Bibliography

Estimating Precipitating Energy Flux, Average Energy, and Hall Auroral Conductance From THEMIS All-Sky-Imagers With Focus on Mesoscales

Recent attention has been given to mesoscale phenomena across geospace (∼10 s km to 500 km in the ionosphere or ∼0.5 RE to several RE in the magnetosphere), as their contributions to the system global response are important yet remain uncharacterized mostly due to limitations in data resolution and coverage as well as in computational power. As data and models improve, it becomes increasingly valuable to advance understanding of the role of mesoscale phenomena contributions—specifically, in magnetosphere-ionosphere coupling. This paper describes a new method that utilizes the 2D array of Time History of Events and Macroscale Interactions during Substorms (THEMIS) white-light all-sky-imagers (ASI), in conjunction with meridian scanning photometers, to estimate the auroral scale sizes of intense precipitating energy fluxes and the associated Hall conductances. As an example of the technique, we investigated the role of precipitated energy flux and average energy on mesoscales as contrasted to large-scales for two back-to-back substorms, finding that mesoscale aurora contributes up to ∼80\% (∼60\%) of the total energy flux immediately after onset during the early expansion phase of the first (second) substorm, and continues to contribute ∼30–55\% throughout the remainder of the substorm. The average energy estimated from the ASI mosaic field of view also peaked during the initial expansion phase. Using the measured energy flux and tables produced from the Boltzmann Three Constituent (B3C) auroral transport code (Strickland et al., 1976; 1993), we also estimated the 2D Hall conductance and compared it to Poker Flat Incoherent Scatter Radar conductance values, finding good agreement for both discrete and diffuse aurora.

Gabrielse, Christine; Nishimura, Toshi; Chen, Margaret; Hecht, James; Kaeppler, Stephen; Gillies, Megan; Reimer, Ashton; Lyons, Larry; Deng, Yue; Donovan, Eric; Evans, Scott;

Published by: Frontiers in Physics      Published on:

YEAR: 2021     DOI:

Observations of Spatial Variations in O/N ₂ During an Auroral Substorm Using the Multichannel Downlooking Camera on the VISIONS Rocket

At 0821 UT on 7 February 2013, during an auroral substorm, the NASA VISIONS rocket was launched northward from Poker Flat Research Range on a flight to approximately 750-km altitude that terminated in the Arctic Ocean. A subpayload jettisoned on the up leg carried a multichannel optical imager that looked downward and observed the auroral emission through four narrow passband filters. Three of the channels had sufficiently strong signal to allow a measure of the time evolution of the horizontal extent of the electron aurora and changes in the ratio of the column O to the column N₂. These data revealed rather rapid changes in this measure of composition over an area larger than would be expected from the changes expected from particle and Joule heating. Although such rapid large changes have been observed previously, and Christensen et al. (1997, https://doi.org/10.1029/97JA01800) had hypothesized that they were due to enhanced turbulent diffusion, this imaging experiment is the first to show their evolution over a large area. On the down leg the camera was able to see the vertical spatial extent of the auroral emission which is consistent with the decrease in O/N₂ seen in the downlooking data. The change in this ratio with altitude suggests the deposition of an additional number of low-energy electrons that would cause a larger decrease in that ratio at higher altitudes.

Hecht, J.; Clemmons, J.; Conde, M.; Hampton, D.; Michell, R.; Rowland, D.; Pfaff, R.; Walterscheid, R.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 07/2018

YEAR: 2018     DOI: 10.1029/2018JA025288

A Comparative Study of Spectral Auroral Intensity Predictions From Multiple Electron Transport Models

It is important to routinely examine and update models used to predict auroral emissions resulting from precipitating electrons in Earth\textquoterights magnetotail. These models are commonly used to invert spectral auroral ground-based images to infer characteristics about incident electron populations when in situ measurements are unavailable. In this work, we examine and compare auroral emission intensities predicted by three commonly used electron transport models using varying electron population characteristics. We then compare model predictions to same-volume in situ electron measurements and ground-based imaging to qualitatively examine modeling prediction error. Initial comparisons showed differences in predictions by the GLobal airglOW (GLOW) model and the other transport models examined. Chemical reaction rates and radiative rates in GLOW were updated using recent publications, and predictions showed better agreement with the other models and the same-volume data, stressing that these rates are important to consider when modeling auroral processes. Predictions by each model exhibit similar behavior for varying atmospheric constants, energies, and energy fluxes. Same-volume electron data and images are highly correlated with predictions by each model, showing that these models can be used to accurately derive electron characteristics and ionospheric parameters based solely on multispectral optical imaging data.

