Huh? There's a "Sun-Earth circuit"?!?!
There is some evidence that a "Sun-Earth circuit" can exist at times of intense coronal mass ejections (CME):
Here is a recent peer-reviewed paper discussing the electric circuit theory of CME's:
2009 peer-reviewed published paper: Central European Astrophysics Bulletin
GENERATION OF LARGE SCALE ELECTRIC FIELDS IN CORONAL FLARE CIRCUITS
A large number of energetic electrons are generated during solar flares. They carry a substantial part of the flare released energy but how these electrons are created is not fully understood yet. This paper suggests that plasma motion in an active region in the photosphere is the source of large electric currents. These currents can be described by macroscopic circuits. Under special circumstances currents can establish in the corona along magnetic field lines. The energy released by these currents when moderate assumptions for the local conditions are made, is found be comparable to the flare energy.
This paper presents the electric circuit theory championed by Hannes Alfven.
Quote from the above paper:
http://arxiv.org/PS_cache/arxiv/pdf/090 ... 0813v1.pdf
Currently several different electron acceleration mechanisms in the solar corona are known. All of these mechanisms have the principle of acceleration due to electric fields in common, but differ in the processes leading to the generation of the electric field. In the present paper the generation of a large scale DC electric field is discussed in terms of electric circuits, which is related to a current generated due to photopheric plasma motion (e.g., Alfven and Carlqvist, 1967; Sen and White, 1972; Martres et al., 1973; Heyvarts, 1974; Obayashi, 1975; Akasofu, 1979; Kan et al., 1983; Melrose, 1997; Zaitsev et al., 1998; Yang et al., 2004; Zaitsev, 2005). Motivated by these papers, the electric currents are investigated in order to obtain a mechanism for acceleration of electrons to high energies. The basic idea of this mechanism is to generate the flare energy by photopheric plasma motion in active regions. This is in contradiction to the reconnection model in which the magnetic field energy in the corona is taken for the flare.
The following NASA press release reports on a CME impacting the Earth's magnetosphere:
Science@NASA (Dec. 16, 2008) -- Giant Breach in Earth's Magnetic Field Discovered
NASA wrote:NASA's five THEMIS spacecraft have discovered a breach in Earth's magnetic field ten times larger than anything previously thought to exist. Solar wind can flow in through the opening to "load up" the magnetosphere for powerful geomagnetic storms. But the breach itself is not the biggest surprise. Researchers are even more amazed at the strange and unexpected way it forms, overturning long-held ideas of space physics.
And, here is the "surprise" expressed by the scientist:
NASA wrote:"At first I didn't believe it," says THEMIS project scientist David Sibeck of the Goddard Space Flight Center. "This finding fundamentally alters our understanding of the solar wind-magnetosphere interaction."
The NASA press release go on:
NASA wrote:The magnetosphere is a bubble of magnetism that surrounds Earth and protects us from solar wind. Exploring the bubble is a key goal of the THEMIS mission, launched in February 2007. The big discovery came on June 3, 2007, when the five probes serendipitously flew through the breach just as it was opening. Onboard sensors recorded a torrent of solar wind particles streaming into the magnetosphere, signaling an event of unexpected size and importance.
And, the scientists attempt to quantify the size of the event:
http://science.nasa.gov/science-news/sc ... antbreach/
NASA wrote:"The opening was huge—four times wider than Earth itself," says Wenhui Li, a space physicist at the University of New Hampshire who has been analyzing the data. Li's colleague Jimmy Raeder, also of New Hampshire, says "1027 particles per second were flowing into the magnetosphere—that's a 1 followed by 27 zeros. This kind of influx is an order of magnitude greater than what we thought was possible."
It's important to investigate whether a connection exists between seperate observations & measurements, to see if it is possible to develop a hypothesis of an over all process or phenomenon, which encompasses the seperate physical observations & measurements.
To that effort, here is another Science@NASA press release describing the shape of CME's:
Science@NASA (April 14, 2009) -- The Surprising Shape of Solar Storms
NASA wrote:Researchers studying data from NASA's twin STEREO probes have found that ferocious solar storms called CMEs (coronal mass ejections) are shaped like a French pastry. The elegance and simplicity of the new "croissant model" is expected to dramatically improve forecasts of severe space weather.
What is a croissant shaped like? Two twisted stands of pastry dough.
http://science.nasa.gov/science-news/sc ... apr_3dcme/
NASA wrote:Coronal mass ejections are billion-ton clouds of hot magnetized gas that explode away from the sun at speeds topping a million mph. Sometimes the clouds make a beeline for Earth and when they hit they can cause geomagnetic storms, satellite outages, auroras, and power blackouts. The ability to predict the speed and trajectory of a CME is key to space weather forecasting.
"This is an important advance," says Lika Guhathakurta, STEREO program scientist at NASA headquarters in Washington DC. "From a distance, CMEs appear to be a complicated and varied population. What we have discovered is that they are not so varied after all. Almost all of the 40-plus CMEs we have studied so far with STEREO have a common shape--akin to a croissant."
Why is the shape of CME's important?
Because the morphology is suggestive of magnetic flux tubes, sometimes called Birkeland currents:
A Birkeland current usually refers to the electric currents in a planet's ionosphere that follows magnetic field lines (ie field-aligned currents), and sometimes used to described any field-aligned electric current in a space plasma. They are caused by the movement of a plasma perpendicular to a magnetic field. Birkeland currents often show filamentary, or twisted "rope-like" magnetic structure. They are also known as field-aligned currents, magnetic ropes and magnetic cables.
Let's compare the descriptions given by NASA and the Birkeland current entry:
NASA wrote:[CME's]have a common shape--akin to a croissant."
Birkeland currents often show filamentary, or twisted "rope-like" magnetic structure.
It would seem the morphology is similar between CME's "croissant" like shape and Birkeland current's twisted "rope-like" shape.
Birkeland currents are part of a "circuit" and, per the peer-reviewed published paper, GENERATION OF LARGE SCALE ELECTRIC FIELDS IN CORONAL FLARE CIRCUITS, above, CME's are also part of an electrical "circuit".
The electric circuit theory championed by Hannes Alfven.
So, yes, there is evidence that at times, there is a "Sun-Earth circuit".