HR: 0830h
AN: V51F-0334    [PDF]
TI: A First Look at Volcanic Ash Detection From GOES-12: Coping Without the 12$\mu$m IR Band
AU: * Ellrod, G P
EM: gary.ellrod@noaa.gov
AF: NOAA/NESDIS, Room 601, WWB, NOAA 5200 Auth Road, Camp Springs, MD 20746 United States
AU: Schreiner, A J
EM: tony.schreiner@ssec.wisc.edu
AF: Cooperative Institute for Meteorological Satellite Studies (CIMSS), University of Wisconsin, 1225 West Dayton St., Madison, WI 53706 United States
AB: On 1 April 2003, Geostationary Operational Environmental Satellite (GOES)-12 became the primary East spacecraft to monitor weather and environmental hazards over North and South America. An important instrument modification to the GOES-12 Imager was the replacement of a 4 km resolution 12$\mu$m Infrared (IR) band with a lower resolution (8 km) IR band centered near 13.3$\mu$m. There has been a concern that the loss of the 12$\mu$m band will negatively impact volcanic ash detection and aviation safety, since that channel has been effectively used for this purpose for nearly a decade, in combination with other spectral bands on GOES. The first opportunity to evaluate GOES-12 capabilities occurred with several moderate eruptions of Soufriere Hills Volcano on Montserrat in the Eastern Caribbean from 12-15 July 2003. The eruptions were triggered by a major lava dome collapse, followed by pyroclastic flows (Montserrat Volcano Observatory). Ash was dispersed throughout the Troposphere across the region, with maximum ash top heights estimated to range from 8-16 km (Washington Volcanic Ash Advisory Center). A new algorithm has been developed to detect ash using an arithmetic combination of GOES-12 IR brightness temperature data in Bands 2 (3.9$\mu$m), 4 (11$\mu$m) and 6 (13.3$\mu$m). The latter channel has shown the ability to discriminate volcanic ash from ice-laden cirrus cloud layers. Examples of the multi-spectral images for these events, including estimation of ash cloud top heights using a "CO2/IRW ratio" technique will be provided, along with an assessment of their reliability.
UR: http://orbit-net.nesdis.noaa.gov/arad/fpdt/volc.html
DE: 0305 Aerosols and particles (0345, 4801)
DE: 3360 Remote sensing
DE: 8409 Atmospheric effects (0370)
DE: 8419 Eruption monitoring (7280)
DE: 8494 Instruments and techniques
SC: Volcanology, Geochemistry, Petrology [V]
MN: 2003 Fall Meeting