The effects of nitric oxide cooling and the photodissociation of molecular oxygen on the thermosphere/ionosphere system over the Argentine Islands
International audience In the past the global, fully coupled, time-dependent mathematical model of the Earth's thermosphere/ionosphere/plasmasphere (CTIP) has been unable to reproduce accurately observed values of the maximum plasma frequency, f oF2, at extreme geophysical locations such as the...
Main Authors: | , , , , |
---|---|
Other Authors: | , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
HAL CCSD
1997
|
Subjects: | |
Online Access: | https://hal.science/hal-00316211 https://hal.science/hal-00316211/document https://hal.science/hal-00316211/file/angeo-15-355-1997.pdf |
id |
ftinsu:oai:HAL:hal-00316211v1 |
---|---|
record_format |
openpolar |
spelling |
ftinsu:oai:HAL:hal-00316211v1 2023-11-12T04:14:12+01:00 The effects of nitric oxide cooling and the photodissociation of molecular oxygen on the thermosphere/ionosphere system over the Argentine Islands Wells, G. D. Rodger, A. S. Moffett, R. J. Bailey, G. J. Fuller-Rowell, T. J. School of Mathematics and Statistics The Hicks Building British Antarctic Survey (BAS) Natural Environment Research Council (NERC) Cooperative Institute for Research in Environmental Sciences (CIRES) University of Colorado Boulder -National Oceanic and Atmospheric Administration (NOAA) 1997 https://hal.science/hal-00316211 https://hal.science/hal-00316211/document https://hal.science/hal-00316211/file/angeo-15-355-1997.pdf en eng HAL CCSD European Geosciences Union hal-00316211 https://hal.science/hal-00316211 https://hal.science/hal-00316211/document https://hal.science/hal-00316211/file/angeo-15-355-1997.pdf info:eu-repo/semantics/OpenAccess ISSN: 0992-7689 EISSN: 1432-0576 Annales Geophysicae https://hal.science/hal-00316211 Annales Geophysicae, 1997, 15 (3), pp.355-365 [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.STU]Sciences of the Universe [physics]/Earth Sciences info:eu-repo/semantics/article Journal articles 1997 ftinsu 2023-10-25T16:25:42Z International audience In the past the global, fully coupled, time-dependent mathematical model of the Earth's thermosphere/ionosphere/plasmasphere (CTIP) has been unable to reproduce accurately observed values of the maximum plasma frequency, f oF2, at extreme geophysical locations such as the Argentine Islands during the summer solstice where the ionosphere remains in sunlight throughout the day. This is probably because the seasonal dependence of thermospheric cooling by 5.3 µm nitric oxide has been neglected and the photodissociation of O 2 and heating rate calculations have been over-simplified. Now we have included an up-to-date calculation of the solar EUV and UV thermospheric heating rate, coupled with a new calculation of a diurnally varying O 2 photodissociation rate, in the model. Seasonally dependent 5.3 µm nitric oxide cooling is also included. With these important improvements, it is found that model values of f oF2 are in substantially better agreement with observation. The height of the F2-peak is reduced throughout the day, but remains within acceptable limits of values derived from observation, except at around 0600 h LT. We also carry out two studies of the sensitivity of the upper atmosphere to changes in the magnitude of nitric oxide cooling and photodissociation rates. We find that hmF2 increases with increased heating, whilst f oF2 falls. The converse is true for an increase in the cooling rate. Similarly increasing the photodissociation rate increases both hmF2 and f oF2. These changes are explained in terms of changes in the neutral temperature, composition and neutral wind. Article in Journal/Newspaper Argentine Islands Institut national des sciences de l'Univers: HAL-INSU Argentine Argentine Islands ENVELOPE(-64.273,-64.273,-65.246,-65.246) |
institution |
Open Polar |
collection |
Institut national des sciences de l'Univers: HAL-INSU |
op_collection_id |
ftinsu |
language |
English |
topic |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
