The University of Southampton
University of Southampton Institutional Repository

Simultaneous observation of auroral substorm onset in Polar satellite global images and ground-based all-sky images

Simultaneous observation of auroral substorm onset in Polar satellite global images and ground-based all-sky images
Simultaneous observation of auroral substorm onset in Polar satellite global images and ground-based all-sky images
Substorm onset has originally been defined as a longitudinally extended sudden auroral brightening (Akasofu initial brightening: AIB) followed a few minutes later by an auroral poleward expansion in ground-based all-sky images (ASIs). In contrast, such clearly marked two-stage development has not been evident in satellite-based global images (GIs). Instead, substorm onsets have been identified as localized sudden brightenings that expand immediately poleward. To resolve these differences, optical substorm onset signatures in GIs and ASIs are compared in this study for a substorm that occurred on December 7, 1999. For this substorm, the Polar satellite ultraviolet global imager was operated with a fixed-filter (170 nm) mode, enabling a higher time resolution (37 s) than usual to resolve the possible two-stage development. These data were compared with 20-s resolution green-line (557.7 nm) ASIs at Muonio in Finland. The ASIs revealed the AIB at 2124:50 UT and the subsequent poleward expansion at 2127:50 UT, whereas the GIs revealed only an onset brightening that started at 2127:49 UT. Thus, the onset in the GIs was delayed relative to the AIB and in fact agreed with the poleward expansion in the ASIs. The fact that the AIB was not evident in the GIs may be attributed to the limited spatial resolution of GIs for thin auroral arc brightenings. The implications of these results for the definition of substorm onset are discussed herein.
1343-8832
1-18
Ieda, Akimasa
4d16ed3d-3fc2-46b8-a4d3-da39e42c99bf
Kauristie, Kirsti
6c818f17-8fe5-4911-9c62-055ae136d88d
Nishimura, Yukitoshi
bd7ece56-a8b4-4c91-b5b2-4f1624e7eaaf
Miyashita, Yukinaga
ae7fa8f7-b102-4d12-92ae-10ae70f20e63
Frey, Harald U.
b0be0511-7629-4151-84f8-3f0cb7e30be4
Juusola, Liisa
f5728e97-a0e0-42ee-af6e-244687f35bf9
Whiter, Daniel
9a30d7b6-ea41-44fb-bd52-3ff1964eca5c
Nosé, Masahito
5d7f00d8-a0b9-49b5-9ce6-3fed4ae492ba
Fillingim, Matthew O.
142a58e6-8c0e-4415-b316-cb55468054e2
Honary, Farideh
97a912c9-da73-4ec1-9cc7-079a3dcd8935
Rogers, Neil C.
b722bf85-27fb-4d6f-bcdb-039a65a05359
Miyoshi, Yoshizumi
c14f7402-1972-43c8-910e-bd4a2a9777e0
Miura, Tsubasa
7d9140eb-43cd-4e40-8168-39150bb5df0a
Kawashima, Takahira
2f7dfa72-9b3e-4b3d-8dc7-12cdfad05cfd
Machida, Shinobu
c8939e9b-7f8f-4db6-9865-d5f726ce2616
Ieda, Akimasa
4d16ed3d-3fc2-46b8-a4d3-da39e42c99bf
Kauristie, Kirsti
6c818f17-8fe5-4911-9c62-055ae136d88d
Nishimura, Yukitoshi
bd7ece56-a8b4-4c91-b5b2-4f1624e7eaaf
Miyashita, Yukinaga
ae7fa8f7-b102-4d12-92ae-10ae70f20e63
Frey, Harald U.
b0be0511-7629-4151-84f8-3f0cb7e30be4
Juusola, Liisa
f5728e97-a0e0-42ee-af6e-244687f35bf9
Whiter, Daniel
9a30d7b6-ea41-44fb-bd52-3ff1964eca5c
Nosé, Masahito
5d7f00d8-a0b9-49b5-9ce6-3fed4ae492ba
Fillingim, Matthew O.
142a58e6-8c0e-4415-b316-cb55468054e2
Honary, Farideh
97a912c9-da73-4ec1-9cc7-079a3dcd8935
Rogers, Neil C.
b722bf85-27fb-4d6f-bcdb-039a65a05359
Miyoshi, Yoshizumi
c14f7402-1972-43c8-910e-bd4a2a9777e0
Miura, Tsubasa
7d9140eb-43cd-4e40-8168-39150bb5df0a
Kawashima, Takahira
2f7dfa72-9b3e-4b3d-8dc7-12cdfad05cfd
Machida, Shinobu
c8939e9b-7f8f-4db6-9865-d5f726ce2616

Ieda, Akimasa, Kauristie, Kirsti, Nishimura, Yukitoshi, Miyashita, Yukinaga, Frey, Harald U., Juusola, Liisa, Whiter, Daniel, Nosé, Masahito, Fillingim, Matthew O., Honary, Farideh, Rogers, Neil C., Miyoshi, Yoshizumi, Miura, Tsubasa, Kawashima, Takahira and Machida, Shinobu (2018) Simultaneous observation of auroral substorm onset in Polar satellite global images and ground-based all-sky images. Earth Planets and Space, 70 (73), 1-18. (doi:10.1186/s40623-018-0843-3).

Record type: Article

Abstract

Substorm onset has originally been defined as a longitudinally extended sudden auroral brightening (Akasofu initial brightening: AIB) followed a few minutes later by an auroral poleward expansion in ground-based all-sky images (ASIs). In contrast, such clearly marked two-stage development has not been evident in satellite-based global images (GIs). Instead, substorm onsets have been identified as localized sudden brightenings that expand immediately poleward. To resolve these differences, optical substorm onset signatures in GIs and ASIs are compared in this study for a substorm that occurred on December 7, 1999. For this substorm, the Polar satellite ultraviolet global imager was operated with a fixed-filter (170 nm) mode, enabling a higher time resolution (37 s) than usual to resolve the possible two-stage development. These data were compared with 20-s resolution green-line (557.7 nm) ASIs at Muonio in Finland. The ASIs revealed the AIB at 2124:50 UT and the subsequent poleward expansion at 2127:50 UT, whereas the GIs revealed only an onset brightening that started at 2127:49 UT. Thus, the onset in the GIs was delayed relative to the AIB and in fact agreed with the poleward expansion in the ASIs. The fact that the AIB was not evident in the GIs may be attributed to the limited spatial resolution of GIs for thin auroral arc brightenings. The implications of these results for the definition of substorm onset are discussed herein.

Text
s40623-018-0843-3 - Version of Record
Available under License Creative Commons Attribution.
Download (3MB)

More information

Accepted/In Press date: 17 April 2018
e-pub ahead of print date: 4 May 2018
Published date: 2018

Identifiers

Local EPrints ID: 420633
URI: https://eprints.soton.ac.uk/id/eprint/420633
ISSN: 1343-8832
PURE UUID: d7a68f5c-91e4-4b2d-a47d-0d27194c9c1d
ORCID for Daniel Whiter: ORCID iD orcid.org/0000-0001-7130-232X

Catalogue record

Date deposited: 11 May 2018 16:30
Last modified: 10 Dec 2019 01:41

Export record

Altmetrics

Contributors

Author: Akimasa Ieda
Author: Kirsti Kauristie
Author: Yukitoshi Nishimura
Author: Yukinaga Miyashita
Author: Harald U. Frey
Author: Liisa Juusola
Author: Daniel Whiter ORCID iD
Author: Masahito Nosé
Author: Matthew O. Fillingim
Author: Farideh Honary
Author: Neil C. Rogers
Author: Yoshizumi Miyoshi
Author: Tsubasa Miura
Author: Takahira Kawashima
Author: Shinobu Machida

University divisions

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of https://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×