Dust Tracking Using Composite Visible/IR Images: A Case Study

Abstract

Visible and infrared (IR) images from the National Oceanic and Atmospheric Administration's (NOAA's) Advanced Very High Resolution Radiometer are composited to improve the depiction of airborne dust over coastlines. On IR images, wind-raised dust stands out well against heated land surfaces. Once advected over ocean, however, dust on IR images can not be easily distinguished from the cool surface. The situation is reversed on visible images: dust contrasts well with dark ocean backgrounds but poorly with bright land surfaces. To illustrate the optimal use of both data types, a composite image juxtaposes visible data over water with IR data over land. Accompanying synoptic data provide additional information about the distribution of dust in the vertical.