Desertification and tornadoes Flashcards
regions with mean annual precipitation of less than 25 cm/year, little vegetation
Deserts
Deserts occur in regions with ____ evaporation compared to amount of precipitation
high
For a desert to form, there must be ____ and ____ air masses
warm and dry
What are the 4 primary classes of deserts?
polar, mid-latitude, trade wind and coastal
What class of desert is this: Area of intense cold but little snow, parts of Antarctica
polar
What class of desert is this: basins of large land masses far from oceans, sparse vegetation and low rainfall
- Gobi, China
mid-latitude
What class of desert is this: located at 30 degrees N and S latitude, persistent areas of sinking air masses, arid
- Sahara
trade-wind
What class of desert is this: on W edges of continents, cold ocean currents
- Peru and Namibia
coastal
What climate regime does this describe: receives less than 2.5 in. of rain/year, little vegetation, sand dunes, central areas
hyper-arid
What climate regime does this describe: receives 2.5-25 cm of rain/year, some drought-resistant vegetation, playas and saline lakes
- Kalahari desert
Arid
What climate regime does this describe: 25-50 cm of rain/year, vegetation, flash floods, at risk for desertification
semi-arid
The US is the only country to have what?
nor’easters
What is capable of producing tornadoes,
large hail, dangerous bursts of
wind or flash floods, and is characterized as mesocyclone?
Super cells
sends out radar waves from ground antenna, objects like rain drops, snow, reflect energy back, also measures frequency of change
Doppler radar
What is it called when a cloud releases negatively charged electrons toward the ground
stepped leaders
rapid heating and cooling of air near the lightning causes what?
thunder
what type of lightning is most dangerous?
Cloud to ground
Where are most people killed by lightning?
open fields
What are the 2 prime factors for tornado initiation?
general topography and local climate
what is the prime season for tornadoes?
spring to early summer
What is the average track length and forward speed of tornadoes?
1-4 miles and 25 mph
What time of day do tornadoes usually occur?
late afternoon to late evening
To form a tornado, there is a ____ level of dry and cool winds from the ___ and a ____ level of warm and wet winds from the ____
high from NW and low from SE
Large thunderstorms pull ____ air upwards from lower levels
warmer
