As we are now well within our season switch, whether it be Autumn or Spring, things across the African continent are changing. When it comes to Africa, there are many different climatic differences and micro-climates all over. There are some really stand out things though with regards to the climate here, things that are either new, or unexplained to our foreign visitors. In this blog we are going to have a look at some of these. In a previous blog we had a look at the rain, so here we will look at a few other things.
Africas great blue sky and red sunsets
Africa always seems to have endless skies, whether it be massive blue skies during the day, or a clear starry night, it feels like you can see forever. Contrary to believe, the sky is not blue because of the reflection of the ocean off of the atmosphere, if this was the case, areas inland would have duller skies than areas along the coastline.
Light travels in waves called an electromagnetic pulse. These waves travel in a straight line until they meet up with something that changes their direction, which in turn changes their characteristics. Light from the sun itself is actually made up of waves. These blue waves tend to be the shortest of these waves, giving them a high frequency with high energy. Red waves on the other hand are the longest waves with smallest amount of energy. Being shorter, the blue waves can be easily deflected and be scattered by dust and moisture in the air. This means blue light is scattered all of the place and the sky has its blue colour.
This is why the sky turns red at sunrise or sunset as well. The red waves become far more visible to us than the shorter blue rays that now disappear from sight. At these times of the day, the suns rays have to travel over a much larger distance of the earth’s atmosphere. Air molecules and dust scatter, deflect and refract the light, causing the sun to look dimmer.
Warm patches
These warm patches that people will often experience on safari, more so in winter than in summer can easily be explained. These patches of different air temperatures are known as temperature inversions. The best way to describe this, is the colder, denser air, moves downwards, forcing the warmer, lighter air upwards. The warmer air will then sit on top of this cooler air. Elevation is a big one and can easily be experienced when crossing a drainage system or climbing a hill side. Cool air sinks and so will quickly take up the lower lying areas. This is why when you drive through a dip, you get that nice warm patches at the end.
Sometimes when you sit underneath large trees you can feel it is a lot warmer as well. This is because large tree canopies can catch heat that is radiating off of the ground. Where there is nothing to hold it, temperature can escape very quickly, hence it is colder driving through open spaces rather than densely vegetated thickets.
Misty mornings
Mist will always form over water and is far more noticeable in the cooler winter months than in summer. It is caused by the larger temperature differences between the water and the air that sits directly above it. Water holds on to heat from the sun very well, with the upper levels being warmer than lower down.
This is also where evaporation takes place throughout the day and night but more obviously in the day when it is warmer. As evaporation is still happening in the early morning, the water vapour that is moving, meets with the cooler air above it. This in turn makes the vapour condense and so turn into mist. It is seen as a cloud covering the water surface. You will find that the higher the humidity and cooler the temperature, the more mist you may get.
Moisture in the sky
There are numerous types of clouds and they are a good way of telling us what we can expect from the weather systems coming through. Clouds are not unique to Africa though and so this can be used for most places around the world.
Africa is famous for the incredible storms that we get and these are thanks to the large cumulonimbus clouds that form during our summer time. These are massive, vertical clouds that cannot be missed. As it is in summer, high temperatures that rise up cause condensation. As these clouds can get nice and high, some of the moisture in them may freeze and so they can be associated with hail as well.
In summer time, especially after some very warm days, feather like clouds, know as cirrus clouds, may form in the air. These clouds are often associated with frontal systems on the way and the build up of moisture starting. Cumulus clouds will often follow these and are large clouds with dark bottoms, showing the presence of moisture. These clouds can bring us rains. They will often take over the whole sky by combining themselves. They have rounded bump like shapes at the bottom of them.
Smoke rising from fires can also help clouds form. Smoke itself carries a lot of small solid particles into the air. Water vapour can collect on these particles and so form clouds above the plume of smoke. This can in time even cause rain to fall over the fire.
Weather patterns though are not set in stone and some places have completely unique systems. Namibia for example, especially further north west towards the Skeleton Coast, where the cold Atlantic Ocean wind meets the warm shoreline. Here large banks of mist can form and are known to spread for inland.
Rainbows may form in many places as well and where there is a lot of moisture, they may even mirror themselves so it looks like two rainbows, one far bolder in colour than the other. The sky above waterfalls is almost always a guarantee for rainbows if the sun is out. Mist rising from the waterfall fills the air with moisture and captures the light.
People don’t often think about the weather systems and how it can change things on their safari adventure. It always helpful to understand a little more about the conditions in your environment, preparing you for a memorable safari even better.
