1 met 112 global climate change met 112 global climate change - lecture 3 clouds and global climate...

1 MET 112 Global Climate MET 112 Global Climate ChangeChange

MET 112 Global Climate Change - Lecture 3

Clouds and global climateDr. Eugene Cordero

San Jose State University

Outline Water in the earth system Clouds and the radiation budget Seasons and energy balance Atmospheric circulation Climate Game


QuestionsQuestions

What role do clouds play on the Earth’s climate?

What would happen to our climate if clouds were to increase/decrease?


Water in the atmosphereWater in the atmosphere

Definitions:

– Evaporation:

– Condensation:

– Precipitation:

Process where a liquid changes into a gasProcess where a liquid changes into a gas

Any liquid or solid water that Any liquid or solid water that falls from the atmosphere to the falls from the atmosphere to the ground. (i.e. RAIN!)ground. (i.e. RAIN!)

Process where a gas changes into a liquidProcess where a gas changes into a liquid


Water freely Water freely evaporating and evaporating and condensingcondensing

Since more water Since more water molecules are molecules are evaporating than evaporating than condensing, then net condensing, then net evaporation is evaporation is occurring.occurring.


Lid on:Lid on:

The humidity is now The humidity is now 100%100%


Lid on:Lid on:

Now, evaporation and Now, evaporation and condensation are equal. condensation are equal. The air above water is The air above water is now called ‘saturated’.now called ‘saturated’.

The humidity is now The humidity is now 100%100%


CondensationCondensation

The process by which water vapor changes to a cloud droplet

Water vapor molecules may ‘stick’ to

condensation nuclei and grow (billions) to eventually form cloud droplet.

Examples of condensation nuclei include:a.a. DustDustb.b. SaltSaltc.c. SmokeSmoke

Condensation occurs primarily as temperature cools:-colder the molecules more likely they are to ‘stick’ to other molecules


http://www.ssec.wisc.edu/data/comp/cmoll/cmoll.html




Clouds and radiationClouds and radiation

Cloud - Climate InteractionsCloud - Climate Interactions

Albedo effect - COOLINGAlbedo effect - COOLING Clouds reflect incoming solar radiation. Clouds reflect incoming solar radiation.

The cloud droplet size and total water content The cloud droplet size and total water content determine the overall reflectivity. determine the overall reflectivity.

Greenhouse effect - WARMINGGreenhouse effect - WARMING Clouds are good absorbers (and emitters) of long Clouds are good absorbers (and emitters) of long

wave (infrared) radiation.wave (infrared) radiation.


Clouds and day to day Clouds and day to day temperaturestemperatures

Imagine that you are going camping in the Sierras Imagine that you are going camping in the Sierras with your friends. On the first day (and evening) it with your friends. On the first day (and evening) it is cloudy, while on the second day (and evening) it is cloudy, while on the second day (and evening) it is clear. Based on this information alone:is clear. Based on this information alone:

Which day would be warmer?Which day would be warmer?

Which evening would be warmer?Which evening would be warmer?

Explain your answers.Explain your answers.


Which day would be warmer?

First d

ay (c

lear

)

Second d

ay (c

loudy)

Both

the

sam

e

0% 0%0%

1. First day (clear)

2. Second day (cloudy)

3. Both the same

0 of 70


Which evening would be warmer?

First d

ay (c

lear

)

Second d

ay (c

loudy)

Both

the

sam

e

0% 0%0%

1. First day (clear)

2. Second day (cloudy)

3. Both the same

0 of 70


Low and High cloudsLow and High clouds

Consider two types of clouds:Consider two types of clouds:

1.1. Low levels clouds Low levels clouds

2.2. High levels cloudsHigh levels clouds

Q: How is the Earth’s surface energy budget Q: How is the Earth’s surface energy budget different for low clouds compared to high different for low clouds compared to high clouds?clouds?


