All-sky Doppler interferometer for thermospheric dynamics studies.

Area of Science:

• Atmospheric Physics
• Geophysics
• Optical Physics

Background:

• Understanding upper-atmosphere dynamics is crucial for atmospheric modeling and space weather.
• Previous methods for measuring thermospheric and mesospheric winds and temperatures were often limited in spatial coverage or temporal resolution.

Purpose of the Study:

• To develop and demonstrate an instrument capable of simultaneously measuring Doppler shifts and widths of nightglow emissions over an entire sky.
• To determine upper-atmosphere neutral wind and temperature fields over large spatial scales (up to ~2000 km).

Main Methods:

• Mating an efficient, all-sky input optical system to a 100-mm-aperture Fabry-Perot interferometer.
• Utilizing a cooled charge-coupled device (CCD) as a photon detector.
• Analyzing Doppler shifts and widths of specific nightglow emission lines (OI 630-nm and OH 799.6-nm).

Main Results:

• The developed all-sky Doppler interferometer can acquire good-quality interferometric images with exposure times of 5-15 minutes.
• Demonstrated capability in measuring thermospheric wind and temperature fields over a large region.
• Successfully mapped upper-atmosphere dynamics using nightglow emissions from both the thermosphere and mesopause.

Conclusions:

• The all-sky Doppler interferometer is an effective tool for comprehensive upper-atmosphere wind and temperature measurements.
• The instrument provides valuable data for studying large-scale atmospheric phenomena.
• This technology advances the capability for remote sensing of the Earth's upper atmosphere.