MADISON’S CURRENT WEATHERMADISON’S CURRENT WEATHER
Madison Weather at 1000 AM CDT 15 JUL 2002 Updated twice an hour at :05 and :25 Sky/Weather: SUNNY Temperature: 80 F (26 C) Dew Point: 60 F (15 C) Relative Humidity: 50% Wind: VRB6 MPH Barometer: 30.12F (1019.10 mb)
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 2929
Last 24 hrs in MadisonLast 24 hrs in Madison
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 3030
Last Night’s Green Bay SoundingLast Night’s Green Bay Sounding
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 3131
CURRENT CURRENT VISIBLEVISIBLE
T.D. #1T.D. #1
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 3232
T.D. #1T.D. #1
CURRENT IRCURRENT IR
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 3434
Current Surface Weather Map Current Surface Weather Map with Isobars (“iso” = equal & “bar” = weight), Fronts and Radarwith Isobars (“iso” = equal & “bar” = weight), Fronts and Radar
T.D. #1T.D. #1
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 3535
Forecast for T.D. 1Forecast for T.D. 1
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 3636
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 3737
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 3939
Current Surface Weather Map Current Surface Weather Map with Isobars (“iso” = equal & “bar” = weight), Fronts and Radarwith Isobars (“iso” = equal & “bar” = weight), Fronts and Radar
T.D. #1T.D. #1
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 4343
Current Temperatures (Current Temperatures (°°F) & IsothermsF) & Isotherms(“iso” = equal +”therm” = temperature)(“iso” = equal +”therm” = temperature)
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 4444
Current Dewpoints Current Dewpoints ((ooF) F)
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 4545
IFR – Instrument Flight RulesIFR – Instrument Flight Rules Red Dots: Ceiling < 1000 ft or Visibility < 3 milesRed Dots: Ceiling < 1000 ft or Visibility < 3 miles
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 4747
Tomorrow AM Forecast MapTomorrow AM Forecast Map
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 4848
AnnouncementsAnnouncements
Homework #3 is due next Thurs. Homework #3 is due next Thurs. 18 July 200218 July 2002
If you have ??, please see me.If you have ??, please see me.
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 4949
ATM OCN 100 - ATM OCN 100 - Summer 2002 Summer 2002 LECTURE 11LECTURE 11
FORMATION OF CLOUDS, FOG, FORMATION OF CLOUDS, FOG, DEW & FROSTDEW & FROST
A. INTRODUCTIONA. INTRODUCTION– What is a cloud?What is a cloud?– Historical PerspectiveHistorical Perspective– Why are clouds important?Why are clouds important?
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 5151
BACKGROUND:BACKGROUND:CLOUDS, FOG, DEW & FROSTCLOUDS, FOG, DEW & FROST
CloudCloud– A visible aggregation of water droplets &/or A visible aggregation of water droplets &/or
ice crystals suspended in air above ground.ice crystals suspended in air above ground. FogFog
– A low-level cloud at ground level that A low-level cloud at ground level that reduces horizontal visibility.reduces horizontal visibility.
Dew & FrostDew & Frost– Surface condensation/deposition Surface condensation/deposition
phenomenaphenomena..
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 5252
B. REQUIREMENTS FOR B. REQUIREMENTS FOR FORMATION of DROPLETSFORMATION of DROPLETS
Statement of Practical ProblemsStatement of Practical Problems Need for Saturation ConditionsNeed for Saturation Conditions Low-level Condensation Process in Low-level Condensation Process in
Dew FormationDew Formation Special Requirements in Free AirSpecial Requirements in Free Air Condensation Process in Cloud Condensation Process in Cloud
FormationFormation
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 5353
C. MECHANISMS for CLOUD C. MECHANISMS for CLOUD (FOG, DEW (FOG, DEW oror FROST) FROST) FORMATIONFORMATION
To Saturate To Saturate – R.H. needs to reach 100% (or TR.H. needs to reach 100% (or Tairair = T = Tdewdew) )
Formation OptionsFormation Options– Add water vapor Add water vapor
(increase T (increase Tdewdew to T to Tairair ); );– Cool air Cool air
(reduce T (reduce Tairair to T to Tdewdew ). ). where... where...
