Atmospheric COAtmospheric CO22 & & Temperature – what is Temperature – what is

normal?normal?Presented by Julie Brigham-Presented by Julie Brigham-

Grette and Beth CaissieGrette and Beth Caissie

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 Get at 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?

– 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

Monitoring of CO2 and other Greenhouse gases around the world

All get similar measurements

Why?

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.

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

http://earthobservatory.nasa.gov/Library/CarbonCycle/carbon_cycle4.html