In situ observations of instabilities in the mesopause region using foil chaff technique during the Waves in Airglow Structures Experiment (WAVE) campaigns

Abstract

[1] In order to investigate the dynamics of the mesopause region, foil chaff experiments were carried out successfully during the WAVE2000 and WAVE2004 campaigns at Kagoshima, Japan. In the WAVE2004 campaign, the height profiles of the horizontal and vertical wind speeds were obtained. The wind shear layers of >40 m/s/km were located around the altitudes of 89 and 95 km, and the profile of the Richardson number reveals the existence of dynamically unstable layers at about the same height region. Ripple observations using the all-sky imagers also support the possibility of dynamical instabilities. In the WAVE2000 campaign, a prominent small-scale feature around an altitude of 90.5 km appeared in both the horizontal and vertical chaff motions. These results demonstrate that the foil chaff technique is a valuable tool for in situ observation of small-scale turbulence features around the mesopause.

Simulations of large winds and wind shears induced by gravity wave breaking in the mesosphere and lower thermosphere (MLT) region

“…In the chemical release experiment by sounding rockets at different latitudes, longitudes, seasons, and local times, large horizontal winds and strong vertical shears have been measured (e.g., Wu and Widdel, 1992;Larsen, 2000Larsen, , 2002Larsen et al, 2005;Larsen and Fesen, 2009;Koizumi et al, 2009). Moreover, both the magnitudes and vertical structures of winds and shears measured by the sodium lidar and non-specular meteor radar are in line with those obtained by sounding rocket measurements (e.g., Larsen et al, 2003Larsen et al, , 2004Larsen and Fesen, 2009;Oppenheim et al, 2009Oppenheim et al, , 2014.…”

Foil chaff ejection systems for sounding rocket measurements of neutral winds in the mesopause region

“…In the WAVE2004 campaign, the foil chaff experiment was performed using only the spring type ejection system on the S-310-33 rocket. Wind shear layers of >40 m/s/km were located around the altitudes of 89 and 95 km, and the profile of the Richardson number reveals the existence of dynamically unstable layers at about the same height region (Koizumi et al, 2009). Between these experiments, the S-310-30 experiment was performed but radar tracking failed due to technical problems.…”

Mini-EUSO mission to study Earth UV emissions on board the ISS

“…2. Airglow: in the chemistry of the atmosphere a particular role is played by airglows that -in the wavelength band 330-400 nm that can be detected by Mini-EUSO -are dominated by the emission from oxygen molecules in the Herzberg I band around the boundary region at an altitude of 95 km between the mesosphere and thermosphere (Koizumi et al 2009;Iwagami et al 2005). Mini-EUSO will study the geographical and time variation of airglows, which are possible effects of geomagnetic disturbances in the upper atmosphere and also of tsunami events.…”