Clouds and climateClouds and climate

Cloud A: Low level, (dark, thick)Cloud A: Low level, (dark, thick)

Cloud B: High level, light Cloud B: High level, light (sub visible or thin)(sub visible or thin)

Excellent reflector of incoming radiation; good absorber/emitter of infrared radiation

Fair/poor reflector of incoming radiation; good/excellent absorber/emitter of

infrared radiation

So, clouds both warm and cool the earth. Overall, though, clouds act to cool the

earth


Changes in cloudsChanges in clouds

Increases in low level clouds will:Increases in low level clouds will:–

Increases in high level clouds will:Increases in high level clouds will:


Changes in cloudsChanges in clouds

Increases in low level clouds will:Increases in low level clouds will:– cool the surface (cooling outweighs cool the surface (cooling outweighs

warming)warming)

Increases in high level clouds will:Increases in high level clouds will:– warm the surface (warming outweighs warm the surface (warming outweighs

cooling)cooling)

Explain how the earth’s climate would change as a result of aircarft contrails.


1. What percentage of the sun’s radiation is a) absorbed by the Earth’s surface?b) absorbed by the atmospherec) reflected out to space?

2. What percentage of the energy received by the earth’s surface comes directly from greenhouse gas emissions?

3. If the sun’s radiation was to increase by 10%, how would the following energy units change (increase, decrease or stay the same)a) Energy gained by the Earth’s surface.b) Energy lost by the Earth’s surface.c) Energy emitted by greenhouse gases.d) Energy lost to space.

Questions


What percentage of the Sun’s radiation is absorbed by the Earth’s surface?

0.19

0.51 0.

71.

17

0% 0%0%0%

1. 19%

2. 51%

3. 70%

4. 117%

0 of 70


What percentage of the Sun’s radiation is absorbed by the Earth’s atmosphere?

0.19

0.51 0.

71.

17

0% 0%0%0%

1. 19%

2. 51%

3. 70%

4. 117%

0 of 70


What percentage of the sun’s radiation is reflected out to space?

0.19 0.

30.

64 0.7

1.11

0% 0% 0%0%0%

1. 19%

2. 30%

3. 64%

4. 70%

5. 111%

0 of 70


What percentage of the energy gained by the earth’s surface comes directly from greenhouse gas emissions?

0 of 70 0.3

0.43

0.51

0.65 0.

7

0% 0% 0%0%0%

1. 30%

2. 43%

3. 51%

4. 65%

5. 70%


If the Sun’s radiation was to increase by 10%, how would the energy gained by the earth’s surface change?

Incr

ease

Decre

ase

Stay

the

sam

e

0% 0%0%

1. Increase

2. Decrease

3. Stay the same

0 of 70


If the Sun’s radiation was to increase by 10%, how would the energy emitted by greenhouse gases change?

Incr

ease

Decre

ase

Stay

the

sam

e

0% 0%0%

1. Increase

2. Decrease

3. Stay the same

0 of 70


If the Sun’s radiation was to increase by 10% the energy

0 of 70Ent

erin

g the

top

of th.

..

Enter

ing th

e to

p of t

..

Enter

ing a

nd leav

ing...

0% 0%0%

1. Entering the top of the atmosphere would exceed the energy leaving

2. Entering the top of the atmosphere would be less than leaving

3. Entering and leaving would be the same

Controls on Climate


DefinitionsDefinitions

Insolation –

Solstice –

Equinox –

Incoming solar radiation

day of the year when the sun shines directly over 23.5°S or 23.5°N

days of the year when the sun shines directly over the equator


Sun angleSun angle


Sun angle (2)Sun angle (2)


What influences incoming What influences incoming solar energy?solar energy?

The Sun’s angle of incidence:– Lower sun angle, – Higher sun angle,

Length of time the Sun shines each day:– Summer season, – Winter season,

more incoming energymore incoming energy

less incoming energyless incoming energy

less sun hoursless sun hours

more sun hoursmore sun hours


Why do we have seasons?Why do we have seasons?


What month do you think this graph represents?What month do you think this graph represents?a) December b) March c) June d) Septembera) December b) March c) June d) September


What month do you think this graph represents?

Decem

ber

Mar

ch

Septe

mber

June

0% 0%0%0%

1. December

2. March

3. June

4. September

0 of 70


Review questionsReview questions

On June 21st, at what latitude is the sun directly overhead at noon?