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 5454
OPTIONS TO SATURATE THE AIROPTIONS TO SATURATE THE AIR
Evaporation MechanismsEvaporation Mechanisms Adding water vapor to saturation Adding water vapor to saturation (increase dewpoint to air temperature)(increase dewpoint to air temperature)
– Require abundant liquid water source Require abundant liquid water source (e.g., ocean, lake, or lush vegetation) (e.g., ocean, lake, or lush vegetation);;
– Mix moisture upward from surface by air Mix moisture upward from surface by air motion.motion.
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 5555
OPTIONS TO SATURATE THE AIROPTIONS TO SATURATE THE AIR (con’t.)(con’t.)
Cooling MechanismsCooling Mechanisms Cool air to saturation Cool air to saturation (reduce air temperature to dewpoint) (reduce air temperature to dewpoint)
by:by:
– Radiational Cooling Radiational Cooling – Expansional CoolingExpansional Cooling– Evaporative CoolingEvaporative Cooling– Advection Cooling - Horizontal TransportAdvection Cooling - Horizontal Transport
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 5656
D. LOW LEVEL SATURATION D. LOW LEVEL SATURATION PROCESSES & PHENOMENAPROCESSES & PHENOMENA
Dew & FrostDew & Frost
– DefinitionsDefinitions
– FormationFormation
– Comparison & ContrastsComparison & Contrasts
– SignificanceSignificance
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 5757
DewDew
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 5858
HoarfrostHoarfrost
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 5959
FrostFrost
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 6060
E. CLOUD (E. CLOUD (oror FOG) FOG) FORMATION REQUIREMENTSFORMATION REQUIREMENTS
A Problem A Problem – Dipolar nature of water moleculesDipolar nature of water molecules– Leads to difficulty in condensing in Leads to difficulty in condensing in
clean airclean air SupersaturationSupersaturation
– Condition where R.H. > 100%.Condition where R.H. > 100%. Mechanism for CondensationMechanism for Condensation
Cloud Condensation Nuclei Cloud Condensation Nuclei
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 6161
CLOUD CONDENSATION NUCLEICLOUD CONDENSATION NUCLEI
Provide sites for condensationProvide sites for condensation Requirement -Requirement -
– Hygroscopic Hygroscopic substances substances (Water loving) (Water loving)
Types of Condensation NucleiTypes of Condensation Nuclei– Sea saltSea salt– Combustion productsCombustion products– Anthropogenic substancesAnthropogenic substances
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 6262
Aerosols from Sea SprayAerosols from Sea Spray
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 6363
Aerosols from WildfiresAerosols from Wildfires
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 6464
Aerosols from Urban PollutionAerosols from Urban Pollution
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 6565
E. MECHANISMS for E. MECHANISMS for CLOUD or FOG FORMATION CLOUD or FOG FORMATION (con’t.)(con’t.)
Cooling Mechanisms
– Expansional Cooling
– Evaporative Cooling
– Advection Cooling - Horizontal Transport
– Radiational Cooling
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 6666
Clouds accompanying a F-18 jet Clouds accompanying a F-18 jet breaking the Sound Barrierbreaking the Sound Barrier
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 6767
EXPANSIONAL COOLING SPECIFICSEXPANSIONAL COOLING SPECIFICS
Review of adiabatic processesReview of adiabatic processes Dry adiabatic lapse rateDry adiabatic lapse rate
– NoNo H H22O phase change when O phase change when R.H. < 100%; R.H. < 100%;
– DALR DALR 10 C10 Coo per 1000 m per 1000 m (5.5 F (5.5 Foo per 1000 ft); per 1000 ft);
– Reversible processReversible process cooling by DALR during ascent = cooling by DALR during ascent = warming by DALR during descent. warming by DALR during descent.
