earthscience test Flashcards
What is the motion of surface winds associated with low pressure systems?
Counterclockwise and toward the center of the low.
Match the instruments to what they measure:
Barometer
Anemometer
psychrometer
wind vane
thermometer
precipitation gauge
Barometer - air pressure
Anemometer - wind speed
psychrometer - relative humidity
wind vane - wind direction
thermometer - air temperature
precipitation gauge - amount of rainfall
What are the two characteristics that are used to identify air masses?
moisture content and temperature
The properties of an air mass are mostly determined by the:
source region where the air mass formed
Where and when do most hurricanes that affect the east coast of the U.S originally form?
warm waters of the atlantic Ocean in summer, like on the coast of Africa.
What are some forms of precipitation?
- hail
- rain
3.snow - sleet
- freezing rain
What do isobars do in a low pressure system?
isobars decrease in millibars when getting closer to the center of the low pressure system.
When do clouds usually form
when air temperature reaches the dewpoint
describe a cold front
when warm moist air and cold dry air collide on a steep slope causing a cummunibulis cloud to form.
describe a warm front
when warm moist air collides with cold air on a gentle slope.
describe an occluded front
when two cold air masses collide with each other pushing the warm air up
describe a stationary front.
when cold and warm air masses meet but dont collide
Which geographic region is the most common source region for the mT air masse that move into New York State?
the Gulf of Mexico
Where does precipitation occur on a cold front?
directly on top of a cold front
where does precipitation occur on a warm front?
in front of a warm front
What best describes the difference in air temperature and humidity between the cP and mT air masses?
The mT air mass is warmer and more humid
Why do clouds form in a hurricane?
BECUASE air rises, expands, cools to the dewpoint and condenses on surface nuclei
why does lake effect snow happen?
because cold air moves over warmer lake region during the winter.
why does the position of the polar jet stream vary with the season?
Because the vertical rays of the Sun shift north of the equator in summer
what is a jet stream?
a band of fast moving air that varies throughout the seasons.
what happens as altitude increases?
temperature deccreases
what is the air pressure of 29.68 inches of mercury in millibars? (use CRT)
1005 mb
what weather change is most likely indicated by rapidly falling air pressure?
a storm approaching
where is high pressure and low air pressure on a hot summer, sunny afternoon?
high pressure is over the water and low pressure over the beach
