Weather Hazards Flashcards
What is global atmospheric circulation?
global atmospheric circulation is the movement of air around the earth to try and balance the temperature.
Why does air move?
Due to the differences in air pressure. winds blow from high pressure areas to low pressure areas.
What is high pressure?
when cool air sinks causing clear skies.
what is low pressure?
When warm air rises forming clouds and rain.
When the sun shines, where does most of it go?
To the equator because the angle between the sun and the equator is very direct, so it does not lose power because it travels a short distance.
Why is the sun have less power in the UK.
There is less of a direct angle and the sun loses power as it has a further distance to travel.
Describe the global circulation model?
The sun warms the Earth at the equator causing the air to rise. This creates a low pressure belt. As the air rises it cools and moves away from the equator. At 30 degrees north and south of the equator, the cool air sinks creating a high pressure belt. At the ground surface the cool air moves either back to the equator as trade winds or towards the poles as westerlies. These winds curve due tot he earths rotation (Coriolis effect). At 60 degrees north and south of the equator the warmer surface winds meet colder air from the poles. The warmer air rises creating low pressure. Some of the air moves back towards the equator and rest moves towards the poles. At the poles the cool air sinks, creating high pressure. The high pressure is then drawn back to the equator.
What type of weather do you see at the equator and why?
At the equator there is a lot of solar radiation, so its hot. Warm air wises forming clouds so it rains a lot.
What type of weather do you see at 30 degrees north and south and why?
When air has reached 30 degrees north and south it has released most of its moisture as rain. the dry air means that their are fewer clouds and little rainfall. often desserts are at this latitude,
What type of weather do you see at 60 degrees north and south and why?
Warm rising air brinks a lot of cloud cover and rainfall.
What are tropical storms?
Tropical storms are huge storms called hurricanes, cyclones and typhoons in different parts of the world.
Where do tropical storms usually form?
Between 5-15 degrees of the equator.
What makes a tropical storm usually form?
ocean temperature being above 27, the earth spinning (Coriolis effect) is very high and intense heat and humidity making the air unstable.
How to tropical storms usually occur?
The warm surface water evaporates, rises and condenses into clouds. this releases huge amounts of energy producing powerful storms. the rising air produces low pressure which increases surface winds.
What is the structure of a tropical storm?
Has the center called the eye. Its caused by descending air. There is low pressure, light winds, no clouds and no rain. The eye is surrounded by the eyewall, where there spiraling rising air, strong winds, storm clouds, rain and a low temperature. Towards the edges of the storm, the wind speeds fall, the clouds become smaller and more scattered the rain is less intense and temperature increases.
