Solar Bulletin September, 2002

• Sudden Ionospheric Disturbance Report
• Sudden Ionospheric Disturbances Supplement

Click image to enlarge. Fig.1.10 cm Solar Flux and Comparison of Ri (provisional) and Ra Estimates for September (r=0.960). (Ri Source: http://sidc..oma.be/index.php3) (10cm Source: http://www.drao.nrc.ca/icarus)

Click image to enlarge. Fig.2 Maximum, Mean, and Minimum Ra Values for Each Month from January 2001 to Present.

Michael Hill, SID Analyst 114 Prospect St Marlborough, MA 01752 USA noatak@aol.com

Observer Code Station(s) monitored P Campbell A100 NLK S Bressan A101 HWU F Steyn A102 NAA NWC E Smith A105 DHO A Clerkin A29 NAA D Toldo A52 HWU NAA NWC J Ellerbe A63 ICV A Panzer A83 NAA W Moos A84 DHO FTA M Hill A87 NAA G DiFillipo A93 HWU T Poulos A95 NAA R Battaiola A96 DAO HWU J Wallace A97 NAA M King A99 HWU

The events listed above meet at least one of the following criteria Event reported by two or more observers within +/- 5 minutes Event matched to GOES-8 XRA event to within +/- 15 minutes and event time < 1000 UT Reported by observer with a high quality rating > 8 (scale 1-10)

Solar Events

Click image to enlarge

Steve lives near Amherst, massachusetts and not far from NOAA's Millstone Hill lonosonde station. Steve has found that the ionosonde also detects SIDs Here is how Steve describes it: I get my fmin data from the Millstone Hill ionosonde which is located in Westford, MA just a few miles south of my location. The data can be obtained from the website at http://digisonde.haystack.edu/ . For analyzing the daily data I use a program called SAOExplorer that can be downloaded from the University of Massachusetts at Lowell's Center for Atmospheric Research at http://ulcar.uml.edu . (SAO stands for Standard ADEP Output, a format for archiving ionosonde data.) So, the second file (927fmin.jpg) shows the fmin record for the same day. Note the two peaks that correspond to the SES events.

Click image to enlarge

Steve is the publisher of "The Bell Jar" a little periodical for amateur scientists interested in vacuum technology. He has been helping Jim Mandaville, A90, build a cosmic ray detector that Jim will use to record Forbish Decreases that are the signature of the sun's coronal mass ejections. This homemade detector is first partially evacuated and then flushed out and filled with Argon and a small amount of ethyl alcohol as a quencher.

Below is a nice chart showing an SID recorded as an SES of VLF station VTX3 in India transmitting on 18.2 kHz. It was made by Biswajit Bose, A103, who lives in Calcutta, India. Biswajit was the first to build a loop antenna receiver I first described in the March issue of the SID Supplement. He has his 1.5 meter loop antenna mounted on the roof with TV antennas because there is no other place to put it in down town Calcutta where he lives. At first he tuned it to NWC in West Australia but the 19.8 kHz signal is too weak to overcome interference from the TV antennas. Later he tuned it to VTX3 which is about 750 km distant and puts in a much more powerful signal that can overcome the TV interference. Unfortunately VTX3 is not on the air continuously so there are interruptions in the trace but other than that it is a good signal source for detecting solar flares. Biswajit is an AAVSO sunspot observer. He is also interested in radio astronomy and belongs to SARA. He is presently working with professional radio astronomers at Pune, India where there is a big 45meter dish. They are observing the peculiar object SS433, a micro quasar.

Click image to enlarge

The last days of September were days when the sun was quite active producing solar flares. Len Anderson, A91, in South Perth, West Australia recorded a flare on 28 September shown below as an SID starting at 0930 UT, about an hour before his sunset pattern reached its minimum value.

Click image to enlarge

James Ellerbe, A63, in Nerja, Spain recorded flares on 28 and 29 September as SIDS using VLF station, ICV, in Sardinia as his signal source. He uses a Gyrator receiver built by Art Stokes and records on a Rustrak strip chart recorder.

Click image to enlarge

Click image to enlarge

Here is a recording of a flare as an SID made by Al McWilliams, A94, in St Cloud Minnesota. Al records the VLF station in La Mourie, North Dakota, USA transmitting on 25.2 kHz. The SID is inverted as are all of his SIDs of this station.

Click image to enlarge

Here is an SID recorded by Jerry Winkler, A50 in Houston, Texas, USA. Jerry uses the same ADR2000A converter that al McWilliams uses. These A/D converters have the advantage that they record in the background while other things are being done with the computer like answering email.

Click image to enlarge

Here is a multiplexed recording made by Domenic Toldo in Johannesburg, South Africa. The three signals that are multiplexed are NAA in Maine, USA, NWC in Northwest Cape, Austrailia. And a signal on 22 kHz which may be HWU in le Blanc, France transmitting on 21.75 kHz. The NWC signal recorded an SES starting at 0245 UT on 13 August but this chart was received too late to appear in the August SID Supplement. This SES was also recorded by A91 and A102.

Return to the Solar Division home page