Climatic Hazards Flashcards
What is Global Atmospheric Circulation?
Transfer of heat from the equator to the poles by movement of air, due to different air pressure. Each cell has rising warm air that creates a low pressure belt and cool sinking air that creates a high pressure belt
Why does the equator recieve the most amount of solar radiation?
energy spread over a smaller area, travels a shorter distance due to curvature of earth
What are trade winds
Winds that flow back towards the equator after cooling and sinking
Explain global atmospheric circulation
At equator, warm, less dense air rises, creating low pressure zones. This air moves towards the poles, where it cools, becomes more dense and sinks, moving back towards the equator as westerlies
Where is the ferrel cell located
between 30 and 60 degrees north ad south of the equator
Describe the requirements for a tropical storm
-between 5 and 30 degrees north and south of the equator
-sea temperatures of 26.5 degrees celcius
-oceans of at least 50m deep
-low pressure (warm surface water evaporating)
-wind speeds of at least 74mph
-Low wind shear (prevents clouds from breaking up)
What are tropical storms called in different parts of the world
-typhoons (Asia e.g China, Japan, India
-Cyclones (Austrilasia and parts of Africa, e.g New Zealand, Australia)
-Hurricanes in Americas, (USA Mexico
What is the coriolis effect?
effect on wind caused by the spin of the earth
Explain the formation of a tropical storm
Solar radiation warms oceans to 26.5 degrees, causing warm moist air to rise in thermals, creating low pressure. This air then cools and begins to sink back down at 1 degree per 100m, and condenses into cumulonimbus clouds. Some cool air sinks further down to form the eye, and air rushes in from higher pressure areas outside the storm to form lower pressure areas. Storm rotates anticlockwise due to coriolis effect
Decribe the features of a tropical storm
-Eye (50km across, caused by descending air. low pressure, light winds, no rain, high temperatures)
-eye wall (160 kmh strong winds spiralling. ascending air, torrential rain)
-cumulonimbus clouds
-clouds smaller around edges, less intense
What causes wind?
Areas of high and low pressure
How much have sea surface temperatures risen since 1900?
1.06 degrees celcius
How does climate change have an effect on the frequency of tropical storms?
-longer period of time when tropical storms can occur. oceans warmer for longer. in the atlantic, 16 ot of the 24 years between 1995 and 2018 had a higher number of tropical storms than average
How does climate change have an effect on the distribution of tropical storms?
more oceans above 27 degrees celcius at higher latitudes.
How does climate change have an effect on the intensity of tropical storms?
higher sea surface temperatures, more evaporation, more clouds formed, releasing more energy, meaning storms are more powerful. in the atlantic, 2014-2018 had almost 2x as many major hurricanes as 1970-75
Name some “planning” strategies
Training emergency services how to react to a storm can reduce the number of deaths.
Planning evacuation routes can allow people to get away from the storm quicker
Doing mock diaster drills
Having disaster packs ready.
Eg after hurricane haiyan, volunteers started rescue simulations
Name some “monitoring” and “predicting” strategies
Using radar, satellites and aircraft that measure wind speeds, barometric air pressure, rainfall and snow. Release sensors called dropsondes that improve forecasting models. Computer models can then be used to calculate a storms predicted path. Eg hurricane haiyan- helped authorities evacuate
Name some “protection” strategies
-storm proof buildings above water levels.
-flood defences (levees, sea walls)
Eg mangrove forests planted in phillipenes to act as a natural flood defence
Why can tropical storms not happen at higher latitudes?
will lose energy from frictional effect of moving over land or cooling effect of passing over cooler water.
Give an example of when strong winds hit the uk
Storm ali, 100mph winds blew over trees and cars, resulted in 2 deaths. Damaged property and transport. uprooted trees and debris causing injuries/deaths
give an example of when heavy rainfall hit the uk
2018 floods in south wales. 180mm of rainfall in 48 hours of storm callum. damaged homes, can drown people and distrupt transport. schools and businesses forced to shut
give and example of when snow and ice hit the uk
march 2018-beast from the east. 50cm of snow, major disruption to traffic and school, injuries from slipping
give and example of when drought hit the uk
2022 drier summer than average. only 62% usual summers rainfall. low ground water levels by autumn. crop failures and rules to conserve water
give and example of when thunderstorms hit the uk
july 2014 central england thunderstorms delayed flights and caused powercuts. causes fires, damages property and environment. can kill
