Geophysical phenomena during an ionospheric modification experiment at Tromsø, Norway
We present an analysis of phenomena observed by HF distance-diagnostic tools located in St. Petersburg combined with multi-instrument observation at Tromsø in the HF modified ionosphere during a magnetospheric substorm. The observed phenomena that occurred during the Tromsø heating experiment in the...
Published in: | Annales Geophysicae |
---|---|
Main Authors: | , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Copernicus Publications
1998
|
Subjects: | |
Online Access: | https://doi.org/10.1007/s00585-998-1212-5 https://doaj.org/article/23c49f4b93cb4d618652c4125bead731 |
id |
ftdoajarticles:oai:doaj.org/article:23c49f4b93cb4d618652c4125bead731 |
---|---|
record_format |
openpolar |
spelling |
ftdoajarticles:oai:doaj.org/article:23c49f4b93cb4d618652c4125bead731 2023-05-15T18:34:12+02:00 Geophysical phenomena during an ionospheric modification experiment at Tromsø, Norway N. F. Blagoveshchenskaya V. A. Kornienko A. V. Petlenko A. Brekke M. T. Rietveld 1998-10-01T00:00:00Z https://doi.org/10.1007/s00585-998-1212-5 https://doaj.org/article/23c49f4b93cb4d618652c4125bead731 EN eng Copernicus Publications https://www.ann-geophys.net/16/1212/1998/angeo-16-1212-1998.pdf https://doaj.org/toc/0992-7689 https://doaj.org/toc/1432-0576 doi:10.1007/s00585-998-1212-5 0992-7689 1432-0576 https://doaj.org/article/23c49f4b93cb4d618652c4125bead731 Annales Geophysicae, Vol 16, Pp 1212-1225 (1998) Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 article 1998 ftdoajarticles https://doi.org/10.1007/s00585-998-1212-5 2022-12-31T16:06:02Z We present an analysis of phenomena observed by HF distance-diagnostic tools located in St. Petersburg combined with multi-instrument observation at Tromsø in the HF modified ionosphere during a magnetospheric substorm. The observed phenomena that occurred during the Tromsø heating experiment in the nightside auroral E s region of the ionosphere depend on the phase of substorm. The heating excited small-scale field-aligned irregularities in the E region responsible for field-aligned scattering of diagnostic HF waves. The equipment used in the experiment was sensitive to electron density irregularities with wavelengths 12–15 m across the geomagnetic field lines. Analysis of the Doppler measurement data shows the appearance of quasiperiodic variations with a Doppler frequency shift, f d and periods about 100–120 s during the heating cycle coinciding in time with the first substorm activation and initiation of the upward field-aligned currents. A relationship between wave variations in f d and magnetic pulsations in the Y -component of the geomagnetic field at Tromsø was detected. The analysis of the magnetic field variations from the IMAGE magnetometer stations shows that ULF waves occurred, not only at Tromsø, but in the adjacent area bounded by geographical latitudes from 70.5° to 68° and longitudes from 16° to 27°. It is suggested that the ULF observed can result from superposition of the natural and heater-induced ULF waves. During the substorm expansion a strong stimulated electromagnetic emission (SEE) at the third harmonic of the downshifted maximum frequency was found. It is believed that SEE is accompanied by excitation of the VLF waves penetrating into magnetosphere and stimulating the precipitation of the energetic electrons (10–40 keV) of about 1-min duration. This is due to a cyclotron resonant interaction of natural precipitating electrons (1–10 keV) with heater-induced whistler waves in the magnetosphere. It is reasonable to suppose that a new substorm activation, exactly above Tromsø, was closely ... Article in Journal/Newspaper Tromsø Directory of Open Access Journals: DOAJ Articles Norway The ''Y'' ENVELOPE(-112.453,-112.453,57.591,57.591) Tromsø Annales Geophysicae 16 10 1212 1225 |
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 N. F. Blagoveshchenskaya V. A. Kornienko A. V. Petlenko A. Brekke M. T. Rietveld Geophysical phenomena during an ionospheric modification experiment at Tromsø, Norway |
topic_facet |
Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 |
description |
We present an analysis of phenomena observed by HF distance-diagnostic tools located in St. Petersburg combined with multi-instrument observation at Tromsø in the HF modified ionosphere during a magnetospheric substorm. The observed phenomena that occurred during the Tromsø heating experiment in the nightside auroral E s region of the ionosphere depend on the phase of substorm. The heating excited small-scale field-aligned irregularities in the E region responsible for field-aligned scattering of diagnostic HF waves. The equipment used in the experiment was sensitive to electron density irregularities with wavelengths 12–15 m across the geomagnetic field lines. Analysis of the Doppler measurement data shows the appearance of quasiperiodic variations with a Doppler frequency shift, f d and periods about 100–120 s during the heating cycle coinciding in time with the first substorm activation and initiation of the upward field-aligned currents. A relationship between wave variations in f d and magnetic pulsations in the Y -component of the geomagnetic field at Tromsø was detected. The analysis of the magnetic field variations from the IMAGE magnetometer stations shows that ULF waves occurred, not only at Tromsø, but in the adjacent area bounded by geographical latitudes from 70.5° to 68° and longitudes from 16° to 27°. It is suggested that the ULF observed can result from superposition of the natural and heater-induced ULF waves. During the substorm expansion a strong stimulated electromagnetic emission (SEE) at the third harmonic of the downshifted maximum frequency was found. It is believed that SEE is accompanied by excitation of the VLF waves penetrating into magnetosphere and stimulating the precipitation of the energetic electrons (10–40 keV) of about 1-min duration. This is due to a cyclotron resonant interaction of natural precipitating electrons (1–10 keV) with heater-induced whistler waves in the magnetosphere. It is reasonable to suppose that a new substorm activation, exactly above Tromsø, was closely ... |
format |
Article in Journal/Newspaper |
author |
N. F. Blagoveshchenskaya V. A. Kornienko A. V. Petlenko A. Brekke M. T. Rietveld |
author_facet |
N. F. Blagoveshchenskaya V. A. Kornienko A. V. Petlenko A. Brekke M. T. Rietveld |
author_sort |
N. F. Blagoveshchenskaya |
title |
Geophysical phenomena during an ionospheric modification experiment at Tromsø, Norway |
title_short |
Geophysical phenomena during an ionospheric modification experiment at Tromsø, Norway |
title_full |
Geophysical phenomena during an ionospheric modification experiment at Tromsø, Norway |
title_fullStr |
Geophysical phenomena during an ionospheric modification experiment at Tromsø, Norway |
title_full_unstemmed |
Geophysical phenomena during an ionospheric modification experiment at Tromsø, Norway |
title_sort |
geophysical phenomena during an ionospheric modification experiment at tromsø, norway |
publisher |
Copernicus Publications |
publishDate |
1998 |
url |
https://doi.org/10.1007/s00585-998-1212-5 https://doaj.org/article/23c49f4b93cb4d618652c4125bead731 |
long_lat |
ENVELOPE(-112.453,-112.453,57.591,57.591) |
geographic |
Norway The ''Y'' Tromsø |
geographic_facet |
Norway The ''Y'' Tromsø |
genre |
Tromsø |
genre_facet |
Tromsø |
op_source |
Annales Geophysicae, Vol 16, Pp 1212-1225 (1998) |
op_relation |
https://www.ann-geophys.net/16/1212/1998/angeo-16-1212-1998.pdf https://doaj.org/toc/0992-7689 https://doaj.org/toc/1432-0576 doi:10.1007/s00585-998-1212-5 0992-7689 1432-0576 https://doaj.org/article/23c49f4b93cb4d618652c4125bead731 |
op_doi |
https://doi.org/10.1007/s00585-998-1212-5 |
container_title |
Annales Geophysicae |
container_volume |
16 |
container_issue |
10 |
container_start_page |
1212 |
op_container_end_page |
1225 |
_version_ |
1766218854389776384 |