Climate Change and Climate Modeling Sample Syllabus Instructor: T.A.: Office: Office: Phone: Phone: email: email: Course web page: Textbook web page: http://www.atmos.ucla.edu/neelin/climatebook Office hours: Prof.: To be announced or by appointment. T.A.: To be announced in discussion section. Global environment issues involving climate change due to human activities or natural climate variations are presented for students with a background in the sciences. This course provides a quantitative introduction to the new science of climate modeling, which attempts to understand and predict these climate changes. The El Niño phenomenon will be used as a primary example of natural climate variation for which predictions with climate models are now possible. Global warming will be the focus for human-induced change. Recommended Text(s) Neelin, J. D., Climate Change and Climate Modeling (Cambridge University Press, 2010) Grading Problem sets (3) 30% (including parts done in discussion section) Midterm 30% Final exam 40% Prerequisites This course is intended for students majoring in any science area (including biological sciences). Some basic calculus and physics preparation is required, but no background in atmospheric sciences is necessary. Web-based material on problem sets Some of the problems sets will include accessing web based material from climate research groups that is not controlled by the instructor; it is recommended to access this well in advance of the deadline. Some problem sets will have a problem that can be done as an exercise in discussion section. Course Outline *Sections in [ ] will not be covered or will be abbreviated this year Note to instructors: for a 10-week (quarter system) course, with lectures of 2h40min/week, a midterm occupying one lecture, and review sessions 1.5 lectures: certain sections should be abbreviated as in this example, or equivalent. Chapter 1 Overview of Climate Variability and the Science of Climate Dynamics • Climate dynamics, climate change and climate prediction • The chemical and physical climate system Chemical and physical aspects of the climate system El Niño and global warming • Climate models - a brief overview • Global change in recent history Trace gas concentrations A word on the ozone hole [Some history of global warming studies] Global temperatures • El Niño: An example of natural climate variability [Some history of El Niño studies] Observations of El Niño: the 1997-98 event The first El Niño forecast with a coupled ocean-atmosphere model • Paleoclimate variability Chapter 2 Basics of Global Climate • Components and phenomena in the climate system Time and space scales Interactions among scales and the parameterization problem • Basics of radiative forcing Blackbody Radiation Solar energy input • Globally averaged energy budget—first glance • Gradients of radiative forcing and energy transports by atmosphere and ocean • Atmospheric circulation [Vertical structure] Latitude structure of the circulation Latitude-longitude dependence of climate features • Ocean circulation Latitude-longitude dependence of climate features The ocean vertical structure The ocean thermohaline circulation • Land surface processes • Carbon cycle Chapter 3 Physical Processes in the Climate System • Conservation of momentum Coriolis force Pressure gradient force Velocity equations Application: geostrophic wind [Pressure-height relation: Hydrostatic balance] Application: pressure coordinates • Equation of state Equation of state for the atmosphere: Ideal gas law Equation of state for the ocean: [Application: height-pressure-temperature relation] Application: thermal circulations Application: sea level rise due to oceanic thermal expansion • Temperature equation Ocean temperature equation Temperature equation for air [Application: the dry adiabatic lapse rate near the surface] [Application: decay of a sea surface temperature anomaly] Time derivative following the parcel • Continuity equation Oceanic continuity equation Atmospheric continuity equation [Application: coastal upwelling] Application: Equatorial upwelling Application: Conservation of warm water mass in an idealized layer above the thermocline • Moisture equation and salinity equation Conservation of mass applied to moisture Sources and sinks of moisture, and latent heat [Conservation of mass applied to salinity] • Moist processes Saturation Saturation in convection; Lifting condensation level The moist adiabat and lapse rate in convective regions [Moist convection] • [Wave processes in the atmosphere and ocean] [Gravity waves] [Kelvin waves] [Rossby waves] • Overview Chapter 4 El Niño and Year-to-Year Climate Prediction • Recap of El Niño basics The Bjerknes Hypothesis • Tropical Pacific climatology • ENSO mechanisms I: Extreme phases • Pressure gradients in an idealized upper layer Subsurface temperature anomalies in an idealized upper layer • Transition into the 1997-98 El Niño Subsurface temperature measurements Subsurface temperature anomalies during the onset of El Niño Subsurface temperature anomalies during the transition to La Niña • El Niño mechanisms II: Dynamics of transition phases Equatorial jets and the Kelvin wave [The Kelvin wave speed] [What sets the width of the Kelvin wave and equatorial jet?] Response of the ocean to a wind anomaly [The delayed oscillator model and the recharge oscillator model] ENSO transition mechanism in brief • El Niño prediction Limits to skill in ENSO forecasts • El Niño remote impacts: teleconnections • Other interannual climate phenomena and prospects for seasonal-to- interannual climate prediction Hurricane season forecasts Sahel drought North Atlantic oscillation and annular modes Chapter 5 Climate Models • Constructing a Climate Model An Atmospheric model Treatment of sub-grid scale processes Resolution and computational cost An ocean model and ocean-atmosphere coupling Land surface, snow, ice and vegetation Summary of principal climate model equations Climate system modeling • [Numerical representation of atmospheric and oceanic equations] [Finite-difference versus spectral models] [Time-stepping and numerical stability] [Staggered grids and other grids] [Parallel computer architecture] • [Parameterization of small scale processes] [Mixing and surface fluxes] [Dry convection] [Moist convection] Sea ice and snow • [The hierarchy of climate models] • Climate simulations and climate drift • Evaluation of climate model simulations for present day climate Atmospheric model climatology from specified SST Climate model simulation of climatology Simulation of ENSO response Chapter 6 The Greenhouse Effect and Climate Feedbacks • The greenhouse effect in Earth’s current climate Global energy balance A global-average energy balance model with a one-layer atmosphere Infrared emissions from a layer The greenhouse effect: example with a completely IR-absorbing atmosphere The greenhouse effect in a one-layer atmosphere, global average model Temperatures from the one-layer energy balance model • Global warming I: example in the global-average energy balance model Increases in the basic greenhouse effect Climate feedback parameter in the one-layer global average model • Climate feedbacks Climate feedback parameter Contributions of various feedbacks to global average temperature response Climate sensitivity • The water vapor feedback • Snow/ice feedback • Cloud feedbacks • [Other feedbacks in the physical climate system] Stratospheric cooling [Lapse rate feedback] • [Climate response time in transient climate change] Transient climate change versus equilibrium response experiments A doubled-CO2 equilibrium response experiment The role of the oceans in slowing warming Climate sensitivity in transient climate change Chapter 7 Climate Model Scenarios for Global Warming • Greenhouse gases, aerosols and other climate forcings Scenarios, forcings and feedbacks Forcing by sulfate aerosols Commonly used scenarios • Global-average response to greenhouse warming scenarios • Spatial patterns of warming for time-dependent scenarios Comparing projections of different climate models Multi-model ensemble averages Poleward amplification of warming Summary of spatial patterns of the response • Climate response time in transient climate change Transient climate change versus equilibrium response experiments A doubled-CO2 equilibrium response experiment The role of the oceans in slowing warming Climate sensitivity in transient climate change • Ice, sea level, extreme events Sea ice and snow Land ice Extreme events • Summary: the best-estimate prognosis • Climate change observed to date Temperature trends & natural variability: scale dependence Is the observed trend consistent with natural variability or anthropogenic forcing? Sea ice, land ice, ocean heat storage and sea level rise • Emissions paths and their impacts • The road ahead