Transcript Observing the Climate System

Monitoring Earth’s Climate System
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Current Weather
The Climate System
Climatic Anomalies and Feedback Loops
Observing the Climate System
Remote Sensing by Satellite
International Cooperation
Modeling Earth’s Climate System
For Next Class: Read Chapter 2 (pp. 50-66)
The Climate System
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System: entity whose components interact in an
orderly manner according to the laws of physics,
chemistry, and biology
Earth’s Climate System: defined as the totality of the
atmosphere, hydrosphere, biosphere and geosphere
and their interactions
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The Climate System
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Atmosphere
• Relatively thin envelope
of gases and tiny
suspended particles
surrounding the planet
• Divided into four layers:
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Troposphere
Stratosphere
Mesosphere
Thermosphere
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What is the Cryosphere and what are
some of its components?
What is the Cryosphere?
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Consists of various forms of frozen water at the
planet’s surface.
Components of the Cryosphere
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Snow – a collection of loosely bonded ice crystals
deposited from the atmosphere.
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Sea ice – any form of ice found at sea which has originated
from the freezing of sea water.
Glaciers – fallen snow that, over many years, compresses into
large, thickened ice masses that move.
Ice Sheet – mass of glacial land ice extending more than
50,000 square kilometers (20,000 square miles). The
Greenland and Antarctic Ice Sheets are the only two that
currently exist.
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Ice Shelves – thick slab of ice, attached to a coastline
and extending out over the ocean as a seaward
extension of an ice sheet or series of glaciers.
Iceberg – massive piece of ice of greatly varying
shape, protruding 5 m or more above sea-level,
which has broken away from a glacier and which
may be afloat or aground.
Driving Question
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How do climate scientists investigate the spatial and
temporal characteristics of climate, climate
variability and climate change?
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Climatic Anomalies
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Departures from the long-term average
• Do not occur with the same sign or magnitude everywhere
 Positive anomalies: above long-term averages
 Negative anomalies: below long-term averages
Westerly wave pattern
exhibits changes in
wavelength, amplitude, and
wave number
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Patterns in the westerlies
determine location of
weather extremes
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Climatic Anomalies
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Feedback Loops
• Many variables in the climate system are linked together
in complex forcing/response chains
• Interactions between variables involve feedback loops that
either amplify (positive feedback) or weaken (negative
feedback) fluctuations in climate
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Group Exercise
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Please discuss the difference between a positive and
negative feedback and provide examples of each.
Climatic Anomalies
Positive feedback
example
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Negative feedback
example
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Observing the Climate System
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In Situ Measurement
• Radiosonde: small instrument package equipped with a
radio transmitter that is carried aloft by a balloon
 Create soundings, or altitude readings of temperature,
air pressure and dewpoint
 Launched at 12 hour intervals
at ground stations world wide
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Radiosonde Release in Peru
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https://www.youtube.com/watch?v=J_6iQkwF9KA
Observing the Climate System
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In Situ Measurement
• Ships, buoys, floats, gliders, piloted
submersibles, autonomous
instrumented platforms and vehicles,
and undersea observatories provide
in situ ocean data
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Argo floats obtain
profiles of
temperature and
salinity in the ocean
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Sample plots
of floatderived
temperature
and salinity
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profiles
Observing the Climate System
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Remote Sensing by Satellite
• Sensors observing Earth from orbiting spacecraft measure
selected wavelengths of the electromagnetic radiation
reflected or emitted by the Earth’s climate system
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Observing the Climate System
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Remote Sensing by Satellite
• Electromagnetic radiation:
both a form of energy and a
means of energy transfer,
travel as waves
• Electromagnetic spectrum:
composed of different forms
of radiation
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Observing the Climate System
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Remote Sensing by Satellite
• Wavelength: distance between
successive wave crests
• Wave Frequency: number of
crests that passes a given point
in a specified period of time
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Observing the Climate System
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Remote Sensing by Satellite
• Satellites fly in either geostationary or polar orbits
Geostationary orbit
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Polar orbit
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Observing the Climate System
Visible Satellite Image
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Observing the Climate System
Infrared Satellite Image
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Observing the Climate System
Water Vapor Satellite Image
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International Cooperation in
Understanding Earth’s Climate System
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Intergovernmental Panel on Climate Change (IPCC)
• Formed in 1988 by the World Meteorological Organization
(WMO) and the United Nations Environmental Programme
(UNEP)
• Evaluates the state of climate science
• Composed of three working groups and a task force
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Modeling Earth’s Climate System
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Model: an approximate representation or simulation
of a real system, incorporating only the essential
features of a system while omitting details
considered non-essential or non-predictable
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Modeling Earth’s Climate System
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Physical Model: small-scale portrayal of a system
Numerical Model: consists of many mathematical
equations that simulate the processes under study
• Numerical weather and climate forecasting done at
National Centers for Environmental Prediction (NCEP)
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Modeling Earth’s Climate System
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Modeling Earth’s Climate System
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Short-Term Climate Forecasting
• NCEP’s Climate Prediction Center
• 30-day (monthly), 90-day (seasonal), and multi-seasonal
climate outlooks prepared
• Outlooks issued two weeks to 12.5 months in advance for
the coterminous U.S., Hawaii, and other Pacific islands
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Climate Prediction Center
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http://www.cpc.ncep.noaa.gov/products/forecasts/
Modeling Earth’s Climate System
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Long-Term Climate Forecasting
• Global Climate Model (GCM): simulates Earth’s climate
system
 Numerical models
 Boundary conditions can be changed to determine how
Earth adjusts to new conditions
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Questions?
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Take out a sheet of paper and write down any
questions about the material we covered in lecture
today.