I'm still mystified by the slow solar wind speed.
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link to umtof.umd.edu]
Here's one possibility:
When the high-speed solar wind emanating from the coronal holes runs into the slower solar wind, the interaction leads to a compression of the plasma and magnetic fields, forming corotating interaction regions (CIR) (Crooker et al., 1999). The CIRs seldom have fast shocks or continuous, strongly southward IMF Bz, and thus drive only moderate magnetospheric activity
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link to solarphysics.livingreviews.org]
Found an index of 111 papers relating to coronal holes and I'm hard-pressed to find any mention of a slow SW speed coronal hole. They're practically synonymous with a high-speed stream (500km/s-800km/s). Also, the big spike in density is out of character for a coronal hole. This disturbance and the one 3 days ago are most unusual. We may see some groundbreaking heliophysics papers coming out next year if somebody figures it out.
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link to solarphysics.livingreviews.org]
all this in normal conditions
this CH in question is of a southern position
the winds from it hit in a negative/southward direction
doing so, they connect with earths magnetic field and cause a storm
some CH winds are super slow, some are super fast
some winds dont connect or cause much differance
some connect and stir up a storm
it all depends on the compasition and location of the coronal hole
Coronal hole SW speeds are never super-slow. Have you any citations?
they are low a lot of the time
the speeds have a lot to do with the size and location of the coronal holes
this because of how and where the winds come from within and around the coronal holes
just look at the last, lets say 10 coronal holes that we have had earth facing
out of those 10, how many of them have had Fast winds associated with them?
how about, lets say, over 500Km?
i will look up the exact number in the morning, but its 1-2 if that
the CH we have facing us right now is only producing wind speeds just above 400km
this is to be expected as solar max arrives
coronal holes act differantly in solar minimum, compaired to solar max
as i said a few days ago, there is a LOT we still have to learn about coronal holes
but, i believe they are the key to knowing exactly when we will see the peak of this solar max. this is why i have been spending most of my spare time researching coronal holes
slower transient coronal holes appear at solar maximum in lower latitudes
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link to docs.google.com (secure)]
coronal holes at solar max
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link to docs.google.com (secure)]
Fast and Slow Wind from Solar Coronal Holes
S. BRAVO AND G. A. STEWART
"Coronal holes have been identified as the sources of high-speed streams that appear in the solar wind, but comparisons of the coronal structure and solar wind observations suggest that they may also be the sources of slow wind, which could be emerging from the bordering, highly divergent regions of the hole."
"In particular, it has been observed that some properties of the solar wind depend on its velocity regime, being clearly different for fast and slow winds. The high-speed wind (u 650 km s-1) is characterized by a high temperature, a low density, and a low mass flux, while the low-speed wind (u 400 km s-1) is cooler, denser, and has a larger mass flux."
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link to iopscience.iop.org]
