How to relate solar indices to HF propagation

HF propagation is notoriously variable as the state of the ionosphere changes. As the ionosphere is created chiefly by radiation from the Sun, the state of the Sun and its radiation is important. Find out what the different solar indices mean, and how they relate to HF propagation conditions:
http://www.electronics-radio.com/articles/antennas-
propagation/ionospheric/solar-indices-flux-a-ap-k-kp.php

 

The link is broken: remove the space between line one and line two to make it work....

 

I wish there was a higher correlation between actual band conditions and the A and K values...I take them as a rough guide. Usually, nowadays, conditions are WORSE than what one would expect from the numbers.

I cant tell you how many times, over the last six months, I turned on the rig and had to make sure the antenna was connected...

73
Chip W1YW

 

Like this?

http://www.electronics-radio.com/ar.../ionospheric/solar-indices-flux-a-ap-k-kp.php

 

Truth... it's been miserable.

I think the 10.7 GHz flux number means more than the K and A indexes.

No matter the index, if you don't have a reflector, the point is moot.

 

Thanks John for a good article. I had some problems to get to it, but once there it gave me a good overview of those values I get from SOLARHAM every day. I have saved it among my USEFUL ARTICKLES, and will print it out and bring it to our clubb-station, SK5DB as a reference on those subjects. I will try to keep my eyes open for any further article from You. Wishing you the best condition in spite of the low SSN that we have now. Ginnie, SM5PEY

 

This might be more helpful:

NOTE!!! The propagation indices "interpretations" are my personal intellectual property. Therefore the radio wave propagation indices interpretations contained herein is copyrighted © 1988-2016 by Thomas F. Giella, W4HM, all rights reserved. Reproduction of information herein is allowed without permission in advance as long as proper credit is given.

All 13 of the following indices have to occur as described below in order to see the best global medium frequency radio wave propagation possible.

The simplest way to look at medium frequencies with respect to radio wave propagation conditions is to accept the fact that propagation is poor the majority of the time, especially past approximately 1250 miles (one refraction off of the E layer), with occasional short-lived good periods as far as 3200 miles.


1.) Dropping geomagnetic field indices numbers are better, Kp of 0 best.

2.) A daily sunspot number under 100, under 70 best.

3.) A daily sunspot number no higher then the 100 for routine stable formation of the E Valley/F Layer ducting mechanism.

4.) Previous 24 hour Ap index under 10, fewer than 7 for several days consecutively are best.

5.) Previous 3 hours Kp index fewer than 3 for mid latitude paths, fewer than 2 for high latitude paths, 0 for several days consecutively is best.

6.) Energetic proton flux levels no greater than 10 MeV (10+0).

7.) Background x-ray flux levels of A0 for several days consecutively.

8.) No current STRATWARM alert.

9.) Interplanetary magnetic field (IMF) Bz with a (positive number) sign, indicates a lesser chance of high latitude path aurora absorption/unpredictable refraction or scattering of medium frequency RF signals, when the Kp is above 3.

10.) A -10 or better towards a positive number Dst index during the recovery time after a geomagnetic storm, as related to the equatorial ring current. A positive number is best.

11.) Galactic cosmic rays decrease to -3 units below zero and trending towards zero.

12.) Energetic electron flux levels no greater than 2 MeV (2+0).

13. A solar wind speed of less than 300 km/s for several days consecutively.


6B.) GENERAL GUIDELINES CONCERNING CORRELATION OF PROPAGATION INDICES TO ACTUAL HF PROPAGATION CONDITIONS-

NOTE!!! The propagation indices "interpretations" are my personal intellectual property. Therefore the radio wave propagation indices interpretations contained herein is copyrighted © 1988-2016 by Thomas F. Giella, W4HM, all rights reserved. Reproduction of information herein is allowed without permission in advance as long as proper credit is given.


All 14 of the following indices have to occur as described below in order to see the best global high frequency radio wave propagation possible.

1.) Dropping geomagnetic field indices numbers are better, Kp of 0 best.

2.) A daily sunspot number of 150 or higher, 200 or higher best.

3.) A daily sunspot number of greater than 100 for routine stable formation of the E Valley/F Layer ducting mechanism.

4.) Previous 24 hour Ap index under 10, fewer than 7 for several days consecutively are best.

5.) Previous 3 hours Kp index fewer than 3 for mid latitude paths, fewer than 2 for high latitude paths, 0 for several days consecutively is best.

6.) Energetic protons no greater than 10 MeV (10+0).

7.) Background x-ray flux levels greater than B1 for several days consecutively, greater than C1 best.

8.) No current STRATWARM alert.

9.) Interplanetary magnetic field (IMF) Bz with a (positive number) sign, indicates a lesser chance of high latitude path aurora absorption/unpredictable refraction or scattering of medium frequency RF signals, when the Kp is above 3.

10.) A -10 or better towards a positive number Dst index during the recovery time after a geomagnetic storm, as related to the equatorial ring current. A positive number is best.

11.) Rising positive T index number. The T Index tracks with the F2 layer critical frequency (foF2) and sunspot number (SSN) and indicates the capability of the F2 layer to refract RF signals.

12.) Galactic cosmic rays decrease to -3 units below zero and trending towards zero.

13.) Energetic electron flux levels no greater than 2 MeV (2+0).

14. A solar wind speed of less than 300 km/s for several days consecutively.

 

I was checking HF propagation on this link http://www.voacap.com/prediction.html

 

This is a great site Thanks KB0HAZ

 

For some of the same information and an explanation from the guy that developed the square box indicator at the top of the QRZ home page, go here: http://www.k9rod.net/Propagation.html

 

Since we can't control any of the above, we just have to use what we have at the moment and don't forget, westill have some years to go until the bottom of the cycle.

 

Here is a good site with visual aid.

http://www.qsl.net/w2vtm/hf_solar.html

 

Also try www.bandconditions.com

Realtime propagation monitoring of the ham bands.

 

Apologies about the broken link - not sure how that happened as I copied it directly in and it worked when I tested it. It was probably something to do with a linefeed getting in there as a result of the CMS formatting?? Here it is again:
http://www.electronics-radio.com/ar.../ionospheric/solar-indices-flux-a-ap-k-kp.php