March 29, 2024

Cloudscapes Over Sumatra: Gorgeous Astronaut Photo Captures Thunderheads and Anvil Clouds

By NASA Earth Observatory
November 13, 2021

July 18, 2021
Damp ocean air and stable winds accumulate thunderheads and anvil clouds around Indonesia.
The image likewise reveals the smaller, surrounding Bangka and Belitung Islands, the Java Sea, and the west coast of Borneo (far ideal margin, above the solar panel). The long, brilliant clouds– created by thunderstorms– cast dark shadows on the land and sea below.
On the day this photo was taken, winds were blowing from the northeast (right to left in this view). After crossing the Java Sea, the damp air would have risen as it was heated. Such heating most likely caused thunderstorms to form over each island.

The long, intense clouds– created by thunderstorms– cast dark shadows on the land and sea listed below. Other anvil clouds formed where air was forced to rise over the high Barisan Mountains on Sumatras southwest coast (far left). Little cumulus clouds also formed over the small line of Mentawai Islands (leading left).
It is provided by the ISS Crew Earth Observations Facility and the Earth Science and Remote Sensing Unit, Johnson Space.

Other anvil clouds formed where air was forced to increase over the high Barisan Mountains on Sumatras southwest coast (far left). Little cumulus clouds also formed over the small line of Mentawai Islands (top left).
Cloud-free zones appear over the Java Sea and the Indian Ocean. Both zones lie downwind of landmasses (Borneo and Sumatra), with air apparently descending onto the sea surface on this day. Descending air normally reduces cloud formation.
It is provided by the ISS Crew Earth Observations Facility and the Earth Science and Remote Sensing Unit, Johnson Space. The image has been cropped and improved to enhance contrast, and lens artifacts have been removed. Caption by Justin Wilkinson, Texas State University, JETS Contract at NASA-JSC.