Phase difference for Teeside Wind Farm

 Looking along the lines of turbines from Hartlepool South Pier, I realised that the turbines were not in phase. Some had blades at the top whilst some were pointing at 10 degrees. However, this amount of phase was not fixed. As I watched, they came in and out of phase. If they had maintained the same "out of phase" we could have said that they were coherent -  a fixed phase relationship.

The next day we went to North Gare and I was able to time some of the turbines. The time periods were so close that I had to time 5 revolutions to get the differences. Three different times for 5T were 35.20s, 34.67s and 40.54s. The time periods are therefore 7.04s, 6.93s and 8.10s. The differences might be due to nuances in the wind speed in different parts of the array,

Haze and humidity at Loweswater

We climbed Low Fell above Loweswater. Although the sky was cloudless, the visibility was poor. We could just about make out Great Gable about 10 miles away. That whiteness is characteristic of Mie Scattering from water vapour that I have posted about before. I was wondering whether it was to do with this current warm air from the Caribbean. Is it that it holds more water vapour than cold air and so is the humidity actually high today, even though it is warm and dry? I checked and the reading for humidity at Keswick was 71%. But then I found this: https://en.wikipedia.org/wiki/Visibility The visibility in the picture can't be called HAZE because you can see further than 3 miles. The earlier part of the article discusses the derivation of a rigorous formula to calculate the distance that should be able to be seen. That will take some thinking about.

String cloud in Hartlepool

If you enlarge the photo, just up and right of the top of the nearest street light there is some faint wispy cloud. The picture hasn't quite conveyed what I saw but there seemed to be thin delicate lines of cloud like strings. This is a minimal form of the mackerel sky I've posted about before. It isn't lenticular cloud but I know that lenticular cloud is caused by stationary wave patterns where vapour condenses into the antinodes. This is such a regular periodic pattern with condensed vapour  between clear gaps that I'm wondering if it might be some kind of stationary wave.

Abergwyngregin and the Foehn Effect

I've posted before about the model of the Aber valley that we found when we went to the Aber Falls. Abergwyngregin at the foot of the valley has been in the news because of some very high temperatures recorded at this time of year. It was the subject of the weather column in The Times newspaper yesterday. The reason for such high temperatures on the north coast of Wales is given as the Foehn Effect https://www.youtube.com/watch?v=pJqQoUXMquQ https://en.wikipedia.org/wiki/Foehn_wind There are several parts to the warming effect but the first part is that as air rises, the pressure is lower so the temperature falls and this means that water vapour condenses. The change of state releases latent heat - the heat energy is the reason why the top of cumulus clouds are lumpy when the bottoms are flat. This latent heat warms the air. The process is irreversible because the water leaves the air as rain. In the case of Abergwyngregin, the rain falls over Snowdonia and the warmer, drier air sweeps down the valley. Drier air means more sunshine so making it warmer still. The film and article cited give the other components to the warming. I now need to figure out why Wigton doesn't seem to benefit from the Lake District mountains in the same way.

Specific heat capacity of water

To help us obtain an accurate value for the specific heat capacity of water, we put insulation round and on top of a beaker of water. We weighed the water and measured the temperature rise for the water over a 15 minute period. We calculated the energy we put in by using E = ItV so that's current from the ammeter x time in seconds x voltage. Then specific heat capacity = E/(mass x temp rise). No insulation would have meant a smaller temperature rise for the same energy and hence a value for SHC that would have been too big. Accurate means getting the right answer.

Syncline: Great Orme

We walked under the impressive limestone cliffs on the Great Orme at Llandudno. Look at the angle of the layers in the photograph. Limestone is sedimentary and must be laid in horizontal beds on the bottom of the sea. Earth movements can then bend these layers. Here the layers are heading downwards. The Great Orme is said to be part of a syncline, where rock goes down on one side and then comes back up. I learned a new term researching this: Dinantian. The part of the Carboniferous age when these rock were made. http://geoscience.wales/wp-content/uploads/2016/12/Llandudno-August-Field-excursion.pdf

Absorbing wave energy at RSPB Conwy

Back to look at the waves on the pond again. Once again, the wind was driving in from the south so the waves were coming towards me. But notice how they stop. I'm guessing that there are plants submerged just below the surface at this point, but whatever it is stops the waves. Something must be either absorbing the energy or reflecting it. Maybe it's like when ultrasound has goes from one medium to another. If the difference in wave speed is big then the majority of the waves are reflected back and only a few are transmitted.