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Keeling's Mauna Loa data]

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  • Pat Neuman
    Q. Where may I obtain information on the properties of CO2? A. National Institute of Standards and Technology s web site
    Message 1 of 1 , Apr 11, 2005
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      Q. Where may I obtain information on the properties of CO2?
      A. National Institute of Standards and Technology's web site
      <http://webbook.nist.gov/cgi/cbook.cgi?Name=carbon+dioxide&Units=SI/>

      Q. I understand that atmospheric concentrations of CO2 are increasing,
      but when I look at a graph (for example, Keeling's Mauna Loa data
      </trends/co2/sio-mlo.htm>), the curve is squiggly. For half of each
      year, the concentrations increases, and for the other half it
      decreases. What is the reason for this?
      A. The variations within each year are the result of the annual cycles
      of photosynthesis and respiration. Photosynthesis, in which plants
      take up carbon dioxide from the atmosphere and release oxygen,
      dominates during the warmer part of the year; respiration, by which
      plants and animals take up oxygen and release carbon oxygen, occurs
      all the time but dominates during the colder part of the year.
      Overall, then, carbon dioxide in the atmosphere decreases during the
      growing season and increases during the rest of the year. Because the
      seasons in the northern and southern hemispheres are opposite, carbon
      dioxide in the atmosphere is increasing in the north while decreasing
      in the south, and vice versa. The magnitude of this cycle is strongest
      nearer the poles and approaches zero towards the Equator, where it
      reverses sign. The cycle is more pronounced in the northern hemisphere
      (which has relatively more land mass and terrestrial vegetation) than
      in the southern hemisphere (which is more dominated by oceans). The
      Carbon Cycle Group <http://www.cmdl.noaa.gov/ccg/> of the NOAA Climate
      Monitoring and Diagnostics Laboratory (CMDL)
      <http://www.cmdl.noaa.gov/>, has an excellent 3-dimensional
      illustration <http://www.cmdl.noaa.gov/ccg/figures/co2rug.gif> of how
      atmospheric CO2 varies with time year, season, and latitude. [RMC]

      Q. How may I perform CO2 calculations of the carbon dioxide system in
      seawater?
      A. The Program Developed for CO2 System Calculations (ORNL/CDIAC-105),
      recently released by Ernie Lewis, Department of Applied Science,
      Brookhaven National Laboratory, and Doug Wallace, Abteilung
      Meereschemie, Institut fuer Meereskunde, was developed to help
      calculate inorganic carbon speciation in seawater.
      This program, CO2SYS </oceans/co2rprt.html>, performs calculations
      relating parameters of the carbon dioxide system in seawater and
      freshwater by using two of the four measurable parameters of the CO2
      system [total alkalinity (TA), total inorganic CO2 (TCO2), pH, and
      either fugacity (fCO2) or partial pressure of CO2 (pCO2)] to calculate
      the other two parameters at a set of input conditions (temperature and
      pressure) and a set of output conditions chosen by the user.

      *Q. How long does it take for the oceans and terrestrial biosphere to
      take up carbon after it is burned? *

      *A. *For a single molecule of CO_2 released from the burning of a
      pound of carbon, say from burning coal, the time required is 3-4
      years. This estimate is based on the carbon mass in the atmosphere and
      up take rates for the oceans and terrestrial biosphere. Model
      estimates for the atmospheric lifetime of a large pulse of CO_2 has
      been estimated to be 50-200 years (i.e., the time required for a large
      injection to be completely dampened from the atmosphere).


      Q. What are the present tropospheric concentrations, global warming
      potentials (100 year time horizon), and atmospheric lifetimes of CO2,
      CH4, N2O, CFC-11, CFC-12, CFC-113, CCl4, methyl chloroform, HCFC-22,
      sulphur hexafluoride, trifluoromethyl sulphur pentafluoride,
      perfluoroethane, and surface ozone?
      A. View a table presenting data and source for current greenhouse gas
      concentrations </pns/current_ghg.html>.
      http://cdiac.esd.ornl.gov/pns/current_ghg.html

      excertpted from

      CDIAC </home.html>Oak Ridge National Laboratory

      (865) 574-0390 (865) 574-2232 (FAX) cdiac@... <mailto:cdiac@...>

      Data and Information Requests: (865) 574-3645
      http://cdiac.esd.ornl.gov/pns/faq.html


      --
      Sonya GarrettKoch PLoS Medicine
      The open-access general medical journal from the Public Library of
      Science
      Inaugural issue: Autumn 2004 Share your discoveries with the world.
      http://www.plosmedicine.org


      --
      Sonya GarrettKoch PLoS Medicine
      The open-access general medical journal from the Public Library of
      Science
      Inaugural issue: Autumn 2004 Share your discoveries with the world.
      http://www.plosmedicine.org
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