Parameter
Proxy
Basic assumption(s/ Empirical relationship
:tCO,
12
[CdlCa)
I) distribution of Cd
[l:CO,)N
and
PO, are related
=166*([CdlCa)lDcd
*
(see 31)
rCa)
+ 0.25)/4*10-4
+
2) C and P
in organic
1946 1lJl101lkg,
matter are in Redfield
where [LCO,)N is
Ratio
[LCO,) normalized for
3) thus Cd and l:CO,
salinity variation and
are related
DCd is the partition
coefficient
PCO,
13
pCO, atm. (ice
I) equilibrium
pCO,., .... =pCO' .•
,mlK..
(surface
core)
between atm. and
where
K.. is a T -Socean)
surface ocean
dependent constant
2) atm.
pCO, is
(Henry's Law)
globally uniform
14
,1./i13c"..,
I)
see 11
An empirical
2) /i13C ofDIC is
relationship between the
reflected in calcite
of
surface-deep /i13C
signal carriers
contrast and the strength
of the biological pump in
combination with
a twolayer ocean model
(Broecker 1982)
15
/i"O
pCO, is correlated
pCO, =
f (/i"O)
with sealevel and can
thus
be traced as
global ice-volume
effect on
/i"O
16
/i"B
/i" B traces pH. In
see 9
combination with
alkalinity or l:CO"
pCO, can be
calculated
Selected reference(s)'
Precision (lab.
Accuracl
reDroducih.l
Lea (1995)
see 31
± 321lJl10llkg
(assuming Pl:CO, and
Cd-P
relationships
are constant
overtime)
(Lea
1995)
Barnola et al. (1987);
± 10 ppm
±0.32
Genthon et al. (1987);
1lJl10llkg
Jouzel et al. (1993);
at
20
'c
Blunier et al. (1998)
(assuming a
10 ppm
aCCUf. fOf ice
corepCO,)
Shackleton and Pisias
see 30
qualitative
(1985)
Berger et al. (1996);
see
2
semiBerger (1996)
quantitative
Sanyal
and Bijma
see 9
see 9
(subm)
Pitfalls
I) P-l:CO, and Cd-P relationships
may not be
constant over time and
vary locally (see 31)
2) dissolution effects (e.g. McCorkle
etal. 1995)
1) not necessarily equilibrium; airsea disequilibrium can be up to 200
ppm (Pisias et al. 1995)
2) contamination with dust
containing carbonate
3) requires temp. estimate
see
30
although pCO, and sea level are
both connected to climate change
(peltier and Tushingham 1989) is
their relationship not clearly
understood (decoupling!)
see 9
()
;:
(\)
'"
S
~
~
J
'" t:rl
~
~
~.
g,
~
(;'
'"
v.
'"
Proxy
Basic assumption(s/ Empirical relationship
:tCO,
12
[CdlCa)
I) distribution of Cd
[l:CO,)N
and
PO, are related
=166*([CdlCa)lDcd
*
(see 31)
rCa)
+ 0.25)/4*10-4
+
2) C and P
in organic
1946 1lJl101lkg,
matter are in Redfield
where [LCO,)N is
Ratio
[LCO,) normalized for
3) thus Cd and l:CO,
salinity variation and
are related
DCd is the partition
coefficient
PCO,
13
pCO, atm. (ice
I) equilibrium
pCO,., .... =pCO' .•
,mlK..
(surface
core)
between atm. and
where
K.. is a T -Socean)
surface ocean
dependent constant
2) atm.
pCO, is
(Henry's Law)
globally uniform
14
,1./i13c"..,
I)
see 11
An empirical
2) /i13C ofDIC is
relationship between the
reflected in calcite
of
surface-deep /i13C
signal carriers
contrast and the strength
of the biological pump in
combination with
a twolayer ocean model
(Broecker 1982)
15
/i"O
pCO, is correlated
pCO, =
f (/i"O)
with sealevel and can
thus
be traced as
global ice-volume
effect on
/i"O
16
/i"B
/i" B traces pH. In
see 9
combination with
alkalinity or l:CO"
pCO, can be
calculated
Selected reference(s)'
Precision (lab.
Accuracl
reDroducih.l
Lea (1995)
see 31
± 321lJl10llkg
(assuming Pl:CO, and
Cd-P
relationships
are constant
overtime)
(Lea
1995)
Barnola et al. (1987);
± 10 ppm
±0.32
Genthon et al. (1987);
1lJl10llkg
Jouzel et al. (1993);
at
20
'c
Blunier et al. (1998)
(assuming a
10 ppm
aCCUf. fOf ice
corepCO,)
Shackleton and Pisias
see 30
qualitative
(1985)
Berger et al. (1996);
see
2
semiBerger (1996)
quantitative
Sanyal
and Bijma
see 9
see 9
(subm)
Pitfalls
I) P-l:CO, and Cd-P relationships
may not be
constant over time and
vary locally (see 31)
2) dissolution effects (e.g. McCorkle
etal. 1995)
1) not necessarily equilibrium; airsea disequilibrium can be up to 200
ppm (Pisias et al. 1995)
2) contamination with dust
containing carbonate
3) requires temp. estimate
see
30
although pCO, and sea level are
both connected to climate change
(peltier and Tushingham 1989) is
their relationship not clearly
understood (decoupling!)
see 9
()
;:
(\)
'"
S
~
~
J
'" t:rl
~
~
~.
g,
~
(;'
'"
v.
'"