Inversion of Atmospheric CO 2 Concentrations
301
least surface data. An overview of the OCO (Orbiting Carbon Observatory) is given
by Crisp et al. (2004). Houweling et al. (2004) compared OCO and SCIAMACHY.
In particular they found that techniques based on near-infrared (rather than thermal infrared) were preferable because of better performance near the surface.
The OCO launch failure in February 2009 has been a major setback to carbon cycle
studies.
11.4 CO 2
11.4.1 CONTEXT
Section 14.1 of Enting (2002) gives an overview of the progression of key ideas about
the carbon cycle (based on pers. comm. from Roger Francey). This can be summarized (and updated) to give
Before 1958: the growth in CO
•
2 was not well established.
Post-1958: about half of the fossil CO
•
2 was found to remain in the
atmosphere.
Circa 1975: models calibrated using
•
14 C indicated an imbalance that became
known as the “missing sink.”
Circa 1980: estimates of large emissions from deforestation (subsequently
•
revised downwards) exacerbated these discrepancies.
1983: Response function analysis (Oeschger and Heimann, 1983) pointed
•
out that present atmospheric budget depends, in part, on past imbalances—
the budget for a particular time cannot be considered in isolation from previous changes.
1985 Onwards: ice-core data provide the requisite information about past
•
changes, allowing a deconvolution of past emissions (Siegenthaler and
Oeschger, 1987).
Circa 1990: confl icting views of the carbon budget: low ocean uptake ver•
sus high ocean uptake from both inversion (Tans et al., 1990; Keeling et al.,
1989) and isotopic (Tans et al., 1993; Quay et al., 1992) studies.
1992: Much of the discrepancy resolved by Sarmiento and Sundquist (1992)
•
by clarifying distinctions between different type of atmospheric budget as
described below—a consistent analysis of the CO 2 / 13 CO 2 budget was produced by Heimann and Maier-Reimer (1996).
Circa 1995:
•
13 C records indicated large interannual variability (Francey
et al., 1995; Keeling et al., 1995).
Mid-1990s: additional constraints were provided by measurements of trends
•
in O 2 /N 2 obtained by a variety of techniques (Keeling et al., 1993; Bender
et al., 1994; Manning et al., 1999).
Circa 1995: concern about the “rectifi er effect” that is, mean gradients
•
induced by diurnal and seasonal covariance between fl uxes and transport,
and the extent to which inversions were biased due to models underestimating the effect (Denning et al., 1995).
© 2010 by Taylor and Francis Group, LLC
301
least surface data. An overview of the OCO (Orbiting Carbon Observatory) is given
by Crisp et al. (2004). Houweling et al. (2004) compared OCO and SCIAMACHY.
In particular they found that techniques based on near-infrared (rather than thermal infrared) were preferable because of better performance near the surface.
The OCO launch failure in February 2009 has been a major setback to carbon cycle
studies.
11.4 CO 2
11.4.1 CONTEXT
Section 14.1 of Enting (2002) gives an overview of the progression of key ideas about
the carbon cycle (based on pers. comm. from Roger Francey). This can be summarized (and updated) to give
Before 1958: the growth in CO
•
2 was not well established.
Post-1958: about half of the fossil CO
•
2 was found to remain in the
atmosphere.
Circa 1975: models calibrated using
•
14 C indicated an imbalance that became
known as the “missing sink.”
Circa 1980: estimates of large emissions from deforestation (subsequently
•
revised downwards) exacerbated these discrepancies.
1983: Response function analysis (Oeschger and Heimann, 1983) pointed
•
out that present atmospheric budget depends, in part, on past imbalances—
the budget for a particular time cannot be considered in isolation from previous changes.
1985 Onwards: ice-core data provide the requisite information about past
•
changes, allowing a deconvolution of past emissions (Siegenthaler and
Oeschger, 1987).
Circa 1990: confl icting views of the carbon budget: low ocean uptake ver•
sus high ocean uptake from both inversion (Tans et al., 1990; Keeling et al.,
1989) and isotopic (Tans et al., 1993; Quay et al., 1992) studies.
1992: Much of the discrepancy resolved by Sarmiento and Sundquist (1992)
•
by clarifying distinctions between different type of atmospheric budget as
described below—a consistent analysis of the CO 2 / 13 CO 2 budget was produced by Heimann and Maier-Reimer (1996).
Circa 1995:
•
13 C records indicated large interannual variability (Francey
et al., 1995; Keeling et al., 1995).
Mid-1990s: additional constraints were provided by measurements of trends
•
in O 2 /N 2 obtained by a variety of techniques (Keeling et al., 1993; Bender
et al., 1994; Manning et al., 1999).
Circa 1995: concern about the “rectifi er effect” that is, mean gradients
•
induced by diurnal and seasonal covariance between fl uxes and transport,
and the extent to which inversions were biased due to models underestimating the effect (Denning et al., 1995).
© 2010 by Taylor and Francis Group, LLC