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ESPM 111 Ecosystem Ecology
Weather, Climate and Ecosystems
Dennis BaldocchiUniversity of California, Berkeley
6/3/2014
ESPM 111 Ecosystem Ecology
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
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– Liquid: Rain, dew, clouds– Solid: snow, sleet, frost, hail, rime, clouds
• Pressure
Many Ecological Processes are a Function of, or Correlate with, Climate and Weather
• Photosynthesis = f(sunlight, temperature, humidity, rainfall)
• Evaporation = f(sunlight, temperature, humidity, rainfall)• Respiration = f(temperature, rainfall)• Decomposition =f(temperature, rainfall)• Ecosystem Structure and Function = f(sunlight,
temperature, rainfall)• Soil Formation and Nutrition= f(temperature, rainfall)
ESPM 111 Ecosystem Ecology
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 cold
ESPM 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
Constrained– Thresholds and Tipping Points– Coherent Features Emerge, like Hurricanes and Tornadoes
ESPM 111 Ecosystem Ecology
Warm and Dry in the West
Cold and Snowy in the East
ESPM 111 Ecosystem Ecology
Berkeley
Day-Year
1980.0 1980.2 1980.4 1980.6 1980.8
Tem
pera
ture
0
5
10
15
20
25
30
Day to Day Variation in Mean Temperature
ESPM 111 Ecosystem Ecology
ESPM 111 Ecosystem Ecology
Chemistry and Physics of the Atmosphere
ESPM 111 Ecosystem Ecology
Atmospheric Composition
• Nitrogen– 78.084%
• Oxygen– 20.946%
• Argon– 0.934%
• Carbon Dioxide– 0.0395%
• Water Vapor– 0.1 to 4%
• Trace Gases– Nitrous Oxide, CO, Methane, Ozone, VOCs
ESPM 111 Ecosystem Ecology
Partial Pressure Law• Total Pressure is the sum of the
partial pressures of its components– P=pn2+po2+par+ph2o+pco2+…
• P at sea level, 101.3 kPa
• P equal mass of overhead atmosphere time acceleration due to gravity, per unit area
AP M g
ESPM 111 Ecosystem Ecology
Atmospheric Temperature Profile
ESPM 111 Ecosystem Ecology
Planetary Boundary Layer
ESPM 111 Ecosystem Ecology
Solar Constant
• 1366 J m-2 s-1 or W m-2
• Amount of Energy Available to Drive Work by the Climate System and Life
ESPM 111 Ecosystem Ecology
Comparison between Planck’s Law for Sun and Earth
Planck's Law
Wavelength, microns
1e-8 1e-7 1e-6 1e-5 1e-4 1e-3
Ene
rgy
(T,
)
1e+3
1e+4
1e+5
1e+6
1e+7
1e+8
1e+9
1e+10
1e+11
1e+12
1e+13
1e+14
1e+15
Earth, T = 298 KSun, T = 5800 K
ESPM 111 Ecosystem Ecology
Wavelength (microns)
1 10 100
Abso
rptio
n C
ross
-Sec
tion
(cm
-1/(m
olec
ule
cm-2
)
1e-21
1e-20
1e-19
1e-18
1e-17
H2O CO2
HI-Tran Database
Many Atmospheric Trace Gases Absorb & Re-emit Infrared Radiation
ESPM 111 Ecosystem Ecology
www.GlobalwarmingArt.com
ESPM 111 Ecosystem Ecologywww.GlobalwarmingArt.com
ESPM 111 Ecosystem Ecology
Trenberth et al 2009 BAMS
ESPM 111 Ecosystem Ecology
Basic Earth/Sun Geometry
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
Hei
ght,
m
zT
unstablethermal
stratifiation
Hei
ght,
m
stablethermal
stratification
zTH
eigh
t,m
near neutralstability
zT
Tparcel > TairTparcel < Tair
Concepts of Thermal Stratification
Temperature
ESPM 111 Ecosystem Ecology
Adiabatic Lapse Rate, Lifted Condensation Level and Clouds
http://www.sci.uidaho.edu/scripter/geog100/lect/05-atmos-water-wx
ESPM 111 Ecosystem Ecology
Orographic PrecipitationAir Lifted by a Mountain, Cools, Can
Condense, Form Clouds and Rain/Snow
http://www.sci.uidaho.edu/scripter/geog100/lect/05-atmos-water-wx
ESPM 111 Ecosystem Ecology
Succession of Weather Fronts off the Pacific Coast of North AmericaRole of High and Low Pressure Zones on Weather
ESPM 111 Ecosystem Ecology
http://www.worsleyschool.net/science/files/aboutweather/coldfront.gif
Cold and Warm Fronts and RainTwo Ways to Lift Parcels of Air, Form Clouds and Rain
ESPM 111 Ecosystem Ecology
LOW
High
Cyclonic CirculationAir is Convergent
Anti-Cyclonic Circulation:Air is Divergent
High and Low Pressure Systems in Northern Hemisphere
ESPM 111 Ecosystem Ecology
Convergence:Air Rises, Temperature Decreases,Vapor Condenses, Clouds Form,Rain Possible
LOW
ESPM 111 Ecosystem Ecology
Divergence:Air Sinks, Temperature WarmsCloud Formation is Suppressed
High
ESPM 111 Ecosystem Ecology
Large Scale Patterns Dominating Weather in California
Aleutian Low Steer Storm Tracks during Winter
North Pacific High Block Storms duringSummer
http://www.pacificstormsclimatology.org/index.php?page=regional-overview
ESPM 111 Ecosystem Ecology
Differential Solar heating causes Air to rises at equator and subsided at poles
This is superimposed upon the Earth’s rotation and the Coriolis Force which determineswind direction
Circulation cells help explain global distribution of rainfall
From Chapin
ESPM 111 Ecosystem Ecology
La Nina
ESPM 111 Ecosystem Ecology
El Nino
http://weatherevents.co.uk/widespread-flooding-in-australia-and-the-affect-of-la-nina/
ESPM 111 Ecosystem Ecology
Climate Distribution
ESPM 111 Ecosystem EcologyIPCC dataset
ESPM 111 Ecosystem EcologyIPCC dataset
ESPM 111 Ecosystem Ecology
ESPM 111 Ecosystem Ecology
Summary• Solar Energy Drives Weather and Climate• Trace Gases that absorb and re-radiate energy
warm the atmosphere and Earth’s surface above its radiative equilibrium value
• Differential heating of the Earth and its Rotation causes circulation of the air
• Different declination, relative to the Sun, causes the seasons.
• Rising air parcels, by fronts, topography or instability, can cool, condense, form clouds and rain
ESPM 111 Ecosystem Ecology
Zachos et al Science 2002
Natural Solar Forcing of Climate Variability Over Geological Time
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
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