A first look at volcanic ash detection in the GOES-12 era

The Geostationary Operational Environmental Satellite (GOES)-12 Imager, which was activated 1 April 2003, has been re-configured with the addition of a 13.3 micrometer Infrared (IR) spectral band, in place of the “split window” 12.0 micrometer band. This suite of spectral bands will remain in place until the GOES-R Advanced Baseline Imager (ABI) becomes operational, circa 2013. Since the 12.0 micrometer band had been successfully used for volcanic ash detection from GOES for nearly ten years, there is some concern about the impact of this change on short term warnings and forecasts for aviation operations over North and South America. The first significant volcanic activity observed by the new GOES-12 satellite occurred at the Soufriere Hills Volcano, Montserrat during 12-15 July 2003. Ash clouds resulting from a series of four eruptions were dispersed throughout the Troposphere in the Eastern Caribbean at altitudes as high as 16 km. As a result, numerous advisories were issued by the Washington Volcanic Ash Advisory Center. GOES-12 was able to observe the eruption clouds adequately during this period using multi-spectral techniques. Although conditions during this event were considered ideal, it nevertheless suggests that GOES-12 and its successors can be used effectively to warn pilots of hazardous ash clouds in most situations. Other new capabilities from GOES-12 that could be utilized in the issuance of volcanic ash advisories are improved cloud top height estimates from the Imager, and sulfur dioxide (SO2) detection using Sounder spectral band differences.