DTG 210431Z APR 2014
Solar Weather

Texas Army MARS would like to thank the scientists and research teams at The University of Massachusetts Lowell Center for Atmospheric Research for providing this valuable resource allowing us to determine the critical frequency (foF2) and maximum usable frequency (MUF).


Austin Ionosonde foF2 Trend

This is a graph of real-time data from the Austin, TX ionosonde in comparison with historic data from the same site. Updated every 15 minutes.

Austin ionosonde foF2 trend



Latest Austin Ionosonde

This is the latest ionogram captured from the Austin Ionosonde. Updated every 5 minutes. This data is pushed to txarmymars.org as soon as it becomes available.

Latest Austin ionogram



Eglin AFB Ionosonde valid for Central Texas at 2014-04-20 22:30:00 CDT

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Eglin AFB Ionosonde valid for Central Texas at 2014-04-20 22:45:00 CDT

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Eglin AFB Ionosonde valid for Central Texas at 2014-04-20 23:00:00 CDT

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Eglin AFB Ionosonde valid for Central Texas at 2014-04-20 23:15:00 CDT

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Eglin AFB Ionosonde valid for Central Texas at 2014-04-20 23:30:00 CDT

Ionogram image not available


Eglin AFB Ionosonde valid for Central Texas at 2014-04-20 23:45:00 CDT

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Eglin AFB Ionosonde valid for Central Texas at 2014-04-21 00:00:00 CDT

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Generally, as planetary K-Index rises, critical frequency is suppressed.

K-IndexEffect
0-2Inactive/Quiet, no impact on HF
3-4Unsettled/Active, minor HF fade in higher latitudes
5-6HF fade at higher latitudes
7-8HF sporadic
9HF impossible above 40M

The X-ray radiation that ionizes the D-layer is the 1.0 - 8.0 A (red) plot. These measurements currently taken from the GOES 15 satelite.

Flare CategoryEffect
A1-B9No or minor impact on HF
C1Low absorption of HF signals
M1Occaisional loss of radio contact on sun-lit side
M5Limited HF blackout for several minutes
X1Wide area HF blackout for approx. 1 hr
X10HF blackout over most of sun-lit side for 1-2 hrs
X20Complete HF blackout of all sun-lit areas lasting hours

The GOES (Geo-Stationary) Hp plot is a measure of the earth's magnetic field from two satellites (the two different colored lines) in orbit above the earth. More details on GOES-13 the primary satellite and GOES-15, the secondary satellite.

The red and blue lines correspond to the different measurements taken from the GOES 13 (primary) and the GOES 15 (secondary) satellites. Use the red plot, corresponding to the primary GOES 13 measurements.

Electron FluxEffect
>1.0e+03Partial to complete HF blackout in polar regions
<1.0e+03Degraded HF propagation in polar regions
<1.0e+02Minor impacts on HF in polar regions
<1.0e+01No impacts on HF

The NOAA Space Weather Prediction Center's proton event threshold is the 10 protons/cm2-s-sr at >=10 MeV (red) plot.

Proton FluxEffect
1.0e+06Complete HF blackout in polar regions
1.0e+05Partial HF blackout in polar regions
1.0e+04Degraded HF propagation in polar regions
1.0e+03Small effects on HF in polar regions
1.0e+02Minor impacts on HF in polar regions
1.0e+01Very minor impacts on HF in polar regions
1.0e+00No impacts on HF