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| Titel |
Sensitivity of Model Estimates of Contemporary Global and Regional Sea-Level Changes to Geothermal Flow |
| VerfasserIn |
Christopher Piecuch, Patrick Heimbach, Rui Ponte, Gael Forget |
| 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 |
250107418
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| Publikation (Nr.) |
 EGU/EGU2015-7119.pdf |
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| Zusammenfassung |
| An ocean general circulation model in a global configuration, constrained to observations
over the period 1993–2010 as part of the ECCO (Estimating the Circulation and
Climate of the Ocean) project, has been used to to infer the influence of geothermal
flow on estimates of contemporary sea level changes. Two distinct simulations are
compared, which differ only with regard to whether they apply geothermal flow as a
bottom boundary condition. Geothermal flow forcing increases the global mean
sea level trend over 1993–2010 by 0.11 mm yr-1 in the perturbation simulation
relative to the control simulation with no geothermal forcing, mostly due to increased
net thermal expansion in the deep ocean (below 2000 m). The Southern Ocean is
particularly sensitive to geothermal flow, with differences between regional sea
level trends from the perturbation and control simulations up to ±1 mm yr-1 in
some places. More generally, it is suggested that ocean heat transports redistribute
the geothermal input along constant pressure surfaces and constant surfaces of
temperature or salinity. This redistribution of heat results in stronger (weaker) steric height
trend differences between the two solutions over deeper (shallower) areas, and
effects anomalous redistribution of ocean mass from deeper to shallower areas
in the perturbation solution relative to the control solution. Given the sparsity of
heat flow measurements, ocean state estimation could (in principle) be a means
to the end of constraining solid Earth heat flow estimates over the global ocean. |
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