Geography - Global Hazards

?
  • Created by: Issy.ryan
  • Created on: 28-12-17 09:59
View mindmap
  • Geography - T1- Global Hazards, Atmospheric Circulation
    • Ferrel Cell
      • Next to Hadley Cell, between 30° N/S and 60° N/S.
      • Opposite direction to other cells, air joins the sinking air from the Hadley Cell and is moved from the high to low pressure belts, at 60° N/S, at low heights.
      • The high pressure belt at 30° N/S has cloudless skies and low rainfall, often very hot.
      • At 60° N/S, the air rises and meets with the polar air and the warm air rises. This is a low pressure belt, with frequent rain.
    • Winds are large scale movements of air from high to low pressure.
      • Winds are part of global atmospheric circulation loops, called cells.
      • When warm air rises it creates low pressure belts, when cool air falls it creates high pressure belts.
        • There are three main loops in each hemisphere, Hadley, Ferrel and Polar
        • Usually 10 -15km high
        • Warm air rises as less dense than cool air, it cools and condenses, forming clouds and rain.
        • Cool air sinks as it is denser, meaning no clouds formed and is sunny.
    • Polar Cell
      • Furthest away from equator, from 60° N/S up or down.
      • Some of the warm air rising from the Ferrel Cell moves towards the poles.
      • The air is cooled and sinks at the poles, creating high pressure, with low temperatures.
      • The high pressure air moves back towards the equator.
    • Climate Zones
      • Polar = low temperatures all year
      • Temperate = moderate summers and winters, rainfall is frequent due to rising air from Ferrel Cell.
      • Arid (dry) = rainfall is very low due to high pressure in-between Ferrel and Hadley Cell. Temperaturea very hot in the year.
      • Tropical = temperatures are hot all the time, and rainfall is high due to the low pressure belt at the equator. Very humid conditions.
    • Extreme Weather
      • Wind
        • Wind is air moving from areas of high to low pressure, meaning some areas are windier than others.
        • Winds are weak in high and low pressure belts and strong in-between.
        • When the difference is large between the high and low pressure areas, the winds can be extremely strong.
      • Temperature
        • The equator receives the most energy from the sun, the poles receive the least.
        • Temperatures can be very high at high pressure areas like at 30° N/S because the sinking air creates no clouds, so there is nothing to absorb and block the sun's energy.
        • However, at the high pressure belts of the poles, the  temperatures are very low because the sun's rays barely heat them.
      • Precipitation
        • Precipitation (rain, snow etc) ocurrs when warm, wet air rises, cools and condenses.
        • Air rises at the low pressure belts, meaning there is higher rainfall in these areas. E.g rainforests have high rainfall as they are in low pressure belts.
        • The exact location of the high and low pressure belts changes over time, so countries between them can also have varied weather over time.

Comments

clansfly6575

Report

Thank you, I appreciate your support in the mind map, it relates to the topics that I am focusing on Geography.

Similar Geography resources:

See all Geography resources »See all Natural hazards resources »