Transcript Propagation - Japan Amateur Radio League

Solar Cycle 23 and Early
Predictions for Solar Cycle 24
Carl Luetzelschwab K9LA
Ham Fair 2005 - K9LA
Cycle 23
Cycle 23
smoothed sunspot number
data to-date
predicted decline
160
120
80
40
we are here
solar
minimum
0
Oct- Oct- Oct- Oct- Oct- Oct- Oct- Oct- Oct- Oct- Oct- Oct96 97 98 99 00 01 02 03 04 05 06 07
Ham Fair 2005 - K9LA
• Maximum
smoothed sunspot
number of 121 in
early 2000
• Secondary peak in
late 2001
– Great 6m F2 DX!
• Minimum
expected in late
2006 / early 2007
• We’re about a year
and a half from solar
minimum
The High Bands: 10m, 12m, 15m
number of hours in the day
Openings from JA on 15m
24
20
16
solar minimum
12
solar maximum
• At solar minimum, F2
openings on 15m to
NA and EU will be of
short duration
8
4
0
EU
SA
AF
OC
NA
winter month
• If 15m is open,
check 12m
number of hours in the day
Openings from JA on 10m
24
20
16
solar minimum
12
solar maximum
8
4
0
EU
SA
AF
OC
NA
winter month
data from ARRL Antenna Book CD
Ham Fair 2005 - K9LA
• At solar minimum,
no openings on 10m
predicted to NA and
EU
17m – A Good Place for a Band
•
•
•
predictions for JA to indicated area
(December around solar minimum)
Prior to the WARC
band allocations, 20m
was the workhorse
band for long haul
DXing around solar
minimum
G
0700-0800 UTC (low probability)
I
0600-0830 UTC
W2
no opening
WØ
2130-2200 UTC (low probability)
17m has the long haul
characteristics of
15m, but the MUF
need not be as high
W6
2130-0030 UTC
PY
2200-0700 UTC
LU
2030-0900 UTC
Get on 17m!
HZ
0300-0900 UTC
VK4
2130-1530 UTC
CN
0730-0800 UTC (low probability)
ZS6
2230-1030 UTC
Working Peter I on 17m
3Y0X Feb 2006 2100-0930 UTC
Ham Fair 2005 - K9LA
data from W6ELProp
80m and 160m
# of Days in Month With Ap < 7 vs Sm oothed Sunspot Num ber
Cycle 21 decline through Cycle 23 decline
Jan-04
0
Jan-02
0
Jan-00
5
Jan-98
40
Jan-96
10
Jan-94
80
Jan-92
15
Jan-90
120
Jan-88
20
Jan-86
160
Jan-84
Geomagnetic field
activity is quietest at
and a couple years
after solar minimum
•
Most severe impact
is to paths that go to
high latitudes (those
through and near the
auroral oval)
25
quietest
# days in month with
Ap < 7
quietest
Jan-82
smoothed sunspot
number
200
•
Month, Year
data from K9LA
Ham Fair 2005 - K9LA
– JA to WØ
– JA to W1, W2,
W3
30m and 40m
• Propagation on 160m and 80m is dependent on
absorption
• Propagation on 20m, 17m, 15m, 12m, and 10m is
dependent on MUF (maximum usable frequency)
• 30m and 40m are transition bands – not as
dependent on absorption and not as dependent on
MUF
– Of all the bands, they probably change the least over a
solar cycle
Ham Fair 2005 - K9LA
Things To Do At Solar Minimum
• Watch for north-south paths on the higher bands
• Monitor the Sun for unusual sunspot activity that
could help the higher bands
• www.dxlc.com/solar, sec.noaa.gov, spaceweather.com, etc
• Participate in contests
• www.ncjweb.com/contestcal.php
• Get on the low bands
Ham Fair 2005 - K9LA
All Recorded Solar Cycles
our lifetime
• Data is cyclic
in nature
• We’ve lived
through the
highest recorded
solar cycles
• It sure looks
like we’re
headed for an
extended
period of low
solar cycles
Ham Fair 2005 - K9LA
Cycle 24 Prediction
from Schatten
Ham Fair 2005 - K9LA
•
As Cycle 23 winds
down, we’re seeing
more and more
predictions from the
scientific community
•
Most predict that Cycle
24 will be no greater
than Cycle 23
•
Some are even
predicting a maximum
smoothed sunspot
number of around 75
– Haven’t seen
anything that low
since Cycle 16 (1923
– 1933)
Summary
• About a year and a half from solar minimum
• Stay active on the higher bands
– Watch for sporadic E and north-south F2 propagation
– Monitor solar activity for unusual sunspot activity
– Participate in contests
• Get your low band station ready
– 2006, 2007, and 2008 should be good years
Ham Fair 2005 - K9LA