Comparing high-latitude thermospheric winds from Fabry–Perot interferometer (FPI) and challenging mini-satellite payload (CHAMP) accelerometer measurements
It is generally assumed that horizontal wind velocities are independent of height above the F 1 region (> 300 km) due to the large molecular viscosity of the upper thermosphere. This assumption is used to compare two completely different methods of thermospheric neutral wind observation, using tw...
Published in: | Annales Geophysicae |
---|---|
Main Authors: | , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Copernicus Publications
2019
|
Subjects: | |
Online Access: | https://doi.org/10.5194/angeo-37-1095-2019 https://doaj.org/article/b91c861633374fac81fc74a1aaba82df |
id |
ftdoajarticles:oai:doaj.org/article:b91c861633374fac81fc74a1aaba82df |
---|---|
record_format |
openpolar |
spelling |
ftdoajarticles:oai:doaj.org/article:b91c861633374fac81fc74a1aaba82df 2023-05-15T17:04:12+02:00 Comparing high-latitude thermospheric winds from Fabry–Perot interferometer (FPI) and challenging mini-satellite payload (CHAMP) accelerometer measurements A. Aruliah M. Förster R. Hood I. McWhirter E. Doornbos 2019-12-01T00:00:00Z https://doi.org/10.5194/angeo-37-1095-2019 https://doaj.org/article/b91c861633374fac81fc74a1aaba82df EN eng Copernicus Publications https://www.ann-geophys.net/37/1095/2019/angeo-37-1095-2019.pdf https://doaj.org/toc/0992-7689 https://doaj.org/toc/1432-0576 doi:10.5194/angeo-37-1095-2019 0992-7689 1432-0576 https://doaj.org/article/b91c861633374fac81fc74a1aaba82df Annales Geophysicae, Vol 37, Pp 1095-1120 (2019) Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 article 2019 ftdoajarticles https://doi.org/10.5194/angeo-37-1095-2019 2022-12-31T15:36:01Z It is generally assumed that horizontal wind velocities are independent of height above the F 1 region (> 300 km) due to the large molecular viscosity of the upper thermosphere. This assumption is used to compare two completely different methods of thermospheric neutral wind observation, using two distinct locations in the high-latitude Northern Hemisphere. The measurements are from ground-based Fabry–Perot interferometers (FPI) and from in situ accelerometer measurements onboard the challenging mini-satellite payload (CHAMP) satellite, which was in a near-polar orbit. The University College London (UCL) Kiruna Esrange Optical Platform Site (KEOPS) FPI is located in the vicinity of the auroral oval at the ESRANGE site near Kiruna, Sweden (67.8 ∘ N, 20.4 ∘ E). The UCL Longyearbyen FPI is a polar cap site, located at the Kjell Henriksen Observatory on Svalbard (78.1 ∘ N, 16.0 ∘ E). The comparison is carried out in a statistical sense, comparing a longer time series obtained during night-time hours in the winter months (DOY 300–65) with overflights of the CHAMP satellite between 2001 and 2007 over the observational sites, within ±2 ∘ latitude ( ±230 km horizontal range). The FPI is assumed to measure the line-of-sight winds at a height of ∼240 km, i.e. the peak emission height of the atomic oxygen 630.0 nm emission. The cross-track winds are derived from state-of-the-art precision accelerometer measurements at altitudes between ∼450 km (in 2001) and ∼350 km (in 2007), i.e. 100–200 km above the FPI wind observations. We show that CHAMP wind values at high latitudes are typically 1.5 to 2 times larger than FPI winds. In addition to testing the consistency of the different measurement approaches, the study aims to clarify the effects of viscosity on the height dependence of thermospheric winds. Article in Journal/Newspaper Kiruna Longyearbyen Svalbard Directory of Open Access Journals: DOAJ Articles Esrange ENVELOPE(21.117,21.117,67.883,67.883) Kiruna Longyearbyen Svalbard Annales Geophysicae 37 6 1095 1120 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 |
spellingShingle |
Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 A. Aruliah M. Förster R. Hood I. McWhirter E. Doornbos Comparing high-latitude thermospheric winds from Fabry–Perot interferometer (FPI) and challenging mini-satellite payload (CHAMP) accelerometer measurements |
