How does global circulation of the atmosphere cause extreme weather conditions in different parts of the world?
Climate zones around the world
Climate: the long term weather patterns of an area.
Linking back to the lesson on the global circulation system, look at the below picture and remember where the cells meet and think about what the climate of these areas will be like.
Generally, but not always, the climate of an area is determined by its latitude so areas with similar latitude have similar climates.
This means the plants and animals that can grow here can be similar. These create biomes of similar conditions.
For more information on biomes, click this link
https://www.internetgeography.net/topics/what-is-a-biome/
Different areas of the world are more likely to experience different types of weather. Tundra areas are more likely to experience extreme cold weather with strong winds, and tropical rainforests are more likely to experience high temperatures and high rainfall.
With records being broken all the time due to a changing climate, extreme weather is becoming more common.
Extreme weather
Extreme weather is a weather event that is significantly different from the usual pattern.
This can differ from place to place, think for a moment about what extreme weather you have experienced where you live?
You may have thought about a storm, or very high or low temperatures, or any combination of these.
For extreme weather, we are going to focus on three types of extreme weather, and where the records are for some of them. They are extreme Wind, Precipitation and Temperature.
Extreme wind
The windiest place on Earth is also the coldest. (think of how being in the wind can make you colder). Commonwealth Bay in Antarctica has average wind speed of over 50mph/80kph and has extremes of 150mph/240kph.
Some places have extreme winds but only for short periods of time, tropical storms can generate winds of near to 200mph/320kph for short periods of time. Hurricane Dorian, which struck the Bahamas in 2019 had wind speeds of over 185mph/298kph as it hit land.
Extreme precipitation
Precipitation is the name for all water falling from the sky, in the form of rain, snow, sleet or hail.
Some areas of the world experience monsoon conditions, which is where they have wet seasons with high rainfall in short timescales. Mawsynram in India has 11m of rain in a year, mostly in the monsoon season from June to September. This is 20 times the average rainfall of London!
Puerto Lopez in Columbia (40 North of the equator) has nearly 13m of rainfall a year, making it one of the wettest places on Earth.
The Atacama desert in Chile (25-300 South of the equator) averages less than 15mm of rain per year. Along with its latitude, it is also in the shadow of the Andes mountains which shield it from rain. These two conditions produce one of the driest places on Earth.
Extreme temperature
As we looked at earlier in extreme wind, the coldest temperatures can be found in Antarctica. The lowest ever recorded temperature was -89.20C at Vostok station in central Antarctica. It is also over 3500m above sea level, which makes it even colder!
For the hottest place on earth we need to look at the Sahara desert and the middle east. This area is around the area where the Hadley cell falls and creates intense dry and hot weather patterns.
Newer temperature records, taken by satellite and have recorded 70.70C in the Lut desert in Iran. Before this the record was 570C in Libya in 1922.
What might the examiner ask?
For this question, you would need to give an example of an extreme weather event and a piece of data (the temperature or wind speed for instance) to get both available marks.
If this question gives a specific location you would need to reference back to this location in your answer.
For example, if the question asked about a desert area:
Desert areas are found at approximately 30 degrees N or S of the equator. These areas have high levels of solar insolation, due to their proximity to the equator, where the solar insolation is highest. The Hadley cell ends at these areas and air is sinking causing high pressure in these areas, this means that clouds cannot form and little or no rain is recorded in these areas. This also means that the clouds cannot cover the areas to give shelter from the sun, increasing temperatures even further.
The highest recorded temperature for these areas was 70.7 degrees in the Out desert in Iran.