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| Titel |
Quantitative analysis of the 16-17 September 2013 resuspended ash event in Iceland |
| VerfasserIn |
Arve Kylling, Frances Beckett, Gudmunda Maria Sigurdardottir, Sibylle von Loewis, Claire Witham |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250104148
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| Publikation (Nr.) |
 EGU/EGU2015-5402.pdf |
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| Zusammenfassung |
| In Iceland more than 20,000 km2 of sandy deserts are active with aeolian processes.
Annually on average 34-135 days are dusty making it one of the dustiest areas of the
world. Substantial amounts of dust are transported southward and deposited in the
North-Atlantic possibly providing significant iron fertilization to regions deficient
in iron. Volcanic ash including resuspended ash may have an adverse effect on
ecosystems and human health, and resuspended ash levels may be high enough to
cause problems to aviation. A strong gale force northerly wind prevailed over south
east Iceland on 16-17 September, 2013. During this period ash from the recent
eruptions of Eyjafjallajokull (2010) and Grimsvotn (2011) was resuspended into the air
and blown southwards. The event was captured by surface based optical particle
counters (OPC) in Iceland, and cloudless skies south of Iceland made it possible to
observe the resuspended ash by the Moderate Resolution Imaging Spectroradiometer
(MODIS) as the ash was transported more than 320 km over the ocean. The aim of
this study is to quantify the amount of ash that was resuspended during the event.
Simulations of the event using the Numerical Atmospheric dispersion Modeling
Environment (NAME) agree well with the location of the resuspended ash cloud observed
by MODIS. By comparing the simulated height of the resuspended ash cloud to
meteorological data we show that the maximum height of the cloud coincides with a
temperature inversion at about 1300 m asl. The total mass column loading was
retrieved from infrared MODIS channels using the ash cloud height identified from
the dispersion model output. The OPC data provide surface ash concentrations.
Using the satellite and OPC measurements the NAME dispersion model output was
calibrated and the total resuspended ash amount for the whole event estimated. |
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