A polar vortex in the Earth's core
Article Abstract:
The observed structure of the Earth's magnetic field and its variation since 1870 have been used to infer the presence of an anticyclonic polar vortex with a polar upwelling in the northern hemisphere of the core. A frozen-flux analysis of the geomagnetic field near the south pole presents some evidence for flux expulsion there. However, there was no evidence of coherent vortex motion in the southern-hemisphere tangent cylinder. Anticyclonic polar vorticity near the core-mantle boundary has implications for the structure of convection deeper in the core.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1999
User Contributions:
Comment about this article or add new information about this topic:
Simulation of equatorial and high-latitude jets on Jupiter in a deep convection model
Article Abstract:
A numerical model of three-dimensional rotating convection in a relatively thin spherical shell that generates both multiple high-latitude jets and an equatorial jet of powerful winds as found on Jupiter is presented. The findings suggest that Jupiter's latitudinal transition in jet corresponds to a separation between the bottom-bounded flow structures in higher latitudes and the deep equatorial flows.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 2005
User Contributions:
Comment about this article or add new information about this topic:
Critical behaviour and the evolution of fault strength during earthquake cycles
Article Abstract:
It has been possible to use numerical calculations of quantized slip in an elastic continuum to indicate that cyclical fault strength develops naturally through a statistical selection for high-strength fault patches (asperities). This means that the asperities accumulate and eventually fail. The main stages of a characteristic quake cycle are opportunism, self organization, criticality and extinction.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1997
User Contributions:
Comment about this article or add new information about this topic:
- Abstracts: Global variation in copy number in the human genome. Effect of extrinsic mortality on the evolution of senescence in guppies
- Abstracts: Making a meal of mother. Comparative evidence for the evolution of genitalia by sexual selection. Reversal of sex roles in nuptial feeding
- Abstracts: The primate amygdala represents the positive and negative value of visual stimuli during learning. Optimal eye movement strategies in visual search
- Abstracts: The lights in the forest. Final song for an unsung hero. Caught in the crossfire: Part II
- Abstracts: A potential catalytic site revealed by the 1.7-angstroms crystal structure of the amino-terminal signalling domain of Sonic hedgehog