Show simple item record

dc.contributor.author
Schmid, Timo
dc.contributor.supervisor
Radic, Valentina
dc.contributor.supervisor
Wernli, Heini
dc.contributor.supervisor
Farinotti, Daniel
dc.contributor.supervisor
Hermann, Mauro
dc.date.accessioned
2022-08-05T11:58:05Z
dc.date.available
2022-08-03T08:11:08Z
dc.date.available
2022-08-03T11:39:00Z
dc.date.available
2022-08-05T11:58:05Z
dc.date.issued
2021-05-31
dc.identifier.uri
http://hdl.handle.net/20.500.11850/561596
dc.identifier.doi
10.3929/ethz-b-000561596
dc.description.abstract
The Greenland Ice Sheet (GrIS) has experienced increasing ice loss in the past decades and the trend is expected to continue due to climate change. However, large uncertainties about the magnitude of Greenland’s future ice loss remain. One process that contributes to this uncertainty are transient ice accelerations, so-called ice speed-up events, caused by a short-term increase in rain-/meltwater, which descends to the glacier bed and can enhance basal sliding. Here, we investigate this phenomenon focusing on two main objectives. First, we present an analysis of local conditions on the Russell glacier in Southwest Greenland, which confirms the importance of meltwater variability for ice speed-up events. We find the strongest influence in early summer with correlations between surface melt and ice velocities above 0.8 in May and identify a typical lag of zero to one day between meltwater peaks and their ice velocity responses. Contrastingly, we find rainfall to have a minor influence with only 4 out of 51 ice speed-up events, where daily increases in water input on the glacier are dominated by rainfall. Secondly, we study the atmospheric drivers of ice speed-up events using a Self-Organizing Maps (SOM) classification of synoptic weather situations over Greenland. Two main patterns that induce most ice speed-up events emerge: The first pattern is characterized by southerly advection of warm and moist air that increases local surface melting by enhanced downward longwave radiation and high sensible heat flux. The second one is a large-scale anticyclone that induces GrIS surface melting through strong downward shortwave radiation and descending air that warm adiabatically. Our study provides new insights into atmospheric drivers of short-term ice accelerations and contributes towards an effort to constrain the impact of ice speed-up events on GrIS mass loss under a changing climate, which can be achieved when more high-resolution ice velocity data is available.
en_US
dc.format
application/pdf
en_US
dc.language.iso
en
en_US
dc.publisher
ETH Zurich
en_US
dc.rights.uri
http://rightsstatements.org/page/InC-NC/1.0/
dc.subject
Greenland ice sheet
en_US
dc.subject
Atmospheric dynamics
en_US
dc.subject
Glaciology
en_US
dc.title
Influence of synoptic scale weather variability on ice speed-up events in Southwest Greenland
en_US
dc.type
Master Thesis
dc.rights.license
In Copyright - Non-Commercial Use Permitted
ethz.size
69 p.
en_US
ethz.publication.place
Zurich
en_US
ethz.publication.status
published
en_US
ethz.leitzahl
ETH Zürich::00002 - ETH Zürich::00012 - Lehre und Forschung::00007 - Departemente::02350 - Dep. Umweltsystemwissenschaften / Dep. of Environmental Systems Science::02717 - Institut für Atmosphäre und Klima / Inst. Atmospheric and Climate Science::03854 - Wernli, Johann Heinrich / Wernli, Johann Heinrich
en_US
ethz.leitzahl
ETH Zürich::00002 - ETH Zürich::00012 - Lehre und Forschung::00007 - Departemente::02350 - Dep. Umweltsystemwissenschaften / Dep. of Environmental Systems Science::02717 - Institut für Atmosphäre und Klima / Inst. Atmospheric and Climate Science::03854 - Wernli, Johann Heinrich / Wernli, Johann Heinrich
ethz.date.deposited
2022-08-03T08:11:18Z
ethz.source
FORM
ethz.eth
yes
en_US
ethz.availability
Open access
en_US
ethz.rosetta.installDate
2022-08-05T11:58:13Z
ethz.rosetta.lastUpdated
2022-08-05T11:58:13Z
ethz.rosetta.exportRequired
true
ethz.rosetta.versionExported
true
ethz.COinS
ctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.atitle=Influence%20of%20synoptic%20scale%20weather%20variability%20on%20ice%20speed-up%20events%20in%20Southwest%20Greenland&rft.date=2021-05-31&rft.au=Schmid,%20Timo&rft.genre=unknown&rft.btitle=Influence%20of%20synoptic%20scale%20weather%20variability%20on%20ice%20speed-up%20events%20in%20Southwest%20Greenland
 Search print copy at ETH Library

Files in this item

Thumbnail

Publication type

Show simple item record