The AVHRR visible channel (Ch 1, 0.58-0.68 µm) is useful in fulfilling a variety of detection and monitoring functions. Meteorological applications include daytime cloud type determination, cloud-edge and cloud-top feature detection, cloud drift wind derivation, monitoring of pollution, smoke, and haze, surface feature identification, and surface albedo.

Select the AVHRR Ch 4 image from the Product Listbox. This image shows the aerial coverage from one AVHRR ascending pass captured at the NWS POES groundstation in Anchorage, AK on 3 March 1997. Note the extensive snow cover over most of Alaska extending south along the Canadian Rockies into the Pacific Northwest. Over the Gulf of Alaska and the eastern Pacific, there are a variety of cloud features. Patchy low-level clouds (darker/warmer in IR) are evident along northern portions of the Gulf Coast while both open and closed cell stratiform clouds extend from the central and eastern Gulf of Alaska southward. Higher level clouds (brighter in visible and brighter/colder in IR) are seen farther to the west extending south from the Aleutian Islands into the Pacific Ocean. Notice how far south this POES pass extends reaching into northern California.