Shigeto Watanabe

Abstract: We report observations of the H+, He+, and O+ polar wind ions in the polar cap (>80° invariant latitude, ILAT) above the collision-dominated altitudes (>2000 km), from the suprathermal mass spectrometer (SMS) on EXOS D (Akebono). SMS regularly observes low-energy (a few eV) upward ion flows in the high-altitude polar cap, poleward of the auroral oval. The flows are typically characteristic of the polar wind, in that they are field-aligned and cold (Ti 80° ILAT), the average H+ velocity reached 1 km/s near 2000 km, as did the He+ velocity near 3000 km and the O+ velocity near 6000 km. At Akebono apogee (10,000 km), the averaged H+, He+, and O+ velocities were near 12,7, and 4 km/s, respectively. Both the ion velocity and temperature distributions exhibited a day-to-night asymmetry, with higher average values on the dayside than on the nightside.

TL;DR: In this article, the authors evaluate the exposure during nadir observations with JEM-EUSO, the Extreme Universe Space Observatory, on-board the Japanese Experiment Module of the International Space Station.

TL;DR: In this paper, the authors studied the climatology of the equatorial zonal wind in the upper thermosphere and found that the solar flux significantly influences both the daytime and nighttime winds.

TL;DR: In this article, an interhemispheric bow-shaped structure was detected at the cloud-top level of Venus in middle infrared and ultraviolet images from the Japanese orbiter Akatsuki.

TL;DR: In this article, the authors made a statistical analysis of the occurrence characteristics of the plasma bubbles and blobs by using more than 1000 cases of observation data from the swept frequency impedance probe aboard the Hinotori satellite.