sabato 22 febbraio 2020

Propagation News – 23 February 2020

The week got off to a good start with the ARRL International DX CW contest. Contacts into the western US states from the UK, including California, Washington and Colorado, were all possible on 20 metres.

On Tuesday the Earth was hit by a high-speed solar wind stream from a coronal hole, which sent the Kp index to four. The unsettled conditions continued before the Kp index hit a hefty five in the early hours of Wednesday morning.

There were reports of auroral contacts on the higher bands. Luckily, the disturbance tailed off on Thursday with the Kp index finally returning to settled levels.

The solar flux index remained at 71 during this time, reflecting a lack of sunspots.

Next week NOAA predicts the Sun will continue with a solar flux index of 71 with zero sunspots, although new regions can occur at any time. The Kp index is predicted to remain around two to three, but with a rise to four around the 26th and 27th due to a returning coronal hole.

Interest in the VP8PJ DXpedition to South Orkney is beginning to rise. At the time of writing the ship Braveheart had just arrived and the station may be on the air some time this weekend.

This may be a difficult path, but suggests that the best time for a short-path contact may be through the night on 40m, with a peak around 6am. There may also be a long-path opening around 8am-noon on 20 or 30 metres.

VHF and up:

I’m sure there were wires and beam elements flapping about in the winds last week, so now that we’re all used to this, you should be able to cope with the coming week too!

It’s looking very much like the unsettled weather continues with low pressure systems tracking across the far north of Britain producing generally windy weather throughout, and at times very windy weather with gales again likely over the north.

The upshot of all this leaves no sign of high pressure tropo propagation to speak of. It is again a case of rain scatter for the GHz bands as the active rain-bearing weather fronts or squally showers pass by, with little else to offer as a variation.

The Sun and the Moon are close to eclipse this Sunday, so sky noise will be very high. Once today’s event is over, it’s quite low for the rest of the week. Moon declination is rising and goes positive again on Wednesday, meaning lengthening Moon windows with the Moon up during the day. This coincides with apogee so path losses will be at their highest.

Aside from EME and satellite operation, keep looking for random meteor scatter QSOs around dawn, when the Earth is rotating towards the main meteor flux, to keep the VHF DX coming. (RSGB)