topic_facet |
Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 |
description |
It is generally assumed that horizontal wind velocities are independent of height above the F 1 region (> 300 km) due to the large molecular viscosity of the upper thermosphere. This assumption is used to compare two completely different methods of thermospheric neutral wind observation, using two distinct locations in the high-latitude Northern Hemisphere. The measurements are from ground-based Fabry–Perot interferometers (FPI) and from in situ accelerometer measurements onboard the challenging mini-satellite payload (CHAMP) satellite, which was in a near-polar orbit. The University College London (UCL) Kiruna Esrange Optical Platform Site (KEOPS) FPI is located in the vicinity of the auroral oval at the ESRANGE site near Kiruna, Sweden (67.8 ∘ N, 20.4 ∘ E). The UCL Longyearbyen FPI is a polar cap site, located at the Kjell Henriksen Observatory on Svalbard (78.1 ∘ N, 16.0 ∘ E). The comparison is carried out in a statistical sense, comparing a longer time series obtained during night-time hours in the winter months (DOY 300–65) with overflights of the CHAMP satellite between 2001 and 2007 over the observational sites, within ±2 ∘ latitude ( ±230 km horizontal range). The FPI is assumed to measure the line-of-sight winds at a height of ∼240 km, i.e. the peak emission height of the atomic oxygen 630.0 nm emission. The cross-track winds are derived from state-of-the-art precision accelerometer measurements at altitudes between ∼450 km (in 2001) and ∼350 km (in 2007), i.e. 100–200 km above the FPI wind observations. We show that CHAMP wind values at high latitudes are typically 1.5 to 2 times larger than FPI winds. In addition to testing the consistency of the different measurement approaches, the study aims to clarify the effects of viscosity on the height dependence of thermospheric winds. |
format |
Article in Journal/Newspaper |
author |
A. Aruliah M. Förster R. Hood I. McWhirter E. Doornbos |
author_facet |
A. Aruliah M. Förster R. Hood I. McWhirter E. Doornbos |
author_sort |
A. Aruliah |
title |
Comparing high-latitude thermospheric winds from Fabry–Perot interferometer (FPI) and challenging mini-satellite payload (CHAMP) accelerometer measurements |
title_short |
Comparing high-latitude thermospheric winds from Fabry–Perot interferometer (FPI) and challenging mini-satellite payload (CHAMP) accelerometer measurements |
title_full |
Comparing high-latitude thermospheric winds from Fabry–Perot interferometer (FPI) and challenging mini-satellite payload (CHAMP) accelerometer measurements |
title_fullStr |
Comparing high-latitude thermospheric winds from Fabry–Perot interferometer (FPI) and challenging mini-satellite payload (CHAMP) accelerometer measurements |
title_full_unstemmed |
Comparing high-latitude thermospheric winds from Fabry–Perot interferometer (FPI) and challenging mini-satellite payload (CHAMP) accelerometer measurements |
title_sort |
comparing high-latitude thermospheric winds from fabry–perot interferometer (fpi) and challenging mini-satellite payload (champ) accelerometer measurements |
publisher |
Copernicus Publications |
publishDate |
2019 |
url |
https://doi.org/10.5194/angeo-37-1095-2019 https://doaj.org/article/b91c861633374fac81fc74a1aaba82df |
long_lat |
ENVELOPE(21.117,21.117,67.883,67.883) |
geographic |
Esrange Kiruna Longyearbyen Svalbard |
geographic_facet |
Esrange Kiruna Longyearbyen Svalbard |
genre |
Kiruna Longyearbyen Svalbard |
genre_facet |
Kiruna Longyearbyen Svalbard |
op_source |
Annales Geophysicae, Vol 37, Pp 1095-1120 (2019) |
op_relation |
https://www.ann-geophys.net/37/1095/2019/angeo-37-1095-2019.pdf https://doaj.org/toc/0992-7689 https://doaj.org/toc/1432-0576 doi:10.5194/angeo-37-1095-2019 0992-7689 1432-0576 https://doaj.org/article/b91c861633374fac81fc74a1aaba82df |
op_doi |
https://doi.org/10.5194/angeo-37-1095-2019 |
container_title |
Annales Geophysicae |
container_volume |
37 |
container_issue |
6 |
container_start_page |
1095 |
op_container_end_page |
1120 |
_version_ |
1766058252445941760 |