Weather Hazards Flashcards
(90 cards)
Describe each stage of tropical storm formation.
***
Warm SEA TEMPERATURES of 27°C cause EVAPORATION. As the WARM, MOIST AIR rises, it CREATES an area of LOW PRESSURE.
-> COOLER AIR then moves towards the LOW-PRESSURE area to REPLACE the RISING WARM AIR and also WARMS UP as it RISES.
->This CYCLE continues which INCREASES WIND SPEEDS the STORM and INCREASES the RATE of the CORIOLIS EFFECT.
->The CORIOLIS EFFECT causes the AIR to spiral, leading to the ROTATION of the STORM. As the air continues to rise, it forms the EYE of the STORM
What is the Eye?
An AREA of EXTREMELY LOW PRESSURE where COOL, DRY AIR DESCENDS
What are the weather conditions like in the Eye?
Usually CALM and CLOUD FREE
What are the weather conditions like in the Eyewall?
**
The MOST INTENSE and POWERFUL with HIGH WINDS and TORRENTIAL RAIN, an area of LOW PRESSURE
What happens in the Eyewall?
WARM MOIST AIR RAPIDLY RISES
What is a Storm Surge?
**
An ABNORMAL RISE in SEA LEVEL which is PUSHED ONTO the COAST due to LOW PRESSURE and STONG WINDS
Why does a Storm Surge occur when a Tropical Storm reaches the coast?
A TROPICAL STORM’S LOW PRESSURE EYE and STRONG WINDS cause SEA WATER to RISE and EXPAND. As the COAST NEARS, the WATER becomes more SHALLOW, its HORIZONTAL SPREAD is RESTRICTED, causing the WATER to RISE VERTICALLY
Why does a Tropical Storm collapse and dissipate when it reaches land?
**
It has NO SUPPLY of ENERGY (warm, moist air from the sea) which causes the EYE to COLLAPSE and the STORM to DISSIPATE
What is the temperature required for Tropical Storms to form?
27 degrees
What does the Air Pressure need to be like for a Tropical Storm to form?
**
LOW PRESSURE so that the AIR can RISE
Why is air pressure important in the formation of Tropical Storms?
Without LOW PRESSURE, the WARM AIR would NOT be ABLE to RISE, meaning the LOW PRESSURE AREA beneath would NOT be FORMED. This means COOLER AIR wouldn’t be able to REPLACE IT, and the CONTINUOUS RISE of AIR , which is ESSENTIAL for STORM FORMATION, would be IMPOSSIBLE.
Why can’t winds be too strong during the formation of a Tropical Storm?
If WINDS are TOO STRONG they CAUSE the STORM from DISPERSE or PREVENT the WARM AIR from RISING
What does warm water provide the Storm with?
**
Energy
-> The EVAPORATION of HEAT and MOISTURE from the OCEAN creates an AREA of LOW PRESSURE
How deep does the Water have to be?
**
50 metres
Why don’t Tropical Storms occur on the Equator?
**
CORIOLIS EFFECT is EXTREMELY WEAK at the EQUATOR as the EARTHS ROTATION DOESN’T cause WINDS to CURVE there
How far from the Equator do most Storms occur?
5 to 20 degrees north or south of the equator
Describe the structure of a Tropical Storm
(BLURT)
Eye: An AREA of LOW PRESSURE and LIGHT WINDS
EYEWALL: EXTREMELY LOW PRESSURE, an AREA where WARM, MOIST AIR is CONSTANTLY RISING. As the AIR RISES, it RELEASES LATENT HEAT and COOLS and CONDENSES to FORM CUMULONIMBUS CLOUDS
Draw and Label the Structure of a Tropical Storm
(BLURT)
What three factors cause air in the atmosphere to move in different directions?
-THE CORIOLIS EFFECT
-PRESSURE DIFFERENCES
-TEMPERATURE DIFFERENCES
What happens at the Hadley Cell?
(BLURT)
- Since THE HADLEY CELL is NEAR the EQUATOR, the AIR WARMS very QUICKLY, causing it to become LESS DENSE and RISE
- As the WARM AIR RISES it then COOLA and SPREADS OUT, around 30 DEGREES NORTH and SOUTH of the EQUATOR
- When the AIR SINKS it CREATES AREAS of HIGH PRESSURE around 30 DEGREES NORTH AND SOUTH of the EQUATOR
- The SINKING AIR is DRY, which REGULATES and FORMS DESSERTS
- As the AIR SINKS, it RETURNS to the EQUATOR, creating TRADE WINDS that blow from the NORTHEAST (NORTHERN HEMISPHERE) to SOUTHEAST of the SOUTHERN HEMISPHERE
What happens at the Ferrel Cell?
(BLURT)
- AIR from the SUBTROPICAL HIGH PRESSURE ZONES (30 DEGREES LATITUDE) towards the SUBPOLAR LOW PRESSURE ZONES (60 DEGREES LATITUDE)
-> These winds are known as WESTERLIES and they flow from NORTHERN NORTHWEST to SOUTHERN SOUTHWEST - As the WESTERLIES approach the POLAR REGIONS they AIR is FORCED to RISE, creating LOW PRESSURE ZONES, CLOUD FORMATION and PRECIPITATION
- After the AIR RISES at around SIXTY DEGREES it COOLS and SINKS back towards the SURFACE at the SUBTROPICAL HIGH-PRESSURE ZONES (30 DEGREES LATITUDE) to COMPLETE the CYCLE
What happens at the Polar Cell?
(BLURT)
- The AIR is COLD and DENSE so it SINKS, creating HIGH PRESSURE ZONES at the POLES (90 DEGREES LATITUDE)
2.This COLD, DENSE AIR FLOWS moves SOUTH in the NORTHERN HEMISPHERE or NORTH in the SOUTHERN HEMISPHERE
- The COLD AIR FLOWING TOWARDS the EQUATOR is DEFLECTED by the CORIOLIS EFFECT which CREATES POLAR EASTERLIES, WINDS that BLOW from the EAST TOWARDS the WEST
- As the air MOVES, it MEETS the WARMER AIR from the FERREL CELL around 60 DEGREES LATITUDE. The WARMER SIR RISES leading to CLOUD FORMATION and PRECIPITATION
- As the AIR RISES, it LOSES ENERGY so COOLS and SINKS at around 60 DEGREES LATITUDE , moving towards the POLAR REGIONS again
Describe the Atmospheric Circulation System.
(BLURT)
Draw the Atmospheric Circulation System.
(BLURT)