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FORECAST SOL: Normal green MAG: Disturbed red ION: Normal green
HomeHF SystemsGlobal HFPolar Cap Absorption Tuesday, Oct 24 2017 05:53 UT
Global HF

Polar Cap Absorption

A polar cap absorption event results from the ionisation of the D-layer of the polar ionosphere by high energy protons. A PCA causes a HF radio blackout for trans polar circuits and can last several days. PCAs are almost always preceded by a major solar flare with the time between the flare event and the onset of the PCA ranging from few minutes to several hours.

See Real Time Riometer Data from Antarctic Stations.

The icon below indicates the estimated absorption in db of a 30 MHz riometer from Casey station in Antarctica. These figures give an indication of the severity of the PCA. The background colour of the icon is red when absorption exceeds 1db and green otherwise.

Details of any current proton event are given below:

(last updated 24 Oct 2017 05:50 UT)

10MeV Proton/PCA Event Began 18 06 2015 1105UT and is in progress 10MeV Proton/PCA Event Ended 19 06 2015 0155UT 10MeV Proton/PCA Event Began 21 06 2015 2020UT and is in progress 10MeV Proton/PCA Event Ended 24 06 2015 0510UT 10MeV Proton/PCA Event Began 26 06 2015 0130UT and is in progress 10MeV Proton/PCA Event Ended 26 06 2015 0240UT 10MeV Proton/PCA Event Began 26 06 2015 0425UT and is in progress 10MeV Proton/PCA Event Ended 27 06 2015 0525UT 10MeV Proton/PCA Event Began 27 06 2015 0650UT and is in progress 10MeV Proton/PCA Event Ended 27 06 2015 0715UT 10MeV Proton/PCA Event Began 29 10 2015 0540UT and is in progress 10MeV Proton/PCA Event Ended 29 10 2015 1445UT 10MeV Proton/PCA Event Began 29 10 2015 1530UT and is in progress 10MeV Proton/PCA Event Ended 29 10 2015 1610UT 10MeV Proton/PCA Event Began 02 01 2016 0415UT and is in progress 10MeV Proton/PCA Event Ended 02 01 2016 0745UT 10MeV Proton/PCA Event Began 14 07 2017 0850UT and is in progress 10MeV Proton/PCA Event Ended 14 07 2017 1135UT 10MeV Proton/PCA Event Began 14 07 2017 1235UT and is in progress 10MeV Proton/PCA Event Ended 14 07 2017 1340UT 10MeV Proton/PCA Event Began 14 07 2017 1430UT and is in progress 10MeV Proton/PCA Event Ended 14 07 2017 1510UT 10MeV Proton/PCA Event Began 14 07 2017 1800UT and is in progress 10MeV Proton/PCA Event Ended 14 07 2017 1835UT 10MeV Proton/PCA Event Began 14 07 2017 1940UT and is in progress 10MeV Proton/PCA Event Ended 15 07 2017 1105UT 10MeV Proton/PCA Event Began 05 09 2017 0020UT and is in progress 10MeV Proton/PCA Event Ended 08 09 2017 1455UT 10MeV Proton/PCA Event Began 08 09 2017 1645UT and is in progress 10MeV Proton/PCA Event Ended 08 09 2017 2255UT 10MeV Proton/PCA Event Began 10 09 2017 1635UT and is in progress 10MeV Proton/PCA Event Ended 14 09 2017 1720UT

/Images/HF%20Systems/Global%20HF/Polar%20Cap%20Absorption/ico_PolarCapAbsorption.gif

(last updated 24 Oct 2017 05:50 UT)

No proton event in progress

Note: Proton event descriptive text will lag realtime due to data smoothing.

Current proton fluxes are as follows:

(last updated 24 Oct 2017 05:50 UT)

GOES Gp satellite Energetic Proton Flux (Courtesy of SWPC, Boulder Colorado, USA) Units: Protons/cm2-s-sr 10MeV and 100MeV threshold proton flux level is 10 proton flux units (PFU) Date: 24 10 2017 0540 UT 1MeV Proton flux: 4.16e+01 5MeV Proton flux: 1.96e-01 10MeV Proton flux: 1.62e-01 100MeV Proton flux: 2.79e-02

GOES satellite proton flux data for this page are provided by US Space Weather Prediction Center in Boulder.

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