Lecture Outlines -- Fall, 2007

• What is Geography?
  • study of spatial aspects of Earth's surface
  • description and analysis of distributions and spatial patterns
  • explanation and understanding of origins of distributions and patterns
  • often divided into human and physical geography
• What is physical geography?
  • interrelationships between
    • atmosphere (climatology)
    • hydrosphere (hydrology)
    • geosphere (geomorphology)
    • biosphere (biogeography)
• What is Earth system science?
  • study of Earth's systems, generally at a global scale
  • analysis of global changes of the past
  • projection of future global changes
• What are the Earth systems?
  • global-scale interrelationships between
    • atmosphere (climatology)
    • hydrosphere (hydrology)
    • geosphere (geomorphology)
    • biosphere (biogeography)
  • the interaction of human systems with all of these spheres is increasingly important

• Short time scales
  • Atmospheric changes (decadal scale)
    • recent rise of atmospheric carbon dioxide (CO₂)
    • instrumental record of Earth surface temperature
  • Sea-level rise as a consequence of global warming
  • Climate changes of the last millenium
    • Little Ice Age
    • Medieval warm period
• Longer time scales
  • Holocene climate changes
  • Pleistocene glacial cycles
    • Evidence for glacial cycles
      • glacial deposits
      • coastal deposits and terraces
      • deep-sea deposits
      • isotopic evidence from ice cores
  • Pre-Pleistocene glaciations
    • Permo-Carboniferous glaciations ~290 my
    • Late Ordovician ~440 my
    • Late Proterozoic ~700 my
    • Huronian ~2,300 my
• Geologic time scale

• Definition of a system
  • state
  • couplings: positive, negative
  • feedback: positive, negative
• Open and closed systems
• Inputs, throughputs, outputs
• Equilibrium
  • stability and instability
• Perturbations
• Forcings

• A simple climate-biosphere system
  • albedo control of temperature
  • biologic response to temperature
  • feedback
  • perturbations to the system
  • forcing the system

• Electromagnetic radiation
  • wavelength
  • frequency
  • speed of light (3.00 x 10⁸ ms^-1)
• Electromagnetic spectrum
• Solar constant (1370 Wm^-2 or Js^-1m^-2)
• Radiation laws
  • Stefan-Boltzmann Law
  • Wien's Law
• Earth's energy balance
  • E_absorbed = E_emitted
  • Earth's equilibrium temperature is about 255 K
  • measured Earth surface temperature is about 288 K
  • therefore the "greenhouse effect" is about 33 K

• Atmospheric composition
  • 78% nitrogen (N₂)
  • 21% oxygen (O₂)
  • 0.9% argon (Ar)
  • all other gases less than 0.1%
• Thermal structure of the atmosphere
  • troposphere
  • stratosphere
  • mesosphere
  • thermosphere
• Absorption of radiation by gasses
  • water vapor (H₂O)
  • carbon dioxide (CO₂)
  • methane (CH₄)
  • oxygen (O₂) and ozone (O₃)
• Clouds
  • increase in Earth's albedo
  • absorb and emit LW
  • importance of cloud thickness and altitude
• Important climate feedbacks
  • water vapor feedback (positive)
  • snow and ice feedback (positive)
  • temperature feedback (negative)

• Atmospheric motion
  • pressure-gradient force
  • Coriolis force
    • velocity-dependent
    • increases with latitude
  • geostrophic wind
  • friction and resultant surface winds
  • cyclones, anticyclones

• General circulation of the atmosphere
  • intertropical convergence zone (ITCZ or doldrums)
  • trade winds (easterlies)
  • Hadley cells
  • subtropical highs
  • polar front
  • polar front jet stream
  • seasonal changes

End of first block -- Exam 1 on Thursday, September 27 (Chapters 1, 2, 3 and part of 4)

• Phase changes of water
  • latent heat of fusion: 335 kJ/kg
  • latent heat of vaporization: 2500 kJ/kg
  • latent heat of sublimation: 2835 kJ/kg
• Measures of humidity
  • vapor pressure (mb)
  • dew point temperature (°C or °F)
  • relative humidity (%)
• Evaporation
  • vapor pressure
  • vapor-pressure gradient
  • transpiration
• Condensation
  • dew and frost
  • radiation fog
  • advection fog
  • orographic fog
  • clouds

• Elements of the global hydrologic cycle
  • ocean evaporation
  • ocean precipitation
  • terrestrial precipitation
  • evapotranspiration
  • storage as ice on land
  • runoff
  • other reservoirs
  • mean residence time

