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ARRL Propagation Bulletin ARLP010 (2000)

ARLP010 Propagation de K7VVV

QST de W1AW  
Propagation Forecast Bulletin 10  ARLP010
From Tad Cook, K7VVV
Seattle, WA  March 10, 2000
To all radio amateurs 

ARLP010 Propagation de K7VVV

There was a nice surprise for participants in last weekend's DX
contest.  ARLB009 predicted stormy geomagnetic conditions, but it
turned out that the energy from solar eruptions did not affect the
earth's geomagnetic field.  Instead of the predicted planetary A
indices of 12, 28 and 25 for Friday through Sunday, the A index for
those days was 5, 5 and 7, which is very quiet.  Solar flux was 189,
167 and 181.

Average solar flux was about the same last week as the week before,
and average sunspot numbers were slightly lower.  Average A indices
have also been lower.

Solar flux is expected to dip below 200 this weekend.  Predicted
flux values for Friday through Tuesday are 200, 195, 190, 185 and
180.  Solar flux is expected to bottom out around 150 on March 17 or
18, then rise above 200 by March 23 and stay around 220 from March
25 to April 4.

Geomagnetic indices are expected to remain quiet until March 22-23,
then settle down again until March 31 and April 1.

We are moving toward the spring equinox, which always means better
HF conditions, especially with the rising solar flux.  Look for more
frequent worldwide openings on 10, 12 and 15 meters.

Cable News Network has an email service which delivers weekly space
news, and some of it concerns solar activity of interest to hams.
The email service sends URL links to articles, such as the one at  You can
subscribe at

In the mail this week was an interesting tip from a ham in Vermont,
who wrote, ''This is Zach Manganello, K1ZK, I am a freshman at
Middlebury College, and I just attended a lecture that I thought was
absolutely fascinating, pertinent to HF propagation, and worthy of
sharing with you at the ARRL.  The lecture was about the Super Dual
Auroral Radar Network (SuperDARN), and these scientists have giant
radar arrays at several locations near the Earth's poles which they
use to study interaction of solar radiation with the Earth's
geosphere and ionosphere.  Check out their web site at ''.

NASA Space Science News has an item this week about predicting
disturbances by seeing what is happening on the other side of the
sun that faces away from earth.  This uses the Michelson Doppler
Imager on the Solar and Heliospheric Observatory, on the web at .
This is important because solar forecasts for the short term are
based on calculating when known active regions will rotate back into
view.  If activity can be observed on the far side of the sun, then
more accurate forecasts can be made which are not dependent on the
last glimpse of the active region before it rotated out of view.

Finally, check out, a site devoted to
this year's peak in solar activity.

Sunspot numbers for March 2 through 8 were 209, 189, 167, 181, 172,
164 and 212 with a mean of 184.9.  10.7 cm flux was 213.2 203.8,
200.2, 220.3, 222.4, 221.8 and 214.9, with a mean of 213.8, and
estimated planetary A indices were 8, 5, 5, 7, 11, 16 and 13, with a
mean of 9.3.

The path projection for this week is from Middlebury, Vermont.

To Europe, 80 meters 2200-0730 UTC, 40 meters 2100-0830 UTC, 30
meters open all hours, best 2300-0600 UTC, weakest 1330-1630 UTC, 20
meters open all hours, except 0630-0930 UTC, 17 meters 1130-2300
UTC, 15 meters 1200-2230 UTC, 12 meters 1330-2130 UTC, 10 meters
1330-2100 UTC.

To Southern Africa, 80 meters 2230-0430 UTC, 40 meters 2200-0500
UTC, 30 meters 2100-0530 UTC, 20 meters 2030-0600 UTC, 17 meters
2000-0130 UTC, 15 meters 2000-0030 UTC, 12 meters and 10 meters
1900-2330 UTC.

To South America, 80 meters 2330-0930 UTC, 40 meters 2300-1000 UTC,
30 meters 2230-1000 UTC, 20 meters 2200-1100 UTC, 17 meters 1100-
0400 UTC, 15 meters 2130-0130 UTC, 12 meters 1230-0030 UTC, 10
meters 1300-2330 UTC.

To the Caribbean, 80 meters 2230-1100 UTC, 40 meters 2100-1230 UTC,
30 meters open all hours, strongest 2330-1000 UTC, weakest 1500-
1830 UTC, 20 meters open all hours, strongest 2300-1030 UTC, weakest
1430-1900 UTC, 17 meters 1100-0600 UTC, 15 meters 1130-0200 UTC, 12
meters 1200-0100 UTC, 10 meters 1200-0030 UTC.

To Australia, 80 meters 0930-1200 UTC, 40 meters 0930-1200 UTC, 30
meters 0830-1300 UTC, 20 meters 0830-1300 UTC, 17 meters 1300-1500
UTC, 15 meters 1400-1530 UTC, 12 meters 1430-1600 UTC, 10 meters
1500-1530 UTC.

To Japan, 80 meters 0900-1130 UTC, 40 meters 0800-1230 UTC, 30
meters 0800-1300 UTC, 20 meters 0730-1300 UTC, 17 meters 0630-1300
UTC, 15 meters 2100-0600 UTC, 10 meters 2130-0130 UTC.


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