A cloud and ice factory
The Sea of Okhotsk is what oceanographers call a marginal sea: a region of a larger ocean basin that is partly enclosed by islands and peninsulas hugging a continental coast. With the Kamchatka Peninsula, the Kuril Islands, and Sakhalin Island partly sheltering the sea from the Pacific Ocean, and with prevailing, frigid northwesterly winds blowing out from Siberia, the sea is a winter ice factory and a year-round cloud factory.
The first natural-color image was acquired by the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument on the Suomi NPP satellite on November 25, 2017. Snow and clouds cover much of the coastal land, and some sea ice appears toward the lower left. The dominant feature of the image is the pattern of cloud streets—parallel lines and arcs of cumulus clouds over the water.
Cloud streets typically form when cold air blows over warmer waters, picking up heat and moisture. As this air becomes warmer and wetter, it starts to rise in columns until its hit a warmer air layer, which makes the rising thermals roll over and loop back on themselves, creating parallel cylinders of rotating air. On the upper edge of these cylinders, clouds form. On the falling side (descending air), skies stay clear. Thanks to strong, cool land breezes and warmer Pacific waters, the Sea of Okhotsk is covered by clouds (with or without streets) for much of the year.
View the full resolution image.