1. WATER IN THE ATMOSPHERE CHAPTER 18.1 HUMIDITY AND CONDENSATION

2. CHARACTERISTICS OF WATER DO NOT WRITE WATER IS UNIQUE BECAUSE IT EXISTS IN ALL THREE PHASES OF MATER IN NATURE WATER IS UNIQUE BECAUSE IT EXISTS IN ALL THREE PHASES OF MATER IN NATURE SOLID – 0 0 C OR BELOW SOLID – 0 0 C OR BELOW LIQUID – 0 0 C – 100 0 C LIQUID – 0 0 C – 100 0 C GAS – 100 0 C OR ABOVE – WATER VAPOR AN INVISIBLE GAS GAS – 100 0 C OR ABOVE – WATER VAPOR AN INVISIBLE GAS

5. EVAPORATION CHANGE FROM LIQUID TO GAS CHANGE FROM LIQUID TO GAS ABSORBS HEAT ABSORBS HEAT COOLING PROCESS COOLING PROCESS EX. SWIMMING POOL OR SWEATING EX. SWIMMING POOL OR SWEATING H 2 O MOLECULES ABSORB HEAT FROM YOUR BODY H 2 O MOLECULES ABSORB HEAT FROM YOUR BODY

7. CONDENSATION CHANGE FROM GAS TO LIQUID CHANGE FROM GAS TO LIQUID RELEASES HEAT RELEASES HEAT EX. GLASS OF WATER IN FREEZER EX. GLASS OF WATER IN FREEZER TYPES OF CONDENSATION TYPES OF CONDENSATION DEW DEW FOG FOG CLOUDS CLOUDS

10. DEPOSITION AND SUBLIMATION CHANGE FROM VAPOR DIRECTLY TO SOLID CHANGE FROM VAPOR DIRECTLY TO SOLID FROST FROST CHANGE FROM SOLID DIRECTLY TO A VAPOR CHANGE FROM SOLID DIRECTLY TO A VAPOR SNOWBANK MELTINGWITH FREEZING REMPS

11. DEPOSITION (Heat released) FREEZINGCONDENSATION MELTING EVAPORATION LIQUID WATER (clouds, rain, dew) ICE (snow, hail, frost) WATER VAPOR (invisible) SUBLIMATION (Heat absorbed) Heat released Heat absorbed

12. HUMIDITY AMT OF WATER VAPOR IN THE AIR VARIES WIDELY AMT OF WATER VAPOR IN THE AIR VARIES WIDELY SPECIFIC HUMIDITY IS THE NUMBER OF GRAMS OF WATER VAPOR IN A Kg OF AIR AT A GIVEN TIME OR LOCATION SPECIFIC HUMIDITY IS THE NUMBER OF GRAMS OF WATER VAPOR IN A Kg OF AIR AT A GIVEN TIME OR LOCATION WARM AIR CAN HOLD MORE MOISTURE THAN COLD AIR WARM AIR CAN HOLD MORE MOISTURE THAN COLD AIR SATURATED AIR OCCURS WHEN EVAPORATION RATE EQUALS CONDENSATION RATE EX. LID ON CUP SATURATED AIR OCCURS WHEN EVAPORATION RATE EQUALS CONDENSATION RATE EX. LID ON CUP

13. RELATIVE HUMIDITY AMOUNT OF WATER VAPOR IN THE AIR COMPARED TO THE AMOUNT THE AIR CAN HOLD AT A GIVEN TEMPERATURE AMOUNT OF WATER VAPOR IN THE AIR COMPARED TO THE AMOUNT THE AIR CAN HOLD AT A GIVEN TEMPERATURE RH = SPECIFIC HUMIDITY X 100 RH = SPECIFIC HUMIDITY X 100 MAXIMUM CAPACITY MAXIMUM CAPACITY PSYCHROMETER – MEASURES HUMIDITY PSYCHROMETER – MEASURES HUMIDITY

15. CONDENSATION THE TEMPERATURE AT WHICH SATURATION OCCURS AND CONDENSATION BEGINS IS CALLED THE DEW POINT THE TEMPERATURE AT WHICH SATURATION OCCURS AND CONDENSATION BEGINS IS CALLED THE DEW POINT IT IS A MEASURE OF THE AMOUNT OF WATER VAPOR IN THE AIR IT IS A MEASURE OF THE AMOUNT OF WATER VAPOR IN THE AIR EX. WARM DAY AND COLD NIGHT EX. WARM DAY AND COLD NIGHT

17. COOLING AND CONDENSATION TWO CONDITIONS NECESSARY FOR CONDENSATION TWO CONDITIONS NECESSARY FOR CONDENSATION 1. MATERIAL TO CONDENSE ON (CONDENSATION NUCLEI SALT, SULFATES OR NITRATES) 1. MATERIAL TO CONDENSE ON (CONDENSATION NUCLEI SALT, SULFATES OR NITRATES) 2. AIR TEMP AT DEW POINT 2. AIR TEMP AT DEW POINT

18. AIR MAY COOL OR LOSE HEAT BY: CONTACT WITH COLDER SURFACE CONTACT WITH COLDER SURFACE RADIATION OF HEAT RADIATION OF HEAT MIXING WITH COLDER AIR MIXING WITH COLDER AIR EXPANSION AS IT RISES EXPANSION AS IT RISES

20. FORMATION OF FROST AND DEW FORM WHEN MOIST AIR CONTACTS COOL SURFACES AND DEW POINT TEMP IS REACHED FORM WHEN MOIST AIR CONTACTS COOL SURFACES AND DEW POINT TEMP IS REACHED BELOW 0 0 C = FROST BELOW 0 0 C = FROST

22. FORMATION OF FOG / CLOUDS FORM WHEN A COLD SURFACE CONTACTS WARMER MOIST AIR FORM WHEN A COLD SURFACE CONTACTS WARMER MOIST AIR THE SLIGHTEST AIR MOVEMENTS KEEP THE TINY DROPLETS OF WATER SUSPENDED THE SLIGHTEST AIR MOVEMENTS KEEP THE TINY DROPLETS OF WATER SUSPENDED

23. RADIATION FOG (DO NOT WRITE) FORMS WHEN THE NIGHT SKY IS CLEAR FORMS WHEN THE NIGHT SKY IS CLEAR GROUND LOSES HEAT RAPIDLY GROUND LOSES HEAT RAPIDLY LIGHT WINDS MIX COOLER BOTTOM AIR WITH WARMER TOP AIR LIGHT WINDS MIX COOLER BOTTOM AIR WITH WARMER TOP AIR DEW POINT IS REACHED DEW POINT IS REACHED FOG IS COLDER THAN AIR ABOVE IT FOG IS COLDER THAN AIR ABOVE IT TEMPERATURE INVERSION TEMPERATURE INVERSION

26. ADVECTION FOG (DO NOT WRITE) FORM WHEN WARM MOIST AIR BLOWS OVER A COOL SURFACE FORM WHEN WARM MOIST AIR BLOWS OVER A COOL SURFACE IN U.S. AND CANADA, FORM WHEN WARM MOIST SOUTHERLY WIND MOVES OVER SNOW COVERED GROUND IN U.S. AND CANADA, FORM WHEN WARM MOIST SOUTHERLY WIND MOVES OVER SNOW COVERED GROUND NEWFOUNDLAND FOG NEWFOUNDLAND FOG WINTER FOGS - MISSISSIPPI WINTER FOGS - MISSISSIPPI