Chris Hunt
Joe Salisbury
Doug Vandemark
Coastal Carbon Group- Ocean Process Analysis Lab
University of New Hampshire
What is alkalinity?
“the number of moles of hydrogen ion equivalent to the excess of proton
acceptors over proton donors…” (Dickson 1981)
Acid-Neutralizing Definition:
Alk = [HCO3−] + 2[CO3−2] + [B(OH)4−] + 2[PO4−3] + [HPO4−2] + [SiO(OH)3−] …+ [Organic-]
Ion Balance Definition
[HCO3−] + 2[CO3−2] +[OH-]- [H+ ] = [Na+]+[K+]+ 2[Ca+2] + 2[Mg+2] - [Cl-] - 2[SO4-2] - [Organic-]
Working Ocean Alkalinity Definition:
C-Alk = [HCO3−] + 2[CO3−2] ≈ [HCO3−]
NC-Alk = [B(OH)4−] + 2[PO4−3] + [HPO4−2] + [SiO(OH)3−] + [Organic-]
Org-Alk = [Organic-] ≈ NC-Alk
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What is alkalinity, and why is it important?
“the number of moles of hydrogen ion equivalent to the excess of proton
acceptors over proton donors…” (Dickson 1981)
The capacity of ocean water to neutralize acid
OR
The chemical buffering capacity of the ocean.
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How do we examine the carbonate system?
Geochemical/biochemical
-Temperature, salinity
Biological
Calcification
-Dissolved oxygen
-Carbonate System Measurements:
*pH
*Total Alkalinity (T-Alk)
*Dissolved Inorganic Carbon (DIC)
*Partial Pressure of Carbon
Dioxide (pCO2)
-Calcium (?)
Doney et al. 2009
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Significance of alkalinity measurements to ocean
acidification studies
From McLaughlin et al. 2015
Measurement of any two allows calculation
of the entire carbonate system (plus Ω)
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Past
 Collection at sea
 Analysis at sea
 Classic titration, becomes semi-automated
Image from Broeker and Peng 1982
Image from http://www.epoc.u-bordeaux.fr/indiv/Abril/titration.html
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Timeline of Ocean Alk Measurements
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Anderson and Robinson 1946
Gripenberg 1960- Baltic Sea
Park 1969- Columbia River Estuary
GEOSECS- 1972-1978
TTO-NAS (Transient Tracers in the Ocean 1980-1982)
SAVE (South Atlantic Ventilation Experiment)- 19871989
 JGOFS, WOCE, OACES- 1990s
 GLOBEC (Global Ocean Ecosystem Dynamics 1990s2000s)
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GEOSECS
 Atlantic: July 1972 to May 1973
 Pacific: August 1973 to June 1974
 Indian Ocean: December 1977 to March 1978
TTO- 1981
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SAVE
 South Atlantic 1987-1988
GEOSECS North Pacific Station
From Broecker and Peng 1982
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WOCE 1990s
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Present
 Synthesis, producing global and regional climatologies
 Semi-automated pH-based titration at sea or in lab
 Spectrophotometric pH (increased accuracy)
 Standardized methods, certified reference materials
beginning in 1990 (Andrew Dickson, Scripps)
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From http://www.ukgeotraces.com/outreach/blog_a10_2010
Apollo SciTech AS-ALK3
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Alkalinity at Salinity 35:
Atlantic: 2313 µmol/kg
Pacific: 2311 µmol/kg
Indian: 2294 µmol/kg
From Millero et al. 1998
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GLODAP Alkalinity From Key et al. 2004
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Takahashi Climatology Map
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From Takahashi et al. 2014
UNH TA-S regression with Lines
from Lee, etc.
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From Millero et al. 1998
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Alkalinity
Potential Alkalinity:
((TA + Nitrate) x 35/Salinity)
GLODAP Surface Alkalinity From Key et al. 2004
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From Lee et al. 2006
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From Lee et al. 2006
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From Lee et al. 2006
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UNH Global Alkalinity Dataset
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Future
From Salisbury et al. 2015
SOCAT fCO2 global data
From Land et al. 2014
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From Cressey 2015
From Cornwall et al. 2015
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TAACT
 Tracking ocean Alkalinity and Acidification using new Carbon

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
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measurement Technologies
Primary Investigator: Joe Salisbury, UNH
Collaborators:
Steffen Aßmann, GEOMAR Helmholtz Centre for Ocean Research, Kiel
Peer Fietzek and Carsten Frank, CONTROS GmbH, GEOMAR Helmholtz
Centre for Ocean Research, Kiel
Jonathan Hare, NOAA NMFS Northeast Fisheries Science Center,
Narragansett, RI
William Mook, Mook Sea Farms, 321 Maine Rt.129, Walpole, ME
Ru Morrison, Northeastern Regional Association of Coastal and Ocean
Observing Systems, Newington, NH
Douglas Vandemark and Christopher W. Hunt, UNH
Rik Wanninkhof, NOAA AOML, Miami, FL
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TAACT Goals
 1. Establish baseline data and autonomous techniques
for OA data collection that support offshore fisheries
and climate applications
 2. Document nearshore OA variability for use in
aquaculture and coastal management applications
 3. Determine suitable and sufficient OA measurement
best practices for the Northeast region
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Contros HydroFIA TA analyzer
 Autonomous operation
 Spectrophotometric, single-point alkalinity determination
 400 µmol range (~20% ocean TA)
 Accuracy +/- 25 µmol/kg
 Precision +/- 5 µmol/kg
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Figure 3- Proposed NERACOOS-CML and MSF shoreside sites (green), current UNH
sampling sites (red), Maine DMR trawl survey sites (blue), NOAA-NMFS sites and track
(yellow), and Skógafoss line (magenta). Insets clockwise from top left: NOAA-NMFS
R/V Bigelow, SOOP Skógafoss,Maine DMR trawler FV Robert Michael, shoreside gas
equilibrator.
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TAACT Implementation
 Phase 1- Evaluation at UNH Coastal Marine Lab
 Phase 2- Deployment at Mook Seafarm and AOML SOOP vessel
 Phase 3- Deployment aboard NMFS-ECOMON cruise
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Mook Sea Farm
 An oyster farm and hatchery located on the
Damariscotta River in mid-coast Maine
 Their need is to identify which parameters affect larval
production and to put reliable, user friendly and
accurate instrumentation in place to monitor these
parameters.
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Yang and Byrne 2015
“There must exist in Baltic water other anions
Of weak acids, which have their own rhythm of
Variation and which seemingly erratically
Influence the alkalinity values.”
-Gripenberg 1960
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K-30 CO2 Sensor
Cable
Silicone
Sealant
Air
Pump
Air Flow
PVC pipe
Float
A
Float
B
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Questions?
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References
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Anderson, D.H., Robinson, R.J., 1946. Rapid Electrometric Determination of Alkalinity of Sea Water
Using Glass Electrode. Ind. Eng. Chem. Anal. Ed. 18, 767–769. doi:10.1021/i560160a011
Cornwall, C.E., Hurd, C.L., 2015. Experimental design in ocean acidification research: problems and
solutions. ICES J. Mar. Sci. fsv118. doi:10.1093/icesjms/fsv118
Cressey, D., 2015. Crucial ocean-acidification models come up short. Nature 524, 18–19.
doi:10.1038/524018a
Dickson, A.G., 1981. An exact definition of total alkalinity and a procedure for the estimation of
alkalinity and total inorganic carbon from titration data. Deep Sea Research Part A. Oceanographic
Research Papers 28, 609–623. doi:10.1016/0198-0149(81)90121-7
Gripenberg, S., 1960. On the Alkalinity of Baltic Waters. J. Cons. int. Explor. Mer 26, 5–20.
doi:10.1093/icesjms/26.1.5
Key, R.M., Kozyr, A., Sabine, C.L., Lee, K., Wanninkhof, R., Bullister, J.L., Feely, R.A., Millero, F.J.,
Mordy, C., Peng, T.-H., 2004. A global ocean carbon climatology: Results from Global Data Analysis
Project (GLODAP). Global Biogeochem. Cycles 18, GB4031. doi:10.1029/2004GB002247
Land, P.E., Shutler, J.D., Findlay, H.S., Girard-Ardhuin, F., Sabia, R., Reul, N., Piolle, J.-F., Chapron, B.,
Quilfen, Y., Salisbury, J., Vandemark, D., Bellerby, R., Bhadury, P., 2015. Salinity from Space Unlocks
Satellite-Based Assessment of Ocean Acidification. Environ. Sci. Technol. 49, 1987–1994.
doi:10.1021/es504849s
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References
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Lee, K., Tong, L.T., Millero, F.J., Sabine, C.L., Dickson, A.G., Goyet, C., Park, G.-H., Wanninkhof, R.,
Feely, R.A., Key, R.M., 2006. Global relationships of total alkalinity with salinity and temperature in
surface waters of the world’s oceans. Geophysical Research Letters 33. doi:10.1029/2006GL027207
McLaughlin, K., Weisberg, S., Dickson, A., Hofmann, G., Newton, J., Aseltine-Neilson, D., Barton, A.,
Cudd, S., Feely, R., Jefferds, I., Jewett, E., King, T., Langdon, C., McAfee, S., Pleschner-Steele, D.,
Steele, B., 2015. Core Principles of the California Current Acidification Network: Linking Chemistry,
Physics, and Ecological Effects. Oceanography 25, 160–169. doi:10.5670/oceanog.2015.39
Millero, F.J., Lee, K., Roche, M., 1998. Distribution of alkalinity in the surface waters of the major
oceans. Marine Chemistry 60, 111–130. doi:10.1016/S0304-4203(97)00084-4
Park, P.K., Webster, G.R., Yamamoto, R., 1969. Alkalinity Budget of the Columbia River1. Limnol.
Oceanogr. 14, 559–567. doi:10.4319/lo.1969.14.4.0559
Salisbury, J., Vandemark, D., Jönsson, B., Balch, W., Chakraborty, S., Lohrenz, S., Chapron, B., Hales,
B., Mannino, A., Mathis, J., Reul, N., Signorini, S., Wanninkhof, R., Yates, K., 2015. How Can Present
and Future Satellite Missions Support Scientific Studies that Address Ocean Acidification?
Oceanography 25, 108–121. doi:10.5670/oceanog.2015.35
Takahashi, T., Sutherland, S.C., Chipman, D.W., Goddard, J.G., Ho, C., Newberger, T., Sweeney, C.,
Munro, D.R., 2014. Climatological distributions of pH, pCO2, total CO2, alkalinity, and CaCO3
saturation in the global surface ocean, and temporal changes at selected locations. Marine Chemistry
164, 95–125. doi:10.1016/j.marchem.2014.06.004
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