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 6868
Response of Ascent/Descent of Air Parcel:Response of Ascent/Descent of Air Parcel: Dry Adiabatic Lapse Rate Dry Adiabatic Lapse Rate
See Fig. 6.8 Moran & Morgan (1997)See Fig. 6.8 Moran & Morgan (1997)
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 6969
Comparison of Dry & Saturation Comparison of Dry & Saturation (Moist) Adiabatic Lapse Rates(Moist) Adiabatic Lapse Rates See Fig. 6.9 Moran & Morgan (1997)See Fig. 6.9 Moran & Morgan (1997)
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 7070
EXPANSIONAL COOLING SPECIFICS EXPANSIONAL COOLING SPECIFICS (con’t.)(con’t.)
Saturation (moist) adiabatic lapse rateSaturation (moist) adiabatic lapse rate– Involves HInvolves H22O phase change whenO phase change when
R.H. = 100%; R.H. = 100%;– Release of latent heat of condensation into parcel Release of latent heat of condensation into parcel
diminishes cooling effect by adiabatic expansion;diminishes cooling effect by adiabatic expansion;– SALR SALR 6 to 7 C6 to 7 Coo per 1000 m per 1000 m
(3 F (3 Foo per 1000 ft); per 1000 ft);– Process may Process may notnot be reversible. be reversible.
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 7272
WAYS TO LIFT FORWAYS TO LIFT FOREXPANSIONAL COOLINGEXPANSIONAL COOLING
Dynamic LiftingDynamic Lifting
– In surface low pressure systems;In surface low pressure systems;– Along frontal surfaces.Along frontal surfaces.
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 7474
WAYS TO LIFT FORWAYS TO LIFT FOREXPANSIONAL COOLINGEXPANSIONAL COOLING
Dynamic LiftingDynamic Lifting– In surface low pressure systems;In surface low pressure systems;– Along frontal surfaces.Along frontal surfaces.
Lifting by ConvectionLifting by Convection– Localized heatingLocalized heating– Ascending convection currentsAscending convection currents
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 7676
WAYS TO LIFT FORWAYS TO LIFT FOREXPANSIONAL COOLINGEXPANSIONAL COOLING
Dynamic LiftingDynamic Lifting– In surface low pressure systems;In surface low pressure systems;– Along frontal surfaces.Along frontal surfaces.
Lifting by ConvectionLifting by Convection– Localized heatingLocalized heating– Ascending convection currentsAscending convection currents
Mechanical LiftingMechanical Lifting Over mountain barriersOver mountain barriers (or orographic lifting)(or orographic lifting)
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 7878
AN EXAMPLEAN EXAMPLEAir Flow over a mountainAir Flow over a mountain
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 7979
AN EXAMPLE AN EXAMPLE (con’.t)(con’.t) Lift unsaturated air to saturationLift unsaturated air to saturation
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 8080
AN EXAMPLEAN EXAMPLE (con’.t)(con’.t) Lift saturated air to topLift saturated air to top
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 8181
AN EXAMPLEAN EXAMPLE (con’.t)(con’.t) Force air to sinkForce air to sink
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 8383
In RealityIn Reality
CloudsClouds Vegetation on upwind vs. downwind slopesVegetation on upwind vs. downwind slopes Special extreme examplesSpecial extreme examples
– Chinook WindsChinook Winds
– Santa Ana Winds Santa Ana Winds where…where…
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 8484
Mountain Wave CloudsMountain Wave Clouds
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 8585
IR Enhanced Satellite23 Oct 2001 7AM PDT
Clouds
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 8686
Mountains Affect ClimateMountains Affect Climate
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 8787
Forest vegetation on West Slopes Forest vegetation on West Slopes of Sierrasof Sierras (in Yosemite N.P., CA)(in Yosemite N.P., CA)
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 8888
Arid Vegetation on East Slopes Arid Vegetation on East Slopes of Sierrasof Sierras (Owens Valley near Bishop, CA)(Owens Valley near Bishop, CA)
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 8989
A Day out WestA Day out West
ChinookChinook
Santa AnaSanta Ana
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 9090
Chinook WindsChinook Winds
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 9191
Santa Ana WindsSanta Ana Winds
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 9292
Effect of moisture on Stability Effect of moisture on Stability
Recall Stability vs. Instability Criteria Recall Stability vs. Instability Criteria for a dry air parcel ….for a dry air parcel ….
