Click image to enlarge. Fig.1.10 cm Solar Flux and Comparison of Ri (provisional) and Ra Estimates for January. (Ri Source: http://sidc..oma.be/index.php3) (!0cm Source: http://www.drao.nrc.ca/icarus)

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Smoothed Mean Sunspot Number (Rsm) for July 2001: 124.0

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Fig. 4a. Plot showing peaks in Ra in July 2000 and September 2001.

Figure 4b Click image to enlarge. Close-up of Critical Region.

Sudden Ionospheric Disturbance Report

Sudden Ionospheric Disturbances (SID) Recorded During January 2002

The events listed above meet at least one of the following criteria

Reported in at least two observer reports Visually analyzed with definiteness rating = 5 Reported by overseas observers with high definiteness rating

Solar Events

January was not an overly busy month for SID recordings, although there were a few days that did have a lot of activity. The most active day, of course, was January 16th , with all but one of the X-Ray flares recorded that day resulting in SID events for many observers. There were 12 in all that day. The GOES-8 Satellite recoreded 202 X-Ray events this month, but many of them were of the smaller scale. Of these, 22 were M-Class flares. There were no X-Class flares at all. Many of the SID events recorded were of small duration; hence most of the events had an average importance rating of 1- to 1+ . There were, however, three events with an importance rating of 3. These were on the 4th at 2016, the 9th at 1755, and the 12th at1842.

We are going to be heading into a time where there will be more and more smaller C-Class flares as opposed to the large M and X Class we have been used to in the past 6 months or so. I just re-tuned my receiver for better reception. I would suggest the same to all observers if you have not done so recently. This will help to catch the smaller SID events that will be more prominent in the months to come. I found that, once adjusted, I had a much cleaner trace and a bit more sensitivity to smaller changes in signal strength. If you are having trouble recording events don't hesitate to try a different station. It might be interesting for European observers to tune in to NAA, which is a strong signal, to get a perspective on the effects in conjunction with American observers looking at the same signal from the south and from the west. Don't be afraid to experiment. That is where the fun comes in this endeavor, and it may lead to some interesting results.

Casper H. Hossfield, SID Sup. Editor PO Box 23 New Milford, NY 10959, USA

SUDDEN IONOSPHERIC DISTURBANCES RECORDED DURING January, 2002

capaavso@aol.com Fax 973 853 2588

There is sad News to report. We have lost Sudden Ionospheric Disturbance observer, A-3, Phil Del Vecchio, our oldest SID observer, who died 28 December, 2001 at age 97. Phil was one of the four original observers when the SEA program started in 1956 as part of the International Geophysical Year, IGY. Phil still had an SES receiver running in the nursing home where he spent his last years and it was still recording solar flares the day he died. The National Bureau of Standards had set up the AAVSO's SID program by loaning them four Brown strip chart recorders one of which went to Phil who was then an AAVSO sunspot observer. Phil lived in Paterson, New Jersey where he wrote the Nature Column for the Paterson Morning Call newspaper and often mentioned his solar flare detector and the big flares of solar cycle 19 he was then recording. I too lived in Paterson and visited Phil one day to see his SEA receiver and decided I had to have one, and became A-5 in 1958. Phil was also an amateur seismologist, and a seismograph he built for the Nature Center in Garret Mountain Park near Paterson can still be seen recording earthquakes for the US Geological Survey. It is the main attraction for school children who visit the Nature Center on field trips. They are fascinated by the line the seismograph draws on paper at 1mm/sec and the way the pen lifts for one second to mark each minute of time. Children intuitively understand how a seismograph works. This was something Phil understood and the reason he built the seismograph for the nature center as a way of sharing the wonders of science with the public. As Director of the Paterson Museum and through his Nature Column Phil spent much of his lifetime popularizing science and getting children interested in doing science as amateurs which sometimes lead to their choosing science as a career. Phil will be missed by the many people whose lives he touched during his long lifetime.

Below is a schematic for an amplifier that Andries Son in Belgium designed for his McWilliams magnetometer. It is basically the same Wheatstone bridge most of us use to draw our magnetograms but adding the 741 operational amplifier has many advantages. Andries uses a 0.25 mm diameter torsion wire 30 cm long whereas most of us use a thinner 0.2 mm wire about 40 cm long. The sensitivity of the magnetometer varies directly as the length and as the fourth power of the diameter of the torsion wire so Andries would have little chance of recording magnetic storms without the amplifier. There are other advantages too. The 10 k potentiometer can be used to center the recording and the 27 k resistor could be made variable to adjust the gain when calibrating the magnetometer with a Helmholtz coil so it will measure the strength of the magnetic storms in nanoTeslas.

Below are two charts made by Jerry Winkler, A-50, in Houston, Texas of flares recorded by monitoring 25.2 kHz in La mourie, North Dakota, USA. The upper halves of these charts are an attempt to monitor NRK on 37.5 kHz in Iceland. Jerry and I have been trying to monitor this distant and weak signal but with no success. The problem seems to be the signal is overwhelmed by interference. I decided the best way to monitor NRK might be to design a better receiver less prone to pick up interference. I have been experimenting with this new receiver by recording NAA in Cutler, Maine, USA on 24 khz. Below Jerry's charts is an NAA chart I made on 4 Feb with the new receiver here in Florida where I spend the winters. It shows two inverted SESs starting at ~1530 and ~1900 UT. Notice the nice clean thin interference-free trace. You might think I got this nice trace by using a big integrating capacitor. Wrong. The capacitor across the DC output is only 0.1 mfd compared to 10.0 mfd used in Gyrator receivers. The response of the receiver is so fast it ignores lightning interference which is plentiful here in Florida. It is a surprisingly simple fixed-frequency receiver consisting of only two Radio Shack TL082 op amps, a 33 mH ferrite core coil, two diodes and six resistors plus capacitors to tune the loop antenna and the 33 mH coil. A 5000 ohm potentiometer across the DC output adjusts the gain. If you would be interested in building one of these simple interference-free receivers send me an email and I'll send you a schematic and additional information how to build it.

Click image to enlarge.

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