Topband: K levels and skew path on 160

[JC]

-----Original Message-----
From: Topband [mailto:topband-bounces at contesting.com] On Behalf Of
donovanf at starpower.net
Sent: Tuesday, January 27, 2015 3:28 PM
To: topband at contesting.com
Cc: nn4t at comcast.net
>>
Because the southern magnetic pole is just off the coast of Antarctica and
directly south of Australia, the SSW long path crosses through the auroral
belt and this long path is significantly affected by geomagnetic activity. 
<<
>From 2300-2330Z (the most likely times for southeast Asia long path in
eastern USA evening) the grey line crosses Uruguay, so the long path to
southeast Asia is likely to be SSE or possibly SE. Because the southern
magnetic pole is on the opposite side of Antarctica, the SSE long path is
much less affected by geomagnetic conditions than the 1145-1300Z SSW long
path. 
<<

Frank

Your observations match my observations since 2009 when I started to work
with Horizontal polarized receiver antenna for 80/160. 2010 and 2011 the
SSE/SSW path was open most of the days. Peter (XU7ACY) was very active and I
heard  him from October to March over 60 days out of 180 days on 160m, and
every single day on 80m at the same operating time you mentioned.

I did try to correlate the openings with K and AL and it is not directly
related. The only index for magnetic storm that was correlated was Dst.  Dst
index is an index of magnetic activity derived from a network of
near-equatorial geomagnetic observatories that measures the intensity of the
globally symmetrical equatorial electrojet (the "ring current").
I started to follow Dst because Alan Melia G3NYK long wave propagation page.
Alan noticed the LF  ( <500KHz) propagation could be good after few days of
Dst above zero, it means low activity of magnetic storm.

K, AL and Dst and all related with solar wind speed, predictions are
available from Colorado and Kyoto.

http://lasp.colorado.edu/space_weather/dsttemerin/dsttemerin.html


http://wdc.kugi.kyoto-u.ac.jp/dst_realtime/presentmonth/index.html

The Dst can be useful when is positive for 5 or more days, indicating good
condition possibility. Activity is more important than possibility, without
activity propagation does not matter. So when a flare or CME hit the
magnetic ring, two things happen, first there is a very good improvement on
the propagation for few hours followed by a depression and degradation of
propagation, that depression last for several days and a good recovery can
take over a week. After the impact the attenuation is high above normal and
the impact on 160m is significate, but not much on 80m.

After a good success with HWF in Florida, some friends in South America, and
Brazil started to use the HWF for long path. I get very serious trying to
understand the physics behind 50% openings on LP and I collect data from
previous QSO on 80 and 160m when directive RX antenna systems was used. 

For my surprise all opening on the South Hemisphere long path were actually
NNW NNE. That result indicate that the actual signal SSE SSW  get refracted
at the equator region and travel inside the darkness. 

Robert DU7ET was a good example of this kind of propagation long path , we
had QSO's every month from Jan to July 2013. For me all openings were SSW
but from my friends on Brazil the path was NNW. 

Based on the observations my conclusion (still a work in progress) is that
the signal does not reach the south pole auroral belt. It's run along the
equator, That s why I am calling this propagation mode TELP , Trans
Equatorial Long Path.

Carl K9LA did a nice paper with the ray traces from my location to XU7 , and
at 40 degree there is a refraction  bending SSW signal to W. It can explain
the same bending for reflated signals NNW to W from Brazil.

Dst also can show how bad the propagation was Dec 2014 to middle Jan 2015.
Ove several years the Dst  was in between 0 and -20 but during the last two
month Dst was between -20 and -40 with very deeps near -100.

I would say that TELP I open on 80m almost every day, we just don't have
much activity to understand it better.

Regards
JC
N4IS




----- Original Message -----

From: "Tom W8JI" <w8ji at w8ji.com>
To: "Steven R Daniel, D.D.S." <nn4t at comcast.net>, topband at contesting.com
Sent: Tuesday, January 27, 2015 7:21:00 PM
Subject: Re: Topband: K levels and skew path on 160 

>I was rereading the article by Cary Oler and Ted Cohen (N4XX), 
>published in  1998, which provided a good primer for understanding, as 
>much as we can,  propagation on Topband. In one section the impact of a 
>high K index on the  auroral oval, and its subsequent impact on signals 
>passing through the  oval,  was discussed. My question is does the K 
>index, especially at higher  levels,  impact the SW or SSW skew path 
>many of us were trying to use this morning  to  work Ken, XW4ZW? Any 
>information or observations will be appreciated.
> Best,

Steve, 

>From my location now, and when I was in Ohio, it was quite normal for any
signal passing near or through the north magnetic pole to never make it
through via the direct path. When signals were heard, they were always
skewed in some other direction. 

The only exception seems to be when sunspots and geomagnetic activity are
very low. In this very last solar minimum, when sunspots were absent, many
stations would appear via north. Of course that gave the northern NA
stations nearly north of me a clear advantage, because they were closer. 

My policy is to not worry about predicting or expecting anything, and I
rarely even look at solar activity. I just listen in all dark directions
when the station is almost on the opposite side of the world, especially
when he is anywhere near the equator and far,far, away. :) 

73 Tom 






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