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 9393
STABLE CONDITIONSSTABLE CONDITIONSCompare Compare EnvironmentEnvironment with with DALRDALR
Colder parcel sinks & returns to startColder parcel sinks & returns to start
0
500
1000
1500
2000
2500
0 5 10 15 20 25 30
TEMPERATURE (C)
AL
TIT
UD
E (m
)
Parcel is colder & Parcel is colder & more densemore dense
Environment is warmer & Environment is warmer & less denseless dense
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 9494
UNSTABLE CONDITIONSUNSTABLE CONDITIONS
Compare Compare EnvironmentEnvironment with with DALRDALR Warmer parcel continues upward Warmer parcel continues upward
0
500
1000
1500
2000
2500
0 5 10 15 20 25 30
TEMPERATURE (C)
AL
TIT
UD
E (
m)
Parcel is warmer & Parcel is warmer & less denseless dense
Environment is colder Environment is colder & more dense& more dense
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 9595
Effect of moisture on Stability Effect of moisture on Stability
Recall Stability vs. Instability Criteria Recall Stability vs. Instability Criteria for a dry air parcel …. for a dry air parcel ….
But now consider water vapor & But now consider water vapor & saturated air …saturated air …
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 9696
ABSOLUTELY STABLE CONDITIONSABSOLUTELY STABLE CONDITIONSCompare Compare EnvironmentEnvironment with with SALRSALR & & DALRDALR
Colder parcel sinks & returns to startColder parcel sinks & returns to start
0
500
1000
1500
2000
2500
0 5 10 15 20 25 30
TEMPERATURE (C)
AL
TIT
UD
E (
m)
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 9797
UNSTABLE CONDITIONSUNSTABLE CONDITIONS
Compare Compare EnvironmentEnvironment with with DALRDALR Warmer parcel continues upward Warmer parcel continues upward
0
500
1000
1500
2000
2500
0 5 10 15 20 25 30
TEMPERATURE (C)
AL
TIT
UD
E (
m)
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 9898
ABSOLUTELY UNSTABLE CONDITIONSABSOLUTELY UNSTABLE CONDITIONS
Compare Compare EnvironmentEnvironment with with SALRSALR & & DALRDALR Warmer parcel continues upwardWarmer parcel continues upward
0
500
1000
1500
2000
2500
0 5 10 15 20 25 30
TEMPERATURE (C)
AL
TIT
UD
E (
m)
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 9999
If STABLE CONDITIONS for DryIf STABLE CONDITIONS for DryCompare Compare EnvironmentEnvironment with with DALRDALR
Colder parcel sinks & returns to startColder parcel sinks & returns to start
0
500
1000
1500
2000
2500
0 5 10 15 20 25 30
TEMPERATURE (C)
AL
TIT
UD
E (
m)
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 100100
But UNSTABLE CONDITIONS for HumidBut UNSTABLE CONDITIONS for HumidCompare Compare EnvironmentEnvironment with with SALRSALR Warmer parcel continues upwardWarmer parcel continues upward
0
500
1000
1500
2000
2500
0 5 10 15 20 25 30
TEMPERATURE (C)
AL
TIT
UD
E (
m)
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 101101
CONDITIONALLY STABLE CONDITIONSCONDITIONALLY STABLE CONDITIONSCompare Compare EnvironmentEnvironment with with SALRSALR & & DALRDALR
0
500
1000
1500
2000
2500
0 5 10 15 20 25 30
TEMPERATURE (C)
AL
TIT
UD
E (
m)
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 102102
Stability CriteriaStability CriteriaSee Fig. 6.14 Moran & Morgan (1997)See Fig. 6.14 Moran & Morgan (1997)
A.A. SuperadiabaticSuperadiabaticB.B. Conditionally Stable, Conditionally Stable,
Lapse Lapse C.C. Absolutely Stable, Absolutely Stable,
LapseLapseD.D. IsothermalIsothermalE.E. InversionInversion
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 103103
F. LOW LEVEL SATURATION F. LOW LEVEL SATURATION PROCESSES & PHENOMENAPROCESSES & PHENOMENA
FogsFogs
– DefinitionDefinition
– Comparison between Fog & Clouds;Comparison between Fog & Clouds;
– Fog Formation MechanismsFog Formation Mechanisms cooling to saturationcooling to saturation addition of moistureaddition of moisture
– SignificanceSignificance
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 104104
Fog over Sydney HarborFog over Sydney Harbor
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 105105
FogFog
Fog is similar to a stratus cloud except that it touches the ground. It is not, necessarily formed in the same manner.
