Flashcards in Lecture #5 Deck (61):
What 2 processes does the suns energy drive?
All Weather phenomena
What % of solar radiation makes it down to earths surface?
What are the gases that make up the atmosphere?
Water vapour, CO2, other trace gases= 1%
What is the structure of the atmosphere?
Which area of the atmosphere is all whether confined too?
Which layer of the atmosphere has the O3 layer?
What does the O3 layer do?
Naturally occurring and protect us form harmful UV rays
What are the 3 prefixes for naming clouds and what elevation do they refer too?
-Heigh of cloud
High cloud: cirro
Mid level: alto
Low cloud: strato
What are the 2 suffixes for naming of clouds and what do they describe?
-Appearance of cloud
What does it mean if a cloud name contains "nimb"?
Cloud will produce precipitation
What are fronts?
Mark the boundaries between 2 air masses
What does the name of fronts describe?
Describes the type of air behind that front
What are the 2 types of fronts?
Hot: less dense
Cold: More dense
At any moment how many thunderstorms are occurring on Earth?
What is required for the development of a thunderstorm?
-Rising air (or a lifting mechanism like a front)
What are the 3 stages of thunderstorm development?
What is hail and where is it formed?
Its formed during thunderstorms in tall clouds
How is hail formed?
Updrafts in the cloud repeatedly force water droplets up. It develops a ring of ice around it each time it enters the cold part of the cloud
A spark of electricity occurring in a cloud
Where does the majority of the lightening strike?
within the cloud
-sometime the atmosphere refracts thunder making it inaudible
What is the main requirement for lightening ?
cumulonimbus cloud containing a region of opposite charges
A rotating column of air touching the ground that formed within a supercell thunderstorm
What is a funnel cloud?
When a rotating column is NOT touching the ground
Characteristics of tornadoes?
- ~300m wide
- Travel SW-->NE ~50km/h
-Exist for less than 30 mins
- Common in spring
What are the 3 defined stages of a tornado life cycle?
1. Organizational stage
2. Mature stage
3. Rope Stage
What is the organizational stage?
-Wind shear causes rotation to develop
-funnel cloud protrudes from above
-dust and debris rotate beneath
What is the mature stage?
Most severe damage occurs at this stage
What is the rope stage?
Tornado stretches out and weakens
What is wind shear?
a change in wind speed or direction over a distance
What scale do we use to classify tornadoes?
Enhanced Fujita Scale
Characteristics of an EF5 tornado?
What is the US and the Canadian tornado Alleys?
US: kansas + Oklahoma
Canada: Southwestern ontario
Why do tornado alleys exist?
They occur where hot and cold air masses collide
-also in areas of relatively flat land
What and when was the "Super Outbreak" of tornadoes
Occurred April 3rd 1974 where 148 tornadoes touched down between Ontario and Alabama in one day
What year did the largest tornado outbreak occur? and how many?
SE USA 358 touched down
-324 people killed
Why is it easy to predict the direction of tornadoes?
They generally move in an almost perfect straight line
Characteristics of the Goderich Tornado?
-Killed 1 person
-Radar showed curved wind formation on RADAR
-Formed over Lake Huron
-Warning issued 12 mins before it reached to town
What are tropical cyclones?
high winds, heavy rains and storm surges
-need warm water and form near the equator
-Includes tropical depressions, tropical storms and hurricanes
What are extratropical cyclones?
Form at latitudes 30-70degrees
-associated with front
-contain rain snow freezing rain
What are the 4 stages of tropical cyclone development ?
1. Tropical disturbance: Large area of low pressure with unsettled weather
2. Tropical Depression: Unorganized area of thunderstorms
3. Tropical Storm: Orangized area of thunderstorms; wind speed 65-119km/h
4. Hurricane: Area of low pressure; wind speed of at least 120km/h
How warm does the water need to be in order to form a tropical cyclone?
26 degrees C
What are the 3 components of a Hurricane?
1. Eye: region in the center with light winds and clear skies
2. Eyewall: ring of intense thunderstorms that whirl around the eye
3. Spiral Rain Bands: Rings of tall clouds and heavy rain that exists throughout the hurricane
What are the 5 letters skipped for male/female naming of thunderstorms?
Q U X Y Z
-naming started in 1953
Do hurricanes typically move faster or slower?
-speed varies depending on what side of the hurricane you're on
What is a storm surge?
When powerful winds create an abnormal rise in sea level
-most devastating effect of hurricanes
What scale do we use to classify hurricanes?
-based on wind speed
When is the official hurricane season?
June 1st-November 30th
-most occur in august-sept
What was the main cause of damage from Katrina?
-actual city is below sea level, and on the other side is the mississippi
What is fog?
It is a cloud with its base at the earths surface and reduces visibility to less than 1 km
When does fog occur?
At night when the air cools to dew point and the vapour condenses to droplets
-stays near the ground because its the coolest
-cold dense air sinks
What characteristics classify a Blizzard?
- Wind at least 40km/h
-Snow falling or blowing
-Visibility less than 400m
-All must occur for at least 4 hours
What is lake effect snow?
Cause by cld air moving over relatively warm water
-heavy snowfall downwind from lakes are the snowballs
What is lake effect clouds?
Clouds form over lakes and move down wind
What are Haboobs?
Sandstorms that occur in arid and semi arid regions
-Forms from downdrafts on the leading edge of a thunderstorm
What are dust devils?
Small spinning vortex of air formed over hot dry land
-caused as hot air rises, the wind direction may change due to obastacles
-results in a spinning column
Ice storm definition?
Mainly caused by freezing rain
-rain freezes upon impacting the surface
-weight major issue
What is a drought?
Extended period of unusually low precipitation
What is wind chill?
It is a correction facto to a temperature reading cause obit the presence of wind making the air feel cooler than the temperature suggests
What is Humidex?
It is a correction factor to a temperature reading caused by high levels of humidity making the air feel warmer than the temperature suggests
How do we minimize severe weather hazards?
weather satellites detecting cloud cover