Basic HTML Version
International Journal of Marine Science 2014, Vol.4, No.72, 1-7
http://ijms.biopublisher.ca
4
Figure 3 Monthly Δ
p
CO
2
between September 2004 – July 2005 plotted as a function of SST at the K1 CELAS site
enhanced sea surface
p
CO
2
(high DIC) is expected
following deep convective mixing and entrainment of
subsurface CO
2
enriched water to the surface of the
ocean. DIC supply to the surface is relatively low
during summertime owing to biology and
stratification of the ocean system. Additionally, sea-air
Δ
p
CO
2
flux variability digressed towards negative
flux following the outset of spring as the seawater
surface starts to warm up. Thus, the Δ
p
CO
2
flux
variability on an annual timescales generally indicates
a consistent undersaturation of the NW subpolar site.
Seasonal sink estimates for the wintertime of 2004
and 2005 were calculated as 4.86 ±0.15 and 4.15 ±
0.98 mol m
-2
CO
2
a
-1
respectively, while 0.29 ± 0.78
and 1.65 ±1.40 mol m
-2
a
-1
were obtained for 2003
and 2004 summertime (Table 1). The CO
2
uptake of
2.36 ± 2.07 and 2.28 ± 1.34 mol m
-2
CO
2
a
-1
were
computed for the autumn of 2003 and 2004
respectively. Based on the
in situ
observed data
available, the short-term interseasonal CO
2
sink of the
Porcupine Abyssal Plain time series site is estimated
to have decreased by approximately 82.4, 3.6 and
17.2% for summer, autumn and wintertime
respectively (Figure 4). Overall, there was persistent
p
CO
2
undersaturation of the surface seawater at the
PAP site throughout the deployment periods, which
Table 1: Air–sea CO
2
flux estimates based on seasonal PAP data given in units of mol m
-2
a
-1
Period
Air – sea CO
2
flux (mol m
-2
a
-1
)*
Min.
Max.
Average
Std. Dev.
Summer 2003
-
0.86
0.26
-
0.29
0.78
Fall 2003
-
4.35
-
0.22
-
2.36
2.07
Winter 2004
-
5.00
-
4.69
-
4.86
0.15
Spring 2004
-
4.58
-
3.62
-
4.03
0.49
Summer 2004
-
3.22
-
0.48
-
1.65
1.40
Fall 2004
-
3.23
-
0.74
-
2.28
1.34
Winter 2005
-
4.77
-
3.01
-
4.15
0.98
Net CO
2
sink
-
2.96
1.73
Note: *Negative indicates invasion of CO
2
into ocean from the atmosphere