scholarly journals Validation of ICON‐MIGHTI thermospheric wind observations: 1. Nighttime Red‐line Ground‐Based Fabry‐Perot Interferometers

2020 ◽  
Author(s):  
J. J. Makela ◽  
M. Baughman ◽  
L. A. Navarro ◽  
B. J. Harding ◽  
C. R. Englert ◽  
...  
Keyword(s):  
Thermospheric Wind ◽  
Fabry Perot ◽  
Red Line

scholarly journals Thermospheric wind variations observed by a Fabry–Perot interferometer at Tromsø, Norway, at substorm onsets

2019 ◽  
Vol 71 (1) ◽  
Author(s):  
Heqiucen Xu ◽  
Kazuo Shiokawa ◽  
Shin-ichiro Oyama ◽  
Yuichi Otsuka
Keyword(s):  
Thermospheric Wind ◽  
Fabry Perot ◽  
Substorm Onsets

Comparisons of wave-length standards emitted by mercury-198 lamps

1951 ◽  
Vol 209 (1096) ◽  
pp. 132-141 ◽  
Keyword(s):  
Wave Length ◽  
Red Shift ◽  
Cold Cathode ◽  
Pressure Broadening ◽  
High Quality ◽  
Carrier Gas ◽  
Nominal Pressure ◽  
Fabry Perot ◽  
Red Line

The reproducibility of high-quality wave-length standards emitted from water-cooled mercury-198 discharge lamps of the electrodeless and cold-cathode (Geissler) types has been investigated by means of a Fabry-Perot interferometer. These lamps, now produced commercially in this country, contain a small quantity of the isotope 198 80 Hg with argon, as carrier gas, at a nominal pressure of 3 or 5 mm, in electrodeless and 10 mm. in cold-cathode lamps; electrodeless lamps containing only the isotope and its vapour are also available. Employing for excitation a 100 Mc./sec. oscillator with electrodeless lamps and a transformer delivering 750 V at 25 mA and 50 c./sec. with cold-cathode lamps, the wave-lengths of six 198 80 Hg lines between 4046 and 5791 Å, emitted from a sample of each kind of argon-filled lamp, have been measured in terms of the cadmium red line at retardations of 5 to 25 cm. These measurements, supplemented by intercomparisons of argon-filled and argon-free slectrodeless lamps at a retardation of 20cm., reveal that 198 80 Hg lines are probably subject to an asymmetrical pressure broadening effect, producing a red shift of about 0.0001Å (— 0.0004 cm. -1 ) per mm. of argon. Wave-length reproducibility among different samples of the same kind of lamp with the same filling is of the order of ± 0.000 05 Å, or ± 1 part in 10 8 , for electrodeless lamps and ± 0-0001Å for cold-cathode lamps.

scholarly journals Lower-thermospheric wind fluctuations measured with an FPI during pulsating aurora at Tromsø, Norway

2010 ◽  
Vol 28 (10) ◽  
pp. 1847-1857 ◽  
Author(s):  
S. Oyama ◽  
K. Shiokawa ◽  
J. Kurihara ◽  
T. T. Tsuda ◽  
S. Nozawa ◽  
...  
Keyword(s):  
Wind Velocity ◽  
Frictional Heating ◽  
Lower Thermosphere ◽  
Thermospheric Wind ◽  
F Region ◽  
Time Period ◽  
Fabry Perot ◽  
Eiscat Radar ◽  
Energy Dissipated ◽  
Uhf Radar

Abstract. Simultaneous observations were conducted with a Fabry-Perot Interferometer (FPI) at a wavelength of 557.7 nm, an all-sky camera at a wavelength of 557.7 nm, and the European Incoherent Scatter (EISCAT) UHF radar during the Dynamics and Energetics of the Lower Thermosphere in Aurora 2 (DELTA-2) campaign in January 2009. This paper concentrated on two events during periods of pulsating aurora. The lower-thermospheric wind velocity measured with the FPI showed obvious fluctuations in both vertical and horizontal components. Of particular interest is that the location of the fluctuations was found in a darker area that appeared within the pulsating aurora. During the same time period, the EISCAT radar observed sporadic enhancements in the F-region backscatter echo power, which suggests the presence of low-energy electron (1 keV or lower) precipitation coinciding with increase in amplitude of the electromagnetic wave (at the order of 10 Hz or higher). While we have not yet identified the dominant mechanism causing the fluctuations in FPI-derived wind velocity during the pulsating aurora, the frictional heating energy dissipated by the electric-field perturbations may be responsible for the increase in ionospheric thermal energy thus modifying the local wind dynamics in the lower thermosphere.

scholarly journals High-latitude thermospheric wind study using a Fabry–Perot interferometer at Tromsø in Norway: averages and variations during quiet times

2019 ◽  
Vol 71 (1) ◽  
Author(s):  
Heqiucen Xu ◽  
Kazuo Shiokawa ◽  
Shin-ichiro Oyama ◽  
Satonori Nozawa
Keyword(s):  
Meridional Wind ◽  
Local Times ◽  
Maximum Speed ◽  
Plasma Convection ◽  
Quiet Time ◽  
Thermospheric Wind ◽  
Ae Index ◽  
Fabry Perot ◽  
Wind Measurements ◽  
Large Wind

Abstract The average winds in the thermosphere during geomagnetically quiet times are important because they provide a baseline wind in the upper atmosphere, but they remain insufficiently understood at high latitudes. This paper reports the first direct ground-based wind measurements of the quiet-time thermospheric wind pattern at Tromsø in Norway using 2009–2015 data from a Fabry–Perot interferometer. We analyzed red-line wind measurements (630.0 nm; altitude: 200–300 km). On average, the zonal wind shows a decrease of eastward wind compared with diurnal tidal wind before midnight. A maximum speed of 100 m/s occurs at both the dusk and dawn sides. The meridional wind has a diurnal tide structure with a minimum value of − 130 m/s around midnight. We also found occasional large wind deviations (> 100 m/s) from the averages, even during geomagnetically quiet times. We suggest that these large wind deviations are caused by the plasma convection associated with weak substorm activities with auroral electrojet (AE) index values of less than 100 nT that occurred at local times different from that at Tromsø.

scholarly journals First daytime thermospheric wind observation from a balloon-borne Fabry-Perot interferometer over Kiruna (68N)

2012 ◽  
Vol 39 (14) ◽  
pp. n/a-n/a ◽  
Author(s):  
Qian Wu ◽  
W. Wang ◽  
R. G. Roble ◽  
Ingemar Häggström ◽  
Anja Strømme
Keyword(s):  
Thermospheric Wind ◽  
Wind Observation ◽  
Fabry Perot

A New Reduction Technique for Thermospheric Wind and Temperature Measurement with Fabry-Perot Interferometer

2013 ◽  
Vol 33 (11) ◽  
pp. 1130003
Author(s):  
王宏 Wang Hong ◽  
刘学斌 Liu Xuebin ◽  
冯玉涛 Feng Yutao ◽  
白清兰 Bai Qinglan
Keyword(s):  
Temperature Measurement ◽  
Reduction Technique ◽  
Thermospheric Wind ◽  
Fabry Perot

scholarly journals A Tiny Fabry-Perot Interferometer with Postpositional Filter for Measurement of the Thermospheric Wind

2016 ◽  
Vol 64 (6) ◽  
pp. 2748-2760 ◽  
Author(s):  
Houmao Wang ◽  
Yongmei Wang ◽  
Jianguo Fu
Keyword(s):  
Thermospheric Wind ◽  
Fabry Perot
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