Astronomy On-Line

The Sun-Earth Connection

A study of the Sun-Earth Connection and its relation to activities in Society

The basic idea of the project is to study the solar activity, predict interplanetary particle storms, and issue warnings to the society about possible events


observe and discuss the events recorded in the hot week and in the preceding month.

October 10, 1996: This page has now been updated with a new link (observations of the Sun) and a few images have been exchanged.

November 18, 1996: A link to "live" images of aurora from Svalbard is now available (if the weather is clear). Under the link "height of aurora", pictures for determinating height of aurora has been made available.

What you can observe

Solar activity

Already from Oct 1st groups in central and southern Europe can observe the Sun, look for sunspots, maybe flares - make a daily sketch of the solar surface seen on a projected telescope image. NOTE: Don't look directly at the sun through a telescope. Record the time carefully. Co-operate with other groups if the sun is not available at your location.

After some time you will discover that some sunspots which disappeared at one limb comes back on the other limb. What can you deduce from this about the solar rotation and the life time of sunspots?

How to observe the sun

Note also that the Siberian Solar Radio Telescope (SSRT) of the Institute of Solar-Terrestrial Physics will make some solar images avaialble. This major astronomical facility is located at a short distance from Lake Baikal. A continuous monitoring of solar activity is being carried out during the daytime at this telescope. A library of the images received from SSRT can be found here.

Magnetic disturbances

At the same time, make contact with some groups in the far North of Europe, which may be able to make a magnetograph in their classroom. How to make such a magnetograph which only requires a magnet needle, a lightsource (laser beam) and a mirror is told below.

How to observe the magnetic variations

The Northern groups should record every hour if the needle is quiet, active, very active etc. and make their log available on the Net. Please send your observations by e-mail. All reports will be collected in a common log.

Question 1: Is there any relation between days with magnetic activity and Solar events, that is Sunspots at a certain location etc.?

Auroral activities

An observation which does not need any instrument, but clear weather, and being at the right location at the right moment, is to observe the aurora, and record its shapes and activity, following a simple classification sceme as shown below. If several groups observe the auroral activity the same night, we can get an idea of how an auroral outburst may move along the auroral oval which each day may change its size and location.

The classification scheme shown in the figure below should be used for reporting auroral activity. Description of time, location and auroral classification should be sent by e-mail to our adress and the observations will be collected in a common log.

HA --- homogeneous arc
RA --- arc with rayed structure
HB --- homogeneous band
RB --- band with rayed structure
R --- rays
C --- coronae
D --- draperies

IMPORTANT: From October 15 it is necessary to get auroral observations from somewhere for every night in order to make predictions for the Astronomy On-Line Hot Week in November.

A special OBSERVATION - The height of Aurora

The height of aurora can be determined by parallaxes observations i.e. 2 groups or more situated 100 km apart, (or thereabout) agree to photograph the aurora at a predefined time, in the same direction. The idea is to recognise distinct auroral forms in front of known stars.

GROUPS who succeed in obtaining such photographs, should post them on the Net, and let other groups do independent measurements of the height of the Aurora. Photographs for this exercise are will be available on the Net after Oct 1.

If you want to take a look at the Aurora in the North right now (weather permitting) you may investigate the last 4 images from the Auroral camera at the Auroral Research station, Svalbard, 78 degrees north.

How to photograph Aurora

Question 2: Is there any connection between the type of aurora and magnetic activity, and the locations aurora are observed, and the height of aurora?

Aurora is the result of ionised particles hitting the upper atmosphere. Such hits may change conditions in the upper atmosphere. In particular ionospheric layers which reflects radio waves may be changed, and radio transmission at certain frequencies may be impossible.

Near Tromsø in Norway, and in Kiruna (Sweden), Sodankyla (Finland) and on Svalbard, radar systems have been constructed to investigate the interactions between particles from the sun and our magnetosphere and ionised parts of the athmosphere. This is called the European Ionospheric Scatter Radar systems, in short EISCAT. A view of the present activities may be interesting.

Investigate Ionospheric conditions:

Get hold of a radio amateur and make contact with other ham operators to the North or the South in Europe and other continents, and find out how the quality of transmission varies.

Question 3:Is there any relation between the time of noise, frequencies of no contact and solar, magnetic and auroral activities?

Other questions: Over the years there have been claims that Solar activity may change weather, increase the chance of traffic accidents, make power line failures etc. By making enquiries to various agencies in your country you may investigate if anything special happens during the HOT WEEK, which can be related to the SUN.

The challenge is to make predictions for the HOT WEEK:

What can we expect of magnetic, auroral, ionospheric and civil disturbances during this week which may be related to the Sun?

and to issue such predictions in the NEWSPAPER of AOL,

and, of cause, collect as many observations as possible during the HOT WEEK, and discuss what predictions - if any - became realised!

You may also investigate what professional astronomers and geophysicists are doing in this field. Below are pointers to interesting places to visit on the Net. You may even discover live aurora in daytime from our Svalbard research station, when 24 hours of darkness arrives at that latitude, and from out Skibotn observatory in the Hot Week.

You may search the net yourself - and here are some interesting starting points:

Sources of solar data and images and various solar and magnetic indices.
Description of our space environment (lots of information).
Where do we find particle precipitation which may result in auroral activity (a very nice map!).
Magnetic indices of Tromsø and some arctic stations may help to find if auroral activity will occur tonight.
To find what radio frequencies are reflected in the ionosphere, we use an instrument called a ionosond. A description of the instrument and some recent soundings.
An updated map of which frequencies can be used for a 3000 km transmission to be used for communication.


When the Marketplace is fully opened you will find office hours for experts on the Sun, Solar Activity, Sun-Earth connections, Ionosphere, Auroral photography, Auroral Physics, Magnetic observations, Radio communication etc.
This exercise has been prepared by:
Jan-Erik Solheim with help from
Franck Pettersen
Steinar Thorvaldsen and the Webmaster in Tromsø
Per-Ivar Emanuelsen

Special thanks to Tony van Eyken for preparing EISCAT observations, Mike Kosch for preparing online auroras from Skibotn Observatory and Fred Sigernes for making online auroras available from Svalbard (Spitzbergen).

Jan-Erik Solheim
Last update: Nov 18, 1996