The Six and Ten Report   October 1998

Sporadic E (Es) as the control for 50 MHz Dx

The tabulations below give the country area sums for each time period in each day in October 1998. [Explanations of country areas, the geographic spread of openings as reported in the UK, and the raw data summarised here can be found in the printed copies of the Six and Ten report]. The first table shows (sporadic) E openings and the second "dx" openings (undifferentiated F2, TEP and F2 or TEP plus an Es link). Rows are labelled by time bands ("06" for the band 0600-0900, "09" for 0900-1200, etc), columns by day of the month.

Sporadic E
50MHz sopradic E summary table

F2, TEP (+/- Es link)
50MHz F2, TEP summary table

Note the similar distributions in these two tables - evidence, perhaps, that many of the October 1998 dx openings involved a sporadic E hop?

Comparison of 50 and 28 MHz dx, and Es with ionospheric data is instructive. In the graphs below, F2 daily maximum critical frequencies are plotted against dx daily area counts. On 28 MHz there is a good positive correlation: dx occurs on days with higher F2 MUFs. But there is no (or slightly negative) correlation at 50 MHz. F2 MUF does not appear to control days of 6m dx.

F2 f0 versus 28 and 50 MHz area counts for Oct 1998

In the second set of graphs, dx area counts are plotted against sporadic E area counts. On 10m there is no significant correlation between F and Es openings - in fact the data suggests an absence of Es might be better for dx. On 6m there is a weak but positive correlation implying propagation to Europe [i.e. via Es] is the more critical factor enabling 50 MHz dx openings to the UK in October. This might help explain why it is often difficult to associate 6m dx openings with days of high solar flux or spot numbers.

Es v DX 28 and 50 MHz area counts for Oct 1998

 

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