spellingShingle |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.STU]Sciences of the Universe [physics]/Earth Sciences Wells, G. D. Rodger, A. S. Moffett, R. J. Bailey, G. J. Fuller-Rowell, T. J. The effects of nitric oxide cooling and the photodissociation of molecular oxygen on the thermosphere/ionosphere system over the Argentine Islands |
topic_facet |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
description |
International audience In the past the global, fully coupled, time-dependent mathematical model of the Earth's thermosphere/ionosphere/plasmasphere (CTIP) has been unable to reproduce accurately observed values of the maximum plasma frequency, f oF2, at extreme geophysical locations such as the Argentine Islands during the summer solstice where the ionosphere remains in sunlight throughout the day. This is probably because the seasonal dependence of thermospheric cooling by 5.3 µm nitric oxide has been neglected and the photodissociation of O 2 and heating rate calculations have been over-simplified. Now we have included an up-to-date calculation of the solar EUV and UV thermospheric heating rate, coupled with a new calculation of a diurnally varying O 2 photodissociation rate, in the model. Seasonally dependent 5.3 µm nitric oxide cooling is also included. With these important improvements, it is found that model values of f oF2 are in substantially better agreement with observation. The height of the F2-peak is reduced throughout the day, but remains within acceptable limits of values derived from observation, except at around 0600 h LT. We also carry out two studies of the sensitivity of the upper atmosphere to changes in the magnitude of nitric oxide cooling and photodissociation rates. We find that hmF2 increases with increased heating, whilst f oF2 falls. The converse is true for an increase in the cooling rate. Similarly increasing the photodissociation rate increases both hmF2 and f oF2. These changes are explained in terms of changes in the neutral temperature, composition and neutral wind. |
author2 |
School of Mathematics and Statistics The Hicks Building British Antarctic Survey (BAS) Natural Environment Research Council (NERC) Cooperative Institute for Research in Environmental Sciences (CIRES) University of Colorado Boulder -National Oceanic and Atmospheric Administration (NOAA) |
format |
Article in Journal/Newspaper |
author |
Wells, G. D. Rodger, A. S. Moffett, R. J. Bailey, G. J. Fuller-Rowell, T. J. |
author_facet |
Wells, G. D. Rodger, A. S. Moffett, R. J. Bailey, G. J. Fuller-Rowell, T. J. |
author_sort |
Wells, G. D. |
title |
The effects of nitric oxide cooling and the photodissociation of molecular oxygen on the thermosphere/ionosphere system over the Argentine Islands |
title_short |
The effects of nitric oxide cooling and the photodissociation of molecular oxygen on the thermosphere/ionosphere system over the Argentine Islands |
title_full |
The effects of nitric oxide cooling and the photodissociation of molecular oxygen on the thermosphere/ionosphere system over the Argentine Islands |
title_fullStr |
The effects of nitric oxide cooling and the photodissociation of molecular oxygen on the thermosphere/ionosphere system over the Argentine Islands |
title_full_unstemmed |
The effects of nitric oxide cooling and the photodissociation of molecular oxygen on the thermosphere/ionosphere system over the Argentine Islands |
title_sort |
effects of nitric oxide cooling and the photodissociation of molecular oxygen on the thermosphere/ionosphere system over the argentine islands |
publisher |
HAL CCSD |
publishDate |
1997 |
url |
https://hal.science/hal-00316211 https://hal.science/hal-00316211/document https://hal.science/hal-00316211/file/angeo-15-355-1997.pdf |
long_lat |
ENVELOPE(-64.273,-64.273,-65.246,-65.246) |
geographic |
Argentine Argentine Islands |
geographic_facet |
Argentine Argentine Islands |
genre |
Argentine Islands |
genre_facet |
Argentine Islands |
op_source |
ISSN: 0992-7689 EISSN: 1432-0576 Annales Geophysicae https://hal.science/hal-00316211 Annales Geophysicae, 1997, 15 (3), pp.355-365 |
op_relation |
hal-00316211 https://hal.science/hal-00316211 https://hal.science/hal-00316211/document https://hal.science/hal-00316211/file/angeo-15-355-1997.pdf |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1782331896995250176 |