Time-series of surface water CO2 and oxygen measurements on a platform in the central Arkona Sea (Baltic Sea): Seasonality of uptake and release

Joachim Kuss; Wolfgang Roeder; K. Peter Wlost; Michael D. DeGrandpre

doi:10.1016/j.marchem.2006.03.004

Time-series of surface water CO₂ and oxygen measurements on a platform in the central Arkona Sea (Baltic Sea): Seasonality of uptake and release

Joachim Kuss
, Wolfgang Roeder
, K. Peter Wlost
, Michael D. DeGrandpre

Chemistry and Biochemistry

Research output: Contribution to journal › Article › peer-review

44 Scopus citations

Abstract

High resolution measurements of carbon dioxide and oxygen were made in surface waters of the central Arkona Sea (Baltic Sea) from May 2003 to September 2004. Sensors for CO₂ partial pressure (pCO₂^w) and oxygen (O₂) concentration were mounted in 7 m depth on a moored platform which is used for hydrographic and meteorological monitoring. The pCO₂^w data were obtained in half hour intervals and O₂ was measured each hour as an average of a 10 min measurement. To check the performance of the sensors, pCO₂^w and O₂ were determined by shipboard measurements on a research vessel which visited the site in 1-2 month intervals. In addition, pCO₂^w was measured on a "volunteer observing ship" (VOS) passing the platform each second day at a distance of about 25 km. Minima of 220 to 250 μatm of pCO₂^w were observed at the time of the spring bloom and a cyanobacteria bloom in mid-summer. During winter the pCO₂^w was mostly close to equilibrium with the atmosphere but maxima of 430 to 530 μatm were also observed. The seasonality of oxygen and pCO₂^w showed an opposing pattern. From a multiple regression analysis, we concluded that two processes primarily controlled pCO₂^w during our study: biological turnover and mixing. A parameterization, based on apparent oxygen utilisation (AOU) and salinity (S) only (pCO₂^w = 1.23 AOU + 43 S), reproduced the seasonality of pCO₂^w in surface water reasonably well. Based on our pCO₂, salinity, and temperature data set, we attempted to separate processes changing total inorganic carbon concentrations (C_T) by using an alkalinity-salinity relation for the area. The contribution of CO₂ gas exchange and mixing were calculated and from this the biological turnover was deduced to reveal the calculated C_T changes. The net annual uptake of CO₂ in the central Arkona Sea was estimated to be about 1.5 Tg (1.5·10¹² g) which was approximately balanced by a net oxygen release considering the uncertainties of the flux calculations. Near-coast CO₂ emission due to episodic upwelling partly compensated the uptake of the central part of the Arkona Sea reducing the overall magnitude of the CO₂ uptake.

Original language	English
Pages (from-to)	220-232
Number of pages	13
Journal	Marine Chemistry
Volume	101
Issue number	3-4
DOIs	https://doi.org/10.1016/j.marchem.2006.03.004
State	Published - Oct 5 2006

Funding

We thank two anonymous reviewers whose comments helped to improve the paper. Thanks to B. Schneider for constructive discussions and for data collected by the volunteer observing ship, S. Krüger for the support from his Measurement and Instrumentation group from early planning and all through the joint collaboration, M. Sommer for the electronic installation of the SAMI-CO 2 , H. Kubsch for alkalinity measurements, and G. Nausch for nutrient data. We are grateful to the Federal Maritime and Hydrographic Agency of Germany for making the Arkona Sea spar-buoy available for field studies in addition to the routine measurement programme and for data, D. Irwin for building a new SAMI, and the captains and the crews of R/V ‘Professor Albrecht Penck’, R/V ‘Gauss’, and R/V ‘A. v. Humboldt’ for excellent support during the campaigns; we acknowledge financial support by the DFG (German Science foundation).

