HF Propagation

Here are some plots that relate to global conditions for HF propagation and some near the end which are more local to my home near Oslo, Norway.

N3KL Propagation Indicators

Solar X-rays: 
Geomagnetic Field:  
K-index (48 hrs): K-index last 48hrs

Last Solar Month's Solar-Terrestrial Data, N0NBH

  • 304A: Ultraviolet radiation at 304 Ångström due to ionized helium in the sun's photosphere. One value measured by the Solar Dynamics Observatory's EVE instrument, and the other by the SOHO satellite's SEM instrument. Responsible for about half of the F layer ionization.
  • X-Ray: Intensity of hard X-rays hitting the earth’s ionosphere. Impacts primarily the D-layer (HF absorption). Value from A0.0 to X9.9. The letter indicates the order of magnitude (A, B, C, M and X), where A is the lowest. The number further defines the level of radiation.

One Year Solar-Terrestrial Activity Report

Credit: Jan Alvestad

K index from Dombås, Norway (geomagnetic activity):

K-indices Dombås Source: University of Tromsø. Dombås is 62 deg N and 9 deg E. K > 5 => Northern Lights as far south as in Oslo (55 deg geomagnetic latitude, 60 deg geographic). A map with levels typical for viewing Northern Lights according to location in Europe is here Aurora Service Europe


Examples of interpreted ionograms (WA5YIX)

Juliansruh (Northern Germany):

Tromsø (Northern Norway):

NCDXF/IARU International Beacon Project

Effective sunspot number, SSNe

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The Cormac Propadex - Current Ionospheric Conditions

Propadex is updated four times per hour and eight hours of history is shown on the graph. For example, if the Propadex shows +110, it means that the maximum usable frequency is 1.10 MHz higher than the 60 day average for this exact same time of day.

Statistics based on the 250 lasts spots from the OH2AQ web cluster

F5LEN statistics

Northern Lights

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Rate of TEC (Total Electron Content) Index (ROTI)

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Other resources