Bibliography

Improving Neutral Density Predictions Using Exospheric Temperatures Calculated on a Geodesic, Polyhedral Grid

A new model of exospheric temperatures has been developed, with the objective of predicting global values with greater spatial and temporal accuracy. From these temperatures, the neutral densities in the thermosphere can be calculated, through use of the Naval Research Laboratory Mass Spectrometer and Incoherent Scatter radar Extended (NRLMSISE-00) model. The exospheric temperature model is derived from measurements of the neutral densities on several satellites. These data were sorted into triangular cells on a geodesic grid, based on location. Prediction equations are derived for each grid cell using least error fits. Several versions of the model equations have been tested, using parameters such as the date, time, solar radiation, and nitric oxide emissions, as measured with the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument on the Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) satellite. Accuracy is improved with the addition of the total Poynting flux flowing into the polar regions, from an empirical model that uses the solar wind velocity and interplanetary magnetic field. Given such inputs, the model can produce global maps of the exospheric temperature. These maps show variations in the polar regions that are strongly modulated by the time of day, due to the daily rotation of the magnetic poles. For convenience the new model is referred to with the acronym EXTEMPLAR (EXospheric TEMperatures on a PoLyhedrAl gRid). Neutral densities computed from the EXTEMPLAR-NRLMSISE-00 models combined are found to produce very good results when compared with measured values.

Weimer, D.; Mehta, P.; Tobiska, W.; Doornbos, E.; Mlynczak, M.; Drob, D.; Emmert, J.;

Published by: Space Weather      Published on: 12/2019

YEAR: 2020     DOI: 10.1029/2019SW002355

How might the thermosphere and ionosphere react to an extreme space weather event?

This chapter explores how the thermosphere and ionosphere (T-I) might respond to extreme solar events. Three different scenarios are considered: (1) an increase in solar UV and EUV radiation for a number of days, (2) an extreme enhancement in the solar X-rays and EUV radiation associated with a flare, and (3) an extreme CME driving a geomagnetic storm. Estimating the response to the first two scenarios is reasonably well defined, and although they would certainly impact the T-I system, those impacts could potentially be mitigated. In contrast, the response to an extreme geomagnetic storm is significantly more complicated, making the response much more uncertain, and mitigation more challenging.

Fuller-Rowell, Tim; Emmert, John; Fedrizzi, Mariangel; Weimer, Daniel; Codrescu, Mihail; Pilinski, Marcin; Sutton, Eric; Viereck, Rodney; Raeder, Joachim; Doornbos, Eelco;

Published by:       Published on:

YEAR: 2018     DOI: 10.1016/B978-0-12-812700-1.00021-2

Ionospheric and Thermospheric Response to the 2015 St. Patrick s Day Storm: a Global Multi-Instrumental Overview

We study the ionospheric response to the geomagnetic storm of 17-18 March 2015 (the St. Patrick s Day 2015 storm) that was up to now the strongest in the 24th solar cycle (minimum

Astafyeva, Elvira; Zakharenkova, Irina; Foerster, Matthias; Doornbos, Eelco; Encarnacao, Joao; Siemes, Christian;

Published by:       Published on:

YEAR: 2015     DOI:

Forcing of the Coupled Ionosphere-Thermosphere (IT) System During Magnetic Storms

Huang, Cheryl; Huang, Yanshi; Su, Yi-Jiun; Sutton, Eric; Hairston, Marc; Coley, Robin; Doornbos, Eelco; Zhang, Yongliang;

Published by:       Published on:

YEAR: 2014     DOI:

Producing density and crosswind data from satellite dynamics observations

Emmert JT, Meier RR, Picone JM, Lean JL, Christensen AB (2006) Thermospheric density 2002–2004: TIMED/GUVI dayside limb observations and satellite drag. J Geophys Res 111(

Doornbos, Eelco;

Published by:       Published on:

YEAR: 2012     DOI: https://doi.org/10.1007/978-3-642-25129-0_4

Empirical modelling of the thermosphere

This chapter will describe the history, context, application and limitations of empirical thermosphere models. Section 2.1 will give an introduction to the atmospheric structure and

Doornbos, Eelco;

Published by:       Published on:

YEAR: 2012     DOI: https://doi.org/10.1007/978-3-642-25129-0_2

Thermospheric density and wind determination from satellite dynamics

Doornbos, Eelco;

Published by:       Published on:

YEAR: 2012     DOI: 10.1007/978-3-642-25129-0

Use of two-line element data for thermosphere neutral density model calibration

Traditional empirical thermospheric density models are widely used in orbit determination and prediction of low-Earth satellites. Unfortunately, these models often exhibit large density errors of up to around 30\% RMS. Density errors translate into orbit errors, adversely affecting applications such as re-entry operations, manoeuvre planning, collision avoidance and precise orbit determination for geodetic missions. The extensive database of two-line element (TLE) orbit data contains a wealth of information on satellite drag, at a sufficiently high spatial and temporal resolution to allow a calibration of existing neutral density models with a latency of one to two days. In our calibration software, new TLE data for selected objects is converted to satellite drag data on a daily basis. The resulting drag data is then used in a daily adjustment of density model calibration parameters, which modify the output of an existing empirical density model with the aim of increasing its accuracy. Two different calibration schemes have been tested using TLE data for about 50 objects during the year 2000. The schemes involve either height-dependent scale factors to the density or corrections to CIRA-72 model temperatures, which affect the density output based on a physical model. Both schemes have been applied with different spherical harmonic expansions of the parameters in latitude and local solar time. Five TLE objects, varying in perigee altitude between 280 and 530km, were deliberately not used during calibration, in order to provide independent validation. Even with a single daily parameter, the RMS density model error along their tracks can already be reduced from the 30% to the 15% level. Adding additional parameters results in RMS errors lower than 12%.

Doornbos, Eelco; Klinkrad, Heiner; Visser, Pieter;

Published by: Advances in Space Research      Published on:

YEAR: 2008     DOI: https://doi.org/10.1016/j.asr.2006.12.025

thermosphere density; satellite drag; Orbit determination; two-line elements