A Near-Real-Time Method for Estimating Volcanic Ash Emissions Using Satellite Retrievals
| Autor: | Rachel E. Pelley, Claire Witham, Alistair J. Manning, Michael Cooke, Helen N. Webster, Matthew C. Hort, David J. Thomson |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Atmospheric Science
volcanic ash emissions source inversion atmospheric dispersion satellite ash retrievals Meteorology Stochastic modelling Gaussian media_common.quotation_subject Astrophysics::High Energy Astrophysical Phenomena Inverse transform sampling Environmental Science (miscellaneous) Physics::Geophysics symbols.namesake Meteorology. Climatology Astrophysics::Solar and Stellar Astrophysics Astrophysics::Galaxy Astrophysics media_common Inversion (meteorology) Atmospheric dispersion modeling Sky symbols Environmental science Satellite QC851-999 Volcanic ash |
| Zdroj: | Atmosphere; Volume 12; Issue 12; Pages: 1573 Atmosphere, Vol 12, Iss 1573, p 1573 (2021) |
| ISSN: | 2073-4433 |
| DOI: | 10.3390/atmos12121573 |
| Popis: | We present a Bayesian inversion method for estimating volcanic ash emissions using satellite retrievals of ash column load and an atmospheric dispersion model. An a priori description of the emissions is used based on observations of the rise height of the volcanic plume and a stochastic model of the possible emissions. Satellite data are processed to give column loads where ash is detected and to give information on where we have high confidence that there is negligible ash. An atmospheric dispersion model is used to relate emissions and column loads. Gaussian distributions are assumed for the a priori emissions and for the errors in the satellite retrievals. The optimal emissions estimate is obtained by finding the peak of the a posteriori probability density under the constraint that the emissions are non-negative. We apply this inversion method within a framework designed for use during an eruption with the emission estimates (for any given emission time) being revised over time as more information becomes available. We demonstrate the approach for the 2010 Eyjafjallajökull and 2011 Grímsvötn eruptions. We apply the approach in two ways, using only the ash retrievals and using both the ash and clear sky retrievals. For Eyjafjallajökull we have compared with an independent dataset not used in the inversion and have found that the inversion-derived emissions lead to improved predictions. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|