| |
I6AAD > PROP 21.08.03 16:24l 172 Lines 7916 Bytes #999 (0) @ EU
BID : 6E2421I6AAD
Read: DF1ND GUEST
Subj: ARLP032/033
Path: DB0FHN<DB0RGB<DB0MRW<DB0SON<DB0ERF<DB0FBB<DB0GOS<DB0EEO<DB0RES<ON0AR<
WB0TAX<SR3BGN<SP7MGD<IK6PYS<IW6CBN
Sent: 030818/2047Z @:IW6CBN.#AN.IMAR.ITA.EU #:46561 [Osimo] FBB7.00i $:6E2421I6
From: I6AAD@IW6CBN.#AN.IMAR.ITA.EU
To : PROP@EU
From: W1AW Mailing List <w1aw-list-request@listserv.arrl.org>
Subject: ARLP032 Propagation de K7RA
Date: venerd́ 8 agosto 2003 18.00
SB PROP @ ARL $ARLP032
ARLP032 Propagation de K7RA
ZCZC AP32
QST de W1AW
Propagation Forecast Bulletin 32 ARLP032
From Tad Cook, K7RA
Seattle, WA August 8, 2003
To all radio amateurs
SB PROP ARL ARLP032
ARLP032 Propagation de K7RA
Average daily sunspot numbers and solar flux were up this week
compared to last. Geomagnetic indices remained about the same. The
quietest day was Tuesday, August 5, when the planetary A index was
9, the high latitude College A index was only 3, and the College K
index actually was 0 over two of the three-hour reporting periods
and one during four of the periods.
Tuesday was followed by the most active geomagnetic day, Wednesday,
August 6, when the planetary A index was 43 and the planetary K
index rose as high as 7. Normally the high latitude geomagnetic
indices are higher than the numbers at lower latitude. The planetary
A and K index are derived from observatories worldwide, and reflect
both high and mid latitude measurements. But on August 6, the high
latitude College A index (from the University of Alaska at
Fairbanks) was 37, actually lower than the planetary A index of 43
and about the same as the mid-latitude A index of 34.
A day with numbers closer to the norm for a stormy space weather day
on earth was Friday, August 1, when the mid-latitude A index was 28,
the planetary A index was 37 and the high latitude College A index
was 74. Because quiet geomagnetic conditions indicated by low
geomagnetic indices seem to correlate with better high frequency
propagation, one will often hear Alaskan radio amateurs complain
during extended periods of high geomagnetic activity that they just
can't work or hear anything. You can see the mid and high latitude
and planetary A and K indices for the past four weeks at
http://www.sec.noaa.gov/ftpdir/indices/DGD.txt .
Scott Cameron, KA1MUY lives in Maine and wrote to report increased
noise to the north during periods of high geomagnetic activity. He
notices a big difference if the A index is high, when he can point
his beam to the north and see a big jump in noise to over S9 on his
S-meter. He is fairly far north in Maine, at 43.89 degrees north
latitude, although not as far north as this author at 47.67 degrees.
Although folks on the east coast may think of Maine as the far
north, Seattle is actually about 260 miles closer to the North Pole
than Scott is in Pemaquid. The furthest north point in Maine is
47.4596 degrees north, which turns out to be about 14 miles south of
this author's location in Seattle, in terms of latitude. This brings
to mind some words from the late Jack Bock, K7ZR when writing in the
"Totem Tabloid," the newsletter of the Western Washington DX Club.
He often referred to locals as "Suffering Sevens," probably
expressing envy for our brethren in a lower latitude location such
as the 5th call area.
So what does the forecast show for the next few days? This weekend
is the Worked All Europe DX CW Contest, but the predicted planetary
A index for August 8 is 40 and 25 for August 9. This could be a
problem for amateurs in the author's area, because the path to
Europe is polar. The predicted solar flux for Friday through Monday,
August 8-11 is 130. The expected geomagnetic activity would be
caused when the earth moves into a solar wind from one of the sun's
coronal holes. The last good hope for the weekend is that the
interplanetary magnetic field is pointing north, and the earth seems
more affected when it turns south, as it did on Friday, August 1. A
good review of the interplanetary magnetic field is on the
Spaceweather web site at http://spaceweather.com/glossary/imf.html .
