ARLA/CLUSTER: Novas previsões de propagação para o primeiro trimestre 2014 por Steve Nichols, G0KYA

[João Costa > CT1FBF]

New propagation predictions for first quarter 2014

Steve G0KYA has now updated his HF propagation prediction charts for
the first quarter of 2014 to take into account the latest predicted
smoothed sunspot numbers.

It is generally thought that we may now be at or past the second hump
of this sunspot maximum, but the sun continues to throw some
surprises.

For example, the observed sunspot numbers for the last six months of
2013 were 57.0, 66.0, 36.9, 85.6, 77.6 and 90.3, which shows the great
variation.

The current predicted smoothed sunspot number (which is that
recommended for VOACAP-based programs) is about 61-62 for the next
three months.

This equates to a 10.7cm solar flux index of about 110 (on 24th
January it was 136 with an actual sunspot number of 121).

A flux over 100 suggests that 10m will continue to open on a fairly
regular basis and the next few months should throw up some good
opportunities for DX on the higher bands. However, the longer-term
trend may be downwards.

On the downward side of the cycle we may also experience more
unsettled geomagnetic conditions due to flares and coronal mass
ejections. These may cause short-term D-layer absorption (especially
on routes over the poles) or depletion of the F layer (with
corresponding poor conditions on the upper HF bands). Looking on the
bright side it may also give raise to aurorae.

The short-path HF predictions from the UK can be found via a link at
the top right on Steve's blog page at http://g0kya.blogspot.co.uk/.
If you want to produce more detailed point-to-point calculations he
recommends VOACAP online at http://www.voacap.com/prediction.html

Steve G0KYA

Chairman, RSGB Propagation Studies Committee

• All propagation reports can be found at:
http://www.southgatearc.org/propagation