Topband: K levels and skew path on 160

Tue Jan 27 22:58:19 EST 2015

Hi JC, 

Thanks for your interesting email. You may be correct that SSE/SSW 
long path propagation may not extend very far into the southern 
hemisphere. I wasn't aware of the NNE/NNW observations by 
our southern hemisphere friends. It also appears that SSE/SSW long 
path is more reliable for more southerly locations in the USA than it is 
for higher latitude locations. 

Unfortunately there usually isn't enough activity in southeast asia for us to 
make regular observations, you were fortunate to be able to have long 
term observations with XU7ACY and DU7ET . 

Thanks 

73 
Frank 
W3LPL 

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

From: "JC" <n4is at comcast.net> 
To: donovanf at starpower.net, topband at contesting.com 
Cc: nn4t at comcast.net 
Sent: Wednesday, January 28, 2015 2:45:05 AM 
Subject: RE: Topband: K levels and skew path on 160 

-----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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