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 106106
Surface Weather Map from an Autumn AM Surface Weather Map from an Autumn AM with with IsobarsIsobars & Fronts & Fronts
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 107107
IFR – Instrument Flight RulesIFR – Instrument Flight Rules Red Dots: Ceiling < 1000 ft or Visibility < 3 milesRed Dots: Ceiling < 1000 ft or Visibility < 3 miles
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 108108
FOGS FOGS (con’t.)(con’t.)
Fog ClassificationFog Classification
Fog types named eitherFog types named either
– by temperature; by temperature; oror
– by formation process.by formation process.
where...where...
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 109109
FOGS FOGS (con’t.)(con’t.)
Fog Type ClassificationFog Type Classification by by TemperatureTemperature– WARM FOGWARM FOG
contains liquid droplets, esp. T > 0 contains liquid droplets, esp. T > 0ooCC– COLD FOGCOLD FOG
contains supercooled liquid droplets contains supercooled liquid droplets with T < 0with T < 0ooC (but T > -30C (but T > -30ooC)C)
– ICE FOGICE FOG ( (oror ICE CRYSTAL FOG) ICE CRYSTAL FOG) contains ice crystals when T < -35 contains ice crystals when T < -35ooCC
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 111111
FOGS FOGS (con’t.)(con’t.)
Fog Type Classification by Fog Type Classification by Formation Process Formation Process
– How did the fog form?How did the fog form?
– With Following Examples…With Following Examples…
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 112112
Radiation FogRadiation Fog (from (from The Weather DoctorThe Weather Doctor, K. C. Heidorn, PhD), K. C. Heidorn, PhD)
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 113113
Radiation FogRadiation FogCool air by loss of IR radiationCool air by loss of IR radiation
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 114114
Valley FogValley Fog (from (from The Weather DoctorThe Weather Doctor, K. C. Heidorn, PhD), K. C. Heidorn, PhD)
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 115115
Radiation Fog (Radiation Fog (oror Valley Fog) Valley Fog)Cool air by IR radiation & cold air drainageCool air by IR radiation & cold air drainage
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 116116
Upslope FogUpslope Fog(from (from The Weather DoctorThe Weather Doctor, K. C. Heidorn, PhD), K. C. Heidorn, PhD)
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 117117
Upslope (Upslope (oror Mountain Fog) Mountain Fog)Cool air by expansion through liftingCool air by expansion through lifting
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 118118
Advection FogAdvection Fog(from (from The Weather DoctorThe Weather Doctor, K. C. Heidorn, PhD), K. C. Heidorn, PhD)
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 119119
Advection FogAdvection FogCool air by transport & contact with cold surfaceCool air by transport & contact with cold surface
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 120120
Steam Fog (Steam Fog (oror Sea Smoke) Sea Smoke)Evaporation & saturation of airEvaporation & saturation of air
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 121121
Steam & Radiation FogSteam & Radiation Fog Cooling along with evaporation to saturate airCooling along with evaporation to saturate air
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 122122
Rain Fog Rain Fog (from (from The Weather DoctorThe Weather Doctor, K. C. Heidorn, PhD), K. C. Heidorn, PhD)
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 123123
Rain FogRain FogEvaporation from falling rainEvaporation from falling rain
ATM OCN 100 Summer 2002ATM OCN 100 Summer 2002 124124
FOGS FOGS (con’t.)(con’t.)
Fog Type Classification by Fog Type Classification by Formation Process Formation Process
– RADIATION FOGRADIATION FOG
– UPSLOPE FOG (UPSLOPE FOG (oror MOUNTAIN FOG) MOUNTAIN FOG)
– ADVECTION FOGADVECTION FOG
– STEAM FOG (STEAM FOG (oror SEA SMOKE) SEA SMOKE)
– RAIN FOGRAIN FOG