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ESPM 111 Ecosystem Ecology
Weather, Climate and Ecosystems
Dennis BaldocchiUniversity of California, Berkeley
2/1/2013
ESPM 111 Ecosystem Ecology
Weather, Climate and Ecosystems: Outline
• Concepts– Atmospheric Meteors and Composition– ‘Greenhouse-Effect’ Principles– Seasons– Global and Regional Circulation
• Climate– Climate Forcing and Variability– Global Temperature, Precipitation and Radiation
Maps
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ESPM 111 Ecosystem Ecology
Weather and Climate Meteors
• Electromagnetic Radiation– Solar (shortwave) and Terrestrial (longwave)– f(season, clouds)
• Temperature– Air, soil, vegetation
• Wind Velocity and Direction• Moisture
– Gaseous: vapor pressure, Relative Humidity, dew point
• Ecosystem Structure and Function = f(sunlight, temperature, rainfall)
• Soil Formation and Nutrition= f(temperature, rainfall)
ESPM 111 Ecosystem Ecology
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Weather vs Climate
• Weather is the Recent Condition of the Atmosphere, yesterday, today, tomorrow– Weather is Chaotic, can Exhibit Extreme
Behavior
• Climate is the Average Condition of the Atmosphere over long-time durations, e.g. 30 years, Century, Millennium– Climate is relatively stable, e.g. summers are
hot, winters are coldESPM 111 Ecosystem Ecology
ESPM 111 Ecosystem Ecology
Weather/Climate Concepts• Atmosphere is a Dynamic and Complex System
– Multiple Positive and Negative Feedbacks that operate across a Spectrum of Time and Space Scales
– Non-Linear Processes– Sensitivity to Initial Conditions– Experiences Strange Attractors, so is Phase Space is
Natural Solar Forcing of Climate Variability Over Geological Time
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ESPM 111 Ecosystem Ecology
Source Rob Rohde, http://www.globalwarmingart.com/images/7/7e/Milankovitch_Variations.png
Natural Forcing of the Climate System, last Million Years
Timing of Ice Ages
• MilankovitchTheory states Glaciers form when solar intensity is weak during summer of northern latitudes, as when Earth is less tilted with orbital plane (e.g. Obliquity with 41 ky cycles)
• Isotope show ice-ages grow and wane with 41 ky cycle for Early Pleistocene (1-3 Million yBP) and 100ky cycle in late Pleistocene (0-1 Million yBP)– Eccentricity of Earth’s orbit with 100 ky cycle has a weak forcing on
summer insolation
• The integral of solar radiation (time x intensity), not peak irradiance, controls 41 ky timing of ice age of the Early Pleistocene (1 to 3 million ybp)– This corresponds with Obliquity, which has 41 ky cycle instead of 100 ky
with Eccentricity because Summers are shorter when Earth is closer to Sun and Radiation is greatest
ESPM 111 Ecosystem Ecology
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ESPM 111 Ecosystem Ecology
Lapse Rates, Temperature Decreases with Height
• Dry Adiabatic Lapse Rate– 9.8 C km-1
• Moist Adiabatic Lapse Rate– 6 C km-1
Change in Internal Energy Equals Change in Work Done on the Air Parcel
ESPM 111 Ecosystem Ecology
Adiabatic Lapse Rate, Lifted Condensation Level and Clouds