Here in North Wales it’s very difficult to escape the effects of the seasons, especially if like us, you work mainly out doors. The sun has come out at last after weeks of dreary days of cloud or rain or what we call Welsh mist. On those days it never really gets light and our solar panels produce nothing!
Spring is my favourite time of the year as we pass through the Spring Equinox,( March20/21 marking the beginning of Spring), when the sun is half way back from its most southerly position of 23 degrees south of the equator. The equinox, of course, is the time when we have equal hours of daylight and dark. And why is it my favourite time? From here on, the days get longer and the sun gets warmer. With the better weather and longer days we can get more done outdoors on the farm. And our off grid electricity system really proves its worth and we don’t need our standby generator.
As the year moves on we get to the Summer Solstice which is not really midsummer, as so often reported, it’s really the official start of summer, June 20/21. The sun is then at its zenith in the sky at midday as it reaches it’s most northerly point of 23 degrees north of the equator. This gives us the shortest night and the longest day and hopefully several months of good weather to follow. But from here on the days begin to get shorter but not too noticeably at first. Thank goodness!
My wife, like some, actually prefers the Autumn Equinox, (Sept 20/21 which marks the start of autumn), because she loves the wonderful colours we get from the trees as they lose their summer leaves. At this time we again return to equal day and night but then the days get even shorter as we head towards the winter.
Once we get past October and the nights really draw in I look forward to the Winter Solstice (Dec 20/21 marking the start of winter) when we have our shortest day. Not because I like the winter, but from this time on, the days start to get longer and we are on our way to a new year and a new spring. Unfortunately the daylight hours are not noticeably longer until about mid February. It’s more the psychological thing that spring is on the way!
So there we have our seasonal cycle which in the northern and southern hemispheres gives us the four 4 distinct seasons that we are familiar with. The nearer you live to the equator the less noticeable the seasons are with less weather variation.
We are very lucky where we live for lots of reasons. One reason is we look out across the Irish Sea, giving us an unfettered view of the setting sun and its position in the sky as the seasons change. Of course it’s not the sun moving but us moving around the sun in our solar year that causes the changes.
So what causes this seasonal variation? All the other planets in the solar system spin on a vertical axis, which means that they present the same face equally to the sun as they orbit it during their solar year and consequently they have one season. But the Earth’s axis is tilted and spins at an angle of 23 degrees, this means that part of the year the southern hemisphere faces, or is closer to the sun. Then as we continue our journey around the sun, the northern hemisphere is closer to the sun. This doesn’t happen suddenly, of course, it’s a steady progression from Solstice to Solstice.
Solstice by the way is Latin for “stand still” because at the time of the summer and winter solstice the sun appears to stand still for about 5 days before there is any discernable movement of its position at sunrise and sunset.
And why does the Earth spin on a titled axis? Well we really don’t know but there are some interesting theories out there. It’s now an accepted theory that the earth was hit by a large meteorite 66 million years ago which caused the extinction of the dinosaurs. In the same way it’s possible that sometime earlier in the history of the Earth that it was either hit by, or given a glancing blow by, a very large astral body as it hurtled through space, knocking us off a vertical axis. Some even suggest this could have caused the great flood recounted in so many ancient legends and myths.
Whatever caused this to happen I hope you enjoy the rest of the seasons of the year, whichever is your favourite.