Grubbs, Guy; Michell, Robert; Samara, Marilia; Hampton, Donald; Hecht, James; Solomon, Stanley; Jahn, Jörg-Micha;

Published by: Journal of Geophysical Research: Space Physics      Published on: 01/2018

YEAR: 2018     DOI: 10.1002/2017JA025026

RENU 2 UV Measurements of Atomic Oxygen in the Cusp Region

Fritz, Bruce; Lessard, Marc; Paxton, Larry; Cook, Timothy; Lynch, Kristina; Clemmons, James; Hecht, James; Hysell, David; Crowley, Geoff;

Published by:       Published on:

YEAR: 2016     DOI:

A new technique for remote sensing of O ₂ density from 140 to 180 km

Observations of molecular oxygen are difficult to make in the Earth\textquoterights atmosphere between 140 and 200 km altitude. Perhaps the most accurate measurements to date have been obtained from satellite instruments that measure solar occultations of the limb. These do provide height-resolved O₂ density measurements, but the nature of this technique is such that the temporal/spatial distribution of the measurements is uneven. Here a new space-based technique is described that utilizes two bright dayglow emissions, the (0,0) transition of the O₂ atmospheric band and the O I (630 nm), to derive the height-resolved O₂ density from 140 to 180 km. Data from the Remote Atmospheric and Ionospheric Detection System, which was placed on the International Space Station in late 2009, are used to illustrate this technique. The O₂ density results for periods in May 2010 that were geomagnetically quiet and disturbed are compared to model predictions.

Hecht, James; Christensen, Andrew; Yee, Jeng-Hwa; Crowley, Geoff; Bishop, Rebeeca; Budzien, Scott; Stephan, Andrew; Evans, Scott;

Published by: Geophysical Research Letters      Published on: 01/2015

YEAR: 2015     DOI: 10.1002/2014GL062355

composition; technique; thermosphere

A new technique for remote sensing of O2 density from 140 to 180 km

Hecht, James; Christensen, Andrew; Yee, Jeng-Hwa; Crowley, Geoff; Bishop, Rebeeca; Budzien, Scott; Stephan, Andrew; Evans, Scott;

Published by: Geophysical Research Letters      Published on:

YEAR: 2015     DOI:

Recent Results of the Remote Sensing of the O/N2 Ratio in the 100 to 200 Km Altitude Region

Hecht, James;

Published by:       Published on:

YEAR: 2014     DOI:

A multiyear (2002--2006) climatology of O/N2 in the lower thermosphere from TIMED GUVI and ground-based photometer observations

Hecht, J.; Mulligan, T.; Correira, J.; Clemmons, J.; Strickland, D.; Walterscheid, R.; Conde, M.;

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

YEAR: 2012     DOI: 10.1029/2011JA017146

An empirical determination of proton auroral far ultraviolet emission efficiencies using a new nonclimatological proton flux extrapolation method

Knight, HK; Strickland, DJ; Correira, J; Hecht, JH; Straus, PR;

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

YEAR: 2012     DOI:

A downward revision of a recently reported proton auroral LBH emission efficiency

Correira, J; Strickland, DJ; Evans, JS; Knight, HK; Hecht, JH;

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

YEAR: 2011     DOI:

Remote Sensing of lower thermospheric temperature and composition based on observations of O2 Atmospheric band emission.

Christensen, AB; Yee, J; Budzien, SA; Bishop, RL; Hecht, JH; Stephan, AW; Crowley, G;

Published by:       Published on:

YEAR: 2011     DOI:

A Multi-Year (2002-2006) Climatology of O/N2 in the Lower Thermosphere from TIMED GUVI and Ground-Based Photometer Data

Hecht, JH; Mulligan, T; Clemmons, JH; Strickland, DJ; Correira, J; Conde, MG;

Published by:       Published on:

YEAR: 2010     DOI:

A new proton auroral extrapolation method applied in the estimation of FUV emission yields

Knight, HK; Strickland, DJ; Correira, J; Evans, JS; Hecht, JH;

Published by:       Published on:

YEAR: 2010     DOI:

The Remote Atmospheric and Ionospheric Detection System on the ISS: Sensor performance and space weather applications from the extreme to the near ultraviolet

Stephan, Andrew; Budzien, Scott; Bishop, Rebecca; Straus, Paul; Christensen, Andrew; Hecht, James; Van Epps, Zachary;

Published by:       Published on:

YEAR: 2009     DOI:

Near Infrared Spectroscopy and Photometry of the Thermosphere from the RAIDS Experiment on the International Space Station

Christensen, AB; Bishop, RL; Budzien, SA; Hecht, JH; Stephan, AW; Straus, PR; van Epps, Z;

Published by:       Published on:

YEAR: 2009     DOI:

Thermospheric density in the Earth s magnetic cusp as observed by the Streak mission

Clemmons, JH; Hecht, JH; Salem, DR; Strickland, DJ;

Published by: Geophysical Research Letters      Published on:

YEAR: 2008     DOI:

Satellite and ground-based observations of auroral energy deposition and the effects on thermospheric composition during large geomagnetic storms: 1. Great geomagnetic storm of 20 November 2003

Hecht, JH; Mulligan, T; Strickland, DJ; Kochenash, AJ; Murayama, Y; Tanaka, Y-M; Evans, DS; Conde, MG; Donovan, EF; Rich, FJ; , others;

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

YEAR: 2008     DOI:

Evidence for significantly greater N2 Lyman-Birge-Hopfield emission efficiencies in proton versus electron aurora based on analysis of coincident DMSP SSUSI and SSJ/5 data

