Meteological Hazards

Question 1

Define Meteorological Hazard

Answer 1

Hazards related to atmospheric patterns or conditions, and are generally caused by weather factors such as precipitation temperature, wind speed and humidity

Question 2

State the 5 ways of classifying Hazards

Answer 2

1. Scale
2. Frequency
3. Nature of Hazard
4. Scale of Intensity
5. By wind speed

Question 3

Using the 5 methods of classification, classify a Tropical Storm

Answer 3

Scale=Regional
Frequency= July-September N.Hemisphere, Jan-March S.Hemisphere
Nature of Hazard=Winds and Flooding
Scale of Intensity=Saffir Simpson
Wind Speed=119-251km/h

Question 4

Using the 5 methods of classification, classify a Tornado

Answer 4

Scale=Local
Frequency=Any time
Nature of Hazard=Wind
Scale of Intensity=Fujita
Wind Speed=100-320km/h

Question 5

Using the 5 methods of classification, classify a Drought

Answer 5

Scale=Local/regional
Frequency=All year round, peak time is summer months
Hazard=Lack of precipitation and extreme temperature

Question 6

Using the 5 methods of classification, classify a Flood

Answer 6

• Local
• All year round
• Precipitation

Question 7

Using the 5 methods of classification, classify Fog

Answer 7

• Local
• All year round
• Precipitation, temperature, Visibility

Question 8

Using the 5 methods of classification, classify Photochemical Smog

Answer 8

-Local (cities)
-All year round, peak time summer months
-Visibility
Emissions of chemicals- health problems

Question 9

Describe the distribution of tropical storms

Answer 9

• Generally found of east coast of continents

- Track away from the equator in a curve due to the Coriolis effect

Question 10

What is a tropical storm

Answer 10

A localised, very intense low pressure wind system, forming over tropical oceans and with winds of up to 39mph

Question 11

What is a cyclone

Answer 11

A hurricane, cyclone or typhoon is a developed tropical storm, wind speeds reach at least 74mph.

Question 12

Define Global Energy Budget

Answer 12

The balance between the incoming solar radiation, the outgoing terrestrial radiation and the redistribution of the sun’s energy

Question 13

What are the 4 vertical transfers of energy

Answer 13

Conduction, Convection, Radiation, Latent Heat

Question 14

What are the 3 horizontal transfers of heat

Answer 14

Atmospheric circulation (tri-cellular model), ocean currents and jet streams

Question 15

Define Conduction

Answer 15

Vertical transfer of heat through direct contact between particles of a substance without moving the particles to a new location

Question 16

Define Convection

Answer 16

Vertical transfer of heat though movement of particles from one location to another, generally occurs in fluids

Question 17

Describe the role of the Coriolis force

Answer 17

• Without the Coriolis force, winds would run North to South or South to North in each of the cells
• The force drags the wind giving them an east or west component
• It describes the pattern of deflection taken by objects not firmly connected to the ground as travel long distances around the world

Question 18

Describe the structure of a tropical storm/cyclone

Answer 18

• It has a central eye that is 30-60km wide. It has calm conditions
• An eyewall is the boundary between the stronger and calmer conditions
• The eye is surrounded by rain bands

Question 19

Describe the formation of tropical storms/cyclones

Answer 19

1. As sea temperatures rise there is an increase in evaporation and the rising of air and water in thermals
2. As these thermals rise their temperatures drops, causing the water vapour to condense leading to the formation of clouds
3. Latent heat is released during the condensation fuelling the storm
4. The water droplets in the clouds collide with each other causing them to become bigger and fall as rain
5. Because the air at the centre of the storm has risen, an area of low pressure forms at the surface
6. The global energy budget act to balance at this pressure difference, as air moves from surrounding high pressure areas to the centre of the storm, this creates high winds.
7. The whole storm migrates across the ocean towards the land, the Coriolis force causes the whole system to rotate about a calmer point which is the eye
8. As they move across the land, they lose their source of energy and die out

Question 20

What sea conditions does a tropical storm require to form, and how does this effect when they occur

Answer 20

Sea temperatures above 26.5C, this process takes a long time as the ocean is constantly moving and redistributing heat. Therefore hurricanes tend to form in late summer

Question 21

Describe the Bernoulli Effect

Answer 21

• Velocity and Pressure are inversely proportional, so low pressure of hurricanes causes an increase in wind speed
• When wind blows at high speeds, a low pressure system is created above the building, so the pressure inside the building is greater than outside the building
• Therefore the roof of a building is blown up towards the wind, rather than being pushed down by the wind as objects move from high pressure regions to low pressure regions

Question 22

How does the Coriolis force cause cyclones to rotate

Answer 22

• At the centre of a cyclone there is low pressure, this means the high pressure surrounding the eye is constantly rushing towards the centre
• But the Coriolis effect the high pressure is deflected off course.
• In the N.Hemisphere the winds are deflected slightly to the right, causing the whole cyclone to rotate in an anti-clockwise direction.

