
doi: 10.1029/2011jb008538
[1] The long‐term temporal behavior of intense geomagnetic flux patches at the core‐mantle boundary and the relation with lower mantle lateral heterogeneity are under debate. We apply an algorithm to detect centers of intense flux patches and track their time‐evolution in a recent archeomagnetic field model in order to study the kinematics of such intense magnetic flux patches on millennial timescale. We find that most intense flux patches appear near the edge of the tangent cylinder. Quasi‐stationary periods with small oscillations of patches occur more than drifts. Detailed comparison of the archeomagnetic patches' behavior with that seen in numerical dynamos with tomographic heat flux boundary conditions suggests that core‐mantle thermal coupling could be the cause of a statistical preference for some longitudes on the long term, which does not exclude significant time spent away from the preferred longitudes. This could explain the roughly coincident locations of high‐latitude patches in the historical geomagnetic field with that of the time‐average paleomagnetic field together with the much weaker patches intensity in the latter. Alternating eastward and westward drifts are also observed. The drifts are more westward than eastward, especially in the southern hemisphere, indicating that the time‐average zonal core flow may also be driven by core‐mantle thermal coupling. An average patch lifetime of ∼300 years is found, which we hypothesize may indicate the vortex lifetime in the outer core.
[SDU] Sciences of the Universe [physics], 550, [SDU]Sciences of the Universe [physics], 550 - Earth sciences
[SDU] Sciences of the Universe [physics], 550, [SDU]Sciences of the Universe [physics], 550 - Earth sciences
| selected citations These citations are derived from selected sources. This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically). | 44 | |
| popularity This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network. | Top 10% | |
| influence This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically). | Top 10% | |
| impulse This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network. | Top 10% |