Knight, HK; Strickland, DJ; Hecht, JH; Straus, PR; Morrison, D; Paxton, LJ; Evans, DS;

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

YEAR: 2008     DOI:

The application of ground-based optical techniques for inferring electron energy deposition and composition change during auroral precipitation events

Hecht, J.H.; Strickland, D.J.; Conde, M.G.;

Published by: Journal of Atmospheric and Solar-Terrestrial Physics      Published on: Jan-09-2006

YEAR: 2006     DOI: 10.1016/j.jastp.2005.06.022

Implications of Auroral Electron Precipitation During the JOULE Experiment

Slocum, PL; Clemmons, JH; Hecht, JH; Larsen, MF; Pfaff, RF; Steigies, CT; Stenbaek-Nielsen, HC; Strickland, DJ;

Published by:       Published on:

YEAR: 2005     DOI:

Lower Thermospheric Composition Studies in the Auroral Zone

Hecht, James;

Published by:       Published on:

YEAR: 2005     DOI:

Near Simultaneous Observations of the Aurora From FUV, Particle and Photometric Instruments on DMSP-F16, TIMED, and IMAGE

Hecht, JH; Strickland, DJ; Knight, HK; Kochenash, AJ; Zhang, Y; Morrison, MD; Paxton, LJ; Mende, SB; Frey, HU; Burke, WJ; , others;

Published by:       Published on:

YEAR: 2005     DOI:

Testing Auroral Far Ultraviolet (FUV) Remote Sensing Techniques Using Coincident FUV and Particle Data From the DMSP F16 Satellite

Knight, HK; Strickland, DJ; Kochenash, AJ; Hecht, JH; Morrison, D; Zhang, Y; Paxton, LJ; Burke, WJ; Rich, FJ;

Published by:       Published on:

YEAR: 2005     DOI:

Composition Change in the Lower Thermosphere during the Great Magnetic Storm of November 20 2003 from TIMED Ground-Based and GUVI Observations

Hecht, JH; Strickland, DJ; Conde, MG; Morrison, MD;

Published by:       Published on:

YEAR: 2004     DOI:

The Interaction of Auroral Electron Precipitation with the Thermosphere During the JOULE Experiment

Slocum, PL; Clemmons, JH; Hecht, JH; Pfaff, RF; Steigies, CT; Larsen, MF; Strickland, DJ;

Published by:       Published on:

YEAR: 2004     DOI:

The State of the Neutral Atmosphere and the Electron Precipitation During JOULE From the Photometer and Electron Energy Analyzer Experiments

Hecht, JH; Clemmons, JH; Slocum, PL; Strickland, D;

Published by:       Published on:

YEAR: 2003     DOI:

Products Derived From GUVI Auroral Data and Comparisons With Ground-Based Results From Poker Flat and Ft. Yukon, AK

Strickland, DJ; Hecht, JH; Meier, RR; Conde, M; Christensen, AB; Morrison, D;

Published by:       Published on:

YEAR: 2003     DOI:

Composition Change in the Lower Thermosphere Over Alaska from TIMED/CEDAR Ground-Based and GUVI Observations

Hecht, JH; Strickland, DJ; Conde, MG;

Published by:       Published on:

YEAR: 2002     DOI:

Comparison of In Situ Auroral Electron Measurements With Distributions Inferred from Global Ultraviolet Imager (GUVI) Measurements

Anderson, PC; Christensen, AB; Paxton, LJ; Hecht, JH; Strickland, DJ; Morrison, DJ; Wolven, BC; Zhang, Y; Kil, H;

Published by:       Published on:

YEAR: 2002     DOI:

Wind-driven transport of thermospheric air parcels in the auroral zone

Data from ground-based optical instruments at Poker Flat and Fort Yukon in Alaska recorded during 2010 were used to examine the relationship between composition changes in the auroral thermosphere and transport effects by neutral winds. Thermospheric column [O]/[N2] estimates were obtained from a pair of four-channel zenith-pointed narrow field photometers located at Poker Flat and Fort Yukon, whereas neutral winds at E and F-region heights were measured using an all-sky imaging Fabry-Perot spectrometer at Poker Flat. Wind fields were obtained over a spatial region around 1400 km in diameter in the F-region, or 700 km in the E-region, with a cadence of one observation every few minutes. We focus in particular on a sustained depletion of column [O]/[N2] observed during the minor storm period of April 4-8, 2010. While various correlated events were noted, no systematic relation was found between between horizontal winds and the column [O]/[N2] during this period (or indeed on any of the several tens of other days that we examined.) However during the storm there was a very obvious increase in activity of vertical winds, horizontal divergence, and associated wave activity. We suggest that the long-lived decrease in column [O]/[N2] during the storm was due to vertical mixing being enhanced by a process akin to eddy diffusion. This is in contrast to the more typical picture of localized “upwellings” being driven by Joule heating, and then carrying molecular species aloft

Conde, Mark; Hecht, James; Anderson, Callum;

Published by:       Published on:

YEAR: 0     DOI: