ocean acidification impacts in the western arctic ocean · 2015-03-18 · nicholas r. bates senior...
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Nicholas R. Bates
Senior Scientist
Bermuda Institute of Ocean Sciences (BIOS), Bermuda
Ocean Acidification Impacts in the Western
Arctic Ocean
Thanks to:
NOAA; RUSALCA colleagues
Keven Neely, Becky Garley, Margaret
Best, Monika Orchowska (BIOS)
Terry Whitledge, Jeremy Mathis (UAF),
Wei-Jun Cai, Kevin Arrigo and
many others
Dissolved inorganic carbon (DIC) • DIC = [HCO3
-] + [CO32-] + [CO2*]
Total Alkalinity (TA)
• TA = [HCO3-] + 2[CO3
2-] +
[B(OH)-] + [OH-] – [H-]
CO2atm + H2O = [CO2*]sea = HCO3-] + [H+] = [CO3
2-] + [H+] (1)
Arctic Seawater CO2-carbonate chemistry
Observed and calculated
seawater CO2-carbonate
chemistry
Partial pressure of CO2 • pCO2 or fCO2
pH • -log10 [H+]
N.R. Bates, RUSALCA 2014
TA
DIC
dissolution
of CaCO3
calcification
net melt/
freshening
sea-ice
melt
freshening/
precipitation
2300
2200
2100
200020001900 2100 22001800
CO2 release
photosynthesis
respiration
CO2 invasion
A
Wa
rag
on
ite
6
5
4
3
2
1
0
Physico-biogeochemical
processes (e.g., sea-ice melt,
production, air-sea fluxes)
impacting CaCO3
saturation states and OA
5. A new assessment of the impact of ocean acidification (OA)
on the bottom waters of the eastern East Siberian Sea and
western Chukchi Sea shelves will be made, and their potential
impact on benthic calcifying organisms.
Ocean Acidification (OA) Impacts
TA
DIC
dissolution
of CaCO3
calcification
net melt/
freshening
sea-ice
melt
freshening/
precipitation
2300
2200
2100
200020001900 2100 22001800
CO2 release
photosynthesis
respiration
CO2 invasion
A
Wa
rag
on
ite
6
5
4
3
2
1
0
Physico-biogeochemical
processes impacting CaCO3
saturation states
(i.e., Waragonite less than one
facilitates dissolution)
Potential dissolution of
CaCO3 (blue and purple
colours in next slides)
Dotted line denotes envelope of RUSALCA data
Western Arctic Inorganic Carbon
N.R. Bates, RUSALCA 2014
RUSALCA and ICESCAPE Distributions
Potential dissolution
of CaCO3 (blue and
purple
colours)
!
areas of low seawater
pH
Hypothesis testing, data synthesis and interpretation 4. Assessment of the Impact of Ocean Acidification in the western Arctic Ocean
areas of higher DOC
content
Areas of low seawater
saturation state for
CaCO3 minerals. Much
of the Chukchi Sea
benthos exposed to
bottom waters that are
corrosive to CaCO3
during summertime.
RUSALCA data combined with 2010/2011 ICESCAPE data
Arctic highly vulnerable to OA
Hypothesis testing, data synthesis and interpretation 4. Assessment of the Impact of Ocean Acidification in the western Arctic Ocean
Areas of low seawater
saturation state for
CaCO3 minerals. At
least 40% of the
Chukchi Sea benthos
is exposed to bottom
waters that are
corrosive to CaCO3
during summertime
Western Arctic OA Impacts
0
20
40
60
80
120
0 1.0 2.00.5 1.5 2.5
200
400
De
pth
(m
)
Waragonite % of samples100%80%20% 40% 60%0%
n5
34
61
108
48
42
19
21
14
Waragonite Values (Key)
<1.0
1.0 - 1.2
1.2 - 1.5
1.5 - 1.8
>2.0
SHELF
SLOPE
BASIN
20022004
A
B
Outflow of corrosive
bottom waters
through Herald Valley
Chukchi Sea and ESS highly
vulnerable to OA
Hypothesis testing, data synthesis and interpretation 4. Assessment of the Impact of Ocean Acidification in the western Arctic Ocean
Bering Strait OA
RUSALCA data combined with 2010/2011 ICESCAPE data
Sections of data combining 2009 RUSALCA and
2010/2011 ICESCAPE
Alyatki to Cape Lisburne
RUSALCA data combined with 2010/2011 ICESCAPE data
Sections of data combining 2009 RUSALCA and
2010/2011 ICESCAPE
Herald Valley
RUSALCA data combined with 2010/2011 ICESCAPE data
Sections of data combining 2009 RUSALCA and
2010/2011 ICESCAPE
Central Channel
RUSALCA data combined with 2010/2011 ICESCAPE data
Sections of data combining 2009 RUSALCA and
2010/2011 ICESCAPE
170°W to Point Narrow
RUSALCA data combined with 2010/2011 ICESCAPE data
Sections of data combining 2009 RUSALCA and
2010/2011 ICESCAPE
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