Bibliography

Middle and low-latitude ionosphere-thermosphere responses to solar wind driving during CME-type storms

Verkhoglyadova, Olga; Mlynczak, MG; Mannucci, Anthony; Paxton, Larry; Hunt, Linda; Komjathy, Attila;

Published by: 42nd COSPAR Scientific Assembly      Published on:

YEAR: 2018     DOI:

Revisiting Ionosphere-Thermosphere Responses to Solar Wind Driving in Superstorms of November 2003 and 2004

We revisit three complex superstorms of 19\textendash20 November 2003, 7\textendash8 November 2004, and 9\textendash11 November 2004 to analyze ionosphere-thermosphere (IT) effects driven by different solar wind structures associated with complex interplanetary coronal mass ejections (ICMEs) and their upstream sheaths. The efficiency of the solar wind-magnetosphere connection throughout the storms is estimated by coupling functions. The daytime IT responses to the complex driving are characterized by combining and collocating (where possible) measurements of several physical parameters (total electron content or TEC, thermospheric infrared nitric oxide emission, and composition ratio) from multiple satellite platforms and ground-based measurements. A variety of metrics are utilized to examine global IT phenomena at ~1\ h timescales. The role of direct driving of IT dynamics by solar wind structures and the role of IT preconditioning in these storms, which feature complex unusual TEC responses, are examined and contrasted. Furthermore, IT responses to ICME magnetic clouds and upstream sheaths are separately characterized. We identify IT feedback effects that can be important for long-lasting strong storms. The role of the interplanetary magnetic field B_y component on ionospheric convection may not be well captured by existing coupling functions. Mechanisms of thermospheric overdamping and consequential ionospheric feedback need to be further studied.

Verkhoglyadova, O.; Komjathy, A.; Mannucci, A.; Mlynczak, M.; Hunt, L.; Paxton, L.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 10/2017

YEAR: 2017     DOI: 10.1002/jgra.v122.1010.1002/2017JA024542

Multiinstrument observations of a geomagnetic storm and its effects on the Arctic ionosphere: A case study of the 19 February 2014 storm

We present a multiinstrumented approach for the analysis of the Arctic ionosphere during the 19 February 2014 highly complex, multiphase geomagnetic storm, which had the largest impact on the disturbance storm-time index that year. The geomagnetic storm was the result of two powerful Earth-directed coronal mass ejections (CMEs). It produced a strong long lasting negative storm phase over Greenland with a dominant energy input in the polar cap. We employed global navigation satellite system (GNSS) networks, geomagnetic observatories, and a specific ionosonde station in Greenland. We complemented the approach with spaceborne measurements in order to map the state and variability of the Arctic ionosphere. In situ observations from the Canadian CASSIOPE (CAScade, Smallsat and Ionospheric Polar Explorer) satellite\textquoterights ion mass spectrometer were used to derive ion flow data from the polar cap topside ionosphere during the event. Our research specifically found that (1) thermospheric O/N 2 measurements demonstrated significantly lower values over the Greenland sector than prior to the storm time. (2) An increased ion flow in the topside ionosphere was observed during the negative storm phase. (3) Negative storm phase was a direct consequence of energy input into the polar cap. (4) Polar patch formation was significantly decreased during the negative storm phase. This paper addresses the physical processes that can be responsible for this ionospheric storm development in the northern high latitudes. We conclude that ionospheric heating due to the CME\textquoterights energy input caused changes in the polar atmosphere resulting in N e upwelling, which was the major factor in high-latitude ionosphere dynamics for this storm.

Durgonics, Tibor; Komjathy, Attila; Verkhoglyadova, Olga; Shume, Esayas; Benzon, Hans-Henrik; Mannucci, Anthony; Butala, Mark; H\oeg, Per; Langley, Richard;

Published by: Radio Science      Published on: 01/2017

YEAR: 2017     DOI: 10.1002/2016RS006106

Multi-Instrument Observations of Physical Processes in the Arctic Ionosphere and Derived Applications

The main focus of this dissertation is the study of the physical processes in the northern high-latitude (or simply Arctic) ionosphere. In addition to the main focus, two further studies are also presented regarding midlatitude ionosphere and neutral atmospheric simulations and observations. This section presents some basic background and the motivation behind these research topics.

