Global Variations in the Geomagnetic Record

I LOVE finding out about different ways to appreciate the Sun and light in general. Use this forum to post your info or questions about various outside the mainstream ways to appreciate our life giving star!
Post Reply
User avatar
Carbon60
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 5491
Joined: Wed Mar 07, 2012 12:33 pm
Location: Lancashire, UK

Global Variations in the Geomagnetic Record

Post by Carbon60 » Sun Dec 14, 2014 2:04 pm

Hi All,

I thought it would be interesting to show how Earth’s magnetic field varies on a global scale with time through one day (Dec 12th) and how this is related to the location of each magnetic recording observatory.

The image below shows the variation in the ‘Y-component’ (East-West magnetic field vector) for selected magnetic observatories located around the globe in Hawaii, North America/Canada, Europe, South East Asia and Asia (China). Time is reported in units of Universal Time, so the data from each of the stations are synchronised throughout the 24hr period. Time in this representation runs from bottom to top as the day progresses. These data are from INTERMAGNET.

I selected December 12th because the magnetographs show some interesting structure as a result of fast flowing solar wind originating from a solar coronal hole and as a result the Kp index, which is a measure of the magnetic variation from a geomagnetically quiet day, ranges from Kp3 (quiet) to Kp5 (storm), with unsettled (Kp4) periods in between.
Global Magnetic Field Variation 20141212.jpg
It is plain to see that not all magnetographs are the same and on a global scale there are strong regional variations. All of the US magnetographs are very similar to each other, but different to those recorded in Europe and Asia (China) over the same period. Likewise, all of the European magnetographs are very similar to each other, but different again from the other regions. This demonstrates that the magnetic field variation recorded on Earth is dynamic (changes with time at any one observatory) and that it is regionally dependent. This might be explained when considering that the observatories are located on the surface of a sphere, rotating inside a magnetic bubble (our magnetosphere) which is distorted into a large teardrop shape and also on a local scale due to local fluctuations in solar wind speed and density. The magnetosphere is compressed on the sunny side of Earth and elongated on the shaded side of Earth.

The inhomogeneous nature of Earth’s magnetic field is further illustrated in the inset images of Earth’s aurora, recorded in UV wavelengths by NASA, which show bright and less bright regions varying with longitude around the poles. Furthermore, these illustrations show as a separate effect how on the sunny side of the Earth there is a bright UV glow. In this case UV (and X-rays) from the Sun excite the ionosphere and create electric currents which themselves generate magnetic fields which may enhance or suppress the local field. As a magnetic observatory rotates under this illuminated region then there will be a magnetic deviation recorded. This is superimposed on the deviations created by the action of the solar wind on the shape of the magnetosphere, which may be positive or negative depending on the nature of the flow. The result is a diurnal fluctuation in magnetic deviation, dominant when the Sun is quiet.

Overall, then, there is a complex interaction between flowing particles from the Sun and Earth’s magnetic field and this interaction depends on the speed of these particles, the density of the solar wind plasma and the magnitude and direction of the magnetic field carried by it. The resulting magnetic deviations vary from place to place on Earth and with time. Interpreting the nature of these variations is complicated by the fact that the observatories are rotating as the Earth rotates within the magnetosphere, which itself is not uniform, but spread out in a teardrop shape, the structure of which changes with the flow of the solar wind.

I hope this might be of some interest.

Thanks for looking.

Stu.
Lunt LS60THa B1200 PTFT
150mm H-alpha Solar telescope with Lunt35 mod
DMK41, Basler acA1920-155
NEQ6 Pro-mount
Fluxgate Magnetometers (1s and 150s Cadence)
More images at http://www.flickr.com/photos/solarcarbon60/

User avatar
swisswalter
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 17951
Joined: Thu Feb 06, 2014 4:28 am
Location: Switzerland
Contact:

Re: Global Variations in the Geomagnetic Record

Post by swisswalter » Mon Dec 15, 2014 5:16 am

Hi Stuart

that is of great interest. Thank you very much for the explanation
Only stardust in the wind, some fine and some less fine scopes, filters and adapters as well. Switzerland 47 N, 9 E, in the heart of EUROPE :)

from 7 am - 7 pm http://www.nanosys.ch

from 7.01 pm - 6.59 am http://www.wastronomiko.com some times vice versa ;)

