Global Climate Change

Global Climate Change

• Climate and Agents

• Models and Measurement

• Biosphere and Human Component

www.meteor.iastate.edu/gccourse/

Jan 12 Overview of Global Change

Jan 14 Evolution of the Earth's Atmosphere

Jan 16 Atmospheric Structure and Circulation

Jan 21 Atmospheric Compos ition, Carb on Dioxide

Jan 23 Carbon Cycle, Met han e

Jan 26 Nitroge n Cycle, Su lfur Cycle; Tropos pheric Ozone

Jan 28 Acid Depo sition

Jan 30 Man-mad e Chemi ca ls, CFCs

Feb 2 Ozone Reactions: Physics, Chemistry of the Stratosphere

Feb 4 Ocean Structure and Circulation

Feb 6 Global Hydrological Cycle

Feb 9 Global Energy Balance

Feb 11 Impact of Clouds on the Radiation Balance

Feb 13 Global Warming Potential

Feb 16 Climate System and Climate Predictability

Feb 18 Climate Models

Feb 20 Climate Model Results - Equilibrium Models

Feb 23 Climate Model Results - Transient Climates

Feb 25 Regional Climate Models

Feb 27 Soil-Vegetation-Atmospheric Modeling

Mar 1 Paleoclimate; Ice Core and Lake Sediment

Records

Mar 3 The Instrument Climate Record, Uncertainties

Mar 5 Trends in Climate Variables, Climate Variability

Mar 8 Climate Variability (El Nino, La Nina)

Mar 10 Satellite Observations of the

Earth/Atmosphere/Ocean/Biosphere

Mar 12 Mission to Planet Earth

Mar 22 Earth System Science

Mar 24 Sea-Level Rise

Mar 26 Plant Physiological Effects of a Changing Environment

Mar 31 Human Population Trends, Controlling Factors

Apr 2 Energy Consumption and Conservation

Apr 5 Global Change and Human Health

Apr 7 BioDiversity

Apr 9 Forests and Deforestation

Apr 12 Land Use Issues

Apr 14 Desertification

Apr 16 Assessment of Impacts of Climate Change

Apr 19 Impact of Global Change on Agriculture

Apr 21 Impact of Global Change on Water Resources

and Water Use

Apr 23 Sustainable Development

Apr 26 Developments in China

Apr 28 Societal Responses to Regional

Climate Change

Apr 30 Legislation and Policy

Review and Wrap-Up

Evolution of the Earth’s Atmosphere

How Did It Get This Way??

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

escape velocity --a balance of gravitational energy at the planet surface and kinetic energy

:mgRp = 1/2 mVe2-->

Ve = (2gRp)1/2

The effective temperature of the body gives an approximation of the temperature of the gaseous constituents at the "outer edge" of its atmosphere.

This temperature determines the most probable velocity of each constituent in this region, as given by the following equation:

VM = (2kT/MmH)1/2

whereVM = most probable velocity for molecule of weight Mk = Boltzmann's constant (1.38 x 10-23 J deg-1)T = effective temperatureM = molecular weight of a particular gas speciesmH = mass of the hydrogen atom ( 1.67 x 10-27kg)

Nitrogen(N2) 28.01 0.7808Oxygen(O2) 32.00 0.2095

Argon(A) 39.94 0.0093Water (H2O) 18.02 0-0.04

CO2 44.01 364 parts per millionNeon(Ne) 20.18 18 parts per millionHelium(He) 4.00 5 parts per million

Krypton(Kr) 83.7 1 part per millionHydrogen(H) 2.02 0.5 parts per millionOzone(03) 48.00 0-12 parts per million

Composition of the Earth's atmosphere below 100 km

Constituent Mol Wt Content

σT4

430 BTU/hr sq ftSOLAR FLUX

RADIATION TO SPACE

(430 BTU/HR SQ FT) (ΠR2) = σT4 (4ΠR2)

σ = 0.1718 X 10-8 BTU/HR SQ FT OR4

T ≈ 500o R ≈ 40o F

FIRST APPROXIMATION OF EARTH'S TEMPERATURE

Unit Absorbtivity and Emissivity

σT4


RADIATION TO SPACE

SECOND APPROXIMATIONMean Albedo = 0.29

125 BTU/hr sq ft

T = 461.4 R = 1.6 F

(actual temperature at 6 km alt)

σT4


RADIATION TO SPACE

THIRD APPROXIMATION

125 BTU/hr sq ft

T = 461.4 R = 1.6 F

Earth sourrounded by a layer of absorbing gasa = 0.9 for long wave lengths

TE = 519 F = 59 F

TE

Global Climate Change

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