Don't miss the Perseids meteor shower, which peaks on August 12-13.
And be certain not to miss gazing up into the sky this month to
marvel at a brighter and closer Mars. On August 27 at 0915z, Mars
will be nearer to earth than at any time in the past 59,620 years.
The last time it was this close was around September 12 in 57,617
BC, when it was 34.62 million miles from earth. This time we'll have
to settle for Mars being 34.65 million miles away, nearly as close,
and in a light polluted environment that our distant Neanderthal
ancestors never dealt with.
For more information on propagation and an explanation of the
numbers used in this bulletin see the Propagation page on the ARRL
Web site at http://www.arrl.org/tis/info/propagation.html .
Sunspot numbers for July 31 through August 6 were 65, 85, 95, 144,
138, 136, and 155, with a mean of 116.9. 10.7 cm flux was 102.1,
107.3, 111.4, 120, 122.5, 130.6, and 128.7, with a mean of 117.5.
Estimated planetary A indices were 32, 37, 21, 15, 14, 9, and 43,
with a mean of 24.4.
NNNN
>/EX
From: W1AW Mailing List <w1aw-list-request@listserv.arrl.org>
Subject: ARLP033 Propagation de K7RA
Date: venerd́ 15 agosto 2003 16.32
SB PROP @ ARL $ARLP033
ARLP033 Propagation de K7RA
ZCZC AP33
QST de W1AW
Propagation Forecast Bulletin 33 ARLP033
From Tad Cook, K7RA
Seattle, WA August 15, 2003
To all radio amateurs
SB PROP ARL ARLP033
ARLP033 Propagation de K7RA
The average daily sunspot number for the week was about the same
this week as last, and daily solar flux was only slightly higher.
Solar flux is expected to peak over the next few days, such as it is
in this declining phase of the solar cycle. Expect solar flux values
around 135 for Saturday, August 16 and then solar flux is expected
to gradually decline to below 100 around August 24. Geomagnetic
indicators should be unsettled to active today (Friday), but should
quiet down over the next week. The predicted planetary A index for
Friday through Monday is 20, 15, 10 and 10.
Currently there is just one sunspot group facing earth, and it seems
to be growing fast as it moves into optimum position for
earth-directed radiation. This presents a wild card for conditions
over the next couple of days, since it could be the source of
increasing solar wind.
Some editions of last week's bulletin contained a claim that in
57,617 BC Mars was only 34.62 miles from earth, which of course was
not the case. So, this error calls for a visit to a news item on the
Bad Astronomy web site at
http://www.badastronomy.com/bad/news/index.html .
Phil Plait of Sonoma State University in California runs the Bad
Astronomy site to help dissuade and debunk some misconceptions that
creep into films, television, popular culture and even science
textbooks. In an August 13 item he talks about the excitement over
Mars being close to earth, and points out that it will be only about
1 percent closer than it was in 1971.
Bruce Irving of Eagle, Idaho was K7ISM many years ago, and he wrote
this week asking about some ghosting he saw on his television set
after 0200z on Sunday, August 10. He wasn't able to ID the station,
but noted that the image of a musical group performing wasn't on any
of his other local channels in the Boise area. He asked if this
could be skip from a channel 2 station out of his area, and I
believe his hunch is correct. He noted that channel 2 is just about
the 6-meter ham band, and being the lowest frequency television
broadcast channel it is the one most likely to experience long
distance propagation. In this case, it was probably some summertime
E-layer propagation.
For more information on propagation and an explanation of the
numbers used in this bulletin see the Propagation page on the ARRL
Web site at http://www.arrl.org/tis/info/propagation.html .
Sunspot numbers for August 7 through 13 were 121, 111, 107, 112,
118, 114, and 112, with a mean of 113.6. 10.7 cm flux was 137,
132.9, 130, 131.1, 129.2, 123.3, and 130.8, with a mean of 130.6.
Estimated planetary A indices were 15, 32, 15, 12, 11, 25, and 17,
with a mean of 18.1.
NNNN
Read previous mail | Read next mail
| |
