Spatial and temporal patterns of ocean acidification during the end-Permian mass extinction – an Earth system model evaluation - Volcanism and Global Environmental Change - page 298

(a) (b) (c)

3 ¥ 10 4

4 11000

3

10000

2.5

2

9000

2

1

8000

0

1.5

7000

−1

6000

1

−2

5000

−3

0.5

4000

−4

0

3000

−5

−6 −0.5 2000

−60 −40 −20 0 20 40 60 −60 −40 −20 0 20 40 60 −60 −40 −20 0 20 40 60

Time from onset of the extinction (kyr)

(d) (e) (f)

27 5.5 7.6

5

26 7.5

4.5

25 7.4

4

24 7.3

3.5

23 7.2

3

22 7.1

2.5

21 2 7

−60 −40 −20 0 20 40 60 −60 −40 −20 0 20 40 60 −60 −40 −20 0 20 40 60

Time from onset of the extinction (kyr)
Figure 19.3 Time-series of environmental parameters for our favorite scenario
(

13 C

flux of C; (b) total amount of
C released; (c) atmospheric p CO 2 ; (d) Global average sea surface temperature
( C);

Ω calcite ¼ 5, δ ¼ - 25 ‰ ), including (a)

(e) Sea-surface saturation state of calcite; (f) Global average ocean

surface pH.

Higher initial flux and amount of C added, as well as

higher peak p CO 2 and sea-surface temperature ( Figures 19.4a

Ω calcite values yield higher peak

calcite of the
ocean surface is most sensitive to initial saturation state for the smaller perturbation
associated with methane release; the initial buffering capacity is more rapidly
overwhelmed for larger perturbations ( Figures 19.4e , f ).

- d ). Ω

19.3.2 Surface Ω calcite and ocean-saturation-horizon response
To evaluate the spatial pattern of ocean-surface acidi

cation, we show the map

view of Ω calcite during peak C addition ( ~ 10 kyr after the onset of extinction)

for four selected scenarios ( Figure 19.5a o ) . Before we applied the perturbation,

high-latitude regions had lower saturation states ( Figure 19.5a

-

c ), but no under-
saturation is observed for the three prescribed initial saturation states. Under
elevated p CO 2 ( Figure 19.5d

-

- o ), the high latitudes tend to become undersaturated