Download What is humidity? What is relative humidity? What is Dew Point?

What is humidity?
What is relative humidity?
What is Dew Point?
a measure of the amount of water vapor in the air
a percentage of water vapor that is actually in the air compared
to the maximum amount of water vapor the air can hold at a
particular temperature
the temperature to which air must be cooled for it to reach
saturation "full capacity" and water condenses to form dew
Which can hold more moisture warm or cool air and why?
When air cools why does dew form?
If there is no evaporation occuring from the wet bulb of a sling
psychrometer, what is the relative humidity and why?
warm- the air particles are more spread out so there is more
space for the water vapor
Water condenses on to solids like the grass, windows, trees,
etc. because the air particles move closer together and there is
not enough space for the water vapor in the air anymore
The relative humidity would be 100% because there is no more
room for the water vapor in the air at the current temperature.
What is the name of the instrument used to measure relative
humidity?
Why does your body sweat?
Why could it be dangerous to work outside on a humid day?
psychrometer
It sweats so the water will evaporate into the air and your body
temperature will cool down.
If the humidity is high, that means the air is almost holding its
maximum amount of water vapor. This means your sweat will
not evaporate from your skin and your body will not cool down
very quickly.
How does wind move?
Why would a sailor want to avoid the Horse Latitudes and
Doldrums?
What global winds shift most of our weather in the United
States?
horizontally, high to low pressure
The Horse Latitudes are areas where cool air is sinking and
from the Polar Easterlies and Prevailing Westerlies, so there is
very little wind.
Prevailing Westerlies
What is the difference between a local and global wind?
Air that is denser than the surrounding air creates an area of
_______________ pressure.
Air that is less dense than the surrounding air creates an area of
____________ pressure.
local - movement of air from high to low pressure over small
distances (only appear when global winds are weak) globalmovement of air from high to low pressure over great distances
High
Low
Which has a greater air pressure, the North Pole or the Equator
and why?
What is a jet stream?
Where is the Polar Jet Stream located?
North Pole- the air is colder, so that makes it denser
A high speed band of wind at the top of the troposphere
blowing west to east (200 to 400 km per hour)
approximately 60 degrees North of the equator
How can jet streams affect air travel?
How is a wind named?
Where does the wind in a Sea Breeze come from?
Pilots use the jet streams to help speed up their plane traveling
west to east. They would want to avoid the jet streams if they
were traveling east to west.
A wind is named by where it is coming from. Ex.) A southwest
wind is coming from the southwest, towards the northeast.
the sea
Where does the wind in a Land Breeze come from?
When does a Sea Breeze occur?
When does a Land Breeze occur?
the land
A Sea Breeze occurs during the day. The land heats up quicker
than the water, creating an area of low pressure above the land.
The air above the sea is cooler so its pressure is higher. The air
will move from high to low pressure.
Night - The sea takes longer to cool down so the air above it is
warmer than the air above land, creating an area of low
pressure. The air above the land has a higher pressure reading,
so it will move towards the sea.
What are the three main types of clouds?
What does cirrus mean in Latin?
What does stratus mean in Latin?
cirrus, stratus, cumulus (cumulonimbus)
curl of hair
layered, spread out (flat)
What does cumulus mean in Latin?
If you see cumulus clouds in the sky, what type of weather
would you see?
If a cumulus cloud continues to grow taller and taller as water
evaporates quickly, what type of cloud may form?
heap, pile
fair, nice
cumulonimbus (thunderhead)
What type of weather do cumulonimbus clouds bring?
How does a cloud form?
Are you more likely to see clouds when there is high or low
pressure? Why?
thunderstorms (possibly tornadoes)
1. Water evaporates and rises into the air. 2. As altitude
increases and temperature decreases causing the water vapor to
condense. 3. There must be particles in the air for the water to
condense on for the cloud to form.
Low- the air is less dense, so it is constantly rising, allowing
water vapor to rise and condense to form clouds
The less the humidity, the ______________ water evaporates.
If the temperature drops from 80 degrees Fahrenheit to 65
degrees overnight, explain what will happen to the water vapor
in the air.
faster (there is more room for water vapor in the air)
The 65 degree air cannot hold all of the water vapor that the 85
degree air could. As the temperature falls the air will reach its
dew point, where it can no longer hold the water vapor. The
water will condense on to solid objects forming dew (or frost).