User avatar
marktownley
Librarian
Librarian
Posts: 24534
Joined: Tue Oct 18, 2011 5:27 pm
Location: Brierley Hills, UK
Contact:

Re: Global Variations in the Geomagnetic Record

Post by marktownley » Mon Dec 15, 2014 6:42 am

Interesting stuff Stu!
Image
http://brierleyhillsolar.blogspot.co.uk/
Solar images, a collection of all the most up to date live solar data on the web, imaging & processing tutorials - please take a look!

User avatar
Montana
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 19801
Joined: Mon Oct 17, 2011 5:25 pm
Location: Cheshire, UK

Re: Global Variations in the Geomagnetic Record

Post by Montana » Mon Dec 15, 2014 12:15 pm

That is really interesting, I had never even thought about the differences before :bow2

Alexandra

User avatar
Carbon60
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 5491
Joined: Wed Mar 07, 2012 12:33 pm
Location: Lancashire, UK

Re: Global Variations in the Geomagnetic Record now with CME

Post by Carbon60 » Wed Dec 17, 2014 7:49 am

Thanks for your interest, Walter, Mark, Alexandra.

Here are some additional plots, on this occasion when two CMEs impacted Earths magnetosphere on the same day (September 12th). Whereas before when Earth was sitting in a fairly steady solar wind stream the geomagnetic response was very regional, on this occasion as each CME impacted Earth the effect was far more 'global' with all magnetometers around the world showing a significant response at substantially the same time, although again the specific details within each magnetograph are regionally dependent. This demonstrates an interesting distinction between the different types of plasma flow; steady versus impulse.
Global Magnetic Field Variation 20140912.jpg
Global Magnetic Field Variation 20140912.jpg (134.29 KiB) Viewed 1838 times
Thanks for looking.

Stu.
Lunt LS60THa B1200 PTFT
150mm H-alpha Solar telescope with Lunt35 mod
DMK41, Basler acA1920-155
NEQ6 Pro-mount
Fluxgate Magnetometers (1s and 150s Cadence)
More images at http://www.flickr.com/photos/solarcarbon60/

User avatar
Montana
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 19801
Joined: Mon Oct 17, 2011 5:25 pm
Location: Cheshire, UK

Re: Global Variations in the Geomagnetic Record

Post by Montana » Wed Dec 17, 2014 10:16 am

Thanks Stu, you are a fountain of knowledge :bow2

Alexandra

User avatar
swisswalter
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 17951
Joined: Thu Feb 06, 2014 4:28 am
Location: Switzerland
Contact:

Re: Global Variations in the Geomagnetic Record

Post by swisswalter » Wed Dec 17, 2014 9:14 pm

Hi Stuart

with your explanation even I see the difference , thank you very much
Only stardust in the wind, some fine and some less fine scopes, filters and adapters as well. Switzerland 47 N, 9 E, in the heart of EUROPE :)

from 7 am - 7 pm http://www.nanosys.ch

from 7.01 pm - 6.59 am http://www.wastronomiko.com some times vice versa ;)

User avatar
grimble_cornet
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 3496
Joined: Tue Jul 10, 2012 5:10 pm
Location: UK West Midlands

Re: Global Variations in the Geomagnetic Record

Post by grimble_cornet » Wed Dec 17, 2014 11:46 pm

WOW...... that is a really interesting and impressive presentation Stu :o
Must have missed your original post of this but glad I caught up.

Many thanks for sharing this :bow2
.

.



.


Mike Garbett

Selection of Solar and Deep Sky images on Flickr: https://www.flickr.com/photos/mikegarbett/

User avatar
Carbon60
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 5491
Joined: Wed Mar 07, 2012 12:33 pm
Location: Lancashire, UK

Re: Global Variations in the Geomagnetic Record

Post by Carbon60 » Thu Dec 18, 2014 8:13 pm

With the 'uptick' in solar activity this week, hopefully we'll see some further CME action on Earth's magnetometers, including my own ;) .

