Climatology and Paleoclimatology Paleoclimate Summary Climate Issues Structure ©2003, Perry Samson, University of Michigan

Climatology and Paleoclimatology Paleoclimate Summary Climate Issues Structure ©2003, Perry Samson, University of Michigan Percent of Atmosphere with Altitude Distribution of Air

Climatology and Paleoclimatology Paleoclimate Summary Climate Issues Structure ©2003, Perry Samson, University of Michigan

Climatology and Paleoclimatology Paleoclimate Summary Climate Issues Structure ©2003, Perry Samson, University of Michigan Density Atmospheric density is a measure of the mass of air molecules per volume of atmosphere.

Climatology and Paleoclimatology Paleoclimate Summary Climate Issues Structure ©2003, Perry Samson, University of Michigan

Climatology and Paleoclimatology Paleoclimate Summary Climate Issues Structure ©2003, Perry Samson, University of Michigan 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

Climatology and Paleoclimatology Paleoclimate Summary Climate Issues Structure ©2003, Perry Samson, University of Michigan 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

Climatology and Paleoclimatology Paleoclimate Summary Climate Issues Structure ©2003, Perry Samson, University of Michigan 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

Climatology and Paleoclimatology Paleoclimate Summary Climate Issues Structure ©2003, Perry Samson, University of Michigan 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

Climatology and Paleoclimatology Paleoclimate Summary Climate Issues Structure ©2003, Perry Samson, University of Michigan 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.

Climatology and Paleoclimatology Paleoclimate Summary Climate Issues Structure ©2003, Perry Samson, University of Michigan 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

Climatology and Paleoclimatology Paleoclimate Summary Climate Issues Structure ©2003, Perry Samson, University of Michigan Oxygen Isotopes 16 O: 99.8% of Oxygen 18 O: 0.2% of Oxygen parts per thousand

Climatology and Paleoclimatology Paleoclimate Summary Climate Issues Structure ©2003, Perry Samson, University of Michigan Oxygen Isotopes

Climatology and Paleoclimatology Paleoclimate Summary Climate Issues Structure ©2003, Perry Samson, University of Michigan Paleoclimatology Redistribution of oxygen isotopes: Interglacial

Climatology and Paleoclimatology Paleoclimate Summary Climate Issues Structure ©2003, Perry Samson, University of Michigan Paleoclimatology Redistribution of oxygen isotopes: Glacial 18 O in precipitation increases with increasing temperatures

Climatology and Paleoclimatology Paleoclimate Summary Climate Issues Structure ©2003, Perry Samson, University of Michigan Oxygen Isotopes For each 4.2°C increase in ocean temperature the  18 O ratio decreases by 1 o/oo

Climatology and Paleoclimatology Paleoclimate Summary Climate Issues Structure ©2003, Perry Samson, University of Michigan 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 m below the surface.

Climatology and Paleoclimatology Paleoclimate Summary Climate Issues Structure ©2003, Perry Samson, University of Michigan Changes in CO 2 ( ,000 YBP) Paleoclimatology Vostok NOW

Climatology and Paleoclimatology Paleoclimate Summary Climate Issues Structure ©2003, Perry Samson, University of Michigan Vostok

Climatology and Paleoclimatology Paleoclimate Summary Climate Issues Structure ©2003, Perry Samson, University of Michigan Enhanced fertilization theory

Climatology and Paleoclimatology Paleoclimate Summary Climate Issues Structure ©2003, Perry Samson, University of Michigan Biological Pump Atmospheric Deposition Riverine Deposition Burial in Sediments Upwelling Biomass Conversion CO 2

Climatology and Paleoclimatology Paleoclimate Summary Climate Issues Structure ©2003, Perry Samson, University of Michigan Feedback Mechanism: Biological Pump Global surface temperature Glacial ice volume Oceanic concentration of phosphate Shelf exposure Atmospheric CO 2 Sea level Riverine flux of phosphate Intensity of biological pump Equator-to-pole temperature gradient East-west wind speed Wind-borne flux of iron

Climatology and Paleoclimatology Paleoclimate Summary Climate Issues Structure ©2003, Perry Samson, University of Michigan 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 CO 2 and CH 4 concentrations through changes in the “biological pump”. 3.The changes in greenhouse gas concentrations then exaggerate the temperature changes over the earth.