Science U4 L1&2 Flashcards
Weather
Condition of Earth;s atmosphere at a certain time and place
What terms can you use to describe weather?
temperature humidity precipitation air pressure wind visibility
An instrument used to measure and display temperature
thermometer
The amount of water vapor in the air
Humidity
The amount of water vapor in the air compared to the amount of water vapor needed to reach saturation
Relative Humidity
The temperature at which more condensation than evaporation occurs
Dew Point
What happens when air cools below its dew point?
More water vapor condenses into water than evaporates
What happens as the air becomes more unsaturated?
More evaporation than condensation occurs
Precipitation
any form of water that falls to Earth’s surface from the clouds
Four main forms of evaporation
rain
snow
hail sleet
What does the translation for the word Cirrus
curly
Air Pressure
force of air molecules pushing on an area
Wind
air that moves horizontally or parallel to the ground
What is used to measure wind speed?
Anemometer
How do you measure wind direction?
Wind vane or windstock
Visibility
a measure of the transparency of the atmosphere
List two factors that may affect visibility
air pollution
fog
Wind moves from ____________ pressure to areas of ____________ pressure
higher to lower
How do you measure precipitation
rain gauge or meterstick
How do you measure relative humidity?
Pschorometer
Cloud
collection of small water droplets or ice crystals
How much precipitation falls in the desert?
less than 25 cm
Evaporation
the change of state from a liquid to a gas
The surfaces on which water droplets condense
cloud condensation nuclei
what is the composition of a cloud in high altitudes?
mostly ice crystals
horizontal movement of air
wind
Explain what orographic lifting is
when an obstacle such as a mountain range forces a mass of air upward
Stratus clouds
thin and flat, edges not clearly defined
Stratus is a Latin word that means what?
Layer
What type of cloud is fog?
Stratus cloud that falls near the ground
Cumulus clouds
thick and puffy on top and generally flat on the bottom
well defined edges
can change shape rapidly
cumulus clouds can be bright white or dark and with severe weather
Cirrus
feathery with curly ends
white clouds
form high in the atmosphere, cold temperatures
made of ice crystals
What does cumulus stand for
heap
Low clouds
nimbus
between Earth’s Surface and 2,000 m
clouds usually made from water droplets
Middle clouds
between 2,000 and 6,000 m
most commonly made from water droplets
alto
High clouds
above 6,000 m
temperature below freezing
mostly made of ice crystals
Cirro
Clouds of vertical development
higher than 12,000 m
commonly formed by the rapid lifting of warm, moist air, which can result in strong vertical growth
eg. cumulus and cumolonumbus
why doesn’t cloud formation take place until the dew-point temperature is reached?
because it has to have enough water.
