Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Modeling ocean-induced rapid Earth rotation variations: an update
https://orcid.org/0000-0003-4132-7395
https://orcid.org/0000-0001-6250-7921
https://orcid.org/0000-0001-7206-6461
https://orcid.org/0000-0002-7584-6356
Abstract We revisit the problem of modeling the ocean’s contribution to rapid, non-tidal Earth rotation variations at periods of 2–120 days. Estimates of oceanic angular momentum (OAM, 2007–2011) are drawn from a suite of established circulation models and new numerical simulations, whose finest configuration is on a $$^\circ $$ grid. We show that the OAM product by the Earth System Modeling Group at GeoForschungsZentrum Potsdam has spurious short period variance in its equatorial motion terms, rendering the series a poor choice for describing oceanic signals in polar motion on time scales of less than $$\sim $$2 weeks. Accounting for OAM in rotation budgets from other models typically reduces the variance of atmosphere-corrected geodetic excitation by $$\sim $$54% for deconvolved polar motion and by $$\sim $$60% for length-of-day. Use of OAM from the $$^\circ $$ model does provide for an additional reduction in residual variance such that the combined oceanic–atmospheric effect explains as much as 84% of the polar motion excitation at periods < 120 days. Employing statistical analysis and bottom pressure changes from daily Gravity Recovery and Climate Experiment solutions, we highlight the tendency of ocean models run at a 1$$^\circ $$ grid spacing to misrepresent topographically constrained dynamics in some deep basins of the Southern Ocean, which has adverse effects on OAM estimates taken along the 90$$^\circ $$ meridian. Higher model resolution thus emerges as a sensible target for improving the oceanic component in broader efforts of Earth system modeling for geodetic purposes.
Modeling ocean-induced rapid Earth rotation variations: an update
https://orcid.org/0000-0003-4132-7395
https://orcid.org/0000-0001-6250-7921
https://orcid.org/0000-0001-7206-6461
https://orcid.org/0000-0002-7584-6356
Abstract We revisit the problem of modeling the ocean’s contribution to rapid, non-tidal Earth rotation variations at periods of 2–120 days. Estimates of oceanic angular momentum (OAM, 2007–2011) are drawn from a suite of established circulation models and new numerical simulations, whose finest configuration is on a $$^\circ $$ grid. We show that the OAM product by the Earth System Modeling Group at GeoForschungsZentrum Potsdam has spurious short period variance in its equatorial motion terms, rendering the series a poor choice for describing oceanic signals in polar motion on time scales of less than $$\sim $$2 weeks. Accounting for OAM in rotation budgets from other models typically reduces the variance of atmosphere-corrected geodetic excitation by $$\sim $$54% for deconvolved polar motion and by $$\sim $$60% for length-of-day. Use of OAM from the $$^\circ $$ model does provide for an additional reduction in residual variance such that the combined oceanic–atmospheric effect explains as much as 84% of the polar motion excitation at periods < 120 days. Employing statistical analysis and bottom pressure changes from daily Gravity Recovery and Climate Experiment solutions, we highlight the tendency of ocean models run at a 1$$^\circ $$ grid spacing to misrepresent topographically constrained dynamics in some deep basins of the Southern Ocean, which has adverse effects on OAM estimates taken along the 90$$^\circ $$ meridian. Higher model resolution thus emerges as a sensible target for improving the oceanic component in broader efforts of Earth system modeling for geodetic purposes.
Modeling ocean-induced rapid Earth rotation variations: an update
https://orcid.org/0000-0003-4132-7395
https://orcid.org/0000-0001-6250-7921
https://orcid.org/0000-0001-7206-6461
https://orcid.org/0000-0002-7584-6356
Abstract We revisit the problem of modeling the ocean’s contribution to rapid, non-tidal Earth rotation variations at periods of 2–120 days. Estimates of oceanic angular momentum (OAM, 2007–2011) are drawn from a suite of established circulation models and new numerical simulations, whose finest configuration is on a $$^\circ $$ grid. We show that the OAM product by the Earth System Modeling Group at GeoForschungsZentrum Potsdam has spurious short period variance in its equatorial motion terms, rendering the series a poor choice for describing oceanic signals in polar motion on time scales of less than $$\sim $$2 weeks. Accounting for OAM in rotation budgets from other models typically reduces the variance of atmosphere-corrected geodetic excitation by $$\sim $$54% for deconvolved polar motion and by $$\sim $$60% for length-of-day. Use of OAM from the $$^\circ $$ model does provide for an additional reduction in residual variance such that the combined oceanic–atmospheric effect explains as much as 84% of the polar motion excitation at periods < 120 days. Employing statistical analysis and bottom pressure changes from daily Gravity Recovery and Climate Experiment solutions, we highlight the tendency of ocean models run at a 1$$^\circ $$ grid spacing to misrepresent topographically constrained dynamics in some deep basins of the Southern Ocean, which has adverse effects on OAM estimates taken along the 90$$^\circ $$ meridian. Higher model resolution thus emerges as a sensible target for improving the oceanic component in broader efforts of Earth system modeling for geodetic purposes.
Modeling ocean-induced rapid Earth rotation variations: an update
Harker, Alexander A. (Autor:in) / Schindelegger, Michael (Autor:in) / Ponte, Rui M. (Autor:in) / Salstein, David A. (Autor:in)
Journal of Geodesy ; 95
2021
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
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