The Earth’s supply of water is a precious resource that can never be replaced. Water, after all, makes up the water cycle that produces different types of weather.
The weather plays a vital role in people’s lives each day. Farmers and gardeners need both enough sunshine and rain to keep their plants healthy. Boatmen wish for fair and calm weather while they're at sea. People decide what to wear depending on the weather forecast and the look of the sky. In addition, you can get sick if it becomes too hot or too cold outside.
In simple terms, we can find five different kinds of weather – when it’s bright and sunny, when it’s cloudy, when it’s windy or breezy, when it’s snowing, and when it’s raining. By these types, you can find out which weather your place is currently having by simply turning your head to the sky.
The Sun has a great effect on what weather will occur at any given moment. It raises temperatures, which can make the surroundings hot and cause more clouds to appear later.
Depending on how many clouds are in the sky, the weather may be partially or fully cloudy (overcast). When the sky is covered with clouds, it blocks the Sun’s rays from reaching the surface – lowering temperatures and cooling an area. People tend to enjoy cloudy days because cooler temperatures tend to be more comfortable.
The heat from the Sun can cause air to expand, lowering the air pressure in the area. This causes air from places with higher pressure to move to the area and maintain a balanced pressure. The process of air moving from one area to another creates wind. Depending on how great the pressure difference is, winds can range from light breezes to violent gusts.
The Sun’s heat also drives evaporation – the changing of water from its liquid to gas phase. Water vapour is fairly light and eventually rises high enough up the atmosphere that it begins to cool – or condense – back into liquid, at which point it becomes too heavy to stay in the sky. Hence, the liquid water falls down to the surface as rain.
If the temperature is cold enough, water may also fall down as ice, snow or hail. All of these are forms of precipitation.
Many spectacular phenomena are associated with weather. Electrons at the bottom of clouds can become attracted to the protons on the surface, producing a giant electrical spark known as lightning. The accompanying thunder occurs when heat from lightning makes the surrounding air suddenly expand.
Another interesting weather event is fog – which is basically a cloud that is very close to the ground. Fogs can make it hard to see your surroundings, and can be hazardous when encountered up mountains and at sea.
One of the most awe-inspiring yet destructive weather events is the tornado. Although it looks solid, especially when it becomes opaque due to dust, it’s actually a column of rapidly rotating air that comes from large thunderstorms.