Author: Hans Westin
Publisher:
ISBN:
Category :
Languages : en
Pages : 6
Book Description
Studies of Infrasonic Waves in the Auroral Zone
Author: Hans Westin
Publisher:
ISBN:
Category :
Languages : en
Pages : 6
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 6
Book Description
Infrasonic Waves from the Auroral Zone
Author: Kaichi Maeda
Publisher:
ISBN:
Category : Auroral zones
Languages : en
Pages : 56
Book Description
Publisher:
ISBN:
Category : Auroral zones
Languages : en
Pages : 56
Book Description
Infrasonic Waves from the Auroral Zone
Author: Kaichi Maeda
Publisher:
ISBN:
Category :
Languages : en
Pages : 40
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 40
Book Description
Energy Research Abstracts
Author:
Publisher:
ISBN:
Category : Power resources
Languages : en
Pages : 500
Book Description
Publisher:
ISBN:
Category : Power resources
Languages : en
Pages : 500
Book Description
Journal of Research of the National Bureau of Standards
Author: United States. National Bureau of Standards
Publisher:
ISBN:
Category : Ionospheric radio wave propagation
Languages : en
Pages : 846
Book Description
Publisher:
ISBN:
Category : Ionospheric radio wave propagation
Languages : en
Pages : 846
Book Description
Scientific and Technical Aerospace Reports
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 1282
Book Description
Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 1282
Book Description
Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Journal of Research
Author: United States. National Bureau of Standards
Publisher:
ISBN:
Category : Radio
Languages : en
Pages : 816
Book Description
Publisher:
ISBN:
Category : Radio
Languages : en
Pages : 816
Book Description
Studies in Mineralogy and Precambrian Geology
Author: Bruce R. Doe
Publisher: Geological Society of America
ISBN: 0813711355
Category : Geology
Languages : en
Pages : 364
Book Description
Publisher: Geological Society of America
ISBN: 0813711355
Category : Geology
Languages : en
Pages : 364
Book Description
Nuclear Science Abstracts
Author:
Publisher:
ISBN:
Category : Nuclear energy
Languages : en
Pages : 640
Book Description
Publisher:
ISBN:
Category : Nuclear energy
Languages : en
Pages : 640
Book Description
Characterization and Diagnostic Methods for Geomagnetic Auroral Infrasound Waves
Author: Justin J. Oldham
Publisher:
ISBN:
Category : Auroras
Languages : en
Pages : 244
Book Description
Infrasonic perturbations resulting from auroral activity have been observed since the 1950's. In the last decade advances in infrasonic microphone sensitivity, high latitude sensor coverage, time series analysis methods and computational efficiency have elucidated new types of auroral infrasound. Persistent periods of infrasonic activity associated with geomagnetic sub-storms have been termed geomagnetic auroral infrasound waves [GAIW]. We consider 63 GAIW events recorded by the Fairbanks, AK infrasonic array I53US ranging from 2003 to 2014 and encompassing a complete solar cycle. We make observations of the acoustic features of these events alongside magnetometer, riometer, and all-sky camera data in an effort to quantify the ionospheric conditions suitable for infrasound generation. We find that, on average, the generation mechanism for GAIW is confined to a region centered about ~60° longitude east of the anti-Sun-Earth line and at ~77° North latitude. We note furthermore that in all cases considered wherein imaging riometer data are available, that dynamic regions of heightened ionospheric conductivity periodically cross the overhead zenith. Consistent features in concurrent magnetometer conditions are also noted, with irregular oscillations in the horizontal component of the field ubiquitous in all cases. In an effort to produce ionosphere based infrasound free from the clutter and unknowns typical of geophysical observations, an experiment was undertaken at the High Frequency Active Auroral Research Program [HAARP] facility in 2012. Infrasonic signals appearing to originate from a source region overhead were observed briefly on 9 August 2012. The signals were observed during a period when an electrojet current was presumed to have passed overhead and while the facilities radio transmitter was periodically heating the lower ionosphere. Our results suggest dynamic auroral electrojet currents as primary sources of much of the observed infrasound, with modulation of the electrojets due to energetic particle precipitation, dispersion due to coupling with gravity waves, and reflection and refraction effects in the intervening atmosphere all potential factors in the shaping of the waveforms observed.
Publisher:
ISBN:
Category : Auroras
Languages : en
Pages : 244
Book Description
Infrasonic perturbations resulting from auroral activity have been observed since the 1950's. In the last decade advances in infrasonic microphone sensitivity, high latitude sensor coverage, time series analysis methods and computational efficiency have elucidated new types of auroral infrasound. Persistent periods of infrasonic activity associated with geomagnetic sub-storms have been termed geomagnetic auroral infrasound waves [GAIW]. We consider 63 GAIW events recorded by the Fairbanks, AK infrasonic array I53US ranging from 2003 to 2014 and encompassing a complete solar cycle. We make observations of the acoustic features of these events alongside magnetometer, riometer, and all-sky camera data in an effort to quantify the ionospheric conditions suitable for infrasound generation. We find that, on average, the generation mechanism for GAIW is confined to a region centered about ~60° longitude east of the anti-Sun-Earth line and at ~77° North latitude. We note furthermore that in all cases considered wherein imaging riometer data are available, that dynamic regions of heightened ionospheric conductivity periodically cross the overhead zenith. Consistent features in concurrent magnetometer conditions are also noted, with irregular oscillations in the horizontal component of the field ubiquitous in all cases. In an effort to produce ionosphere based infrasound free from the clutter and unknowns typical of geophysical observations, an experiment was undertaken at the High Frequency Active Auroral Research Program [HAARP] facility in 2012. Infrasonic signals appearing to originate from a source region overhead were observed briefly on 9 August 2012. The signals were observed during a period when an electrojet current was presumed to have passed overhead and while the facilities radio transmitter was periodically heating the lower ionosphere. Our results suggest dynamic auroral electrojet currents as primary sources of much of the observed infrasound, with modulation of the electrojets due to energetic particle precipitation, dispersion due to coupling with gravity waves, and reflection and refraction effects in the intervening atmosphere all potential factors in the shaping of the waveforms observed.