Princeton University - The Graduate School

The Program in Atmospheric and Oceanic Sciences (AOS) offers graduate study under the sponsorship of the Department of Geosciences. An understanding of the complex behavior of the atmosphere and oceans requires a balanced effort in theoretical analysis, numerical modeling, laboratory experiments and analysis of observations.

The AOS program benefits from the research capabilities of the Geophysical Fluid Dynamics Laboratory (GFDL) of the National Oceanic and Atmospheric Administration, which is located on the Forrestal campus. GFDL has a major in-house supercomputer facility to which students have direct access for their research. Many GFDL scientists are active in the AOS program as lecturers with the rank of assistant through full professor. The geosciences department, with its activities in physical and chemical oceanography, paleoceanography and paleoclimatology, collaborates with GFDL in providing an academic program of courses and seminars.

Admission
A candidate for admission should apply to the program, and upon acceptance is placed as a program student in the Department of Geosciences. Preference is given to applicants with strong preparation in the physical sciences, such as applied mathematics, chemistry, engineering science, fluid dynamics, geophysics and physics. Previous experience in meteorology or oceanography may be helpful, but does not weigh as heavily in the admission decision as the quality of the basic preparation. Applicants are required to take the aptitude and advanced tests of the Graduate Record Examination.

Financial Aid
Graduate students in the AOS program are normally provided with funding for tuition and stipends (living expenses). Funding comes from a variety of sources, including outside (external) fellowships, research grants, GFDL funds, teaching positions (AIs) and the University. In return for support, graduate students are expected to make adequate progress on research and course work (as determined by their advisory committees) .

Plan of Study
Upon entering the program, the student is advised by the graduate work committee until he or she selects an adviser from the program staff. The plan of study is flexible and is tailored to the needs of the individual, but during the first two years it normally concentrates on course work and independent preparation for the general examination.

The highly flexible graduate program offers students opportunities for research and courses in a wide variety of disciplines related to climate, atmospheric sciences and oceanography, including geophysical fluid dynamics, atmospheric physics, atmospheric chemistry, biogeochemistry of the land and ocean, atmospheric modeling, ocean modeling, climate dynamics, global climate change and paleo-climate. Through the Science, Technology and Environmental Policy (STEP) Program at the Woodrow Wilson School of Public and International Affairs and the Princeton Environmental Institute, students can explore climate- [and air pollution-] related policy.

General Examination
The general examination, which is taken by the end of the second year, probes the student’s knowledge of basic geophysical fluid dynamics and certain specialty areas through written examinations and a research seminar presentation. The purpose of the research seminar is to demonstrate the student’s ability to work independently and analyze a research problem.

Students qualify for the award of the Master of Arts (M.A.) by successfully completing all course work and passing the written portion of the general examination.

Teaching Requirements
Students are encouraged to teach as an assistant in instruction (AI) for two semesters during their time at Princeton, and teaching for at least one semester is a requirement. This normally comes after the general exam, in the third and fourth years in the program.

Dissertation and Final Public Oral Examination
The dissertation must show that a candidate has technical mastery in the chosen field and is capable of independent research. The dissertation is expected to be a positive contribution that is of publishable quality. The final public oral examination is a broad examination in the field of study.

Atmospheric and Oceanic Sciences

AOS 522/GEO 522    Inverse methods: theory and applications
      David M. Medvigy

Course treats inverse problems from both theoretical and applied perspectives. Students learn to develop the necessary theory to pose, interpret, and solve inverse problems, focusing on topics including error characterization, linear and non-linear methods, approximations, Kalman filters, use of prior constraints, and observing system design. Concepts are illustrated with examples from the current literature on the Earth's carbon cycle.

AOS 523    Water in the Atmosphere
      Stephan Fueglistaler

Course analyzes observations and discusses theoretical approaches (both basic concepts and novel ideas) to the problem. Specifically, it considers how the general circulation, mesoscale dynamics, and cloud microphysics interact to determine the atmospheric water vapor distributions.

AOS 527/GEO 527    Atmospheric Radiative Transfer
      Venkatachalam Ramaswamy

The structure and composition of terrestrial atmospheres. The fundamental aspects of electromagnetic radiation, absorption and emission by atmospheric gases, optical extinction by particles, the roles of atmospheric species in the Earth's radiative energy balance, the perturbation of climate due to natural and anthropogenic causes, and satellite observations of climate systems are also studied.

AOS 537/GEO 537    Atmospheric Chemistry
      Hiram Levy

Natural gas phase and heterogeneous chemistry in the troposphere and stratosphere, with a focus on elementary chemical kinetics; photolysis processes; oxygen, hydrogen, and nitrogen chemistry; transport of atmospheric trace species; tropospheric hydrocarbon chemistry and stratospheric halogen chemistry; stratospheric ozone destruction; local and regional air pollution, and chemistry-climate interactions are studied.

AOS 547    Atmospheric Thermodynamics and Convection
      Leo Donner

The thermodynamics of water-air systems. The course gives an overview of atmospheric energy sources and sinks. Planetary boundary layers, closure theories for atmospheric turbulence, cumulus convection, interactions between cumulus convection and large-scale atmospheric flows, cloud-convection-radiation interactions and their role in the climate system, and parameterization of boundary layers and convection in atmospheric general circulation models are also studied.

AOS 547/GEO 547    Atmospheric Thermodynamics and Convection
      Leo Donner

The thermodynamics of water-air systems, an overview of atmospheric energy sources and sinks, planetary boundary layers, closure theories for atmospheric turbulence, cumulus convection, inter-actions between cumulus convection and large-scale atmospheric flows, cloud-convection-radiation interactions and their role in the climate system, and parameterization of boundary layers and convection in atmospheric general circulation models are studied.

AOS 571    Introduction to Geophysical Fluid Dynamics
      Stephen T. Garner

Physical principles fundamental to the theoretical, observational, and experimental study of the atmosphere and oceans; the equations of motion for rotating fluids; hydrostatic and Boussinesq approximations; circulation theorem; and conservation of potential vorticity; scale analysis, geostrophic wind, thermal wind, quasigeostrophic system; and geophysical boundary layers.

AOS 572    Atmospheric and Oceanic Wave Dynamics
      Sonya A. Legg, Isidoro Orlanski

Observational evidence of atmospheric and oceanic waves; laboratory simulation. Surface and internal gravity waves; dispersion characteristics; kinetic energy spectrum; critical layer; forced resonance; and instabilities. Planetary waves: scale analysis; physical description of planetary wave propagation; reflections; normal modes in a closed basin. Large-scale baroclinic and barotropic instabilities, Eady and Charney models for baroclinic instability, and energy transfer.

AOS 573    Physical Oceanography
      Geoffrey K. Vallis

Response of the ocean to transient and steady winds and buoyancy forcing. A hierarchy of models from simple analytical to realistic numerical models is used to study the role of the waves, convection, instabilities, and other physical processes in the circulation of the oceans.

AOS 575    Numerical Prediction of the Atmosphere and Ocean
      Robert W. Hallberg

Barotropic and multilevel dynamic models; coordinate systems and boundary conditions; finite difference equations and their energetics; spectral methods; water vapor and its condensation processes; orography, cumulus convection, subgrid-scale transfer, and boundary layer processes; meteorological and oceanographic data assimilation; dynamic initialization; verification and predictability; and probabilistic forecasts.

AOS 576/APC 576    Current Topics in Dynamic Meterology
      Isaac M. Held

An introduction to topics of current interest in the dynamics of large-scale atmospheric flow. Possible topics include wave-mean flow interaction and nonacceleration theorems, critical levels, quasigeostrophic instabilities, topographically and thermally forced stationary waves, theories for stratospheric sudden warmings and the quasi-biennial oscillation of the equatorial stratosphere, and quasi-geostrophic turbulence.

AOS 577/GEO 577    Weather and Climate Dynamics
      Ngar-Cheung Lau

An examination of various components of the Earth's climate system. Emphasis is placed on the role of radiative processes, climate feedbacks and sensitivity, and the nature of energy and water balances. The dynamics and physical interpretation of principal tropospheric circulation systems, including stationary and transient phenomena observed in middle and low latitudes, are studied. Phenomena of topical interest, such as El Niño, seasonal climate anomalies, and natural and anthropogenic climate changes, are also reviewed.

AOS 578/GEO 578    Chemical Oceanography
      Jorge L. Sarmiento

The chemical composition of the oceans and the nature of the physical and chemical processes governing this composition in the past and the present. The cycles of major and minor oceanic constituents, including interactions with the biosphere, and at the ocean-atmosphere and ocean-sediment interfaces.

AOS 580    Special Topics
      Staff

Topics covered in recent years include baroclinic instability theory, convection; paleoclimatology, atmospheric radiative transfer, isotope geochemistry, El Niño and related phenomena, tropospheric chemistry, and ocean dynamics in the Southern Hemisphere.