climatology and paleoclimatology paleoclimate summary climate issues structure ©2003, perry samson,...
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©2003, Perry Samson, University of Michigan
Climatology and Paleoclimatology
Paleoclimate
Summary
Climate
Issues
Structure
Climatology and Paleoclimatology
Paleoclimate
Summary
Climate
Issues
Structure
©2003, Perry Samson, University of Michigan
Percent of Atmosphere
with Altitude
Distribution of Air
©2003, Perry Samson, University of Michigan
Climatology and Paleoclimatology
Paleoclimate
Summary
Climate
Issues
Structure
©2003, Perry Samson, University of Michigan
Climatology and Paleoclimatology
Paleoclimate
Summary
Climate
Issues
Structure
Density
Atmospheric density is a measure of the mass of air molecules per volume of atmosphere.
©2003, Perry Samson, University of Michigan
Climatology and Paleoclimatology
Paleoclimate
Summary
Climate
Issues
Structure
©2003, Perry Samson, University of Michigan
Climatology and Paleoclimatology
Paleoclimate
Summary
Climate
Issues
Structure
Pressure
Temperature
Force exerted per unit area. In most sciences the standard unit of measure is the pascal (Pa), but in meteorology either millibar (1 mb = 100 Pa) or inches of Mercury (in Hg = 3386 Pa) are used.
A measure of the average kinetic energy of the molecules comprising a substance.
The Structure of the Atmosphere
©2003, Perry Samson, University of Michigan
Climatology and Paleoclimatology
Paleoclimate
Summary
Climate
Issues
Structure
Pressure
Temperature
Force exerted per unit area. In most sciences the standard unit of measure is the pascal (Pa), but in meteorology either millibar (1 mb = 100 Pa) or inches of Mercury (in Hg = 3386 Pa) are used.
A measure of the average kinetic energy of the molecules comprising a substance.
The Structure of the Atmosphere
©2003, Perry Samson, University of Michigan
Climatology and Paleoclimatology
Paleoclimate
Summary
Climate
Issues
Structure
• The thermosphere is the fourth layer of the Earth's atmosphere and is located above the mesosphere.
• The air is extremely thin in the thermosphere. A small change in energy can cause a large change in temperature.
• When the sun is active, the thermosphere can heat up to 1,500°C or higher.
• The Earth's thermosphere also includes the region of the atmosphere called the ionosphere. The ionosphere is a region of the atmosphere that is filled with charged particles.
Thermosphere
©2003, Perry Samson, University of Michigan
Climatology and Paleoclimatology
Paleoclimate
Summary
Climate
Issues
Structure
In the Earth's mesosphere, the air is relatively mixed together and the temperature decreases with altitude.
The atmosphere reaches its coldest temperature of around -90°C in the mesosphere. This is also the layer in which a lot of meteors burn up while entering the Earth's atmosphere.
Mesosphere
©2003, Perry Samson, University of Michigan
Climatology and Paleoclimatology
Paleoclimate
Summary
Climate
Issues
Structure
In the Earth's stratosphere, the temperature increases with altitude. On Earth, ozone causes the increasing temperature in the stratosphere.
Stratosphere
Ozone is concentrated around an altitude of 25 kilometers in the “ozone layer.” The ozone molecules absorb dangerous kinds of sunlight, which heats the air around them.
©2003, Perry Samson, University of Michigan
Climatology and Paleoclimatology
Paleoclimate
Summary
Climate
Issues
Structure
The troposphere is the layer in contact with the Earth’s surface and hence its temperature structure is predicated by energy transmitted to and from the surface.
Troposphere
©2003, Perry Samson, University of Michigan
Climatology and Paleoclimatology
Paleoclimate
Summary
Climate
Issues
Structure
Oxygen Isotopes
16O: 99.8% of Oxygen18O: 0.2% of Oxygen
parts per thousand
©2003, Perry Samson, University of Michigan
Climatology and Paleoclimatology
Paleoclimate
Summary
Climate
Issues
Structure
Oxygen Isotopes
©2003, Perry Samson, University of Michigan
Climatology and Paleoclimatology
Paleoclimate
Summary
Climate
Issues
Structure
PaleoclimatologyRedistribution of oxygen isotopes:
Interglacial
©2003, Perry Samson, University of Michigan
Climatology and Paleoclimatology
Paleoclimate
Summary
Climate
Issues
Structure
PaleoclimatologyRedistribution of oxygen isotopes:
Glacial
18O in precipitation increases with increasing temperatures
©2003, Perry Samson, University of Michigan
Climatology and Paleoclimatology
Paleoclimate
Summary
Climate
Issues
Structure
Oxygen Isotopes
For each 4.2°C increase in ocean temperature the 18O ratio
decreases by 1 o/oo
©2003, Perry Samson, University of Michigan
Climatology and Paleoclimatology
Paleoclimate
Summary
Climate
Issues
Structure
Sintering: Air moves freely through snow and ice in the first 15 m of an ice sheet, but movement is restricted below this with air bubbles eventually sealed off completely about 50-100 m below the surface.
©2003, Perry Samson, University of Michigan
Climatology and Paleoclimatology
Paleoclimate
Summary
Climate
Issues
Structure
Age (Myr BP)
180
200
220
240
260
280
300
320
340
360
380
25 20 15 10 5 0
(e)
180
200
220
240
260
280
300
320
340
360
380
Age (kyr BP)
0100200300400
Changes in CO2 (0 - 450,000 YBP)
Paleoclimatology
VostokNOW
©2003, Perry Samson, University of Michigan
Climatology and Paleoclimatology
Paleoclimate
Summary
Climate
Issues
Structure
Vostok
©2003, Perry Samson, University of Michigan
Climatology and Paleoclimatology
Paleoclimate
Summary
Climate
Issues
Structure
Enhanced fertilization theory
©2003, Perry Samson, University of Michigan
Climatology and Paleoclimatology
Paleoclimate
Summary
Climate
Issues
Structure
Biological Pump
Atmospheric Deposition
RiverineDeposition
Burial in Sediments
Upwelling
Biomass Conversion
COCO22 COCO22
©2003, Perry Samson, University of Michigan
Climatology and Paleoclimatology
Paleoclimate
Summary
Climate
Issues
Structure
Feedback Mechanism: Biological Pump
Global surfacetemperature
Glacialice volume
Oceanic concentrationof phosphate
Shelfexposure
AtmosphericCO2
Sea level
Riverine fluxof phosphate
Intensity ofbiological pump
Equator-to-poletemperature gradient
East-westwind speed
Wind-borneflux of iron
©2003, Perry Samson, University of Michigan
Climatology and Paleoclimatology
Paleoclimate
Summary
Climate
Issues
Structure
Lessons from Vostok
1. Past changes in climate have often been triggered by changes in orbital characteristics.
2. These initial changes are then amplified by changes in CO2 and CH4 concentrations through changes in the “biological pump”.
3. The changes in greenhouse gas concentrations then exaggerate the temperature changes over the earth.