Magyar oldal English site

Site map
2012-07-13 19:27:21 (Originally published at: -)

Don't miss the next aurora!

You may be living too far from the south or the north pole to see the aurora regularly. But rarely auroral activity can be so intense that it can be seen even from equator (once in 100 years). If you are living farther from the equator you may see auroras more often (maybe once per 20 year). But the problem is that nobody can really predict when does the auroras come down from the poles enough to see it from your country. But there are signs of the upcoming auroras.

Is aurora visible in my country now?

You can see how big the auroral oval now, here: http://www.swpc.noaa.gov/pmap/ (NOAA POES Auroral Activity)

Or here: https://cssdp.ca/ssdp/app/static/related_projects/rt_oval.html (CSSDP real time auroral oval)

Also a numeric representation exists called Kp index which is a logarithmic scale and represents the geomagnetic activity. You can see the current Kp index plot here: http://www.swpc.noaa.gov/rt_plots/Kp.gif

The bigger the Kp index is the more the auroral oval will expand. You can translate Kp indexes to places using maps that can be found here: http://www.spaceweather.com/glossary/magneticlatitude.html (What’s My Geomagnetic Latitude?)

Will aurora be visible in my country tomorrow?

Kp index depends on the speed of the solar wind. When solar activity is high, the Sun often spits out massive amounts of plasma with high speeds (even 2000km/s), this is called coronal mass ejection. If one such cloud hits Earth it can trigger high aurora activity. To see whether such cloud heading towards our Earth you can view the movie of the latest 100 LASCO images here: http://sohodata.nascom.nasa.gov/cgi-bin/soho_movie_theater. Or look at the latest news on the http://spaceweather.com/.

A fast CME can arrive to Earth in one day.

When does CME’s happen?

When magnetic field lines near sunspots reconnect releasing huge amounts of energy. This event is called solar flare. When solar flare happens, the Sun’s X-ray radiation increase. The GOES satellites can detect this. The X-ray radiation levels is updating in every minute and the plots are available to the general public here: http://www.swpc.noaa.gov/rt_plots/xray_5m.html. When X-ray flux reaches 10-4W/m2, that’s a strong (X class) flare. If it happened on an Earth-facing sunspot, then it’s sure that a CME going towards Earth.

When does strong flares happen?

During and little after solar maximum. Solar maximums occur roughly 9-13 years. During the maximum a lot of sunspot appear and solar flares are frequent. The last maximum was in 2000, the next will be sometime in 2012 or 2013.

Which sunspot can cause strong flares?

Usually the big sunspot groups. Big sunspots often have twisted magnetic fields that can reconnect and cause flares. These sunspots often have delta magnetic field. The magnetic class of the sunspots can be seen in the NOAA daily reports. The sunspot groups are numbered. To see which spot number corresponds to which sunspot, look at this page for example: http://solarmonitor.org.

Now you know everything. Don’t miss the next aurora.

Recently updated:

Content is available on IPFS! Feel free to host and pin my content if you like it. http://gateway.ipfs.io/ipns/calmarius.net/index.htm

comments powered by Disqus
Logo