Sunspot 484

General "Science" forum - where you may ask questions about the science of propagation, as well as help answer the technical questions regarding propagation.

Sunspot 484

Postby ku4a » Wed Oct 22, 2003 4:07 pm

I understand that Sunspot 484, which I believe is on the visible side of the sun, is one of the biggest sunspots in years. Is a large sunspot good or bad? I.e., is it more likely to flare and cause geomagnetic disturbances, or just increase the F-layer ionoization nicely and give us higher MUFs?
Chris
KU4A
ku4a
Friend
 
Posts: 67
Joined: Mon Aug 18, 2003 12:31 pm
Location: Kentucky

big CME from 484

Postby ku4a » Thu Oct 23, 2003 8:38 pm

http://www.foxnews.com/story/0,2933,100981,00.html

Looks like I got the answer to my question :) at least for now.
Chris
KU4A
ku4a
Friend
 
Posts: 67
Joined: Mon Aug 18, 2003 12:31 pm
Location: Kentucky

Re: big CME from 484

Postby NW7US » Thu Oct 23, 2003 9:06 pm

ku4a wrote:http://www.foxnews.com/story/0,2933,100981,00.html

Looks like I got the answer to my question :) at least for now.


I don't think that this news story fully explores the current event. The latest warning/alert forecast for this is as follows:

(From NOAA):
Code: Select all
Forecast for next 24 hours:

Space weather for the next 24 hours is expected to be minor.
Geomagnetic storms reaching the G1 level are expected.
Radio blackouts reaching the R1 level are expected.


This takes into account that the IMF is mostly oriented toward the north. When this is oriented south (Bz is negative), then it will affect the geomagnetic field. But, if north (Bz is positive), then it will not affect the geomagnetic field.

When the CME glances the Earth's magnetosphere, the IMF has to be south (Bz negative), if it were to cause a geomagnetic storm. The thinking at this time is that the Bz will not go negative, or if it will, it will not go very far. Thus, the geomagnetic activity level should not go too high, at most minor storm level during the late afternoon and early evening of the 24th (local time).

By the way, the large sunspot is not the cause of geomagnetic storms. The IMF and solar wind speed, along with enhancements from CMEs, cause geomagnetic storminess. If the sunspot group throws a flare, however, we might have a short radio blackout.

The forecast is for minor to moderate flaring.
73, de NW7US (Tomas David Hood)
.. Contributing editor, Propagation Columns in:
.... CQ Magazine, CQ VHF Quarterly, Popular Communications Magazine

Some of my websites:
My Amateur Radio hobby... | YouTube - NW7US Channel
SunspotWatch.com | NW7US on Facebook | Space Weather and Radio on Facebook
User avatar
NW7US
Site Admin
 
Posts: 260
Joined: Tue Aug 05, 2003 7:25 am
Location: Omaha, NE
Callsign: NW7US
Twitter: @NW7US
YouTube Channel: http://youtube.com/user/NW7US


Return to Questions and Answers about Propagation

Who is online

Users browsing this forum: No registered users and 1 guest