CyMISS Image of the Month: A 3D Moonlit View of Tropical Cyclone Oma from the ISS

In the most recent phase of the CyMISS (tropical Cyclone intensity Measurements from the ISS) project, our team has been exploring improvements we can make to our observing techniques. One of our investigations involves observing storms at night using moonlight as the source of illumination. On February 20, 2019, the Expedition 58 crew of ISS acquired a series of 240 image pairs of Tropical Cyclone Oma with the exposure times alternating between 1/30th and 1/8th of a second. The image sequence spans from 16:58:46 to 17:02:45 GMT when the Moon, which provided the only source of illumination for the storm, was about 25 hours past full. At this time, Tropical Cyclone Oma was located at about 22.1° S, 160.6° E in the South Pacific off the east coast of Australia and was rated as Category 2 storm on the Australian tropical cyclone intensity scale with sustained winds of about 105 kph (65 mph).
A typical image from this sequence with an exposure time of 1/8th of a second is shown below. Apparent in the image is the moonlit eye of the Tropical Cyclone Oma as well as stars above the horizon. Visible above the horizon is the airglow layer at ...