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dc.contributor.author
Eugster, Werner
dc.contributor.contactPerson
Eugster, Werner
dc.contributor.dataCollector
Eugster, Werner
dc.contributor.producer
Eugster, Werner
dc.contributor.projectLeader
Eugster, Werner
dc.contributor.projectManager
Eugster, Werner
dc.date.accessioned
2018-02-09T09:20:14Z
dc.date.available
2017-11-05T15:44:38Z
dc.date.available
2017-11-06T13:34:27Z
dc.date.available
2017-11-29T09:54:32Z
dc.date.available
2018-02-09T09:20:14Z
dc.date.issued
2017
dc.identifier.uri
http://hdl.handle.net/20.500.11850/204632
dc.identifier.doi
10.3929/ethz-b-000204632
dc.description.abstract
The vernal equinox total solar eclipse of 20 March 2015 produced a maximum occultation of 65.8 to 70.1% over Switzerland during the morning hours (09:22 to 11:48 CET). Skies were generally clear over the Swiss Alps due to a persistent high-pressure band between the UK and Russia associated with a rather weak pressure gradient over the continent. To assess the effects of penumbral shading on near-surface meteorology across Switzerland, air temperature data measured at 10-minute intervals at 184 MeteoSwiss weather stations that reported air temperature at 10-minute intervals were used. Wind speed and direction data were available from 165 of these stations. Additionally, six Swiss FluxNet eddy covariance flux (ECF) sites provided turbulent measurements at 20 Hz resolution. During maximum occultation the temperature drop was up to 5.8 K at a mountain site where cold air can pool in a topographic depression. The bootstrapped average of the maximum temperature drops of all 184 MeteoSwiss sites during the solar eclipse was 1.51 ± 0.02 K (mean ± SE). A detailed comparison with literature values since 1834 showed a temperature decrease by 2.6 ± 1.7 K (average of all reports), with extreme values up to 11 K. On fair weather days under weak larger scale pressure gradients, local thermo-topographic wind systems develop that are driven by small-scale pressure and temperature gradients. At one ECF site, the penumbral shading delayed the morning transition from down-valley to up-valley wind conditions. At another site, it prevented this transition from occurring at all. Data from the 165 MeteoSwiss sites measuring wind direction did not show a consistent pattern of wind direction response to the passing of the penumbral shadow. These results suggest that the local topographic setting had an important influence on the temperature drop and the wind flow patterns during the eclipse. A significant cyclonic effect of the passing penumbral shadow was found in the elevation range ≈1700–2700 m a.s.l., but not at lower elevations of the Swiss Plateau. This contrasts with an earlier theory that the anticyclonic outflow should reach as far as ≈2400 km from the center of the eclipse, which would have included all of Switzerland during the 2015 eclipse. Thus, measurable effects of penumbral shading on the local wind system could be even found at ≈2000 km from the path of the eclipse (that is, Switzerland during the 2015 eclipse), and our results tend to lend support to a newer theory that the anticyclonic cold-air outflow from the center of the eclipse only extends ≈1600 km outwards, with cyclonic flow beyond that distance.
en_US
dc.format
text/plain
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dc.format
text/csv
en_US
dc.format
application/zip
en_US
dc.format
image/jpeg
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dc.language.iso
en
en_US
dc.publisher
ETH Zurich
en_US
dc.rights.uri
http://creativecommons.org/licenses/by-sa/4.0/
dc.subject
solar eclipse
en_US
dc.subject
temperature drop
en_US
dc.subject
wind direction change
en_US
dc.subject
Switzerland
en_US
dc.title
Supplement to: Effects of vernal equinox solar eclipse on temperature and wind direction in Switzerland
en_US
dc.type
Dataset
dc.rights.license
Creative Commons Attribution-ShareAlike 4.0 International
ethz.size
28.67 MB
en_US
ethz.publication.place
Zurich
en_US
ethz.leitzahl
ETH Zürich::00002 - ETH Zürich::00012 - Lehre und Forschung::00007 - Departemente::02350 - Dep. Umweltsystemwissenschaften / Dep. of Environmental Systems Science::02703 - Institut für Agrarwissenschaften / Institute of Agricultural Sciences::03648 - Buchmann, Nina / Buchmann, Nina
en_US
ethz.leitzahl
ETH Zürich::00002 - ETH Zürich::00012 - Lehre und Forschung::00007 - Departemente::02350 - Dep. Umweltsystemwissenschaften / Dep. of Environmental Systems Science::02722 - Institut für Terrestrische Oekosysteme / Institute of Terrestrial Ecosystems::03798 - Kirchner, James W. / Kirchner, James W.
en_US
ethz.leitzahl.certified
ETH Zürich::00002 - ETH Zürich::00012 - Lehre und Forschung::00007 - Departemente::02350 - Dep. Umweltsystemwissenschaften / Dep. of Environmental Systems Science::02703 - Institut für Agrarwissenschaften / Institute of Agricultural Sciences::03648 - Buchmann, Nina / Buchmann, Nina
en_US
ethz.leitzahl.certified
ETH Zürich::00002 - ETH Zürich::00012 - Lehre und Forschung::00007 - Departemente::02350 - Dep. Umweltsystemwissenschaften / Dep. of Environmental Systems Science::02722 - Institut für Terrestrische Oekosysteme / Institute of Terrestrial Ecosystems::03798 - Kirchner, James W. / Kirchner, James W.
ethz.date.retentionend
indefinite
en_US
ethz.date.retentionendDate
n/a
ethz.relation.isSupplementTo
10.3929/ethz-b-000211219
ethz.date.deposited
2017-11-05T15:44:39Z
ethz.source
FORM
ethz.eth
yes
en_US
ethz.availability
Open access
en_US
ethz.rosetta.installDate
2017-11-06T13:35:01Z
ethz.rosetta.lastUpdated
2019-02-02T14:29:25Z
ethz.rosetta.versionExported
true
ethz.COinS
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