November 8, 2021 - Dust and Snow in Asia

Dust and Snow in Asia, Uzbekistan, Kyrgyzstan, Tajikistan

A heavy dust storm blanketed parts of Uzbekistan, Turkmenistan, Kazakhstan, and Tajikistan in early November 2021.

The Moderate resolution Imaging Spectroradiometer (MODIS) on board NASA’s Terra satellite acquired a true-color image of the storm on November 5. A heavy shroud of dust and sand obscures the Gissar Valley of Turkmenistan and parts of Uzbekistan (north) and Tajikistan (south) at the western edge of the Gissar Mountains. Meanwhile, the air at higher elevations remains crisp and clean, allowing a clear view of the snow-topped mountain ranges that surround the Gissar Valley.

According to reporting by Eurasianet, this storm was the worst to strike Uzbekistan since meteorological records began 150 years ago. The storm began on November 4 in Kazakhstan, driven by strong winds at the leading edge of a cold front. Visibility in some areas of Uzbekistan dropped to 100-200 meters (328-656 feet) at the peak of the storm.

Due to the dry climate and copious sand and dust across the region, dust storms are common. Usually, the wind drives dust and sand across a region in a cloud that disperses rather quickly. What made this storm particularly difficult was that the dust was the formation of an inversion over the dust. An inversion occurs when a mass of warmer air lays over a cooler layer of surface air. The warm air acts like a like, keeping low-lying air—and any dust or haze trapped in that air layer—trapped near the surface and unable to dissipate.

Image Facts
Satellite: Terra
Date Acquired: 11/5/2021
Resolutions: 1km (751.2 KB), 500m (1.9 MB), 250m (1.2 MB)
Bands Used: 1,4,3
Image Credit: MODIS Land Rapid Response Team, NASA GSFC