Im working on atmospheric chemistry. It is impossible, the questions are so vague and I haven't a clue where to start on any of them. Here is an
this is only 1 question of many) Any one got any answers? (j/k)
6. 8 Sinks of atmospheric CO2 deduced from changes in atmospheric O2 Measurement of the long-term trend in atmospheric O2 has been used to determine
the fate of fossil fuel CO2 in the atmosphere and the relative
importance of uptake by the ocean and by the biosphere. We describe here the principle of the method.
1. We first examine the O2:CO2 stoichiometry of the individual CO2 sources and
1.1 The mean stoichiometric composition of fossil fuel burned is CH1.6 (1 part carbon for 1.6 parts hydrogen). We view fossil fuel combustion as a
stoichiometric reaction where CH1.6 is oxidized by O2 to yield CO2 and H2O. Show that 1.4 moles of O2 are consumed per mole of CO2 emitted by fossil
1.2 How many moles of O2 are produced per mole of CO2 taken up by the biosphere?
1.3 Is any O2 produced or consumed when CO2 dissolves into the ocean as CO2.H2O/HCO3-/CO32- ?
2. We are now equipped to use the method. Observations from July 1991 to July
1994 (3 years) indicate a 3.2 ppmv increase in atmospheric CO2 and a 8.8 ppmv
decrease in atmospheric O2. Global fossil fuel combustion during this period
was 6.3x1012 kg C yr-1.
2.1 If fossil fuel were the only process affecting CO2 and O2 concentrations during the 1991-1994 period, by how much would these concentrations
2.2 From the observed trends of atmospheric CO2 and O2, determine the fraction of CO2 emitted from fossil fuel combustion over the 3-year period that
taken up by the biosphere, (b) dissolved in the oceans, (c) accumulated in the atmosphere.
[Source: Keeling, R.F., et al., Global and hemispheric CO2 sinks deduced from
changes in atmospheric O2 concentrations, Nature, 381, 218-221, 1996.]
[Edited on 23-10-2003 by jrod]