Durgonics, Tibor; H\oeg, P; Olsen, N; Coster, AJ; Wintoft, P; Komjathy, A; von Benzon, H;

Published by:       Published on:

YEAR: 2017     DOI:

Superstorms of November 2003 and 2004: the role of solar wind driving in the ionosphere-thermosphere dynamics

Verkhoglyadova, Olga; Komjathy, Attila; Mannucci, Anthony; Mlynczak, Martin; Hunt, Linda; Paxton, Larry;

Published by:       Published on:

YEAR: 2017     DOI:

Solar wind driving of ionosphere-thermosphere responses in three storms near St. Patrick's Day in 2012, 2013, and 2015

We identify interplanetary plasma regions associated with three intense interplanetary coronal mass ejections (ICMEs)-driven geomagnetic storm intervals which occurred around the same time of the year: day of year 74\textendash79 (March) of 2012, 2013, and 2015. We show that differences in solar wind drivers lead to different dynamical ionosphere-thermosphere (IT) responses and to different preconditioning of the IT system. We introduce a new hourly based global metric for average low-latitude and northern middle-latitude vertical total electron content responses in the morning, afternoon, and evening local time ranges, derived from measurements from globally distributed Global Navigation Satellite System ground stations. Our novel technique of estimating nitric oxide (NO) cooling radiation in 11\textdegree latitudinal zones is based on Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics (TIMED)/Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) measurements. The thermospheric cooling throughout the storm phases is studied with this high latitudinal resolution for the first time. Additionally, TIMED/Global Ultraviolet Imager (GUVI) observations of the dynamical response of the thermospheric composition (O/N₂ ratio) are utilized to study negative ionospheric storm effects. Based on these data sets, we describe and quantify distinct IT responses to driving by ICME sheaths, magnetic clouds, coronal loop remnants, plasma discontinuities, and high-speed streams following ICMEs. Our analysis of coupling functions indicates strong connection between coupling with the solar wind and IT system response in ICME-type storms and also some differences. Knowledge of interplanetary features is crucial for understanding IT storm dynamics.

Verkhoglyadova, O.; Tsurutani, B.; Mannucci, A.; Mlynczak, M.; Hunt, L.; Paxton, L.; Komjathy, A.;

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

YEAR: 2016     DOI: 10.1002/jgra.v121.910.1002/2016JA022883

Heliosphere-ionosphere-thermosphere coupling and energy budget in geomagnetic storms

1. Solar irradiance: F10. 7 2. High-latitude electric and magnetic field potential patterns and field-aligned currents (FAC): empirical Weimer05 model (Weimer, 2005), can use AMIE input

Verkhoglyadova, OP; Mannucci, AJ; Meng, X; Komjathy, A; Mlynczak, MG; Hunt, LA; Tsurutani, BT;

Published by:       Published on:

YEAR: 2016     DOI:

Analysis of High-Latitude Ionospheric Processes During the Nov 2015 HSS and CME-Induced Geomagnetic Storm: A Multi-Instrument Observational Approach

Durgonics, Tibor; Komjathy, Attila; Verkhoglyadova, Olga; Hoeg, Per; Paul, Ashik;

Published by:       Published on:

YEAR: 2016     DOI:

Multi-Instrument Observations of Geomagnetic Storms in the Arctic Ionosphere

Durgonics, Tibor; Komjathy, Attila; Verkhoglyadova, Olga; Shume, Esayas; Benzon, Hans-Henrik; Mannucci, Anthony; Butala, Mark; H\oeg, Per; Langley, Richard;

Published by:       Published on:

YEAR: 2016     DOI:

Use of radio occultation to probe the high-latitude ionosphere

We have explored the use of COSMIC data to provide valuable scientific information on the ionospheric impacts of energetic particle precipitation during geomagnetic storms. Ionospheric electron density in the E region, and hence ionospheric conductivity, is significantly altered by precipitating particles from the magnetosphere. This has global impacts on the thermosphere\textendashionosphere because of the important role of conductivity on high-latitude Joule heating. Two high-speed stream (HSS) and two coronal mass ejection (CME) storms are examined with the COSMIC data. We find clear correlation between geomagnetic activity and electron density retrievals from COSMIC. At nighttime local times, the number of profiles with maximum electron densities in the E layer (below 200 km altitude) is well correlated with geomagnetic activity. We interpret this to mean that electron density increases due to precipitation are captured by the COSMIC profiles. These "E-layer-dominant ionosphere" (ELDI) profiles have geomagnetic latitudes that are consistent with climatological models of the auroral location. For the two HSS storms that occurred in May of 2011 and 2012, a strong hemispheric asymmetry is observed, with nearly all the ELDI profiles found in the Southern, less sunlit, Hemisphere. Stronger aurora and precipitation have been observed before in winter hemispheres, but the degree of asymmetry deserves further study. For the two CME storms, occurring in July and November of 2012, large increases in the number of ELDI profiles are found starting in the storm\textquoterights main phase but continuing for several days into the recovery phase. Analysis of the COSMIC profiles was extended to all local times for the July 2012 CME storm by relaxing the ELDI criterion and instead visually inspecting all profiles above 50\textdegree magnetic latitude for signatures of precipitation in the E region. For 9 days during the July 2012 period, we find a signature of precipitation occurs nearly uniformly in local time, although the magnitude of electron density increase may vary with local time. The latitudinal extent of the precipitation layers is generally consistent with auroral climatology. However, after the storm main phase on 14 July 2012 the precipitation tended to be somewhat more equatorward than the climatology (by about 5\textendash10\textdegree latitude) and equatorward of the auroral boundary data acquired from the SSUSI sensor onboard the F18 DMSP satellite. We conclude that, if analyzed appropriately, high-latitude COSMIC profiles have the potential to contribute to our understanding of MI coupling processes and extend and improve existing models of the auroral region.

Mannucci, A.; Tsurutani, B.; Verkhoglyadova, O.; Komjathy, A.; Pi, X.;

Published by: Atmospheric Measurement Techniques      Published on: 07/2015

YEAR: 2015     DOI: 10.5194/amt-8-2789-2015

Solar wind driving of ionosphere-thermosphere responses during three storms on St. Patrick's Day.

Verkhoglyadova, Olga; Tsurutani, Bruce; Mannucci, Anthony; Komjathy, Attila; Mlynczak, Martin; Hunt, Linda; Paxton, Larry;

Published by:       Published on:

YEAR: 2015     DOI:

Interplanetary magnetic field By control of prompt total electron content increases during superstorms

Large magnitude increases in ionospheric total electron content (TEC) that occur over 1\textendash3\ h on the dayside are a significant manifestation of the main phases of superstorms. For the largest superstorms of solar cycle 23 (based on the Dst index), ground networks of GPS receivers measured peak total electron content increases greater than a factor of 2 relative to quiet time TEC averaged over the broad latitude band \textpm40\textdegree for local times 1200\textendash1600\ LT. Near 30\textdegree latitude, the Halloween storms of October 29\textendash30, 2003 appeared to produce storm-time TEC exceeding quiet time values by a factor of 5 within 2\textendash3\ h of storm onset, at 1300\ LT. The physical cause of these large positive phase ionospheric storms is usually attributed to prompt penetration electric fields (PPEFs) initiated by Region 1 current closure through the ionosphere ( Nopper and Carovillano, 1978 mechanism). An unresolved question is what determines variation of the TEC response for different superstorms. It has been suggested that the cross polar cap potential and Region 1 currents are significant factors in determining PPEF in the equatorial ionosphere, which are related to the solar wind reconnection electric field estimated by Kan\textendashLee and others. In this paper, we show evidence that suggests B_y may be a significant factor controlling the TEC response during the main phase of superstorms. We analyzed the interplanetary conditions during the period that TEC was increasing for eight superstorms. We find that increasing daytime TEC during superstorms only occurs for large reconnection electric fields when B_y magnitude is less than B_z. The data suggest that B_z is a far more important factor in the TEC response than the reconnection electric field. We also find that TEC decreases following its peak storm-time value for two superstorms, even though B_z remains large and B_y magnitudes are less than B_z. Such decreases during the geomagnetic disturbance may indicate the role of magnetospheric shielding currents, or of changes in the thermosphere that have developed over the prolonged period of large solar wind electric field. Further analysis is warranted covering a wider range of storm intensities on the role of B_y in affecting the daytime TEC response for a range of storm intensities.