• net poleward transport of heat
• winds and surface currents
• Ekman transport
• upwelling and downwelling
• western boundary currents
• eastern boundary currents
• ocean circulation and surface temperatures

• salinity
• thermohaline circulation
• deep-water formation
• the thermohaline "conveyor belt"
• the ocean's role in poleward heat transport
• possible interruptions of thermohaline circulation

• Materials of the Earth
  • minerals
  • rocks
    • igneous (extrusive, intrusive)
    • sedimentary
    • metamorphic
• Structure of the Earth
  • crust
  • mantle
  • core
• Geologic time scale

• sea-floor spreading
• lithosphere, asthenosphere
• lithospheric plates
• plate boundaries
  • divergent
  • convergent
    • oceanic-continental
    • oceanic-oceanic
    • continental-continental
  • transform
• mantle convection and heat loss
• the rock cycle
  • recycling of crustal rocks: the rock cycle
  • endogenic and exogenic processes
  • weathering and erosion
  • sediment accumulation
  • metamorphism and melting

End of second block -- Exam 2 on Thursday, October 25 (Chapters 4, 5 and 7)

• active reservoirs
  • atmosphere
  • terrestrial biota
  • soils
  • oceans
• natural fluxes
  • photosynthesis
  • respiration
  • atmosphere-ocean gas exchange
• fluxes as augmented by human action
• residence times
• short-term fluctuations in atmospheric carbon

• Organic carbon cycling on long time scales
  • carbon burial in sedimentary rocks
  • maintenance of atmospheric O₂
  • formation of fossil fuel
  • weathering of organic carbon in rocks
• Cycling of inorganic carbon on long time scales
  • carbonic acid in precipitation and soils
  • chemical weathering
    • carbonate rocks
    • silicate rocks
  • subduction and decarbonation
  • long-term feedbacks in inorganic carbon cycle

• evidence of climate changes
  • glacial deposits
    • moraines
    • till
    • striations
  • loess
  • marine oxygen-isotope record
• Milankovitch orbital cycles
  • eccentricity changes (~100,000-yr and ~400,000-yr cyclicities)
  • obliquity changes (~41,000-yr cyclicity)
  • precession of the equinoxes (~19,000-yr and ~23,000-yr cyclicities)

• ice-albedo feedbacks
• cloud-albedo feedbacks
• feedbacks involving atm CO₂
  • biological pump
  • iron fertilization hypothesis
  • coral reef hypothesis

• Proxy climate data
  • palynology
  • dendroclimatology
  • other data sources
    • ice cores
    • marine cores
• Late-glacial and Holocene climates
  • Younger Dryas
  • climatic optimum
  • Medieval warm period
  • Little Ice Age

• Some possible causes
  • volcanoes
  • orbital changes
  • solar variability

End of third block -- Exam 3 on Tuesday, November 20 (Chapters 8, 14 and part of 15)

• El Niño - Southern Oscillation (ENSO)
  • Hadley cell circulation
  • zonal Walker circulation
  • Coriolis deflection of surface water
  • upwelling
  • Southern Oscillation (SO) (Tahiti - Darwin)
  • El Niño - La Niña differences
  • teleconnections

• "greenhouse" gasses
  • water vapor
  • carbon dioxide
  • methane
  • nitrous oxide
  • chlorofluorocarbons (CFCs)
• carbon cycle
• fossil fuels
• deforestation
• global temperature record
• predictions of climate models
• effects of aerosols

• sea-level rise
  • thermal expansion
  • change in storage of water on land
  • predicted sea-level changes
• soil moisture changes
• growing season changes
• changes in frequency of severe storms
• spread of certain diseases
  • malaria
  • dengue
  • schistosomiasis
• CO₂ and changes in agricultural productivity
• space heating costs

• alternative energy sources
  • nuclear power options
  • wind power generation
  • solar thermal and photovoltaic
  • other
• Government policy options
  • carbon tax
  • emission permits
  • international agreements

• ozone (O₃)
• ozone concentration in the stratosphere
• stratospheric ozone formation
• natural stratospheric ozone destruction
• stratospheric circulation
• characteristics of CFCs (chlorofluorocarbons)
• diffusion of CFCs in the atmosphere
• breakdown of CFCs in the stratosphere
• Southern Hemisphere circumpolar vortex
• stratospheric clouds
• (ClO)₂ reactions

• efforts to control CFCs in the atmosphere
  • Vienna Convention (1985)
  • Montreal Protocol (1987)
  • London Agreement (1990)
  • Copenhagen Amendment (1992)

End of fourth block -- Exam 4 TBA Exam Week (Chapters 15, 16 and 17)