CALIPSO lidar detected the ash plumes from La Soufriere eruption just ~80 km east from the volcano during an overpass on 04/10. Volcanic ash layers are visible between 12-18.5 km and possibly below (see left figure). Those ash layers coincide with a large SO2 cloud observed by AIRS/Aqua which CALIPSO crossed the western edge 1h30 after with an estimated -0.4 Tg of SO2. The InfraRed Imager on CALIPSO indicates negative Brightness Temperature differences (10-12 micron) consistent with the presence of ash and SO2. The tropopause (white line) from the NASA GEOS-5 model suggests that a fraction of the plume is very likely in the stratosphere possibly ~1-1.5 km above the tropopause. This is ~1km above the plume height detected by the meteorological radar data from MPI at Barbados and consistent with the greater sensitivity of lidar obs. compared to radar for detected volcanic cloud top.
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Jean-Paul Vernier
CALIPSO lidar detected the ash plumes from La Soufriere eruption just ~80 km east from the volcano during an overpass on 04/10. Volcanic ash layers are visible between 12-18.5 km and possibly below (see left figure). Those ash layers coincide with a large SO2 cloud observed by AIRS/Aqua which CALIPSO crossed the western edge 1h30 after with an estimated -0.4 Tg of SO2. The InfraRed Imager on CALIPSO indicates negative Brightness Temperature differences (10-12 micron) consistent with the presence of ash and SO2. The tropopause (white line) from the NASA GEOS-5 model suggests that a fraction of the plume is very likely in the stratosphere possibly ~1-1.5 km above the tropopause.
This is ~1km above the plume height detected by the meteorological radar data from MPI at Barbados and consistent with the greater sensitivity of lidar obs. compared to radar for detected volcanic cloud top.