Gravity Waves Across A Streamer of Snow off Alaska

Gravity Waves Across A Streamer of Snow off Alaska. Alaska was a frozen field of white on January 13, 2004, when the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite captured this image. Strong winds blew from the north, pulling streamers of snow from the Alaska Peninsula out over the Gulf of Alaska. Further evidence of moving air can be seen in the clouds south of the peninsula. When the air moving across Bristol Bay and the Bering Sea meets the mountains of the Alaska Peninsula, it is forced up and over the land. This sets up a wave in that layer of the atmosphere. The waves are called atmospheric gravity waves, and they are affecting the cloud patterns south of the peninsula. Faint wavy clouds have formed along the rise and fall of the disrupted air mass.

The Pacific Ocean lies to the south and southwest. It is the largest U.S. state by area and the seventh largest subnational division in the world. In addition, it is the 3rd least populous and the most sparsely populated of the 50 United States; nevertheless, it is by far the most populous territory located mostly north of the 60th parallel in North America: its population—estimated at 738,432 by the United States Census Bureau in 2015 is more than quadruple the combined populations of Northern Canada and Greenland. Approximately half of Alaska’s residents live within the Anchorage metropolitan area. Alaska’s economy is dominated by the fishing, natural gas, and oil industries, resources which it has in abundance. United States armed forces bases and tourism are also a significant part of the economy. Gravity Waves Across A Streamer of Snow off Alaska are common along the coast.

Credit: Jacques Descloitres, MODIS Rapid Response Team, NASA/GSFC