GEO MAGNETIC FIELD etc.
According to the present structure of the GMF, there could be 3 local vortices in the mantle two in the Northern Hemisphere and one in the South Hemisphere , each creating its own bar magnet. If it is thermal convection initiated circulation from the centre towards periphery, than it is more likely to be a conical shape vortex, supported by Coriolis Force, rather than a cylindrical vortex (suggested by Jackson et al).
There is also problem in explaining the South Atlantic anomaly using Jackson's model. In the above conical vortex model solution is simple: Cone's apex is deep down in the mantle, off centre, inclined towards South America, so. the vector sum of the two weaker fields from the North and the stronger from the South, add to the low intensity as it is currently observed.
Standard model (Jackson et al) of rotating cylinders does not lend itself to an easy reversal, since rotation needs to be reversed. However, if the field is generated by separate cylindrical vortices as suggested above, then these can move around globe freely (as paleo records show) maintaining direction of rotation. In such a scenario there would not be a catastrophic change in the Sun-Earth electromagnetic connection and no major disruption of the Earth's biosphere.
Closest to the surface is probably the Hudson Bay area vortex. Solar storms induce strong electric currents, acting as an electro-magnetic brake on the vortex itself, as reflected in the negative correlation between solar activity and geomagnetic field in the HB area.
Correspondingly the Siberian vortex was gaining in the strength, which may indicate that there is physical link between two, and the thermal convection energy is re-channelled from the Hudson Bay to the Siberian vortex, which may be located further down and less affected by the solar activity.
It appears that the annual change in the Siberia’s magnetic pole is directly responding to the solar output, while the Hudson Bay with some 30+ years delay.
Another possible effect of the strong 'ring' currents induction under the Arctic ocean may manifest itself as an electro-magnetic brake on the magma vortex. As the angular momentum of the Earth's rotation must be conserved, slowdown of the Hudson Bay vortex and increased velocity in the stronger Siberian one, will be reflected on the Earth's rotation . If so than this would be registered in the 'Length of Day' - LOD. This indeed is the case as there is a close correlation between LOD and the Earth's (z) field intensity as calculated for the North Pole. As the Hudson Bay weakens the effect may eventually disappear.
As already stated effect of the solar storms appear to be mainly on the Hudson Bay vortex, where the strength of magnetic field is falling, it is likely that in the foreseeable future (century scale), this vortex may weaken so much and eventually disappear, in which case the magnetic pole would be found in the Central Siberia (64-65N, 107-110E).
This may have profound consequences for the Earth's magnetic field, having a bulge in the East hemisphere with opposite pole at ~ 60S, 140E).
NASA's fleet of THEMIS spacecraft discovered a flux rope pumping a 650,000 Amp current into the Arctic. "The satellites have found evidence for magnetic ropes connecting Earth's upper atmosphere directly to the Sun," says Dave Sibeck, project scientist for the mission at the Goddard Space Flight Center. "We believe that solar wind particles flow in along these ropes, providing energy for geomagnetic storms". Even more impressive was the substorm's power. Angelopoulos estimates the total energy of the two-hour event at five hundred thousand billion (5 x 1014) Joules. That's approximately equivalent to the energy of a magnitude 5.5 earthquake.
See also Solar Activity Modulation
There are two high-latitude current systems. One system comprises Hall currents, which flow perpendicular to both the electric and magnetic fields and are strongest near 105 kilometers altitude. The other system is made up of Pedersen currents, which flow perpendicular to the magnetic field and parallel to the electric field and are strongest near 125 kilometres altitude. These two ionospheric current systems connect via field-aligned currents to the magnetospheric current system.
Geomagnetic field in both North and the South hemisphere has an effect on the polar vortex, eventually reflecting its influence on the global atmospheric movements, polar and global temperatures.
In the winter difference in insolation between mid and high latitudes is the greatest. Deprived of energy, the stratosphere over the Arctic grows cold creating a low-pressure system in the stratosphere that sits over the Arctic throughout the winter. Further south the air is warmer and air pressure is higher in the stratosphere causing the air to flow away from the high-pressure system towards the low-pressure system. Due to the Earth's rotation strong counter-clockwise Arctic vortex is generated.
Polar vortex in the arctic often is split up, and this appear to affect not only stratosphere but troposphere too. In contrast Antarctica vortex is pretty constant, only one case of sudden stratospheric warming SSW was recorded since 1950 (in 2002, science is puzzled by the event, but there is a simple explanation for it). Polar vortex is frequently (but not all the time) under the influence of the geomagnetic field, I suspect it depends on the extent of ionisation.
Here is an example of the North Hemisphere's magnetic field's bifurcation possible effect on the Arctic's winter temperatures:
Antarctic’s magnetic field
HUDSON BAY AREA MAGNETIC FLUX AND GLOBAL TEMPERATURE
the very first result of a foray into climate science, for more details see:
More charts can be found here:
Graphs and Formulae
© m.a. vukcevic