On September 22nd, at what latitude is the sun directly overhead at noon?

How many hours of daylight are present at the South Pole on February 20th?

Where would you expect to have longer days; 45 ° N on June 21st or 50°S on Dec 21st?


On June 21st, at what latitude is the sun directly overhead at noon?

Equat

or (0)

23.5

°N

23.5

°S

90°N

(north

pole

)

90°S

(south

pole

)

0% 0% 0%0%0%

1. Equator (0)

2. 23.5°N

3. 23.5°S

4. 90°N (north pole)

5. 90°S (south pole)

0 of 70


How many hours of daylight are present at the South Pole on February 20th?

0 hours

6 hours

12 h

ours

18 h

ours

24 h

ours

0% 0% 0%0%0%

1. 0 hours

2. 6 hours

3. 12 hours

4. 18 hours

5. 24 hours

0 of 70


On September 22nd, at what latitude is the sun directly overhead at noon?

0 of 70Equ

ator (

0)

23.5

°N

23.5

°S

90°N

(north

pole

)

90°S

(south

pole

)

0% 0% 0%0%0%

1. Equator (0)

2. 23.5°N

3. 23.5°S

4. 90°N (north pole)

5. 90°S (south pole)


Where would you expect to have longer days; 45 ° N on June 21st or 50°S on Dec 21st?

Choic

e One

Choic

e Tw

o

Choic

e Th

ree

Choic

e Fo

ur

0% 0%0%0%

1. 45°N

2. 50°S

3. They are the same

4. Impossible to tell

0 of 70


Controls on ClimateControls on Climate

Seasonal temperature and precipitation patters Seasonal temperature and precipitation patters are generally attributable to: are generally attributable to:

LatitudeLatitude Mountains and highlandsMountains and highlands Land and water locationLand and water location Prevailing windsPrevailing winds Pressure and wind systems Pressure and wind systems Ocean currentsOcean currents

Annual Surface TemperatureAnnual Surface Temperature


QuestionsQuestions

Indicate the warmest and coldest areas of the Indicate the warmest and coldest areas of the Earth.Earth.

Consider the temperature at 60N latitude. Indicate Consider the temperature at 60N latitude. Indicate on the map the coldest and warmest places at 60N. on the map the coldest and warmest places at 60N.

What is the temperature difference between these What is the temperature difference between these locationslocations

What factors might explain this temperature What factors might explain this temperature difference?difference?

Why is there not a similar difference seen at 60S?Why is there not a similar difference seen at 60S?


Annual Surface TemperatureAnnual Surface Temperature


Climate controls: Climate controls: Latitude/MountainsLatitude/Mountains

LatitudeLatitude– Higher latitude climates are generally Higher latitude climates are generally

(cooler/warmer)(cooler/warmer)– Lower latitudes climates are generally Lower latitudes climates are generally

(cooler/warmer)(cooler/warmer) MountainsMountains

– Higher altitudes climate are generally Higher altitudes climate are generally (cooler/warmer): cooler temperatures(cooler/warmer): cooler temperatures

– Windward side of mountains are generally Windward side of mountains are generally (cooler/warmer) and (wetter/drier), than leeward side(cooler/warmer) and (wetter/drier), than leeward side


Controls on ClimateControls on Climate

Seasonal temperature and precipitation patters Seasonal temperature and precipitation patters are generally attributable to: are generally attributable to:

LatitudeLatitude Mountains and highlandsMountains and highlands Land and water locationLand and water location Prevailing windsPrevailing winds Pressure and wind systems Pressure and wind systems Ocean currentsOcean currents


Controls on Climate: OceansControls on Climate: Oceans

Ocean TemperaturesOcean Temperatures– Coasts of continents are affected by ocean Coasts of continents are affected by ocean

temperatures: Generally less temperature temperatures: Generally less temperature extremes compared to interior of continentsextremes compared to interior of continents

– Cold oceans: Cold oceans:

– Warm oceans:Warm oceans:

generally produce cooler/drier conditionsgenerally produce cooler/drier conditions

generally produce more warm/humid conditionsgenerally produce more warm/humid conditions


Cold ocean Warm ocean


Dry Humid


Controls on Climate: Controls on Climate: Pressure systemsPressure systems

Rising and sinking motion associated with low Rising and sinking motion associated with low and high pressure affects climateand high pressure affects climate

Areas where pressure seasonally low, Areas where pressure seasonally low, –

Areas where pressure seasonally high, Areas where pressure seasonally high, –

Tropics: rainyTropics: rainy

Subtropical high (30N/3OS): warm and drySubtropical high (30N/3OS): warm and dry


January Average sea-level Pressure and surface wind patternJanuary Average sea-level Pressure and surface wind pattern


July Average sea-level Pressure and surface wind patternJuly Average sea-level Pressure and surface wind pattern

Climate Game Climate Game Names ___________________________Names ___________________________

Match the city with the corresponding climatology Match the city with the corresponding climatology by indicating the appropriate letterby indicating the appropriate letter

Sacramento, California (38°°N) _____________ Phoenix, Arizona (33Phoenix, Arizona (33°°N)N) __________________________ Denver, Colorado (40Denver, Colorado (40°°N)N) __________________________ Iquitos, Peru (4Iquitos, Peru (4°°S)S) __________________________ Mobile, Alabama (30°°N) _____________ Winnipeg, Canada (50°°N) _____________ Fairbanks, Alaska (65°°N) _____________


City A

Sacra

men

to, C

alifo

rnia

Phoen

ix, A

rizona

Denve

r, Col

orado

Iquito

s, P

eru

Mobile

, Ala

bama

Win

nipeg

, Can

ada

Fairb

anks

, Ala

ska

9%11%

14%

20%

43%

3%0%

1. Sacramento, California

2.2. Phoenix, ArizonaPhoenix, Arizona

3.3. Denver, ColoradoDenver, Colorado

4.4. Iquitos, PeruIquitos, Peru

5. Mobile, Alabama

6. Winnipeg, Canada

7. Fairbanks, Alaska


City B

Sacra

men

to, C

alifo

rnia

Phoen

ix, A

rizona

Denve

r, Col

orado

Iquito

s, P

eru

Mobile

, Ala

bama

Win

nipeg

, Can

ada

Fairb

anks

, Ala

ska

82%

0%5% 3%

8%

0%3%





5. Mobile, Alabama

6. Winnipeg, Canada



City C

Sacra

men

to, C

alifo

rnia

Phoen

ix, A

rizona

Denve

r, Col

orado

Iquito

s, P

eru

Mobile

, Ala

bama

Win

nipeg

, Can

ada

Fairb

anks

, Ala

ska

0%3%

11%

3%5%

70%

8%





5. Mobile, Alabama

6. Winnipeg, Canada



City D

Sacra

men

to, C

alifo

rnia

Phoen

ix, A

rizona

Denve

r, Col

orado

Iquito

s, P

eru

Mobile

, Ala

bama

Win

nipeg

, Can

ada

Fairb

anks

, Ala

ska

0% 0% 3% 3%5%3%

87%1. Sacramento, California




5. Mobile, Alabama

6. Winnipeg, Canada



City E

Sacra

men

to, C

alifo

rnia

Phoen

ix, A

rizona

Denve

r, Col

orado

Iquito

s, P

eru

Mobile

, Ala

bama

Win

nipeg

, Can

ada

Fairb

anks

, Ala

ska

8%

0%

53%

8%

16%16%

0%





5. Mobile, Alabama

6. Winnipeg, Canada



City F

Sacra

men

to, C

alifo

rnia

Phoen

ix, A

rizona

Denve

r, Col

orado

Iquito

s, P

eru

Mobile

, Ala

bama

Win

nipeg

, Can

ada

Fairb

anks

, Ala

ska

0%

8%5%

61%

26%

0%0%


2. Phoenix, Arizona

3. Denver, Colorado

4. Iquitos, Peru

5. Mobile, Alabama

6. Winnipeg, Canada


1 met 112 global climate change met 112 global climate change - lecture 3 clouds and global climate...

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