Global, long-term sulphur dioxide measurements from TOVS data: A new tool for studying explosive volcanism and climate

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A new technique for retrieving sulphur dioxide concentrations from TIROS Operational Vertical Sounder (TOVS) data is described. The retrieval technique relies on absorption of infrared radiation by the anti-symmetric stretch of the sulphur dioxide (SO2) molecule centred around 7.3 μm. The High-resolution infrared radiation sounder (HIRS/2) is part of the TOVS package and has a channel that covers this absorption region. The HIRS/2 data are global, span almost 24 years, have a sub-satellite spatial resolution of about 18 km and can be used both day and night. The retrieval method is described and its accuracy and sources of error discussed. Case studies for the June 1991 Pinatubo eruptions, for the August 1991 eruptions of Cerro Hudson and for several eruptions of Hekla volcano, are used to illustrate the retrievals and the results are compared with independent SO2 retrievals from the TOMS instrument. These new SO2 data provide a potentially valuable tool for studying the climatic effects of explosive eruptions. Because the satellite measurements are global, long-term and can simultaneously provide other climate parameters (e.g. surface temperatures, temperature profiles, humidity profiles, cloudiness, ozone amount and long- and short-wave radiation) they can be used to test and validate volcanically-induced effects in global climate simulations.

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Copyright 2003 by the American Geophysical Union. Publisher's version of record: https://dx.doi.org/10.1029/139GM05

Publication Title

Volcanism and the Earths Atmosphere