April 15, 2021 - Cloud Streets Franz Josef Islands

Cloud Streets Franz Josef Islands

Located just 600 miles (970 kilometers) from the North Pole, Franz Josef Land is a frigid archipelago made up of 91 islands, and perpetually wears a coat of ice. Glaciers cover roughly 85 percent of the land masses and sea ice floats in the channels between islands even in the summertime.

In mid-April 2021, frigid air temperatures and strong wind combined to create a dramatic canopy of cloud over the islands. The Moderate Resolution Imaging Spectroradiometer (MODIS) on board NASA’s Aqua satellite acquired a true-color image of the scene on April 13.

The stunning cloud formations are not your typical cumulus clouds. They are organized in rows parallel to the direction of the wind. Called “cloud streets”, this formation is created when a cold air mass moves over a relatively warmer body of water. When this occurs, columns of warm air rise through the atmosphere, carrying heat away from the sea surface. The moist air rises until it hits a warmer layer of air (a temperature inversion) which ends up acting like a lid, stopping the rising air. They rising thermals then roll over on themselves to form parallel cylinders of rotating air. As the air rises, clouds form and where the air descends the skies remain clear. In this case, most of the frigid air mass originates over a large mass of sea ice rather than land.

Image Facts
Satellite: Aqua
Date Acquired: 4/13/2021
Resolutions: 1km (393.4 KB), 500m (1.2 MB), 250m (3.6 MB)
Bands Used: 1,4,3
Image Credit: MODIS Land Rapid Response Team, NASA GSFC