Re: [Methane Hydrate Club] Solar Activity Report for 1/31/03
- View SourceDavid, I have some questions down in the text. Thanks. Walter
On Sat, 01 Feb 2003 07:26:03 -0000 "David <b1blancer1@...>"
** Aurora Watch In Effect **
In a perfect illustration of the fact that you don't have to have a
flare to create a CME, a disappearing filament generated a full-halo
CME on the 30th.
OK filaments as well as holes can cause CMEs. You said it was
pointing in the right direction, does this mean towards us? Or close
enough to the South pole to combine with my SE idea?
A filament is a giant loop of gas which is suspended
by a magnetic field above the visible surface of the sun. If the
magnetic field becomes unstable, the filament can suddenly collapse
back down. It causes a "splash," much the same as a rock falling into
water, except in this case the material thrown up by the spash is
about a billion tons of white-hot plasma in the form of a CME, and
it's headed this way.
How do you know if it is headed this way? Can you see it coming
and its progressing path as it comes? Also do any of the loops or holes
in the Northern Hemisphere of the Sun cause CMEs? Or are the CMEs that
come our way mostly directed at us on the central Sun area? It is my
thinking that CMEs don't cause SE, but it is caused by steady South
currents put into motion by central Sun functions. Walter
It should arrive sometime tomorrow, and
geomagnetic storm conditions are at least a possibility. There's also
a fairly large coronal hole that has rotated into an Earth-pointing
position. The solar wind gusts from that should arrive on or about
The current solar and geomagnetic conditions are :
NOAA sunspot number : 96
SFI : 120
A index : 13
K index : 2
Solar wind speed : 407.3 km.sec
Solar wind density : 0.4 protons/cc
Solar wind pressure : 0.1 nPa
IMF : 8.9 nT
IMF Orientation : 5.7 nT North
Conditions for the last 24 hours :
Space weather for the past 24 hours has been minor. Geomagnetic storms
reaching the G1 level occurred.
Forecast for the next 24 hours :
No space weather storms are expected for the next 24 hours.
Solar activity forecast :
Solar activity is expected to be low for the next three days.
Geonagnetic activity forecast :
The geomagnetic field is expected to be mostly unsettled tomorrow, but
there is a chance for some active periods. Effects from the halo CME
of 30 January are expected to arrive some time around midday tomorrow
and should increase levels to active through the second day.
Conditions should decline to unsettled to slightly active on the third
Recent significant solar flare activity :
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- View Source
>OK filaments as well as holes can cause CMEs. You said it wasOne clarification I need to make : A coronal hole doesn't generate a
> pointing in the right direction, does this mean towards us? OR close
> enough to the South pole to combine with my SE idea?
CME. What a coronal hole does allow is high speed solar wind to
escape. The solar wind is generated below the corona. The corona
slows the solar wind down as it passed through it. When there's a
coronal hole, the solar wind isn't slowed down as it passes through
the hole. The collapsing filament I mentioned shot off a Coronal Mass
Ejection (CME) towards us.
> How do you know if it is headed this way? Can you see it comingI knew it was headed this way because the Space Environment Center
> and its progressing path as it comes? Also do any of the loops or holes
> in the Northern Hemisphere of the Sun cause CMEs? Or are the CMEs that
> come our way mostly directed at us on the central Sun area? It is my
> thinking that CMEs don't cause SE, but it is caused by steady South
> currents put into motion by central Sun functions. Walter
said so! ;-) They seem to know what they're talking about. If you
see an Earth-directed CME on the images from the SOHO satellite
coronagraph, it looks like a giant, expanding smoke-ring, or halo,
thus the phrase full-halo CME. Now, the SOHO cameras suffer from the
same limitation that any camera does, and that it has no depth
perception. A CME fired off directly away from Earth looks very
similar to one coming right at us. That's why the folks who analyze
the ddata from SOHO also look for other indications such as radio wave
burts, to correlate with the event. If you see a full-halo CME at the
same time you see a radio burst from the sun, it's a pretty safe bet
the CME is headed our way. If, on the other hand, you see the CME and
no other indications of any activity, then it was probably a backside
event and headed away from us.
Northern hemispere solar flares and filaments can certainly generate
CME's. Their exact direction of travel will be directed by the
magnetic field that's in the area at the time.