This video is taken from a hang glider surfing a 3000ft wave of air caused by a sea breeze.
A sea breeze occurs near the coast and requires a specific set of weather ingredients:
1. An unstable air-mass over land.
2. Inland temperatures warmer than the sea.
3. Relatively light winds.
In these conditions, the rising warm air caused by the unstable air-mass will start to suck air from the relatively colder sea. This movement of air will generate a localised wind called a 'sea breeze' which blows from the sea on to the land.
As the land gets warmer throughout the day the sea breeze grows and spreads further inland. If there is a predominant light wind blowing in the opposite direction, ie from the land to the sea, then the two winds will collide and the converging air rises upwards. This will typically create a line of clouds that follows the shape of the coastline. The clouds in this convergence zone often have a prominent step in height. You can see this clearly in the video.
Where the two layers of cloud meet there is a magic line of smooth lift that you can fly in a hang glider. If you are lucky enough to fly in these conditions the experience is amazing because there is lift everywhere. There are also spectacular views to behold.
I believe the Suffolk sea breeze is quite special for a few reasons. First of all, sea breezes occur quite often during the spring and early summer. Secondly, due to the concave shape of the Norfolk and Suffolk coastline, the sea breeze in this region holds its shape and strength longer. Finally, convergence lines can develop in many different wind directions from Northerly winds all the way round to Southerlies.
Flying a sea breeze in a hang glider does require a word of caution. Although the inland convergence zone is marked by smooth lift there can be quite rough turbulence on the coastal side of the zone. If you are low and forced to land near the convergence zone it can be very uncomfortable. You must also be aware that the wind direction can be completely different to that you experienced on take off. In fact I have see it where I have been drifting with the wind at a 1000ft in one direction but below me at the surface a flag was showing that it was nearly 180 degrees different.
Music: Ray AnDrey by Delta Worldwide
19 ноя 2017
