Blowing dust from the Copper River Delta in south-central Alaska
Strong gap winds accelerating out of the Copper River Valley along the southern coast of Alaska were lofting fine particles of glacial silt/sand and transporting those aerosols southward across the Gulf of Alaska on 20 October 2020. 1-minute Mesoscale Domain Sector GOES-17 (GOES-West) “Red” Visible (0.64 µm) and Dust Red-Green-Blue (RGB) images (above) displayed the plume of airborne dust during the period of 1700-2300 UTC.A good visualization of the dust plume was provided by GOES-17 True Color RGB images created using Geo2Grid (below).
A comparison of Suomi NPP VIIRS Visible (0.64 µm), Shortwave Infrared (3.74 µm) and Infrared Window (11.45 µm) images at 2040 UTC is shown below — note that the dust plume appeared warmer (darker shades of gray) on the Shortwave Infrared image, since the small dust particles were efficient reflectors of incoming solar radiation. The dust plume also exhibited a good signature in the VIIRS Aerosol Optical Thickness (AOT) product from the eIDEA-AK site (below).