GUVI Biblio

Disappearance of the Polar Cap Ionosphere During Geomagnetic Storm on 11 May 2019

Multi-instrument data from Jang Bogo Station (JBS) in Antarctica were utilized to study ionospheric responses to the 11 May 2019 moderate geomagnetic storm. These include Vertical Incident Pulsed Ionospheric Radar (VIPIR)/Dynasonde, Fabry-Perot Interferometer (FPI), GPS vertical total electron content (vTEC), and magnetometer. The VIPIR/Dynasonde observed long-lasting (\textgreater11 hr) severe depletion of the electron density in the F-region ionosphere over JBS. During the depletion interval, GPS TEC also correspondingly d ...

Kwon, H.-J.; Kim, K.-H.; Jee, G.; Seon, J.; Lee, C.; Ham, Y.-B.; Hong, J.; Kim, E.; Bullett, T.; Auster, H.-U.; Magnes, W.; Kraft, S.;

Published by: Space Weather      Published on:

YEAR: 2022     DOI: 10.1029/2022SW003054

The Far Ultraviolet Signatures of Conjugate Photoelectrons Seen by the Special Sensor Ultraviolet Spectrographic Imager

This study investigates the origin of anomalous far ultraviolet emissions observed at night at the subauroral region by the Special Sensor Ultraviolet Spectrographic Imager on board the Defense Meteorological Satellite System-F16 satellite. The global distribution of the anomalous emission is derived using the measurements of the oxygen atom 130.4-nm emission in 2017. Our results show the extension of the anomalous emission from high latitudes to middle latitudes in the Northern American-Atlantic sector during the Decembe ...

Kil, Hyosub; Schaefer, Robert; Paxton, Larry; Jee, Geonhwa;

Published by: Geophysical Research Letters      Published on: 01/2020

YEAR: 2020     DOI: 10.1029/2019GL086383

conjugate photoelectron; far ultraviolet emission; thermosphere; remote sensing data

The far ultraviolet signatures of conjugate photoelectrons seen by the Special Sensor Ultraviolet Spectrographic Imager

Kil, Hyosub; Schaefer, Robert; Paxton, Larry; Jee, Geonhwa;

Published by: Geophysical Research Letters      Published on:

YEAR: 2020     DOI:

Plasma Blobs Associated With Medium-Scale Traveling Ionospheric Disturbances

Plasma blobs represent plasma density enhancements with respect to ambient plasma. The formation of blobs in low and middle latitudes is understood in association with either equatorial plasma bubbles or medium-scale traveling ionospheric disturbances (MSTIDs). This study reports four blob events identified from the Swarm satellite observations in 2014. Those blobs show the conjugate property and the alignment in the northwest-southeast direction in the Northern Hemisphere and southwest-northeast direction in the Southern ...

Kil, Hyosub; Paxton, Larry; Jee, Geonhwa; Nikoukar, Romina;

Published by: Geophysical Research Letters      Published on: 03/2019

YEAR: 2019     DOI: 10.1029/2019GL082026

Plasma blobs associated with medium-scale traveling ionospheric disturbances

Kil, Hyosub; Paxton, Larry; Jee, Geonhwa; Nikoukar, Romina;

Published by: Geophysical Research Letters      Published on:

YEAR: 2019     DOI:

Daytime evolution of equatorial plasma bubbles observed by the first Republic of China satellite

Kil, Hyosub; Paxton, Larry; Lee, Woo; Jee, Geonhwa;

Published by: Geophysical Research Letters      Published on:

YEAR: 2019     DOI:

Direct observational evidence for disturbance dynamo on the daytime low-latitude ionosphere: A case study based on the 28 June 2013 space weather event

A case of the westward disturbance dynamo (DD) electric field, influencing the daytime equatorial and low-latitude ionosphere, during a geomagnetic storm that occurred on 28\textendash29 June 2013 is presented. The GPS total electron content (TEC) observations from a network of stations in the Indian equatorial, low and middle latitude regions along with the radio beacon TEC, ionosonde, and magnetic field observations are used to study the storm time behavior of the ionosphere. Negative ionospheric storm effects were seen ...

Thampi, Smitha; Shreedevi, P.; Choudhary, R.; Pant, Tarun; Chakrabarty, D.; Sunda, S.; Mukherjee, S.; Bhardwaj, Anil;

Published by: Journal of Geophysical Research: Space Physics      Published on: 09/2016

YEAR: 2016     DOI: 10.1002/2016JA023037

On the latitudinal changes in ionospheric electrodynamics and composition based on observations over the 76--77 E meridian from both hemispheres during a geomagnetic storm

The relative contributions of the composition disturbances and the disturbance electric fields in the redistribution of ionospheric plasma is investigated in detail by taking the case of a long-duration positive ionospheric storm that occurred during 18\textendash21 February 2014. GPS total electron content (TEC) data from the Indian Antarctic station, Bharti (69.4\textdegreeS, 76.2\textdegreeE geographic), the northern midlatitude station Hanle (32.8\textdegreeN, 78.9\textdegreeE geographic), northern low-latitude statio ...

