We present the scientific targets, instrumental design, principle of measurement, and development of the Visible and near-Infrared Spectral Imager (VISI) which will be launched onto International Space Station (ISS) in January 2012. VISI is equipped with fast optics including a grism, and a high-sensitivity CCD to obtain airglow emissions at wavelengths of O (630 nm), OH Meinel band (650 nm) and O 2 (0-0) atmospheric band (762 nm). VISI has two field-of-views (FOVs), 45 degrees forward and 45 degrees backward to nadir, to subtract background contaminations. The data acquisition of VISI will be continuously performed with short exposure cycle less than several seconds when ISS is orbiting in the night side of the earth, and then provide the seamless line scanning images of the airglows with a spatial resolution better than 50 km. After manufacturing VISI, we checked its performance though optical and electric function tests as well as environmental tests that are necessary to be launched.

We present a study of concentric gravity waves (CGWs) event from the coordinated observation between Ionosphere, Mesosphere, upper Atmosphere, and Plasmasphere mapping (IMAP)/Visible and near‐Infrared Spectral Imager (VISI), all‐sky camera at Rikubetsu, Multi‐functional Transport Satellite (MTSAT), Tropical Rainfall Measuring Mission, and MF radar at Wakkanai combined with Modern‐Era Retrospective Analysis for Research and Application data. IMAP/VISI is the first space‐based imager that capable of imaging the airglow in the mesosphere and lower thermosphere region in the nadir‐looking direction. Therefore, it has a unique ability to observe a great extend of CGWs propagation. Arc‐like shaped, part of CGWs pattern was observed around the mesopause (~95 km) in the O2 762 nm airglow emission obtained by IMAP/VISI at 1204 UT on 18 October 2012. Similar patterns were also observed by the all‐sky imager at Rikubetsu (43.5°N, 143.8°E) in OI 557.7 nm and OH band airglow emissions from ~1100 to 1200 UT. Horizontal wavelengths of the observed small‐scale gravity waves are ~50 km (OH band and OI 557.7 nm) and ~67 km (O2 762 nm). The source is suggested to be a deep convective activity over Honshu Island which likely was an enhanced convective activity related to a typhoon in the south of Japan. The data showed that the CGWs could propagate up to ~1400–1500 km horizontally from the source to the mesopause but not farther away. Using atmospheric temperature profiles obtained by Thermospheric Ionosphere Mesosphere Energetics Dynamics/Sounding of the Atmosphere using Broadband Emission Radiometry, we conclude that this long‐distance propagation of the waves could be caused by thermal duct in the middle atmosphere. The arc‐like shaped instead of full circle pattern points out that the wind filtering effect is significant for the particular direction of wave propagation.

Spaceborne imagers are able to observe the airglow structures with wide field of views regardless of the tropospheric condition that limits the observational time of the ground‐based imagers. Concentric wave structures of the O2 airglow in 762 nm wavelength were observed over North America on 1 June 2013 from the International Space Station. This was the first observation in which the entire image of the structure was captured from space, and its spatial scale size was determined to be 1200 km radius without assumptions. The apparent horizontal wavelength was 80 km, and the amplitude in the intensity was approximately 20% of the background intensity. The propagation velocity of the structure was derived as 125 ± 62 m/s and atmospheric gravity waves were estimated to be generated for 3.5 ± 1.7 h. Concentric structures observed in this event were interpreted to be generated by super cells that caused a tornado in its early phase.