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High correlations between temperature and nitric oxide in the thermosphere

Obtaining accurate predictions of the neutral density in the thermosphere has been a long‐standing problem. During geomagnetic storms the auroral heating in the polar ionospheres quickly raises the temperature of the thermosphere, resulting in higher neutral densities that exert a greater drag force...

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Autores principales: Weimer, D. R., Mlynczak, M. G., Hunt, L. A., Tobiska, W. Kent
Formato: Online Artículo Texto
Lenguaje:English
Publicado: John Wiley and Sons Inc. 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5014240/
https://www.ncbi.nlm.nih.gov/pubmed/27668141
http://dx.doi.org/10.1002/2015JA021461
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author Weimer, D. R.
Mlynczak, M. G.
Hunt, L. A.
Tobiska, W. Kent
author_facet Weimer, D. R.
Mlynczak, M. G.
Hunt, L. A.
Tobiska, W. Kent
author_sort Weimer, D. R.
collection PubMed
description Obtaining accurate predictions of the neutral density in the thermosphere has been a long‐standing problem. During geomagnetic storms the auroral heating in the polar ionospheres quickly raises the temperature of the thermosphere, resulting in higher neutral densities that exert a greater drag force on objects in low Earth orbit. Rapid increases and decreases in the temperature and density may occur within a couple days. A key parameter in the thermosphere is the total amount of nitric oxide (NO). The production of NO is accelerated by the auroral heating, and since NO is an efficient radiator of thermal energy, higher concentrations of this molecule accelerate the rate at which the thermosphere cools. This paper describes an improved technique that calculates changes in the global temperature of the thermosphere. Starting from an empirical model of the Poynting flux into the ionosphere, a set of differential equations derives the minimum, global value of the exospheric temperature, which can be used in a neutral density model to calculate the global values. The relative variations in NO content are used to obtain more accurate cooling rates. Comparisons with the global rate of NO emissions that are measured with the Sounding of the Atmosphere using Broadband Emission Radiometry instrument show that there is very good agreement with the predicted values. The NO emissions correlate highly with the total auroral heating that has been integrated over time. We also show that the NO emissions are highly correlated with thermospheric temperature, as well as indices of solar extreme ultraviolet radiation.
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spelling pubmed-50142402016-09-23 High correlations between temperature and nitric oxide in the thermosphere Weimer, D. R. Mlynczak, M. G. Hunt, L. A. Tobiska, W. Kent J Geophys Res Space Phys Research Articles Obtaining accurate predictions of the neutral density in the thermosphere has been a long‐standing problem. During geomagnetic storms the auroral heating in the polar ionospheres quickly raises the temperature of the thermosphere, resulting in higher neutral densities that exert a greater drag force on objects in low Earth orbit. Rapid increases and decreases in the temperature and density may occur within a couple days. A key parameter in the thermosphere is the total amount of nitric oxide (NO). The production of NO is accelerated by the auroral heating, and since NO is an efficient radiator of thermal energy, higher concentrations of this molecule accelerate the rate at which the thermosphere cools. This paper describes an improved technique that calculates changes in the global temperature of the thermosphere. Starting from an empirical model of the Poynting flux into the ionosphere, a set of differential equations derives the minimum, global value of the exospheric temperature, which can be used in a neutral density model to calculate the global values. The relative variations in NO content are used to obtain more accurate cooling rates. Comparisons with the global rate of NO emissions that are measured with the Sounding of the Atmosphere using Broadband Emission Radiometry instrument show that there is very good agreement with the predicted values. The NO emissions correlate highly with the total auroral heating that has been integrated over time. We also show that the NO emissions are highly correlated with thermospheric temperature, as well as indices of solar extreme ultraviolet radiation. John Wiley and Sons Inc. 2015-07-29 2015-07 /pmc/articles/PMC5014240/ /pubmed/27668141 http://dx.doi.org/10.1002/2015JA021461 Text en ©2015. The Authors. This is an open access article under the terms of the Creative Commons Attribution‐NonCommercial‐NoDerivs (http://creativecommons.org/licenses/by-nc-nd/4.0/) License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non‐commercial and no modifications or adaptations are made.
spellingShingle Research Articles
Weimer, D. R.
Mlynczak, M. G.
Hunt, L. A.
Tobiska, W. Kent
High correlations between temperature and nitric oxide in the thermosphere
title High correlations between temperature and nitric oxide in the thermosphere
title_full High correlations between temperature and nitric oxide in the thermosphere
title_fullStr High correlations between temperature and nitric oxide in the thermosphere
title_full_unstemmed High correlations between temperature and nitric oxide in the thermosphere
title_short High correlations between temperature and nitric oxide in the thermosphere
title_sort high correlations between temperature and nitric oxide in the thermosphere
topic Research Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5014240/
https://www.ncbi.nlm.nih.gov/pubmed/27668141
http://dx.doi.org/10.1002/2015JA021461
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