Keywords

Air-sea gas exchange
Annual cycle
Baltic Sea
Carbon dioxide
Oxygen

Access to Document

10.1016/j.marchem.2006.03.004

Cite this

@article{c1c6ae4af3cf4752992d3b4fa9f38595,

title = "Time-series of surface water CO2 and oxygen measurements on a platform in the central Arkona Sea (Baltic Sea): Seasonality of uptake and release",

abstract = "High resolution measurements of carbon dioxide and oxygen were made in surface waters of the central Arkona Sea (Baltic Sea) from May 2003 to September 2004. Sensors for CO2 partial pressure (pCO2w) and oxygen (O2) concentration were mounted in 7 m depth on a moored platform which is used for hydrographic and meteorological monitoring. The pCO2w data were obtained in half hour intervals and O2 was measured each hour as an average of a 10 min measurement. To check the performance of the sensors, pCO2w and O2 were determined by shipboard measurements on a research vessel which visited the site in 1-2 month intervals. In addition, pCO2w was measured on a {"}volunteer observing ship{"} (VOS) passing the platform each second day at a distance of about 25 km. Minima of 220 to 250 μatm of pCO2w were observed at the time of the spring bloom and a cyanobacteria bloom in mid-summer. During winter the pCO2w was mostly close to equilibrium with the atmosphere but maxima of 430 to 530 μatm were also observed. The seasonality of oxygen and pCO2w showed an opposing pattern. From a multiple regression analysis, we concluded that two processes primarily controlled pCO2w during our study: biological turnover and mixing. A parameterization, based on apparent oxygen utilisation (AOU) and salinity (S) only (pCO2w = 1.23 AOU + 43 S), reproduced the seasonality of pCO2w in surface water reasonably well. Based on our pCO2, salinity, and temperature data set, we attempted to separate processes changing total inorganic carbon concentrations (CT) by using an alkalinity-salinity relation for the area. The contribution of CO2 gas exchange and mixing were calculated and from this the biological turnover was deduced to reveal the calculated CT changes. The net annual uptake of CO2 in the central Arkona Sea was estimated to be about 1.5 Tg (1.5·1012 g) which was approximately balanced by a net oxygen release considering the uncertainties of the flux calculations. Near-coast CO2 emission due to episodic upwelling partly compensated the uptake of the central part of the Arkona Sea reducing the overall magnitude of the CO2 uptake.",

keywords = "Air-sea gas exchange, Annual cycle, Baltic Sea, Carbon dioxide, Oxygen",

author = "Joachim Kuss and Wolfgang Roeder and Wlost, \{K. Peter\} and DeGrandpre, \{Michael D.\}",

note = "Funding Information: We thank two anonymous reviewers whose comments helped to improve the paper. Thanks to B. Schneider for constructive discussions and for data collected by the volunteer observing ship, S. Kr{\"u}ger for the support from his Measurement and Instrumentation group from early planning and all through the joint collaboration, M. Sommer for the electronic installation of the SAMI-CO 2 , H. Kubsch for alkalinity measurements, and G. Nausch for nutrient data. We are grateful to the Federal Maritime and Hydrographic Agency of Germany for making the Arkona Sea spar-buoy available for field studies in addition to the routine measurement programme and for data, D. Irwin for building a new SAMI, and the captains and the crews of R/V {\textquoteleft}Professor Albrecht Penck{\textquoteright}, R/V {\textquoteleft}Gauss{\textquoteright}, and R/V {\textquoteleft}A. v. Humboldt{\textquoteright} for excellent support during the campaigns; we acknowledge financial support by the DFG (German Science foundation).",

year = "2006",

month = oct,

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doi = "10.1016/j.marchem.2006.03.004",

language = "English",

volume = "101",

pages = "220--232",

journal = "Marine Chemistry",

issn = "0304-4203",

publisher = "Elsevier B.V.",

number = "3-4",

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TY - JOUR

T1 - Time-series of surface water CO2 and oxygen measurements on a platform in the central Arkona Sea (Baltic Sea)

T2 - Seasonality of uptake and release

AU - Kuss, Joachim

AU - Roeder, Wolfgang

AU - Wlost, K. Peter

AU - DeGrandpre, Michael D.

