MISSIONScience

Like the Japanese meteorological satellite "Himawari" orbiting the Earth, Akatsuki's four cameras (IR1, IR2, LIR, UVI) are designed to obtain images of the cloud cover on Venus (its position, shape, temperature, and volume of substances forming the clouds). Clouds are created and disappear, changing shape; by tracing their characteristics common in images taken over time, we can see the movement of the clouds. These long-lasting clouds are believed to travel on the flow (winds) of the atmosphere, which would allow for measuring the east-west and north-south movement of Venusian atmosphere. Since these cameras observe clouds at different altitudes, it allows for measuring the winds in Venusian atmosphere in a three-dimensional fashion. Furthermore, if the lightning and airglow camera (LAC) detects the presence of lightning, this would lead to the elucidation of updrafts like those seen in cumulonimbus clouds, which produce lightning, and the atmospheric flow that ties different altitudes together.

Analyzing the change in cloud shape mentioned above over time allows for obtaining data on the waves in the atmosphere. When a large earthquake occurs on the sea floor on the Earth, tsunamis are conveyed to distant locations. In the atmosphere, too, atmospheric waves (the causes are various) transported in various directions transmit energy. In this way, atmospheric waves play a crucial role on planets. The data on atmospheric waves obtained from Akatsuki is expected to lead to further understanding about the interaction of large-scale circulations such as "super rotation" with much smaller-scale circulations, as well as how energy is exchanged between the upper and lower atmospheres.

Meteorology on the Earth has developed thanks to a range of data measurements and observations. The wealth of data that Akatsuki sends down to the Earth will in turn elucidate the meteorological phenomena on Venus, which will allow us to deepen our understanding of the Earth's own meteorology.