Climate System

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Climate System • Atmosphere Nitrogen N 2 78% Oxygen O 2 21% – Argon Ar 0.93% Carbon dioxide CO 2 0.035% – Other minor gases 0.035%

description

Climate System. Atmosphere Nitrogen N 2 78% Oxygen O 2 21% Argon Ar 0.93% Carbon dioxide CO 2 0.035% Other minor gases 0.035%. Greenhouse Gases. CO 2 , H 2 0 and methane (CH 4 ): Absorb and re-radiate radiation Insulates and raises Earth temperature. - PowerPoint PPT Presentation

Transcript of Climate System

Page 1: Climate System

Climate System

• Atmosphere– Nitrogen N2 78%

– Oxygen O2 21%

– Argon Ar 0.93%

– Carbon dioxide CO2 0.035%

– Other minor gases 0.035%

Page 2: Climate System

Greenhouse Gases

• CO2, H20 and methane (CH4):

• Absorb and re-radiate radiation

• Insulates and raises Earth temperature

Page 3: Climate System

GEOLOGIC RESERVOIRSGEOLOGIC RESERVOIRS

Fossilorganiccarbon

Fossilorganiccarbon

Rockcarbonates

Rockcarbonates

Fossil-fuel

burning(5.3 Gt/yr)

Fossil-fuel

burning(5.3 Gt/yr)

OCEANOCEAN

Cement production (0.1 Gt/yr)Cement production (0.1 Gt/yr)

Land-use change:

deforestation,agriculture(1.7 Gt/yr)

Land uptakeBy new plantgrowth(1.9 Gt/yr)

Ocean uptake by air-sea gas

exchange(1.9 Gt/yr)

Terrestrial biosphere

LANDLAND

ATMOSPHEREATMOSPHERE

The influence of Carbon on climate change

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GEOLOGIC RESERVOIRSGEOLOGIC RESERVOIRS

Fossilorganiccarbon

Fossilorganiccarbon

Rockcarbonates

Rockcarbonates

Fossil-fuel

burning(5.3 Gt/yr)

Fossil-fuel

burning(5.3 Gt/yr)

OCEANOCEAN

Cement production (0.1 Gt/yr)Cement production (0.1 Gt/yr)

Land-use change:

deforestation,agriculture(1.7 Gt/yr)

Land uptakeBy new plantgrowth(1.9 Gt/yr)

Ocean uptake by air-sea gas

exchange(1.9 Gt/yr)

Terrestrial biosphere

LANDLAND

ATMOSPHEREATMOSPHERE

Human activities releasea total of 7.1 Gt of carbon into the atmosphere each year.

New plant growth andair-sea gas exchangeremove 3.8 Gt/yr,…

…yielding a netatmosphericincrease of3.3 Gt/yr.

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Climate Change

Understanding Natural Climate Variability:

Use the geologic record to understand Earth Climate in the past

(Uniformitarianism)

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Milankovitch cyclesRelated to variations in:

1. Eccentricity2. Tilt of axis3. Precession (wobble)

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All of these variables change the earth-sun distance

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Is Human-induced climate change

possible?

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Long-term change can be assessed from ice cores, which record annual cycles of ice formation from snow.

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Tem

pera

ture

rela

tive t

o p

resen

t clim

ate

(°C

)

Thousands of years before presentR

ela

tive c

arb

on

dio

xid

e a

nd

meth

an

e c

on

cen

trati

on

s

High

Low

Key:TemperatureCO2

Methane

Ice Ages Deglaciation

Climate has been relatively warm andstable during the last 10,000 years.

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Years

Temperature

CO2 concentration

The 20th-century is clearly anomalous when compared with the last millennium.

Nort

hern

Hem

isp

here

tem

pera

ture

an

om

aly

(°C

)

CO

2 c

on

cen

trati

on

(p

pm

)

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Keeling Curve

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Years

Temperature

CO2

concentration

Glo

bal te

mp

era

ture

an

om

aly

(°C

)

A recent warming trend correlateswith the increase in CO2.