Question 23

How is the pattern of intensity for tropical storms changing

Answer 23

-Hurricanes are becoming more devastating than in the past because they have a lower velocity resulting in the impacts being amplified and dragged out over larger areas

Question 24

How is the pattern of periodicity for tropical storms changing

Answer 24

The number of tropical storms doesn’t seem to be changing, but the number reaching hurricane status is increasing

Question 25

How is the location of tropical storms changing

Answer 25

Warmer seas mean more locations are being effected and source areas are increasing further North and South

Question 26

How is the enhanced greenhouse effect leading to tropical storms changing

Answer 26

- Warming temperatures slow storms down - Climate change is increasing intensity and dangers posed by hurricanes - wind speeds increasing by 2-11%, rainfall rates during these storms are projected to increase by 20%

Question 27

Describe the formation of a tornado

Answer 27

- As the ground is heated air rises due to low pressure, normally clouds form as it rises. However, if the atmosphere is unstable the warm air continues to rise much higher eventually forming Storm Cumulonimbus clouds - Clouds with these strong updraughts are known as Supercells - As you increase in height, wind speed increases, this is known as wind shear. This results in higher faster air spins and rolls over slower air blow, creating a horizontal axis spin - Powerful updrafts and force from the clouds and precipitation tilt the spinning cylinder vertically - falling down draughts of cold air help to bring the column down - Once the column reaches the ground a tornado is formed

Question 28

Where do Tornadoes occur

Answer 28

All around the world, but most common in the US along Tornado Alley

Question 29

Conditions needed for the occurrence of a tornado

Answer 29

- Most form from thunderstorms | - You need warm, moist air, as when warm moist air meets cool dry air they create instability in the atmopshere

Question 30

Characteristics of a tornado

Answer 30

- Swirling column of air with a hollow core | - Circulating air moves in an upward spiral at high speeds

Question 31

Details of a Case study of a Tornado

Answer 31

- Oklahoma, USA 2013 - Category 5 with winds up to 200mph - 24 people were killed and 300 homes demolished - $2 billion worth of damages

Question 32

Formation of Hail

Answer 32

- Thunderclouds are very high, meaning water droplets in the cloud freeze - But the powerful updrafts created by warmer weather keep the droplets supported in the clouds - The droplets are forced upwards where they collect more water with new layers freezing on in a separate shell - Eventually there are so many layers they are too heavy to be supported and they fall to the ground

Question 33

Conditions required for the formation of hail

Answer 33

-Violent thunderstorms | Summer thermals- warm column of rising air in the lower altitudes

Question 34

Case Study of Hail

Answer 34

-Dallas, March 2016 -Caused hailstones bigger than 2 inches -Affected 1 million homes $700 million in insurance claims

Question 35

What criteria must be met for a snowstorm to be classed as a blizzard

Answer 35

-Large amounts of snowfall -Winds greater than 35mph Less than 1/4 miles visibility -Conditions last for over 3 hours Temperature below 0C

Question 36

Conditions required for Blizzards to form

Answer 36

Cool, calm conditions - Stratus Clouds - Warm air rises over cold air

Question 37

Describe the formation of a blizzard

Answer 37

- When polar air meets warm moist air, the air temperature is cold - A sufficient source of water vapour is required. The air must blow over the water source and some is evaporated into the air - The warm air must then rise over the cooler air in order for the blizzard to form. When the warm and cold air meet a front is formed resulting in precipitation

Question 38

Case Study for a Blizzard

Answer 38

- Beast from the East, UK, 2018 - The jet stream was disturbed allowing cold winds from Russia to reach the UK - It led to 50cm of snow and temperatures falling to -12C - 12 people died - 1000s of schools were shut, hospital operations cancelled and travel disrupted

Question 39

Formation of advection fog

Answer 39

Forms when moist air moves over already cold surfaces and cools and cools them from below so that the temperature reaches its dew point and the air gets saturated and condensation takes place

Question 40

How is photochemical fog formed

Answer 40

Photochemical smog is produced when pollutants from the combustion of fossil fuels react with sunlight. The energy in the sunlight converts the pollutants into other toxic chemicals. In order for photochemical smog to form, there must be other pollutants in the air, specifically nitrous oxides and other volatile organic compounds

Question 41

Extent to which tropical storms can be tracked

Answer 41

The development of tropical storms or cyclones requires high sea surface temperatures. These could be monitored in the areas where tropical cyclones are known to develop. Once a depression is formed, it could be monitored, often with the aid of satellites and its development and movement tracked. However, the movement of cyclones is always uncertain, especially where it will hit land. Many change direction at the last moment. Also, the technology may not be available.