Particle precipitations during NEIAL events: simultaneous ground based observations at Svalbard
In this paper we present Naturally Enhanced Ion Acoustic Lines (NEIALs) observed with the EISCAT Svalbard Radar (ESR). For the first time, long sequences of NEIALs are recorded, with more than 50 events within an hour, ranging from 6.4 to 140 s in duration. The events took place from ~08:45 to 10:00...
Published in: | Annales Geophysicae |
---|---|
Main Authors: | , , , , |
Format: | Text |
Language: | English |
Published: |
2018
|
Subjects: | |
Online Access: | https://doi.org/10.5194/angeo-25-1323-2007 https://angeo.copernicus.org/articles/25/1323/2007/ |
id |
ftcopernicus:oai:publications.copernicus.org:angeo36187 |
---|---|
record_format |
openpolar |
spelling |
ftcopernicus:oai:publications.copernicus.org:angeo36187 2023-05-15T16:04:43+02:00 Particle precipitations during NEIAL events: simultaneous ground based observations at Svalbard Lunde, J. Gustavsson, B. Løvhaug, U. P. Lorentzen, D. A. Ogawa, Y. 2018-09-27 application/pdf https://doi.org/10.5194/angeo-25-1323-2007 https://angeo.copernicus.org/articles/25/1323/2007/ eng eng doi:10.5194/angeo-25-1323-2007 https://angeo.copernicus.org/articles/25/1323/2007/ eISSN: 1432-0576 Text 2018 ftcopernicus https://doi.org/10.5194/angeo-25-1323-2007 2020-07-20T16:27:04Z In this paper we present Naturally Enhanced Ion Acoustic Lines (NEIALs) observed with the EISCAT Svalbard Radar (ESR). For the first time, long sequences of NEIALs are recorded, with more than 50 events within an hour, ranging from 6.4 to 140 s in duration. The events took place from ~08:45 to 10:00 UT, 22 January 2004. We combine ESR data with observations of optical aurora by a meridian scanning photometer at wavelengths 557.7, 630.0, 427.8, and 844.6 nm, as well as records from a magnetometer and an imaging riometer. The large numbers of observed NEIALs together with these additional observations, enable us to characterise the particle precipitation during the NEIAL events. We find that the intensities in all optical lines studied must be above a certain level for the NEIALs to appear. We also find that the soft particle precipitation is associated with the down-shifted shoulder in the incoherent scatter spectrum, and that harder precipitation may play a role in the enhancement of the up-shifted shoulder. The minimum energy flux during NEIAL events found in this study was ~3.5 mW/m 2 and minimum characteristic energy around 50 eV. Text EISCAT Svalbard Copernicus Publications: E-Journals Svalbard Annales Geophysicae 25 6 1323 1336 |
institution |
Open Polar |
collection |
Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
description |
In this paper we present Naturally Enhanced Ion Acoustic Lines (NEIALs) observed with the EISCAT Svalbard Radar (ESR). For the first time, long sequences of NEIALs are recorded, with more than 50 events within an hour, ranging from 6.4 to 140 s in duration. The events took place from ~08:45 to 10:00 UT, 22 January 2004. We combine ESR data with observations of optical aurora by a meridian scanning photometer at wavelengths 557.7, 630.0, 427.8, and 844.6 nm, as well as records from a magnetometer and an imaging riometer. The large numbers of observed NEIALs together with these additional observations, enable us to characterise the particle precipitation during the NEIAL events. We find that the intensities in all optical lines studied must be above a certain level for the NEIALs to appear. We also find that the soft particle precipitation is associated with the down-shifted shoulder in the incoherent scatter spectrum, and that harder precipitation may play a role in the enhancement of the up-shifted shoulder. The minimum energy flux during NEIAL events found in this study was ~3.5 mW/m 2 and minimum characteristic energy around 50 eV. |
format |
Text |
author |
Lunde, J. Gustavsson, B. Løvhaug, U. P. Lorentzen, D. A. Ogawa, Y. |
spellingShingle |
Lunde, J. Gustavsson, B. Løvhaug, U. P. Lorentzen, D. A. Ogawa, Y. Particle precipitations during NEIAL events: simultaneous ground based observations at Svalbard |
author_facet |
Lunde, J. Gustavsson, B. Løvhaug, U. P. Lorentzen, D. A. Ogawa, Y. |
author_sort |
Lunde, J. |
title |
Particle precipitations during NEIAL events: simultaneous ground based observations at Svalbard |
title_short |
Particle precipitations during NEIAL events: simultaneous ground based observations at Svalbard |
title_full |
Particle precipitations during NEIAL events: simultaneous ground based observations at Svalbard |
title_fullStr |
Particle precipitations during NEIAL events: simultaneous ground based observations at Svalbard |
title_full_unstemmed |
Particle precipitations during NEIAL events: simultaneous ground based observations at Svalbard |
title_sort |
particle precipitations during neial events: simultaneous ground based observations at svalbard |
publishDate |
2018 |
url |
https://doi.org/10.5194/angeo-25-1323-2007 https://angeo.copernicus.org/articles/25/1323/2007/ |
geographic |
Svalbard |
geographic_facet |
Svalbard |
genre |
EISCAT Svalbard |
genre_facet |
EISCAT Svalbard |
op_source |
eISSN: 1432-0576 |
op_relation |
doi:10.5194/angeo-25-1323-2007 https://angeo.copernicus.org/articles/25/1323/2007/ |
op_doi |
https://doi.org/10.5194/angeo-25-1323-2007 |
container_title |
Annales Geophysicae |
container_volume |
25 |
container_issue |
6 |
container_start_page |
1323 |
op_container_end_page |
1336 |
_version_ |
1766400343186341888 |