14 Result(s)

Reference Work Entry In depth

Core Dynamo

Ulrich R. Christensen in Encyclopedia of Solid Earth Geophysics (2021)

Living Reference Work Entry In depth

Core Dynamo

Ulrich R. Christensen in Encyclopedia of Solid Earth Geophysics

Article

Global-scale equatorial Rossby waves as an essential component of solar internal dynamics

The Sun’s complex dynamics is controlled by buoyancy and rotation in the convection zone. Large-scale flows are dominated by vortical motions¹ and appear to be weaker than expected in the solar interior². One pos...

Björn Löptien, Laurent Gizon, Aaron C. Birch, Jesper Schou… in Nature Astronomy (2018)

Reference Work Entry In depth

Core Dynamo

Ulrich R. Christensen in Encyclopedia of Solid Earth Geophysics (2011)

Article

Paleomagnetic Records of Meteorites and Early Planetesimal Differentiation

The large-scale compositional structures of planets are primarily established during early global differentiation. Advances in analytical geochemistry, the increasing diversity of extraterrestrial samples, and...

Benjamin P. Weiss, Jérôme Gattacceca, Sabine Stanley… in Space Science Reviews (2010)

Chapter

Paleomagnetic Records of Meteorites and Early Planetesimal Differentiation

The large-scale compositional structures of planets are primarily established during early global differentiation. Advances in analytical geochemistry, the increasing diversity of extraterrestrial samples, and...

Benjamin P. Weiss, Jérôme Gattacceca, Sabine Stanley… in Planetary Magnetism (2010)

Article

Energy flux determines magnetic field strength of planets and stars

Some planets and many stars have magnetic fields that are generated by a convection-driven dynamo process. Stellar fields, known from their effect on the emitted light, are often 1,000 times stronger than that...

Ulrich R. Christensen, Volkmar Holzwarth, Ansgar Reiners in Nature (2009)

Article

A sheet-metal geodynamo

A decade of modelling Earth's core on computers has led to the belief that we understand what produces Earth's magnetic field. More realistic simulations are now shaking that complacency.

Ulrich R. Christensen in Nature (2008)

Article

A deep dynamo generating Mercury’s magnetic field

The latest numerical models of the geodynamo can account for the behaviour of Earth's magnetic field pretty well: Mercury has proved a harder nut to crack. Like Earth, it has a dipolar magnetic field, probably...

Ulrich R. Christensen in Nature (2006)

Article

Power requirement of the geodynamo from ohmic losses in numerical and laboratory dynamos

In the Earth's fluid outer core, a dynamo process converts thermal and gravitational energy into magnetic energy. The power needed to sustain the geomagnetic field is set by the ohmic losses (dissipation due t...

Ulrich R. Christensen, Andreas Tilgner in Nature (2004)

Article

A one-plume model of martian mantle convection

FOR at least the past two billion years, volcanism on Mars has been restricted to the Tharsis region¹. In addition, most tectonic activity on Mars², together with the long-wavelength topography and the non-hydros...

Helmut Harder, Ulrich R. Christensen in Nature (1996)

Chapter

Mantle Convection with Active Chemical Heterogeneities

The main source of mantle heterogeneity is the subduction of basaltic oceanic crust. Whether or not coherent lumps of continental crust are recycled in significant amounts is unkown. These heterogeneities will...

Ulrich R. Christensen in Crust/Mantle Recycling at Convergence Zones (1989)