An investigation of the Archean climate using the NCAR CCm

Miscellaneous · Tue Jan 01 00:00:00 EST 1991

OSTI ID:7303620

Jenkins, G S

The Archean (2.5 to 3.8 billion years ago) is of interest climatically, because of the 'Faint-Young Sun Paradox', which can be characterized by the Sun's reduced energy output. This lower energy output leads to a frozen planet if the climate existed as it does today. But, the geologic record shows that water was flowing at the earth's surface 3.8 billion years ago. Energy Balance Models (EBMs) and one-dimensional radiative-convective (1DRC) models predict a frozen planet for this time period, unless large carbon dioxide (CO2) concentrations exist in the Archean atmosphere. The goal is to explore the Archean climate with the National Center for Atmospheric Research (NCAR), Community Climate Model (CCM). The search for negative feedbacks to explain the 'Faint-Young Sun Paradox' is the thrust of this study. This study undertakes a series of sensitivity simulations which first explores individual factors that may be important for the Archean. They include rotation rate, lower solar luminosity, and land fraction. Then, these climatic factors along with higher CO2 concentrations are combined into a set of experiments. A faster rotation rate may have existed in the Archean. The faster rotation rate simulations show warmer globally averaged surface temperatures that are caused by a 20 percent decrease in the total cloud fraction. The smaller cloud fraction is brought about by dynamical changes. A global ocean is a possibility for the Archean. A global ocean simulation predicts 4 K increase in global mean surface temperatures compared to the present-day climate control.

• Research Organization: Michigan Univ., Ann Arbor, MI (United States)
• OSTI ID: 7303620
• Resource Relation: Other Information: Thesis (Ph.D.)
• Country of Publication: United States
• Language: English

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54 ENVIRONMENTAL SCIENCES
58 GEOSCIENCES
29 ENERGY PLANNING
POLICY AND ECONOMY
CARBON DIOXIDE
ECOLOGICAL CONCENTRATION
CLIMATIC CHANGE
FORECASTING
PALEOCLIMATOLOGY
AMBIENT TEMPERATURE
CLIMATE MODELS
CLOUDS
ENERGY BUDGETS
LUMINESCENCE
PRECAMBRIAN ERA
SIMULATION
SOLAR RADIATION
SUN
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
GEOLOGIC AGES
MAIN SEQUENCE STARS
MATHEMATICAL MODELS
OXIDES
OXYGEN COMPOUNDS
PALEONTOLOGY
RADIATIONS
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STELLAR RADIATION
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