Thanks for your interest.

Cheers

Stuart
Lunt LS60THa B1200 PTFT
150mm H-alpha Solar telescope with Lunt35 mod
DMK41, Basler acA1920-155
NEQ6 Pro-mount
Fluxgate Magnetometers (1s and 150s Cadence)
More images at http://www.flickr.com/photos/solarcarbon60/

User avatar
Montana
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 19801
Joined: Mon Oct 17, 2011 5:25 pm
Location: Cheshire, UK

Re: Global Variations in the Geomagnetic Record

Post by Montana » Fri Dec 19, 2014 2:36 pm

Congratulations on SPOD :hamster: :hamster: :hamster:

Alexandra

User avatar
grimble_cornet
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 3496
Joined: Tue Jul 10, 2012 5:10 pm
Location: UK West Midlands

Re: Global Variations in the Geomagnetic Record

Post by grimble_cornet » Fri Dec 19, 2014 4:26 pm

Congratulations Stu - well deserved :band
.

.



.


Mike Garbett

Selection of Solar and Deep Sky images on Flickr: https://www.flickr.com/photos/mikegarbett/

User avatar
Carbon60
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 5491
Joined: Wed Mar 07, 2012 12:33 pm
Location: Lancashire, UK

Re: Global Variations in the Geomagnetic Record

Post by Carbon60 » Fri Dec 19, 2014 8:22 pm

Cheers Alexandra/Mike. It was certainly a surprise when I logged on just now!

I hope it raises the profile of magnetometry, even if only a little bit.

Regards

Stuart
Lunt LS60THa B1200 PTFT
150mm H-alpha Solar telescope with Lunt35 mod
DMK41, Basler acA1920-155
NEQ6 Pro-mount
Fluxgate Magnetometers (1s and 150s Cadence)
More images at http://www.flickr.com/photos/solarcarbon60/

User avatar
marktownley
Librarian
Librarian
Posts: 24534
Joined: Tue Oct 18, 2011 5:27 pm
Location: Brierley Hills, UK
Contact:

Re: Global Variations in the Geomagnetic Record

Post by marktownley » Fri Dec 19, 2014 9:38 pm

Well deserved fella! You are exploring new territory in the solar world ;)
Image
http://brierleyhillsolar.blogspot.co.uk/
Solar images, a collection of all the most up to date live solar data on the web, imaging & processing tutorials - please take a look!

User avatar
swisswalter
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 17951
Joined: Thu Feb 06, 2014 4:28 am
Location: Switzerland
Contact:

Re: Global Variations in the Geomagnetic Record

Post by swisswalter » Sat Dec 20, 2014 7:15 am

Hi Stuart

congratulations on the pic of the day, very well deserved
Only stardust in the wind, some fine and some less fine scopes, filters and adapters as well. Switzerland 47 N, 9 E, in the heart of EUROPE :)

from 7 am - 7 pm http://www.nanosys.ch

from 7.01 pm - 6.59 am http://www.wastronomiko.com some times vice versa ;)

Derek Klepp
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 12660
Joined: Wed Oct 19, 2011 10:02 am

Re: Global Variations in the Geomagnetic Record

Post by Derek Klepp » Sun Dec 21, 2014 6:44 am

This is very interesting Stu I often wonder if it affects my Bees

User avatar
Carbon60
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 5491
Joined: Wed Mar 07, 2012 12:33 pm
Location: Lancashire, UK

Re: Global Variations in the Geomagnetic Record

Post by Carbon60 » Sun Dec 21, 2014 9:27 am

Many thanks, Mark, Walter, Derek.

An interesting thought, Derek. Apparently bees are magneto receptive.

http://web.gps.caltech.edu/~jkirschvink/pdfs/Bees.pdf

Stu
Lunt LS60THa B1200 PTFT
150mm H-alpha Solar telescope with Lunt35 mod
DMK41, Basler acA1920-155
NEQ6 Pro-mount
Fluxgate Magnetometers (1s and 150s Cadence)
More images at http://www.flickr.com/photos/solarcarbon60/

Post Reply

Who is online

Users browsing this forum: Google [Bot] and 2 guests