Climate describes the temperature, precipitation, and other weather conditions of a certain area. The climate of an area describes how these variables may be over a long period, for instance the South of France in the summer is hot and dry.
However this is not always the case as there are some days when it is raining and fairly cool. These daily changes do not affect the overall climate of the area, and are described as the weather of the area for that day.
The map below shows the main climatic regions of the world:
Many factors affect the climate of different areas around the world. Themain ones are described below:
Altitude: Temperature falls the higher youare. The loss in temperature is approximately 10°C for every kilometre yourise. This fall in temperature with height is due to the fact that the airat higher altitudes is thinner. There are fewer molecules available to receive and retain heat. Wind chill may also mean that the temperatures inupland areas are lower than expected.
Aspect: This relates to the direction in which a place is facing. Aspect only really affects local climate, not global ones. In the Northern Hemisphere, south facing slopes receive far more sunlight than north facing ones. These are therefore much better for agriculture and often settlement will locate there due to the better aspect.
Distance from the Sea: The sea can have agreat influence over climates in maritime regions. The sea takes much longer to heat up but retains that heat far better than the land. Consequently the land is often warmer than the sea during the day, however the situation is reversed at night.
This means that places like Britain, which are near the sea, have relatively cool days and warm nights, as well as warm summers and mild winters. The influence ofthe sea diminishes as you move further inland, for instance to central Europe, where warmer winters and cooler summers will be experienced.
Latitude: on global climates. Lines of Latitude are those that run horizontally around the world. The most famous line of latitude is the Equator. Using the lines of latitude we can easily divide the world in to specific climatic sections.
- Between 23.5 South and 23.5 North is the region called thetropics. These receive the most heat from the sun because itis almost directly overhead and so the solar radiation does not have to travel through very much of the atmosphere. It heats a very concentrated area of the surface of the ground.
- Between 23.5 and 66.5 in both the Northern and Southern Hemispheres are the temperate regions. These have reasonably hot summers and mild winters.
- Above 66.5 in both hemispheres are the Polar Regions, which are very cold. They receive sunlight for only half the year due to the angle of the Earth on its rotation. During the months when they do have sunlight, it travels to them at a very shallow angle, meaning that it has to travel through a lot of the atmosphere and has to heat a wide area of the surface.
Ocean Currents: Many areas beside the sea are affected by ocean currents. These can be either warm or cold currents. The United Kingdom is directly in the path of the Gulf Stream and the Northern Atlantic Stream, which bring warm water from the Caribbean across the Atlantic to our shores. This current alone is the reason why our climate is mild compared to places of similar latitude like Newfoundland.
Prevailing Winds: The prevailing (most common) wind in the United Kingdom comes form the South West. If a prevailing wind travels over a warm surface it will bring warm weather, whilst if it travels over a cold surface it will bring cold weather.
The south-westerly winds in Britain travel across the Atlantic. In the summer this means that the air is cooled, whilst in the winter the water warms the air, bringing warmer winters than we might expect.