More Information in the link. Enjoy.An upper layer of Earth's atmosphere recently collapsed in an unexpectedly large contraction, the sheer size of which has scientists scratching their heads, NASA announced Thursday.
The layer of gas called the thermosphere is now rebounding again. This type of collapse is not rare, but its magnitude shocked scientists.
"This is the biggest contraction of the thermosphere in at least 43 years," said John Emmert of the Naval Research Lab, lead author of a paper announcing the finding in the June 19 issue of the journal Geophysical Research Letters. "It's a Space Age record."
The collapse occurred during a period of relative solar inactivity called a solar minimum from 2008 to 2009. These minimums are known to cool and contract the thermosphere, however, the recent collapse was two to three times greater than low solar activity could explain.
I think what they're failing to acknowledge is electromagnetic induction from the fluctuating Interplanetary Magnetic Field (a time-varying field) causing inductive heating in the thermosphere, which should be treated as a plasma because with a significant population of free ions and electrons, that's what it is. The Ap index, which measures geomagnetic storms, is a pretty good proxy for IMF activity. The slope of the Ap index matches the slope of the thermosphere density/temp more closely than the other indices of EUV and F10.7 solar flux.According to Emmert and colleagues, low solar EUV accounts for about 30% of the collapse. Extra CO2 accounts for at least another 10%. That leaves as much as 60% unaccounted for.
Now, consider the fact that the IMF is a time-varying magnetic field.An inductively coupled plasma (ICP) is a type of plasma source in which the energy is supplied by electrical currents which are produced by electromagnetic induction, that is, by time-varying magnetic fields.
This graph of the Ap index (a measure of geomagnetic storm activity) illustrates the influence of the time varying Interplanetary Magnetic Field. From 2000 until nearly 2006, the higher frequency and higher degree of the oscillations with the stronger field intensity would induce more heating in the thermosphere while the less frequent lower degree oscillations with the weaker field intensity would induce less heating. The frequency and strength of CME's, as well as "coronal holes" (phase space holes anyone?) would be a contributing factors as well, since they also produce geomagnetic storms.The response of the neutral thermosphere to geomagnetic storms is an important aspect of the study of “space weather”. Yet, this response above the magnetic dip equator has rarely been measured on the dayside because a satellite-borne instrument is required. WINDII, the WIND Imaging Interferometer on board UARS, NASA's Upper Atmosphere Research Satellite, measured emission rates and apparent temperatures to altitudes as high as 270 km using its O(1S) 558 nm green line channel several days each week during 1993. On 2 days close to equinox in 1993 the maximum Kp index exceeded 7, and these days were selected for comparison with surrounding days of lesser magnetic activity.
Evidence for thermospheric heating is seen in the Doppler broadening increase of 100 K, the green line volume emission rate increase of 30–78%, and the emission rate scale height increase of 5 km, all measured at 250 km in comparisons between storm and non-storm conditions.
I think the Ap index will drop back down again due to less frequent and lower degree IMF oscillations recently.Important clues may be found in the way the thermosphere rebounds. Solar minimum is now coming to an end, EUV radiation is on the rise, and the thermosphere is puffing up again. Exactly how the recovery proceeds could unravel the contributions of solar vs. terrestrial sources.
[Aug 10, 2010] Raging wildfires in western Russia have reportedly doubled average daily death rates in Moscow. Diluvial rains over northern Pakistan are surging south – the UN reports that 6 million have been affected by the resulting floods.
It now seems that these two apparently disconnected events have a common cause. They are linked to the heatwave that killed more than 60 in Japan, and the end of the warm spell in western Europe. The unusual weather in the US and Canada last month also has a similar cause.
According to meteorologists monitoring the atmosphere above the northern hemisphere, unusual holding patterns in the jet stream are to blame. As a result, weather systems sat still. Temperatures rocketed and rainfall reached extremes...
Stationary patterns in the jet stream are called "blocking events". They are the consequence of strong Rossby waves, which push westward against the flow of the jet stream. They are normally overpowered by the jet stream's eastward flow, but they can match it if they get strong enough. When this happens, the jet stream's meanders hold steady, says Blackburn, creating the perfect conditions for extreme weather....
There is some tentative evidence that the sun may be involved. Earlier this year astrophysicist Mike Lockwood of the University of Reading, UK, showed that winter blocking events were more likely to happen over Europe when solar activity is low – triggering freezing winters (New Scientist, 17 April, p 6).
Now he says he has evidence from 350 years of historical records to show that low solar activity is also associated with summer blocking events (Environmental Research Letters, in press). "There's enough evidence to suspect that the jet stream behaviour is being modulated by the sun," he says.
Blackburn says that blocking events have been unusually common over the last three years, for instance, causing severe floods in the UK and heatwaves in eastern Europe in 2007. Solar activity has been low throughout.
http://www.latimes.com/news/local/la-me ... 7349.storyHe was aboard the station's helicopter shooting footage of sunset over the ocean about 5 p.m. when he noticed a spiral-shaped vapor trail and zoomed in to get a better look. The on-board camera showed a plume twisting up from the horizon and narrowing as it climbed into the sky northwest of Santa Catalina Island, he said. "Whatever it was, it was spinning up into the sky kind of like a spiral," he said. "It was quite a sight to see. It was spectacular."
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