.C.; Paxton, L.; Lu, G.; Tsai, H.F.; Su, S.-Y.;

Published by: Journal of Geophysical Research      Published on: Jan-01-2005

YEAR: 2005     DOI: 10.1029/2004JA010900

Violent Sun-Earth Connection Events of October-November 2003-A09S28-Large-scale variations of the low-latitude ionosphere during the October-November 2003 superstorm

Lin, CH; RichmondJ Y Liu, AD; Yeh, HC; Paxton, LJ; Lu, G; Tsai, HF; Su, SY;

Published by: Journal of Geophysical Research-Part A-Space Physics      Published on:

YEAR: 2005     DOI:

Large-scale variations of the low-latitude ionosphere during the October-–November 2003 superstorm: Observational results

The GPS-derived total electron content (TEC), ion drift measurements from the ROCSAT-1 spacecraft at around 600 km altitude, and far-ultraviolet airglow measured by the Global Ultraviolet Imager (GUVI) carried on board the NASA TIMED satellite are utilized for studying large disturbances of the low-latitude ionosphere during the October–November 2003 superstorm period. Two chains of GPS receivers, one in the American sector (∼70°W) and the other in the Asian/Australian sector (∼120°E), are used to simultaneously observe the daytime equatorial ionization anomaly (EIA) during the entire storm period. It is found from the GPS-TEC measurements that the EIA expanded to very high latitudes with large increases of TEC right after the storm started. The large expansion of the EIA was associated with strong upward E × B drifts measured from the Ionospheric Plasma and Electrodynamics Instrument (IPEI) on board the ROCSAT-1, providing evidence of a penetration electric field and a strong plasma fountain effect. Suppression of the EIA was observed during the storm recovery, associated with downward E × B drifts that were observed by the ROCSAT-1. Significant negative storm effects in the southern hemisphere were also observed in the GPS-TEC during the first day of the recovery phase. The areas of negative storm effects are in good agreement with reductions in the [O]/[N2] density ratio inferred from the ratio of OI (135.6 nm) to LBH emissions measured from GUVI. An enhancement of the EIA was observed on the day, 1 November, that the storm was about to fully recover.

Lin, C.; Richmond, A.; . Y. Liu, J; Yeh, H.; Paxton, L.; Lu, G.; Tsai, H.; Su, S.-Y.;

Published by: Journal of Geophysical Research: Space Physics      Published on:

YEAR: 2005     DOI: https://doi.org/10.1029/2004JA010900

ionospheric disturbances; Magnetic storm; TEC enhancement

Large-scale variations of the low-latitude ionosphere during the October—November 2003 superstorm: Observational results

Lin, CH; Richmond, AD; Liu, JY; Yeh, HC; Paxton, LJ; Lu, G; Tsai, HF; Su, S-Y;

Published by: Journal of Geophysical Research: Space Physics      Published on:

YEAR: 2005     DOI: