Bibliography

Lower Thermospheric Material Transport via Lagrangian Coherent Structures

We show that inter-model variation due to under-constraint by observations impacts the ability to predict material transport in the lower thermosphere. Lagrangian coherent structures (LCSs), indicating regions of maximal separation (or convergence) in a time-varying flow, are derived in the lower thermosphere from models for several space shuttle water vapor plume events. We find that inter-model differences in thermospheric transport manifest in LCSs in a way that is more stringent than mean wind analyses. LCSs defined using horizontal flow fields from the Specified Dynamics version of the Whole Atmosphere Community Climate Model with thermosphere-ionosphere eXtension (SD-WACCMX) at 109 km altitude are compared to Global Ultraviolet Imager (GUVI) observations of the space shuttle main engine plume. In one case, SD-WACCMX predicts an LCS ridge to produce spreading not found in the observations. LCSs and tracer transport from SD-WACCMX and from data assimilative WACCMX (WACCMX + DART) are compared to each other and to GUVI observations. Differences in the modeled LCSs and tracer positions appear between SD-WACCMX and WACCMX + DART despite the similarity of mean winds. WACCMX + DART produces better tracer transport results for a July 2006 event, but it is unclear which model performs better in terms of LCS ridges. For a February 2010 event, when mean winds differ by up to 50 m/s between the models, differences in LCSs and tracer trajectories are even more severe. Low-pass filtering the winds up to zonal wavenumber 6 reduces but does not eliminate inter-model LCS differences. Inter-model alignment of LCSs improves at a lower 60 km altitude.

Datta-Barua, Seebany; Pedatella, Nicholas; Greer, Katelynn; Wang, Ningchao; Nutter, Leanne; Harvey, Lynn;

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

YEAR: 2021     DOI: 10.1029/2020JA028834

Effects of CME and CIR induced geomagnetic storms on low-latitude ionization over Indian longitudes in terms of neutral dynamics

Chakraborty, Sumanjit; Ray, Sarbani; Sur, Dibyendu; Datta, Abhirup; Paul, Ashik;

Published by: Advances in Space Research      Published on:

YEAR: 2020     DOI:

Effects of CME and CIR induced geomagnetic storms on low-latitude ionization over Indian longitudes in terms of neutral dynamics

This paper presents the response of the ionosphere during the intense geomagnetic storms of October 12\textendash20, 2016 and May 26\textendash31, 2017 which occurred during the declining phase of the solar cycle 24. Total Electron Content (TEC) from GPS measured at Indore, Calcutta and Siliguri having geomagnetic dips varying from 32.23\textdegreeN, 32\textdegreeN and 39.49\textdegreeN respectively and at the International GNSS Service (IGS) stations at Lucknow (beyond anomaly crest), Hyderabad (between geomagnetic equator and northern crest of EIA) and Bangalore (near magnetic equator) in the Indian longitude zone have been used for the storms. Prominent peaks in diurnal maximum in excess of 20\textendash45 TECU over the quiet time values were observed during the October 2016 storm at Lucknow, Indore, Hyderabad, Bangalore and 10\textendash20 TECU for the May 2017 storm at Siliguri, Indore, Calcutta and Hyderabad. The GUVI images onboard TIMED spacecraft that measures the thermospheric O/N₂ ratio, showed high values (O/N₂ ratio of about 0.7) on October 16 when positive storm effects were observed compared to the other days during the storm period. The observed features have been explained in terms of the O/N₂ ratio increase in the equatorial thermosphere, CIR-induced High Speed Solar Wind (HSSW) event for the October 2016 storm. The TEC enhancement has also been explained in terms of the Auroral Electrojet (AE), neutral wind values obtained from the Horizontal Wind Model (HWM14) and equatorial electrojet strength from magnetometer data for both October 2016 and May 2017 storms. These results are one of the first to be reported from the Indian longitude sector on influence of CME- and CIR-driven geomagnetic storms on TEC during the declining phase of solar cycle 24.

Chakraborty, S.; Ray, S.; Sur, D.; Datta, A.; Paul, A.;

Published by: Advances in Space Research      Published on: 10/2019

YEAR: 2019     DOI: 10.1016/j.asr.2019.09.047

First light from a kilometer-baseline Scintillation Auroral GPS Array

Datta-Barua, S; Su, Y; Deshpande, K; Miladinovich, D; Bust, GS; Hampton, D; Crowley, G;

Published by: Geophysical Research Letters      Published on:

YEAR: 2015     DOI:

FUSION++: A New Data Assimilative Model for Electron Density Forecasting

Bust, Gary; Comberiate, Joseph; Paxton, Larry; Kelly, Mike; Datta-Barua, Seebany;

Published by:       Published on:

YEAR: 2014     DOI:

First storm-time plasma velocity estimates from high-resolution ionospheric data assimilation

Datta-Barua, Seebany; Bust, Gary; Crowley, Geoff;

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

YEAR: 2013     DOI:

Comparison of GUVI data and CORS Data to Examine Auroral Trough

Datta-Barua, Seebany;

Published by:       Published on:

YEAR: 2005     DOI: