Research inAtmospheric, Oceanic andPlanetary Physics
at Oxford, UKDavid Andrews

Before I start…
• Many thanks to Prof Hirooka for inviting
me to Fukuoka and arranging my trip !
• Many thanks also to you all forwelcoming me and my wife here, andlooking after us so well !

Yesterday at Dazaifu

Important notice:
Please stop me if I talk too fast !!

The Oxford Physics Department• Is one of the largest Physics departments in
the UK (and Europe)– Nearly 100 Faculty– Over 600 undergraduate students• Has 6 sub-departments:– Astrophysics– Atmospheric, Oceanic and Planetary Physics (AOPP)– Atomic and Laser Physics– Condensed Matter Physics (including Biophysics)– Particle Physics– Theoretical Physics

AOPP is one of the smaller
Sub-Departments
We have about 75 members:
12 Senior Faculty members~ 25 Post-Doctoral Researchers~ 25 PhD Students+ support staff

Head: Professor Peter Read

AOPP has a broad spectrumof interests:

Building space
instruments

Dataanalysis

Modellingandinterpretation

Main research areas:• Observations from space of– Earth’s atmosphere– Other planets’ atmospheres (Venus, Mars,Jupiter, Saturn, Titan…)• Modelling of– Earth’s atmosphere and oceans, including

Climate Change– Other planets’ atmospheres

Space Instrument
Development and Testing(Earth Observation)(John Barnett)

High-resolution Dynamics Limb Sounder (HIRDLS), in
collaboration with U of Colorado, etc.

HIRDLS inAOPP’s 2.2m
testchamber…

…andintegrated
onto
NASA’sAura
spacecraft

HIRDLS data, 17 July 2007
oTemperature at 63 S in the stratosphere

Note wavy
structure inupper
stratosphere:
inertia-gravity
waves?

[Diagram courtesy of J J Barnett]

Data Analysis from Space
Instruments (Earth)(Don Grainger, Anu Dudhia)

Retrievals Using High
Resolution Infrared
Spectral Measurements(e.g. MIPAS)

Retrievals Using Nadir
Imager Radiometers (e.g.
ATSR series)

Also retrieval of aerosol and cloud; laboratory and field studies(volcanic ash, aircraft emissions)Space Instrument
Development and Testing(Other planets)(Fred Taylor, Simon Calcutt, Neil Bowles)

Cassini at Saturn, including
AOPP’s CIRS instrument

AOPP’s planetary instrument lab

Data Analysis from Space
Instruments (Planets)(Pat Irwin)• Analysing data for Saturn and Titan
from Cassini/CIRS• Also data from Mars Climate Sounder
on Mars Reconnaissance Orbiter• And from VIRTIS instrument on Venus
Express• Also some ground-based measurementsof Jupiter (UKIRT)Probing Titan’s Polar Vortex with chemical tracers (Nick Teanby)• Confinement of tracer
species within polarvortex• Confinement is closer topole > 300km, i.e. above
stratopause• Tongues of enriched air
extend from pole toequator in stratosphere

Contours = Zonal Wind (m/s)
λ = photochemical lifetime

Climate Modelling(Myles Allen)• Quantifying uncertainty in climate predictions– Attributing external influences on climate.
– Quantifying the contribution of human influences tothe risk of specific, harmful weather events.
– Probabilistic climate forecasting, using very large
ensemble simulations with comprehensive climate
models, based on distributed computing: theclimateprediction.net initiative.

climateprediction.net(Myles Allen)

A distributed computing project toproduce predictions of the Earth's
climate up to 2080 and to test theaccuracy of climate models.
It addresses the uncertainty inpredictions of climate response torising levels of greenhouse gases, using‘perturbed physics’ ensembles.
Currently about 50,000 regularvolunteers are participating. Over 41
million years have been simulated.

Stainforth et al, Nature, 2005

climateprediction.net: the world’s largest
climate modelling facility?

814 in Japan>300,000 volunteers, >140 countries, >41M model-years

Hiro Yamazaki
and Kuniko Yamazaki are
postdocs in this groupClimate Processes(Philip Stier)Aerosols and clouds: their interactions, and role in theclimate system
Aerosol modelling: aerosol mixing
ratio isosurfaces colour-coded bycomponent as simulated with theaerosol-climate model ECHAM5-HAM.
Used together with measurement
data from satellites, aircraft andground-based instruments.

Geophysical Fluid Dynamics
Laboratory(Peter Read)
Laboratory studies of rotating fluid systems, together withnumerical models and data assimilation techniques

Rotating turntable (R Wordsworth)Modelling of other planets’
atmospheres(Peter Read)

Mars GCM (with French and Spanish groups): studies ofsynoptic-scale and planetary waves, dust storms, etc.

Also:
Jupiter/SaturnVenus…

Modelling of Oceans(David Marshall)• Joint research programme with theEarth Sciences Department• Main research interests:– Next Generation Ocean Model (with Imperial
College London, etc), based on finite elements andunstructured, dynamically-adaptive meshes.
– Meridional Overturning Circulation– Boundary Current Separation (e.g. Gulf Stream)

Uses of adaptive meshfor modelling complex
ocean circulation
processes

Adjustment of the Atlantic
thermohaline circulation. The graphshows eastern boundary
thermocline depth according toanalytical theory (solid line) andfrom a full numerical calculation(dots).
Wind-driven circulation in an idealised
rectangular basin. The mesh is adapted to
track the evolving flow structures.
Shading shows poleward velocity

About myself…
• Research– Have mainly worked on Middle AtmosphereDynamics in the past.
– But have recently been working on simple climatemodels…

• Administration and Teaching– Head of AOPP 2000-08. Now Ex-head!!
– Lecture to Physics undergraduates on Mathematics,Fluid Dynamics, Geophysical Fluid Dynamics– I am a Physics Tutor at one of the Oxford CollegesThis year (Oct 2008 – Sept 2009)
I am on sabbatical leave• Part of the time, I’m preparing a 2nd Edition ofmy book
“An Introduction to Atmospheric Physics”Main addition: a new chapter on the physics ofClimate Change.
• Also, catching up on unfinished research…

My research interests are mostly
theoretical/mathematical:• Middle Atmosphere Dynamics (but not
currently spending much time on this).
– Recent PhD student (Matthew Rigby) has
worked with Prof Lesley Gray (Reading) andme on modelling Stratospheric Sudden
Warmings, using intermediate GCMs.
– I am also collaborating with researchers inthe UK Met Office on applying EP
diagnostics to their non-hydrostatic GCM.

An example of Rigby’s
PhD work: sensitivityof modelledstratosphericwarmings to equatorial
wind profile:
N Polar temperature at32 km.
20-member ensembles,
perpetual January,
with equatorial zonal
wind relaxed toprofiles shown on right.

Targetequatorial
windprofiles

• Use of simple Energy
Balance climate model
to provide diagnostics
for IPCC climate
forecasting models(Andrews & Allen,Atmos. Sci. Lett. 9,7-12, 2008)
Clearest interpretation is interms offeedback response time
andtransient climate response

Two problems I am currently working on:• Simple energy-balance climate models,including oceanic upwelling and diffusion:– analytical solutions give insight into relevant
parameters (e.g several different timescales).

• Why is the radiative forcing due to CO2
roughly logarithmic in the increase inabsorber density?
– An interesting mathematical problem.