A comparison of thermospheric winds and temperatures from Fabry-Perot interferometer and EISCAT radar measurements with models

Kosch, M. J.; Ishii, Mamoru; Nozawa, S.; Rees, D.; Cierpka, K.; Kohsiek, A.; Schlegel, K.; Fujii, Ryoichi; Hagfors, T.; Fuller‐Rowell, T. J.; Lathuillére, C.

doi:10.1016/s0273-1177(00)00041-7

Cited by 21 publications

(39 citation statements)

References 15 publications

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“…At high latitudes and for F-region altitudes the data coverage is relatively poor and therefore it is mostly influenced by the mid-latitude measurements (E. Griffin, private communication). However, comparisons between FPI measured neutral temperatures and those from the MSIS model show good agreement for quiet geomagnetic activity conditions (Kosch et al, 2000a). In our case, Kp=0 throughout the experiment.…”

Section: Modellingsupporting

confidence: 63%

Heater-induced altitude descent of the EISCAT UHF ion line enhancements: Observations and modelling

Ashrafi

Kosch

Honary

2006

Advances in Space Research

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On 12 November 2001, artificial optical annuli were produced using the EISCAT highfrequency (HF) ionospheric Heating facility. This unusual phenomenon was induced using O-mode transmissions at 5.423 MHz with 550 MW effective isotropic radiated power and the pump beam dipped 9 degrees south. The pump frequency corresponds to the fourth electron gyro-harmonic frequency at 215 km altitude. The EISCAT UHF radar observed a persistent pump-induced enhancement in the ion line data near the HF reflection altitude. The optical and radar signatures of HF pumping started at ∼230 km and descended to ∼220 km within ∼60 s. This effect has been modelled using the solution to differential equations describing pump-induced electron temperature and density perturbations. The decrease in altitude of the ion line by ∼10 km and changes in electron density have been modelled. The results show that an electron temperature enhancement of up to ∼5700 K can be achieved, which is not sufficient to explain the observed optical emissions.

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Section: Modellingsupporting

confidence: 63%

Heater-induced altitude descent of the EISCAT UHF ion line enhancements: Observations and modelling

Ashrafi

Kosch

Honary

2006

Advances in Space Research

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“…However, the poor response to geomagnetic activity is also apparent in the Northern Hemisphere from both our Kiruna data and previous work at EISCAT (Kosch et al, 2000). In Fig.…”

Section: Comparisons Demonstrating Response To Geomagnetic Activitysupporting

confidence: 72%

Comparison of high-latitude thermospheric meridionalwinds I: optical and radar experimental comparisons

et al. 2004

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Abstract. Thermospheric neutral winds at Kiruna, Sweden (67.4 • N, 20.4 • E) are compared using both direct optical Fabry-Perot Interferometer (FPI) measurements and those derived from European incoherent scatter radar (EISCAT) measurements. This combination of experimental data sets, both covering well over a solar cycle of data, allows for a unique comparison of the thermospheric meridional component of the neutral wind as observed by different experimental techniques. Uniquely in this study the EISCAT measurements are used to provide winds for comparison using two separate techniques: the most popular method based on the work of Salah and Holt (1974) and the Meridional Wind Model (MWM) (Miller et al., 1997) application of servo theory. The balance of forces at this location that produces the observed diurnal pattern are investigated using output from the Coupled Thermosphere and Ionosphere (CTIM) numerical model. Along with detailed comparisons from short periods the climatological behaviour of the winds have been investigated for seasonal and solar cycle dependence using the experimental techniques. While there are features which are consistent between the 3 techniques, such as the evidence of the equinoctial asymmetry, there are also significant differences between the techniques both in terms of trends and absolute values. It is clear from this and previous studies that the high-latitude representation of the thermospheric neutral winds from the empirical Horizontal Wind Model (HWM), though improved from earlier versions, lacks accuracy in many conditions. The relative merits of each technique are discussed and while none of the techniques provides the perfect data set to address model performance at high-latitude, one or more needs to be included in future HWM reformulations.

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“…Both CHAMP and SOFDI daytime wind data compare very well and are in disagreement with HWM07 (and previous versions) winds. Such differences between observations and HWM07 have been observed in other studies, e.g., in (Kosch et al, 2000), in Brazilian FPI observations by Meriwether and Makela (J. Makela, personal communications, 2011), etc. However, we note that there are a large number of issues with that need to be addressed in comparing empirical climatologies with "semi-synoptic" observations (D. Drob, personal communications, 2011).…”

Section: Discussionsupporting

confidence: 54%

Initial daytime and nighttime SOFDI observations of thermospheric winds from Fabry-Perot Doppler shift measurements of the 630-nm OI line-shape profile

Gerrard¹,

Meriwether

2011

Ann. Geophys.

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Abstract.In this paper we present both night and day thermospheric wind observations made with the Second-generation, Optimized, Fabry-Perot Doppler Imager (SOFDI), a novel triple-etalon Fabry-Perot interferometer (FPI) designed to make 24-h measurements of thermospheric winds from OI 630-nm emission. These results were obtained from the northeastern United States and from under the magnetic equator at Huancayo, Peru and demonstrate the current instrument capability for measurements of Doppler shifts for either night or day. We found the uncertainties in the measurements agree with expected values based upon forward modeling calculations; nighttime wind components having an uncertainty of ∼20-m s −1 at 30-min resolution and daytime wind components having an uncertainty of ∼70-m s −1 at 20-min resolution. The nighttime uncertainties are typically larger than those seen with traditional single-etalon FPIs, which occur at the cost of being able to achieve daytime measurements. The thermospheric wind measurements from Huancayo replicate recently reported CHAMP zonal winds and are in disagreement with current empirical wind climatologies. In addition, we discuss the incorporation of how multiple point heads in the SOFDI instrument will allow for unique studies of gravity wave activity in future measurements.

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A comparison of thermospheric winds and temperatures from Fabry-Perot interferometer and EISCAT radar measurements with models

Cited by 21 publications

References 15 publications

Heater-induced altitude descent of the EISCAT UHF ion line enhancements: Observations and modelling

Heater-induced altitude descent of the EISCAT UHF ion line enhancements: Observations and modelling

Comparison of high-latitude thermospheric meridionalwinds I: optical and radar experimental comparisons

Initial daytime and nighttime SOFDI observations of thermospheric winds from Fabry-Perot Doppler shift measurements of the 630-nm OI line-shape profile

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