Solar Storms and You!

Activity 9: A Soda Bottle Magnetometer....Data

Data taken between February 8-12, 1999 at NASA, Goddard Space Flight Center with the Mark 2 magnetometer by Dr. Sten Odenwald.

Solar conditions during this time:
2-8-99 auroral oval
2-9-99   Quiet
2-10-99   Quiet..weak oval present
2-11-99   Quiet..Weak oval over US, Substorm in progress over Iceland
2-12-99   Quiet
Note, the Quiet/Disturbed/Active index used at the Space 
Weather site is 
rather crude. In several instances a 'Quiet' condition was posted even though 
the 'Current View' image of the Earth from space by the POLAR satellite clearly showed the 
ring-shaped oval of auroral activity in progress over Alaska and Canada. In 
the next data runs I will indicate both the posted condition, and the strength 
of the  'auroral oval'  on a scale  B=Bright, W=weak and A=absent.

All times are in local Eastern Standard Time.


9:00     10.5s
9:25     10.0s
10:10     9.5s
10:35     8.0s
11:35     8.0s
12:35     6.5s
13:10    -3.0s
13:30    -2.0s
14:00     4.5s
14:30     4.5s
15:20     5.0s
15:50     5.0s
16:20     4.0s
17:00     5.0s


9:55      6.0s
10:25     6.0o  +/- 1 centimeter amplitude of oscillation
11:05     4.0s
11:30     4.0s
13:35     4.0s
14:10     4.0s
14:55     5.0s
15:05     5.5s
15:20     4.5s
15:50     5.0s
16:40     5.0s
17:00     4.5s


9:55       3.0s
10:30      2.5s
12:55      1.5s
13:30      0.0s
15:35      0.0s
16:35     -3.0s
17:05     -2.0s    Day 41, POLAR UV imager shows 21:45UT strong oval, substorm
                   over Iceland. 

9:00       0.0s
9:35       0.0s     shifted to 8.0 cm for next measurement
9:50       7.5s     
11:10      6.0s
13:30     11.0o   +/- 2 cm amplitude oscillation. Day 42 weak oval over US, 
                   strong sub-storm over Siberia  18:29 UT
14:00      5.0s
14:25      5.0s
14:55      5.0s
15:45      5.0s
15:55      4.5s    Latest POLAR image shows sub-storm over Canada 20:54 UT
17:00      5.0s


16:55     15.0s    Local storm front passes through. Cloudy with heavy rains

This completes the third consecutive week of observations. We feel certain that the activity seen on 2-10-99 was caused by the geomagnetic sub-storm which was strong over Iceland and Siberia. We note that, in distinction to lightning storms which cause almost constant oscillations in the magnetometer, geomagnetic storms cause a gradual change in the pointing direction with no detectable oscillations at each moment of measurement! The progress of the 2-10-99 substorm can be seen in the following two images taken on Day 41 at 21:45 UT and on Day 42 at 20:54 UT.

We found the two 'real-time' magnetometer stations at Kiruna, Sweden system and Flinders very helpful in corroborating the effects of the 2-10-99 storm. Also, the Effective Sun Spot Number value of 70 during this day was a good cross check, but not very helpful. In the future, this number will be more important in long-term studies of detected activity.