atmospheric co 2 & temperature – what is normal? what is normal? presented by julie...
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Atmospheric COAtmospheric CO22 & & Temperature –Temperature –
what is normal?what is normal?Presented byPresented by
Julie Brigham-Grette and Beth CaissieJulie Brigham-Grette and Beth Caissie
July 2010
CO2 and Temperature—What is Normal?
• Concepts to Address before you begin– Climate vs. Weather– Greenhouse Gasses– The Carbon Cycle
• Play the game?• Photosynthesis and Decomposition
• Concepts to grasp During the Activity– How much of a change in CO2 concentration and
other GHGs is natural?
– What is the normal range of CO2 and temperature variability? How is normal defined in this context?
– What is the relationship between CO2 and global temperatures?
Season Change in the Biosphere
What causes this change in annual Carbon dioxide?
Seasonal changes cause up/downs in CO2 in the atmosphere
Especially driven by Northern Hemisphere. Spring - photosynthesis drops CO2, Fall - decomposition causes increase in CO2
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Monitoring of CO2 and other Greenhouse gases around the world
All get similar measurements
Why?
http://www.esrl.noaa.gov/gmd/ccgg/trends/
Global View CO2 http://www.esrl.noaa.gov/gmd/ccgg/globalview/co2/co2_int
ro.html
Thermal drilling on Quelccaya, 2003
Drilling in Greenland
http://passporttoknowledge.com/polar-palooza/pp09a.php
Video podcast from Polar Palooza
Summit Station, Greenland photo by Michael Morrison, GISP2 SMO, University of New Hampshire; NOAA Paleoslide SetCore: Eric Cravens, Assistant Curator, U.S. National Ice Core Laboratory;
Matt Nolan, UAF
Fossil air!
Trapped in the ice; records
past atmospher
e
Raynaud, 1992 Gases within bubbles = fossil atmospheric air
Firn-ice transition• Depth of transition depends on surfacetemperature and accumulation rate• Camp Century, Greenland:
68 m below ice sheet surface• Vostok, Antarctica:
100 m below ice sheet surface
Low precip. and cold = long time to make ice
High precip. and warm =short time to make ice
Classroom options:
Plot by hand on graph paper,Plot on computer using ExcelOverlay Temperature on CO2
Instructions for Excel on website
Analysis:
Defining amplitude, frequency, periodicity
Defining Normal?
Understanding the relationship between Greenhouse gases and temperature.
wikipedia art
Oxygen (8 protons)
16O 17O 18O
99.8% 0.04% 0.2%
Hydrogen (1 proton)
1H 2H (Deuterium) 3H (tritium) 99.98% 0.016% (bombs)
So, can make 9 isotopic combinations of H2O,e.g., 18 (1H2
16O) to 22 (2H218O)
“light water” “heavy water”In paleoclimate studies…1H1H16O to
1H218O
General Equation:
18O = 18O/16O sample - 18O/16O standard x 1000
18O/16O standard
Expressed in per mille (0/00)
Negative values = lower ratios = isotopically lighter(less 18O than 16O)
Positive values = higher ratios = isotopically heavier(more 18O than 16O)
Ice Sheet
ocean
0
-10
-20-30
-40-5018O isotopic depletion
In Sea In Ice
Glacials = enriched 18O depleted 18O
Interglacials = depleted 18O enriched 18O
Evaporation of more 16 O
Ice Sheet
ocean
D isotopic depletiondepends on temp of source area,Distance and processes during precipitation
Isotopic ratios are used to model temperature, at Vostok; empirically this is roughly:
Temperature (deg-C) = -55.5 + (δD + 440) / 6http://eesc.columbia.edu/courses/ees/climate/labs/vostok/
See also http://www.globalchange.umich.edu/gctext/Inquiries/Inquiriesby_Unit/Unit_8a.htm
mixed sources for data
http://earthobservatory.nasa.gov/Library/CarbonCycle/carbon_cycle4.html