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| Titel |
Equatorward dispersion of the Sarychev volcanic plume and the relation to the Asian summer monsoon |
| VerfasserIn |
Xue Wu, Sabine Griessbach, Lars Hoffmann |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250141497
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| Publikation (Nr.) |
 EGU/EGU2017-5018.pdf |
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| Zusammenfassung |
| Sulfur dioxide emissions and subsequent sulfate aerosols from strong volcanic eruptions have
large impact on global climate. Although most of previous studies attribute the global
influence to volcanic eruptions in the tropics, high-latitude volcanic eruptions are also an
important cause for global climate variations. In fact, the potential climate impact of volcanic
also largely depends on the season when eruptions occur, the erupted plume height and the
surrounding meteorological conditions.
This work focuses on the eruption of a high-latitude volcano Sarychev, and the role of
Asian summer monsoon (ASM) during the transport and dispersion of the erupted plumes.
First, the sulfur dioxide emission rate and height of emission of the Sarychev eruption in June
2009 are modelled using a Lagrangian particle dispersion model named Massive-Parallel
Trajectory Calculations (MPTRAC), together with sulfur dioxide observations of the
Atmospheric Infrared Sounder (AIRS/Aqua) and a backward trajectory approach. Then, the
transport and dispersion of the plumes are modelled with MPTRAC and validated with
sulfur dioxide observations from AIRS and aerosol observations from the Michelson
Interferometer for Passive Atmospheric Sounding (MIPAS). The modelled trajectories and
the MIPAS data both show the plumes are transported towards the tropics from
the southeast edge of the ASM (in the vertical range of 340-400K) controlled by
the clockwise winds of ASM, and from above the ASM (above 400K) in form of
in-mixing process. Especially, in the vertical range around 340-400K, a transport barrier
based on potential vorticity (PV) gradients separates the ‘aerosol hole’ inside of
the ASM circulation and the aerosol-rich surrounding area, which shows the PV
gradients based barrier may be more practical than the barrier based on the geopotential
height.
With help of ASM circulation, the aerosol transported to the tropics and stayed in the
tropical lower stratosphere for about eight months, which were the main aerosol sources
during that time. This enables the Sarychev eruption to have potential impact on global
radiative budget similar to a tropical volcanic eruption. |
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