Download Coupled Ocean and Atmosphere Climate Dynamics

Coupled Ocean and
Atmosphere Climate Dynamics
ENVI3410
Module Information
• Module manager: Ian Brooks
– [email protected]
– Room 3.25 Environment (chemistry building)
• Lecturers:
– Ian Brooks : surface-atmosphere interactions
– Ken Carslaw / Stewart Davis : aerosol, clouds, and radiation
– Sarah-Jane Lock : ocean & cryosphere processes
• Webpage: www.env.leeds.ac.uk/~ibrooks/envi3410
– Lecture slides, animations, etc
– links to background material
– Access to online climate model
ENVI3410: Coupled Ocean & Atmsophere Climate Dynamics
• 15 Lectures
– Tuesday 3-4pm
EC Stoner 08.60
– Thursday 12-1pm
Baines Wing 1.15
• Assessment
– Exam: 60%
– Climate modelling
exercise: 40%
• 2 workshops in
computer cluster
– Textiles G34 cluster
– 1) Thursday Oct. 26,
11:00-13:00
– 2) Thursday Nov 16
11:00-13:00
N.B. These replace
the Thursday lectures.
ENVI3410: Coupled Ocean & Atmsophere Climate Dynamics
Outline
• The coupling and feedback systems between the atmosphere
and ocean that is driving energy transfer and climate change.
• Concepts of surface exchange of heat and greenhouse gas
transfer between atmosphere / land / ocean / biosphere.
• The role of clouds in the climate system, including their effect
on radiation and energy transfer.
• How clouds are parameterised in climate models and the very
large uncertainties in their effect on climate change.
• Changing aspects of water mass formation and its implication
on the oceans thermohaline circulation and climate.
• Cause and consequence of sea ice recession on the
atmosphere and global sea levels.
ENVI3410: Coupled Ocean & Atmsophere Climate Dynamics
Suggested Reading
• IPCC Third Assessment Report - Climate Change 2001: The
Scientific Basis. 2001, Cambridge University Press. [available free
online at http://www.grida.no/climate/ipcc_tar/wg1/index.htm]
• Global warming. John Houghton, Rep. Prog. Phys. 68 (2005)
1343–1403. Online at http://stacks.iop.org/RoPP/68/1343
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TEXT BOOKS:
The Physics of Atmospheres. John Houghton, 2002, Cambridge
University Press.
Boundary Layer Meteorology. Roland Stull,1988, Kluwer
Academic Press.
The Atmosphere and Ocean: A Physical Introduction. Neil Wells,
1997, Wiley.
Human Impacts on Weather and Climate. William Cotton & Roger
Pielke, 1995, Cambridge University Press.
ENVI3410: Coupled Ocean & Atmsophere Climate Dynamics
Online Resources
• Intergovernmental Panel on Climate Change:
http://www.ipcc.ch/index.html
• Real Climate – comment on climate issues by climate
scientists. http://www.realclimate.org/
• SOLAS program – ocean-atmosphere exchange &
climate processes: http://www.uea.ac.uk/env/solas/
• US National Snow and Ice Data Centre: http://nsidc.org/
ENVI3410: Coupled Ocean & Atmsophere Climate Dynamics
Climate & Climate Change
• Climate change is often considered
synonymous with global warming – a
result of human activities. This is an oversimplification.
• Climate processes are many, and interact
in complex ways, not always obvious.
Feedbacks between different processes
may amplify or inhibit the first order
effects.
ENVI3410: Coupled Ocean & Atmsophere Climate Dynamics
Climate System
The climate systems consists of 5 major components:
• Atmosphere
• Cryosphere
– Includes gaseous
atmosphere, clouds,
aerosols
• Hydrosphere
– Polar icecaps, ice sheets,
glaciers, snow-covered
landmass, permafrost
• Land surface
– Oceans, rivers,
precipitation
– Surface type
• Biosphere
– Plants, animals,
plankton,…
External forcing: solar radiation, volcanic activity (addition
of aerosols & gases to atmosphere), human activity.
ENVI3410: Coupled Ocean & Atmsophere Climate Dynamics
Climate Processes
(Houghton, Rep. Prog. Phys. 68 (2005) 1343–1403)
ENVI3410: Coupled Ocean & Atmsophere Climate Dynamics
IPCC : http://www.ipcc.ch/present/graphics.htm
ENVI3410: Coupled Ocean & Atmsophere Climate Dynamics
IPCC : http://www.ipcc.ch/present/graphics.htm
ENVI3410: Coupled Ocean & Atmsophere Climate Dynamics
Sea surface temperature anomalies relative to 1961-1990 mean for North
Atlantic (tropical: blue, extra-tropical : red, black lines are 10-year running
averages).
(Trenberth, 2005: Uncertainty in Hurricanes and Global Warming. Science, vol 208, doi: 10.1126/science.1112551)
ENVI3410: Coupled Ocean & Atmsophere Climate Dynamics
CO2 concentration (grey line) and mean polar temperature difference from now
(Black line) from Vostock ice core measurements. CO2 concentration estimates
projected forward to 2100. (Houghton, Rep. Prog. Phys. 68 (2005) 1343–1403)
ENVI3410: Coupled Ocean & Atmsophere Climate Dynamics
Northern Hemisphere ice extent is decreasing at a rate of -2.7 ± 0.5% per
decade. The rate of decline in summer (-4.9 ± 1.5%) is considerably greater
than that for winter (-1.8 ± 0.6%)
ENVI3410: Coupled Ocean & Atmsophere Climate Dynamics
ENVI3410: Coupled Ocean & Atmsophere Climate Dynamics
ENVI3410: Coupled Ocean & Atmsophere Climate Dynamics
2002 : record minimum in Arctic sea ice concentration
ENVI3410: Coupled Ocean & Atmsophere Climate Dynamics
Change of climate state
• Changes to either the
mean or variance in
climate state both
lead to increased
occurrence of
extreme conditions.
ENVI3410: Coupled Ocean & Atmsophere Climate Dynamics
• There is substantial evidence that climate is changing:
increasing globally averaged temperature, decreasing
ice extent, changing precipitation patterns,…
• There is also substantial evidence that human activity
has increased the levels of ‘greenhouse’ gases in the
atmosphere.
• There are strong correlations between greenhouse gas
concentrations and temperature, and basic physics
suggests higher concentrations should lead to warming,
but…
– How can we be sure what the real relationships are between our
activities and climate?
ENVI3410: Coupled Ocean & Atmsophere Climate Dynamics
ENVI3410: Coupled Ocean & Atmsophere Climate Dynamics
• The remainder of this course will examine
(some of) the many and varied processes
that control climate, their response to
anthropogenic forcing, and the
uncertainties in our understanding of them.
ENVI3410: Coupled Ocean & Atmsophere Climate Dynamics