CO

2 c

on

cen

trati

on

(p

pm

)

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Atmospheric CO2 Projections Under 3 Alternate Scenarios….

2000 2020 2040 2060 2080 2100

Year

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….and Estimated Average Surface Temperatures for Those Scenarios

Uncertainty envelope due to lack of knowledge of climate system

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Feedback enhances warming

• Positive Feedback: – Amplifies changes in the system.

– Temperature increase decreases Earth’s albedo by reducing snow and ice cover

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Evidence for Warming

• Weather is highly variable*

• Glaciers provide long-term trends

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1941

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2004

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Columbia glacier

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Greenland

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Greenland

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Weather Related Hazards

1. Drought2. Desertification3. Heat waves4. Snow and Ice5. Global Warming6. El Niño

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NMSU Rainfall

-2

0

2

4

6

8

10

12

14

1 19 37 55 73 91 109 127 145 163 181 199 217 235 253 271 289 307 325 343 361

Days since Jan 1

Cumulative Rainfall (Inches)

200620052004200320022001200020072008

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Transition zones between desertsand humid areas are fragile

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Soil gets eroded by wind and waterProductive land becomes degraded

Main culprits:OvergrazingOverplowing

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Human activity can stress the ecosystem

• Grazing• Cutting trees for charcoal• Some agriculture

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El Niño

• Pacific Ocean is pushed westward by trade winds

• Warm water off Peru is replaced by upwelling of cold, deep, nutrient-rich water

• Circulation reverses: El Niño

• 6 Year cycle

• Opposite extreme in weather patterns is La Nina

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El Niño

Subtropical trade winds weaken

Warm surface water remains in east Pacific

Incessant rain to west coasts

Fisheries suffer (no cold, nutrient-rich upwelling water)

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El Niño

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• Drainage Basins

• Discharge

• Sediment load

• Meandering/Braided rivers

• Floodplains

• Flooding

Outline

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SEA SEA LAND LAND+ 336 Runoff from land+ 398 Precipitation

over sea+ 434 Evaporation

+ 434 Evaporation– 398 Precipitation + 436 Excess to land

via precipitation

+ 107 Precipitation– 371 Evaporation

+ 436 Runoff toocean

+ 107 Precipitation– 336 Runoff to ocean

+ 471 Evaporation

Evaporation434

Precipitation398

Runoff 36

Groundwatertable Groundwater

flow

Infiltration

Surfacerunoff

Precipitation107

Evaporation71

Flux in and flux out over oceans is almost balanced.

Excess is moved toland and precipitates.Excess is moved toland and precipitates.

…or filters into soiland rock, where it moves as groundwater.

The precipitationruns off intolakes, streams,and oceans…

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Drainage Basin/Watershed

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Drainage Basins/Watersheds

• Rio Grande River basin includes:– Chama– Puerco– Pecos (and all of its tributaries)

• It doesn’t include the Gila, because it flows into Colorado

• Continental Divide (in NM) separates: – Rio Grande drainage– Colorado River drainage

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Rio Grande

Rio Grande Pecos

ColoradoGila

San Juan

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Rio Grande Watershed

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• Q=VA

• Q is discharge

• V is average velocity (m/s)

• A is cross-sectional area (m2)

• units of Q?

Discharge/Total Flow

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Discharge/Total Flow

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Discharge/Total Flow

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Stream profile depends on location

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Sediment Load and Grain Size

• Streams can be provided with particles of any size from mud to giant boulders

• Volume and velocity of flow limit size and amount of sediment that stream can carry

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Sediment Load and Grain Size

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Alluvial fans have braided streams

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Gravel delta at mouth of braided river, Cook Inlet, Alaska

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Delta reworked by wave action, Cook Inlet, Alaska