WATER IN THE AIR
• THERE IS ALWAYS WATER VAPOR IN
THE AIR
WATER VAPOR
• WATER IN THE GAS FORM
A
HOW DOES WATER GET INTO AND OUT
OF THE AIR?
B
Here are two samples of air – A and B
Is there the same number of air molecules in each sample?
Is air in sample A colder or warmer than air in the sample
B? Why? Use the space on the side to answer
BASED ON OUR MODEL
• COLDER, HIGHER PRESSURE AIR
CAN HOLD LESS WATER BECAUSE
IT LACKS SPACE
• WARMER, LOWER PRESSURE AIR
CAN HOLD MORE WATER
BECAUSE THERE IS MORE SPACE
• IS WARMER AIR HEAVIER OR
LIGHTER THAN COLDER AIR?
• WHY? USE THE SPACE ON THE
SIDE TO ANSWER
EVAPORATION (LIQUID TO GAS)
• AS ENERGY ENTERS THE
SYSTEM, AIR AND WATER MOLECULES
MOVE FASTER AND GET FARTHER
APART
• SOME OF THE WATER MOLECULES
GAIN ENOUGH ENERGY TO TURN
FROM A LIQUID TO A GAS AND
ENTER THE ATMOSPHERE
• USE THE TOP OF PAGE 51 TO DRAW
AND COLOR THE NEXT SLIDE PICTURE
• UNDERLINE/HIGHLIGHT THE RED
CAPTIONS IN THE SLIDES
EVAPORATION IS A COOLING PROCESS
• ENERGY IS REQUIRED TO EVAPORATE WATER
• (ADD AS CAPTION TO THE PICTURE ON PAGE 51)
• THAT ENERGY LEAVES WITH THE WATER VAPOR
• THERE IS A NET LOSS OF ENERGY FROM THE SURFACE THAT IS
EVAPORATING THE WATER
• THAT IS HOW SWEATING WHEN YOU’RE HOT COOLS YOUR BODY
CONDENSATION (GAS TO LIQUID)
IS THE OPPOSITE OF EVAPORATION
• THE AIR LOSES ENERGY, BECOMES
COOLER AND MORE DENSE
• THERE IS NOT AS MUCH ROOM LEFT IN THE AIR
TO HOLD THE WATER
• THE WATER MOLECULES LOSE ENOUGH
ENERGY TO TURN FROM A GAS TO A LIQUID
BY CONDENSING
• CONDENSATION RELEASES ENERGY
TO THE ATMOSPHERE
• WATER VAPOR IS THE GAS THAT SUPPLIES THE
ENERGY FOR THUNDERSTORMS AND
HURRICANES WHEN IT CONDENSES
(RE-WRITE THESE TWO LAST BULLET POINTS ON
THE NEXT SLIDE NEXT TO THE PICTURE)
CONDENSATION
• CONDENSATION OCCURS BY EXPANSION OF AIR
• EXAMPLE CLOUDS
• CONDENSATION OCCURS BY CONTACT WITH A COLD SURFACE
• EXAMPLE DEW, ADD YOURS…
HUMIDITY
• THE AMOUNT OF WATER IN THE AIR AT
ANY TIME
• ADD “VAPOR” TO THE DEFINITION!!!
• USE A BRIGHT COLOR
SATURATED:
THE AIR IS SATURATED IF THE AIR IS
HOLDING ALL OF THE WATER
VAPOR THAT IT CAN HOLD.
WHAT IS THE RELATIVE HUMIDITY
WHEN THE AIR IS SATURATED?
___%
CLOUDS
THE FORMATION OF CLOUDS:
• AIR REACHES DEW POINT TEMPERATURE BECAUSE THEY EXPAND AND
COOL
• ADD TO YOUR RIGHT DEW POINT TEMP DEFINITION: THE TEMPERATURE
AT WHICH WATER VAPOR CONDENSES.
THAT IS THE TEMPERATURE AT WHICH SATURATION OCCURS
(HUMIDITY=100%)
• AS IT COOLS, WATER DROPLETS BEGIN TO CONDENSE.
• IS ENERGY ADDED OR RELEASED?...ANSWER!
• THE WATER, STILL UP IN THE AIR, BEGINS TO REFLECT THE LIGHT COMING
FROM THE SUN OR MOON
• AND WE SEE IT AS CLOUDS. CLOUDS ARE CLASSIFIED BASED ON THEIR
SHAPE
• CLOUDS ARE MADE BY … CONFIRM/DISCONFIRM YOUR PREDICTION ON
PAGE 49
• KINDS OF CLOUDS
HTTPS://WWW.YOUTUBE.COM/WATCH?V=32UFVSSBS6E
CUMULUS
• DESCRIPTION
• PICTURE
• THEY PRODUCE
KINDS OF CLOUDS
STRATUS
• DESCRIPTION
• PICTURE
• THEY PRODUCE
KINDS OF CLOUDS
CIRRUS
•
DESCRIPTION
•
PICTURE
•
THEY PRODUCE
•
GO OUTSIDE TO TAKE PICTURE OF CLOUDS AND NAME THEM
• DRAW THE CURRENT SKY CLOUDS ON THE BOTTOM OF PAGE 51
KIND OF PRECIPITATIONS
RAIN, SLEET OR SNOW
• WHAT ARE RAIN, SLEET OR SNOW KNOWN AS?
PRECIPITATIONS
• IF THE AIR CONTINUES TO LOSE ENERGY AND COOL FURTHER, MORE
WATER VAPOR IS FORCED OUT OF THE AIR
• WHAT IS THIS PROCESS CALLED? ------------
• THE cohesive TENDENCY OF WATER CAUSES IT TO COLLECT INTO
LARGER AND LARGER DROPLETS UNTIL THEY ARE SO HEAVY TO FALL
• WHAT DOES COHESIVE MEAN? CONNECTION OF DROPS AROUND
PARTICLES LIKE SALT, SULFATE AND NITRATE PARTICLES
• GRAVITY TAKES OVER AND THE WATER FALLS FROM THE SKY AS
PRECIPITATION.
DEW AND FROST
• AS THE SUN GOES DOWN AT NIGHT, THE SOURCE OF
ENERGY LEAVES THE SYSTEM
• THE SURFACE OF THE EARTH COOLS FASTER THAN THE AIR.
• AS THE AIR LOSES ENERGY CONDENSATION OCCURS.
• IF THE TEMPS. ARE ABOVE FREEZING… IT EXITS AS DEW
• BELOW FREEZING… IT EXITS AS FROST