Mannucci, A.J.; Crowley, G.; Tsurutani, B.T.; Verkhoglyadova, O.P.; Komjathy, A.; Stephens, P.;

Published by: Journal of Atmospheric and Solar-Terrestrial Physics      Published on: 08/2014

YEAR: 2014     DOI: 10.1016/j.jastp.2014.01.001

Geomagnetic storms; Ionosphere

Ensemble Modeling with Data Assimilation Models: A New Strategy for Space Weather Science, Specifications and Forecasts

Schunk, Robert; Scherliess, L; Eccles, JV; Gardner, LC; Sojka, JJ; Zhu, L; Pi, X; Mannucci, A; Wilson, BD; Komjathy, A; , others;

Published by:       Published on:

YEAR: 2012     DOI:

Ionospheric VTEC and thermospheric infrared emission dynamics during corotating interaction region and high-speed stream intervals at solar minimum: 25 March to 26 April 2008

Verkhoglyadova, O.; Tsurutani, B.; Mannucci, A.; Mlynczak, M.; Hunt, L.; Komjathy, A.; Runge, T.;

Published by: Journal of Geophysical Research      Published on: Jan-01-2011

YEAR: 2011     DOI: 10.1029/2011JA016604

Estimating The Forces That Drive Ionosphere And Thermosphere Variability: Continuous Data And Assimilative Modeling

onosphere-thermosphere science has long been hampered by a lack of measurements of the underlying forces that determine plasma structure. These forces include electric fields, thermospheric composition, winds and solar EUV irradiance. All of these forces are dynamic quantities and of great importance to the underlying science. The rapid proliferation of electron density and total electron content measurements from ground and space-borne GPS receivers and other instruments suggests a great potential in the following indirect approach to estimating these forces: developing a model-based approach to retrieving the forces from the electron density structure and dynamics. The research community has just begun to explore such an approach, which addresses significant science questions previously out of reach.

Mannucci, Anthony; Pi, Xiaoqing; Butala, Mark; Stephens, Phil; Wilson, Brian; Komjathy, Attila; Iijima, Byron; Akopian, Vardan; Dumett, Miguel;

Published by: To advocate developing a model-based approach to retrieving the driving forces from measurements of electron density structure and dynamics      Published on:

YEAR: 2010     DOI:

Local time dependence of the prompt ionospheric response for the 7, 9, and 10 November 2004 superstorms

We investigate the effects of penetration electric fields, meridional thermospheric neutral winds, and composition perturbation zones (CPZs) on the distribution of low-latitude plasma during the 7\textendash11 November 2004 geomagnetic superstorm. The impact on low-latitude plasma was assessed using total electron content (TEC) measurements from a latitudinally distributed array of ground-based GPS receivers in South America. Jicamarca Radio Observatory incoherent scatter radar measurements of vertical E\texttimesB drift are used in combination with the Low-Latitude IONospheric Sector (LLIONS) model to examine how penetration electric fields and meridional neutral winds shape low-latitude TEC. It is found that superfountain conditions pertain between \~1900 and 2100UT on 9 November, creating enhanced equatorial ionization anomaly (EIA) crests at \textpm20\textdegree geomagnetic latitude. Large-amplitude and/or long-duration changes in the electric field were found to produce significant changes in EIA plasma density and latitudinal location, with a delay time of \~2\textendash2.5h. Superfountain drifts were primarily responsible for EIA TEC levels; meridional winds were needed only to create hemispherical crest TEC asymmetries. The [O/N2] density ratio (derived from the GUVI instrument, flown on the TIMED satellite) and measurements of total atmospheric density (from the GRACE satellites), combined with TEC measurements, yield information regarding a likely CPZ that appeared on 10 November, suppressing TEC for over 16h.

Mannucci, Anthony; Tsurutani, Bruce; Kelley, Michael; Iijima, Byron; Komjathy, Attila;

Published by: Journal of Geophysical Research      Published on: Jan-01-2009

YEAR: 2009     DOI: 10.1029/2009JA014043

GNSS-based space weather systems including COSMIC ionospheric measurements

LORAAS on ARGOS, GUVI on TIMED SSUSI/SSULI on DMSP TIP on COSMIC

Komjathy, Attila; Mandrake, Lukas; Wilson, Brian; Iijima, Byron; Pi, Xiaoqing; Hajj, George; Mannucci, Anthony;

Published by:       Published on:

YEAR: 2006     DOI: