Thermospheric gravity waves in Fabry-Perot Interferometer measurements of the 630.0nm OI line

Ford, Elaina; Aruliah, A. L.; Griffin, E. M.; McWhirter, I.

doi:10.5194/angeo-24-555-2006

Cited by 14 publications

(29 citation statements)

References 30 publications

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“…Aruliah et al, 2004). Atmospheric gravity waves (AGW) have been detected in FPI measurements of the 630.0 nm atomic oxygen by Ford et al (2006) and Ford et al (2007). This emission occurs at an altitude of 240 km, and therefore these gravity waves are in the high-latitude upper thermosphere.…”

Section: Introductionmentioning

confidence: 94%

“…The primary purpose of this was for co-located ion-neutral coupling studies made with the EISCAT radars, which are at the same locations as the FPIs. The results from this were presented in Aruliah et al (2004Aruliah et al ( , 2005, Ford et al (2006). At Svalbard, in the polar cap region, the southeast and south-west positions are viewed, again to increase coverage towards the auroral oval, this time to the south of the site.…”

Section: Data and Analysismentioning

confidence: 99%

“…Data from a case study of atmospheric gravity waves from 25 November 2003 were given in Ford et al (2006). Gravity waves were seen in the atomic oxygen intensities and neutral temperatures from the FPI data from three instruments in mainland Scandinavia.…”

Section: Case Studymentioning

confidence: 99%

“…This is created by the cycles of look directions, and other effects, such as the absence of data points, due to either cloud cover or the non-fitting of spectra due to poor signal to noise in the intensities. The application of this analysis to the FPI data is described in Ford et al (2006). An additional advantage of the Lomb-Scargle analysis programme is that it normalises the time series using the mean of the data, which means that various data sets from different sites and under different conditions can be directly compared.…”

Section: Data and Analysismentioning

confidence: 99%

“…Particle precipitation in auroral regions will create localised heating that could set off waves, as could the Lorentz forces and Joule heating from electrojet currents (de Deuge et al, 1994). The theory of gravity wave behaviour and the expected properties of the waves have been reviewed by Hunsucker (1982) and Hocke and Schlegel (1996).Variations in the neutral atom emission intensities, neutral temperatures and winds have been detected, that have been caused by atmospheric gravity waves and were described in Ford et al (2006) for a case study of 25 November 2003 (and see Sect. 3.1).…”

Section: Introductionmentioning

confidence: 99%

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Statistical analysis of thermospheric gravity waves from Fabry-Perot Interferometer measurements of atomic oxygen

et al. 2008

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Abstract. Data from the Fabry-Perot Interferometers at KEOPS (Sweden), Sodankylä (Finland), and Svalbard (Norway), have been analysed for gravity wave activity on all the clear nights from 2000 to 2006. A total of 249 nights were available from KEOPS, 133 from Sodankylä and 185 from the Svalbard FPI. A Lomb-Scargle analysis was performed on each of these nights to identify the periods of any wave activity during the night. Comparisons between many nights of data allow the general characteristics of the waves that are present in the high latitude upper thermosphere to be determined. Comparisons were made between the different parameters: the atomic oxygen intensities, the thermospheric winds and temperatures, and for each parameter the distribution of frequencies of the waves was determined. No dependence on the number of waves on geomagnetic activity levels, or position in the solar cycle, was found. All the FPIs have had different detectors at various times, producing different time resolutions of the data, so comparisons between the different years, and between data from different sites, showed how the time resolution determines which waves are observed. In addition to the cutoff due to the Nyquist frequency, poor resolution observations significantly reduce the number of short-period waves (<1 h period) that may be detected with confidence. The length of the dataset, which is usually determined by the length of the night, was the main factor influencing the number of long period waves (>5 h) detected. Comparisons between the number of gravity waves detected at KEOPS and Sodankylä over all the seasons showed a similar proportion of waves to the number of nights used for both sites, as expected since the two sites are at similar latitudes and therefore locations with respect to the auroral oval, confirming this as a likely source region. Svalbard showed fewer waves with short periods than KEOPS data for a season when both had the same time resolution data. This Correspondence to: E. A. K. Ford (eakf@bas.ac.uk) gives a clear indication of the direction of flow of the gravity waves, and corroborates that the source is the auroral oval. This is because the energy is dissipated through heating in each cycle of a wave, therefore, over a given distance, short period waves lose more energy than long and dissipate before they reach their target.

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Section: Introductionmentioning

confidence: 94%

Section: Data and Analysismentioning

confidence: 99%

Section: Case Studymentioning

confidence: 99%

Section: Data and Analysismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Statistical analysis of thermospheric gravity waves from Fabry-Perot Interferometer measurements of atomic oxygen

et al. 2008

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First ever cross comparison of thermospheric wind measured by narrow‐ and wide‐field optical Doppler spectroscopy

et al. 2015

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We present the first ever cross comparisons of F region horizontal neutral wind measurements taken using two different types of optical Doppler spectrometer: all‐sky scanning Doppler imagers (SDI) and narrow‐field Fabry‐Perot interferometers (NFPIs). Horizontal neutral winds were inferred using bistatic observations from three NFPIs, together with monostatic and bistatic observations from two SDIs. All instruments were located in Alaska. Cross comparisons were made for a total of seven nights in January and February 2010. The results show a high degree of correlation between the diurnal behaviors of the line‐of‐sight (LOS) winds measured by both instruments. The SDI and NFPI LOS wind time series also often contained high‐frequency fluctuations with similar overall characteristics, strongly suggesting that these fluctuations were geophysical in origin. However, the amplitude of the high‐frequency component was stronger in the NFPI LOS wind than in the SDI data. Even the smallest SDI angular resolution element is much larger than the NFPI field of view, suggesting that its relative insensitivity to high frequencies is because these fluctuations are associated with local‐scale structures whose spatial extent is smaller than ∼40 km spanned by the smallest SDI viewing field. Upon fitting vectors to the LOS wind data, close agreement was found between the wind components estimated by the two types of instrument. Discrepancies that did arise occurred most often when the neutral wind speed was weak, suggesting that conditions capable of driving higher neutral wind speeds also suppressed the development of small‐scale structures in the thermospheric neutral wind fields.

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Multi-instrument observations of large-scale atmospheric gravity waves/traveling ionospheric disturbances associated with enhanced auroral activity over Svalbard

Katamzi‐Joseph

Aruliah

Oksavik

et al. 2019

Advances in Space Research

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This study reports on observations of atmospheric gravity waves/traveling ionospheric disturbances (AGWs/TIDs) using Global Positioning System (GPS) total electron content (TEC) and Fabry-Perot Interferometer's (FPI) intensity of oxygen red line emission at 630 nm measurements over Svalbard on the night of 6 January 2014. TEC TIDs have primary periods ranging between 29 and 65 minutes and propagate at a mean horizontal velocity of ∼749-761 m/s with azimuth of ∼345 •-347 • (which corresponds to poleward propagation direction). On the other hand, FPI AGWs have much larger periods of ∼128-174 minutes (i.e 2.1-2.9 hours). These large-scale AGWs/TIDs were linked to enhanced auroral activity identified from co-located all-sky camera and IMAGE magnetometers. Similar periods, speed and poleward propagation were found for all-sky camera (∼41-49 minutes, ∼823 m/s) and IMAGE magnetometers (∼32-53 minutes and ∼708 m/s). Joule heating as a result of particle precipitation was identified as a likely generation mechanism for these disturbances.

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Thermospheric gravity waves in Fabry-Perot Interferometer measurements of the 630.0nm OI line

Cited by 14 publications

References 30 publications

Statistical analysis of thermospheric gravity waves from Fabry-Perot Interferometer measurements of atomic oxygen

Statistical analysis of thermospheric gravity waves from Fabry-Perot Interferometer measurements of atomic oxygen

First ever cross comparison of thermospheric wind measured by narrow‐ and wide‐field optical Doppler spectroscopy

Multi-instrument observations of large-scale atmospheric gravity waves/traveling ionospheric disturbances associated with enhanced auroral activity over Svalbard

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