Shreedevi, P.; Thampi, Smitha; Chakrabarty, D.; Choudhary, R.; Pant, Tarun; Bhardwaj, Anil; Mukherjee, S.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 02/2016

YEAR: 2016     DOI: 10.1002/2015JA021841

Geomagnetic storms; High latitude low latitude coupling; Ionosphere; positive ionospheric storm

Equatorial broad plasma depletions associated with the evening prereversal enhancement and plasma bubbles during the 17 March 2015 storm

Kil, Hyosub; Lee, Woo; Paxton, Larry; Hairston, Marc; Jee, Geonhwa;

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

YEAR: 2016     DOI:

Dynamics of the Dayside Aurora as Viewed from the South Pole

McEwen, Donald; Sivjee, Gulamabas; Zhang, Yongliang;

Published by:       Published on:

YEAR: 2015     DOI:

A study on ionospheric scintillation near the EIA crest in relation to equatorial electrodynamics

Equatorial electrojet (EEJ) data, which are considered as a proxy index of equatorial electric field, are analyzed in conjunction with equatorial ionosonde, total electron content (TEC) and scintillation data near the equatorial ionization anomaly (EIA) crest for the equinoctial months of high solar activity years (2011\textendash2012) to identify any precursor index of postsunset evolution of equatorial electron density irregularities and subsequent occurrence of scintillation near the northern EIA crest. Only geomagneti ...

Chatterjee, S.; Chakraborty, S.; Veenadhari, B.; Banola, S.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 02/2014

YEAR: 2014     DOI: 10.1002/2013JA019466

scintillations in relation to equatorial electrodynamics

A long-lived band of plasma density enhancement at mid-latitudes during the 2003 Halloween magnetic storm

Park, Jaeheung; Lühra, Hermann; Jakowski, Norbert; Gerzen, Tatjana; Kil, Hyosub; Jee, Geonhwa; Xiong, Chao; Min, Kyoung; Noja, Max;

Published by: Journal of Atmospheric and Solar-Terrestrial Physics      Published on: Jan-05-2012

YEAR: 2012     DOI: 10.1016/j.jastp.2012.03.009

The source of the steep plasma density gradient in middle latitudes during the 11--12 April 2001 storm

A steep plasma density gradient has been observed in the middle-latitude F region during large geomagnetic storms. This phenomenon can be understood as a special form of the middle-latitude ionization trough (hereafter trough), but its causal linkage has not yet been clarified. We investigate the association of the steep density gradient and the trough by comparing their morphologies and occurrence locations using the satellite and ground observation data during the 11\textendash12 April 2001 storm. Steep density ...

Park, S.; Kim, K.-H.; Kil, H.; Jee, G.; Lee, D.-H.; Goldstein, J.;

Published by: Journal of Geophysical Research      Published on: 05/2012

YEAR: 2012     DOI: 10.1029/2011JA017349

geomagnetic storm; plasma trough; steep density gradient

Mid-latitude ionosphere observed by ground-based GPS during intense geomagnetic storms in October 2003 and November 2004

Chung, J; Jee, Geonhwa;

Published by:       Published on:

YEAR: 2010     DOI:

Extreme Enhancements in GPS TEC on 8 and 10 November 2004

Chung, Jong-Kyun; Jee, Gun-Hwa; Kim, Eo-Jin; Kim, Yong-Ha; Cho, Jung-Ho;

Published by: Bulletin of the Korean Space Science Society      Published on:

YEAR: 2010     DOI:

Seasonal Characteristics of the Longitudinal Wavenumber-4 Structures in the Total Electron Contents (TEC) from the TOPEX/Poseidon mission

Kim, E; Jee, Geonhwa; Kim, Yong;

Published by:       Published on:

YEAR: 2008     DOI:

First terrestrial soft X-ray auroral observation by the Chandra X-ray Observatory

Bhardwaj, Anil; Gladstone, Randall; Elsner, Ronald; Ostgaard, Nikolai; Waite, Hunter; Cravens, Thomas; Chang, Shen-Wu; Majeed, Tariq; Metzger, Albert;

Published by: Journal of Atmospheric and Solar-Terrestrial Physics      Published on: Jan-02-2007

YEAR: 2007     DOI: 10.1016/j.jastp.2006.07.011

Comparison of Global Ultraviolet Imager Observations of Thermospheric Composition Changes to Those Deduced From Ground Observations

Morrison, D; Sivjee, A; Paxton, L; Zhang, Y; Wolven, B; Kil, H; Meng, C; Christensen, A;

Published by:       Published on:

YEAR: 2002     DOI: