SIT WITH YOUR GROUP TODAY TOPIC # 12 HOW CLIMATE

WORKS

Tuesday Oct 26th

I-3 IS DUE TODAY! Please deposit your I-3 WORKSHEET [STAPLED!] at the FRONT OF THE CLASSROOM according to GROUP # (NOTE: we will also accept Worksheets on Thursday if you don’t have yours today or need it to finish your write-up tonight.)

The I-3 Write-Up is due in D2L Dropbox by 11:59 pm tonight.

As soon as you come in today, get your GROUP FOLDER & finish up G-3 if your group is not quite done . . . .

RQ-6 is due on THURSDAY Oct 28th Warning: there is LOTS of reading for this one!

TEST #3 is scheduled for a week from TODAY. . . . . The Top 10 List will be posted by Friday.

WRAP –UP of G-3 ASSIGNMENT

Applying the Energy Balance Terms

Your task is to decide which component or components working together are most directly related to or responsible for the observed phenomenon.

p 53

# 13 - #15: Right side of equation

# 1 – #12 : Left side of equation

THE G-3 ANSWERS

2. 3.

4. Noon: more & dusk: more

1. gases of atmosphere scatter shorter blue wavelengths

5. + together = the Greenhouse Effect

The LEFT side of the equation:

6. (dust, thicker atmosphere scatters longer red/orange wavelengths)

7. radiates day & night; camera senses IR

8.

9. leads to distinct shadows, while diffuse SW radiation does not

10. All wavelengths of visible part of spectrum are scattered & transmitted in a colored spectrum by raindrops

11. Attempt to increase absorption & reduce into eyes; reduces glare

12. More is absorbed, leads to more which can then warm up car

13. Hot air (less dense than surroundingcool air) rises in a convection current & lifts balloon

H

14. Wet mud evaporates from pig & cools him: also heat from pig’s body is conducted into soil:

LEG

LE H

15. June is hot & dry in Tucson. Dry, hot air can “hold” more water vapor, so water in cooler pads is evaporated easily. Hence more energy goes into instead of This cools the house!

The RIGHT Side of the Equation:

Topic # 12How Climate Works

A “Primer” on How the Energy Balance Drives

Atmospheric & Oceanic Circulation, Natural Climatic Processes

pp 63-68 in Class Notes

How do we get energy from this . . . .

. . . . to drive this ?

http://www.vets.ucar.edu/vg/T341/index.shtml

. . . . or this ?

. . . .which leads to Global Climatic Regions:

. . . .and CHANGES in these regions!

from Dire Predictions text

Drier!

Hotter!

Wetter!

It all happens because of changes in the RADIATION /

ENERGY BALANCE !

“Radiation Balance” part

All components are referring to electromagnetic radiation

“Energy Balance” partAll components are referring to modes of heat energy transfer

or heat energy storage involving

matter

“Radiation Balance” part

Start out here, with energy from the SUN radiated to Earth and so forth . . .

=

“Energy Balance” part

The is then able to be used in thermal energy “heat transfer” processes which manifest themselves as weather & climate!

Thermal Energy Review

Heat (def) = the thermal energy that is transferred from one body to another because of a temperature difference. 

• Sensible Heat transfer (H)

• Latent Heat transfer (LE)

plus (after transfer) thermal energy can be STORED (G)

Review

ENERGY IN THE EARTH-ATMOSPHERE SYSTEM

Ultimate source of energy is the

SUN (SW) After absorption of

SW, LW energy is

radiated in & out by EARTH & Atmosphere

Any NET

(leftover) energy

Goes into the HEAT TRANSFER

processes that drive

WEATHER & CLIMATE !

The Earth [as viewed from space] . . . has the organized, self-contained look of a live creature, full of information, marvelously skilled in handling the sun.

~ Lewis Thomas

LINKING THE ENERGY BALANCE TO ATMOSPHERIC

CIRCULATION . . .

We’ll start with the SUN (SOLAR INSOLATION)

IN – SOL- ATION =

Amount of incoming solar energy received by a point on Earth’s

surface

p 63

To drive the circulation, the initial source of energy is from the Sun:

Not to scale!

http://mesoscale.agron.iastate.edu/agron206/animations/

01_EarthSun.html

1) Earth orbits Sun in one year 2) Orbit is not a perfect circle ( = an ellipse )3) Earth’s orbit around Sun can be “traced” on a plane

(“Plane of the Ecliptic” – plane passes thru the center of Sun & Earth)

4) Earth’s axis tilts 23.5 from a to the “Plane of The Ecliptic”

4 Things to Know about Earth-Sun Relationships:

EARTH-SUN

Relationships

These 4 Earth-Sun Properties lead to:

the 2 factors that determine the AMOUNT OF SOLAR INSOLATION

as the seasons progress:

p 63

(1) INTENSITY of sun’s rays(perpendicular to surface = more intense)

(2) DURATION of daily insolation(longer day length = more insolation)

A useful term:

ZENITH =The point directly

overhead

INTENSITY is greatest at any spot on Earth when

sun is closest to the

ZENITH!

Zenith point changes with latitude

QUICKIE LATITUDE REVIEW:

66.5 N

66.5 S

90 N

90 S

0

23.5 N

23.5 S

EARTH-SUN RELATIONSHIPS & The SEASONS:

VIEW THE ANIMATION:http://mesoscale.agron.iastate.edu/agron206/animations/

01_EarthSun.html

As viewed from one side of Sun

JUNE SOLSTICE

JUNE SOLSTICE

As viewed from the other side of the

Sun

JUNE SOLSTICE

p 63

Most intense solar radiation

24 hours of sunlight

JUNE SOLSTICE

p 63

p 79

MARCH EQUINOX

Equinox = “equal night”

SEPTEMBER EQUINOXdifferent seasonal position in

orbit . . .

. . . but same latitudinal insolation as March

Equinox

Most intense solar radiation

12 hours of sunlight

MARCH & SEPTEMBER EQUINOXES

p 63

DECEMBER SOLSTICE

Most intense solar radiation

24 hours of darkness

DECEMBER SOLSTICE

p 63

Recap

http://mesoscale.agron.iastate.edu/agron206/animations/

01_EarthSun.html

THE RADIATION BALANCE

& THE GENERAL

CIRCULATION OF THE ATMOSPHERE

p 64

Over the course of a year . . .

The amount of INCOMING SW (Insolation) absorbed by EARTH varies by LATITUDE

(MORE comes in near the Equator, less near the Poles)

The amount of outgoing TERRESTRIAL LW / IR varies by latitude too --

p 64

HOW IT ALL FITS TOGETHER:

HOWEVER . . .

LOW LATITUDES absorb MORE energy than HIGH LATITUDES

MORE LW / IR is emitted at warmer LOW LATITUDES, LESS in coolerHIGH LATITUDES

p 64

The EQUATOR-POLE DIFFERENCES of what goes OUT from the EARTH

EQUATOR-POLE DIFFERENCES of what comes IN from the SUN

are less than the

p 64

BUT the amount of outgoing LW is

only slightly different from

latitude to latitude & Equator to Pole

LESS SW coming in

MORE SW coming in

SW in < LW out

SW in > LW out

The result is a NET SURPLUS of energy in the low latitudes & a NET DEFICIT in

the high latitudes

p 64

POLE EQUATOR POLE

Now lets look at a Pole to Pole Transect

p 64

(at top of atmosphere)

Net radiation surplus

Net radiation deficit

Net radiation deficit

What do the black & gray areas represent?

p 64

http://geography.uoregon.edu/envchange/clim_animations/

HOT TROPICS

COLD POLAR

REGIONS

COLD POLAR

REGIONS

Northern Hemisphere Southern HemisphereEQUATOR

Global-scale air motions are driven by thermal differences:

HOT TROPICS

COLD POLAR

REGIONS

COLD POLAR

REGIONS

From SGC-I Chapter 4

cold polar air vs.

warm low lat air

rising tropical warm,

moist air

sinking dry subtropical

air

warm low lat airvs.

cold polar air

sinking dry subtropical

air

LOW PRESSURE AREAS:

Hot surface Rising air expansion and cooling of air, and condensation of water vapor

clouds, and possibly

precipitation . . .

HUMID REGIONS

How do H2O droplets in warm, tropical clouds coalesce and grow so that they become heavy enough to fall as rain in the ITCZ?

Mini-Zombie Break !

This dances shows how a rain drop can form when one SLIGHTLY LARGER RAIN DROP is present among a population of smaller drops.

In the tropics, really large drops (heavy enough to fall as rain ) only form after

mixing occurs.

DANCE YOUR PH.D!“Precipitation Initiation in Warm

Clouds”

In the “mixing process” the H2O droplets connect with “condensation nuclei partners”

Women are H2O droplets

Men are Condensatio

n nuclei

Through “coalescence” a single nucleus attracts all the other water droplets !

. . . but eventually some H2O’s abandon their original nuclei for a larger one!

When the H2O droplet grows large enough . . . . . . RAIN FALLS!http://www.youtube.com/watch?

v=4O7G7F_e7I0

HIGH PRESSURE AREAS:

Forced sinking (e.g. in HADLEY CELL)leads to “compaction” and warming of the sinking air

Air warms increase in the water vapor holding capacity clear skies, dry air and ARID REGIONS / DESERTS!

The opposite of rain = subsidence (sinking air)In HIGH PRESSURE ares!

In general: Winds tend to flow from HIGH LOW Pressure areas

p 64

Sub-tropical HIGH PRESSURE

Intertropical

Convergence ITCZ

H H

H H

LL

Sub-tropical HIGH PRESSURE

HADLEY CELLS =

key drivers!

Convection cell transfer of thermal energy from low latitude area of energy SURPLUS to higher latitude area of energy DEFICIT

p 64

BUT -Hadley cell circulation does

not reach high latitudes!

BUT –Hadley cell circulation

does not reach high latitudes!

Why Hadley convective cell transport breaks down at higher latitudes:

64

“Wave” transport of thermal energy instead of Hadley cell

transport!p 65

UPPER LEVEL CIRCUMPOLAR WINDS !

Hadley Cells are only efficient in transporting energy to the mid-latitudes

Hadley Cells + Rossby Wavestogether are needed!

Energy is transported from areas of surplus to deficit in form of: (sensible heat) & (latent

energy)

IN TWO MAIN WAYS:

p 65

Atmospheric circulation moves warm & cold air north & south across latitudes

H2O condenses in high latitudes LE H

H2O is evaporated in low latitudes H LE

http://www.vets.ucar.edu/vg/T341/index.shtml

The Community Climate System Model (CCSM) is a coupled climate model for simulating Earth's climate

system. It simulates the earth's atmosphere, ocean, land surface and sea-ice

water vapor = WHITE precipitation rate = ORANGE.

(at top of atmosphere)

Net radiation surplus

Net radiation deficit

Net radiation deficit

p 64

THERMAL ENERGY IS TRANSPORTED FROM LOW TO

HIGH LATITUDES TO BALANCE OUT THE DEFICIT!

p 64

BUT WHAT ABOUT G ?G is a STORAGE component, not a transfer

component BUT energy stored in the OCEAN, can later be transported via ocean currents as

H !

P 97p 66

WARM & COLD SURFACE OCEAN CURRENTS:

Large OCEAN GYRES -- driven by Trade Winds & Westerlies in Oceanic Subtropical

HIGH PRESSURE CELLS (STH)

HH

H H

H

H

P 97

Leads to SURFACE ocean currents

p 66

Energy is transported from areas of surplus to deficit

via: H (sensible heat)

p 65

& LE (Latent Energy)

P 67

Both ATMOSPHERE & OCEAN play important roles in BALANCING OUT ENERGY SURPLUS & DEFICIT AREAS:

OCEAN transports MOST of the energy in LOW subtropical latitudes

ATMOSPHERE more important in mid high latitudes

Poleward transport of energy in N.H.

ZOMBIE BREAK !

Turn to Page 30

in Class Notes . . . .

As you watch the segments of this film . . . .

Check off the changes on p 30 in CLASS NOTES :

p 30

Checklist of Direct Observations of Recent

Climate Change:

etc., etc.

Watch the video carefully – at some point a feedback loop process is described.

Can you recognize it ???(HINT: it is one of the loops shown on p 56 in Class Notes)

Make a note of it . . . . .

AFTER THE FILM: GROUP BONUS POINT CHALLENGE - PART 1:

State which feedback loop was described in the film and sketch the FEEDBACK DIAGRAM for it on one side of the INDEX CARD provided.

NOW – on the back of the index card, as a group, complete the feedback loop on the bottom of page 58 by linking the components with the proper coupling arrow symbols as used in the SGC text

p 58

GROUP BONUS POINT CHALLENGE - PART 2:

albedo

Extent of ice cover

SW radiation absorbed

Ocean temperature

Amount of melting

albedo

Extent of ice cover

SW radiation absorbed

Ocean temperature

Amount of melting

++

+

+

--

-

The ANSWER!

SNOW AND ICE ALBEDO Feedback

BE SURE TO REVIEW THE CLASS FOLLOW-UP IF YOU WANT TO GO OVER THESE

ANSWERS AGAIN . . . . .

See you on Thursday – don’t forget RQ-6!