Re: [Propagation] TEC vs T Index

["Thomas Giella KN4LF" <kn4lf@tampabay.rr.com>]

Steve,
The TEC index is related to satellite operation. It is the T index that we 
are interested in as far as HF operation.

Basically the T index is a measure of the maximum usable frequency on a 
given day, versus what it should be at a particular point in the present 
sunspot cycle.

When sunspot group #10720 was visible it elevated the solar flux to 149, 
sunspot # to 109 and MUF's were high at 30+ mc. Therefore we had an enhanced 
T index because normally you do not expect the MUF to be that high. Then 
after the geomagnetic storming began MUF's were suppressed down as low as 14 
mc, so the T index was suppressed.

Personally I don't really find any practical use for the T index. I project 
MUF's along a propagation path using software and looking at ionsonde scaled 
data like at:
http://digisonde.haystack.edu/cgi-bin/latest.exe? .

73 & GUD DX,
Thomas F. Giella, KN4LF
Retired Space & Atmospheric Weather Forecaster
Plant City, FL, USA
Grid Square EL87WX
Lat & Long 27 58 33.6397 N 82 09 52.4052 W
kn4lf@arrl.net

Propagation eReflector: 
http://lists.contesting.com/mailman/listinfo/propagation
KN4LF Daily Solar Space Weather & Geomagnetic Data Archive: 
http://www.kn4lf.com/kn4lf5.htm
KN4LF Daily LF/MF/HF Radio Propagation Outlook: 
http://www.kn4lf.com/kn4lf6.htm
KN4LF HF/MF Radio Propagation Theory Notes: http://www.kn4lf.com/kn4lf8.htm
KN4LF Amateur & SWL Radio History: http://www.kn4lf.com/index.htm

----- Original Message ----- 
From: "Pnu7t" <nu7t@gbis.com>
To: <propagation@contesting.com>
Sent: Tuesday, January 25, 2005 1:40 AM
Subject: [Propagation] TEC


> Total Electron Content
> I have found three sources for TEC values: www.ips.gov.au "TEC of North
> America"..... www.propagation.dxers.info  ......  www.sel.noaa.gov/ustec
>      On 24 Jan, the values from each site were 3 from IPS, 10-15 from 
> NOAA,
> 69 ( a smoothed number )from dxer info.   Which is most pertinent to HF
> operation and should TEC be considered for HF propagation ??
> Steve, nu7t
>
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