N1 - Funding Information: We thank two anonymous reviewers whose comments helped to improve the paper. Thanks to B. Schneider for constructive discussions and for data collected by the volunteer observing ship, S. Krüger for the support from his Measurement and Instrumentation group from early planning and all through the joint collaboration, M. Sommer for the electronic installation of the SAMI-CO 2 , H. Kubsch for alkalinity measurements, and G. Nausch for nutrient data. We are grateful to the Federal Maritime and Hydrographic Agency of Germany for making the Arkona Sea spar-buoy available for field studies in addition to the routine measurement programme and for data, D. Irwin for building a new SAMI, and the captains and the crews of R/V ‘Professor Albrecht Penck’, R/V ‘Gauss’, and R/V ‘A. v. Humboldt’ for excellent support during the campaigns; we acknowledge financial support by the DFG (German Science foundation).

PY - 2006/10/5

Y1 - 2006/10/5

N2 - High resolution measurements of carbon dioxide and oxygen were made in surface waters of the central Arkona Sea (Baltic Sea) from May 2003 to September 2004. Sensors for CO2 partial pressure (pCO2w) and oxygen (O2) concentration were mounted in 7 m depth on a moored platform which is used for hydrographic and meteorological monitoring. The pCO2w data were obtained in half hour intervals and O2 was measured each hour as an average of a 10 min measurement. To check the performance of the sensors, pCO2w and O2 were determined by shipboard measurements on a research vessel which visited the site in 1-2 month intervals. In addition, pCO2w was measured on a "volunteer observing ship" (VOS) passing the platform each second day at a distance of about 25 km. Minima of 220 to 250 μatm of pCO2w were observed at the time of the spring bloom and a cyanobacteria bloom in mid-summer. During winter the pCO2w was mostly close to equilibrium with the atmosphere but maxima of 430 to 530 μatm were also observed. The seasonality of oxygen and pCO2w showed an opposing pattern. From a multiple regression analysis, we concluded that two processes primarily controlled pCO2w during our study: biological turnover and mixing. A parameterization, based on apparent oxygen utilisation (AOU) and salinity (S) only (pCO2w = 1.23 AOU + 43 S), reproduced the seasonality of pCO2w in surface water reasonably well. Based on our pCO2, salinity, and temperature data set, we attempted to separate processes changing total inorganic carbon concentrations (CT) by using an alkalinity-salinity relation for the area. The contribution of CO2 gas exchange and mixing were calculated and from this the biological turnover was deduced to reveal the calculated CT changes. The net annual uptake of CO2 in the central Arkona Sea was estimated to be about 1.5 Tg (1.5·1012 g) which was approximately balanced by a net oxygen release considering the uncertainties of the flux calculations. Near-coast CO2 emission due to episodic upwelling partly compensated the uptake of the central part of the Arkona Sea reducing the overall magnitude of the CO2 uptake.

AB - High resolution measurements of carbon dioxide and oxygen were made in surface waters of the central Arkona Sea (Baltic Sea) from May 2003 to September 2004. Sensors for CO2 partial pressure (pCO2w) and oxygen (O2) concentration were mounted in 7 m depth on a moored platform which is used for hydrographic and meteorological monitoring. The pCO2w data were obtained in half hour intervals and O2 was measured each hour as an average of a 10 min measurement. To check the performance of the sensors, pCO2w and O2 were determined by shipboard measurements on a research vessel which visited the site in 1-2 month intervals. In addition, pCO2w was measured on a "volunteer observing ship" (VOS) passing the platform each second day at a distance of about 25 km. Minima of 220 to 250 μatm of pCO2w were observed at the time of the spring bloom and a cyanobacteria bloom in mid-summer. During winter the pCO2w was mostly close to equilibrium with the atmosphere but maxima of 430 to 530 μatm were also observed. The seasonality of oxygen and pCO2w showed an opposing pattern. From a multiple regression analysis, we concluded that two processes primarily controlled pCO2w during our study: biological turnover and mixing. A parameterization, based on apparent oxygen utilisation (AOU) and salinity (S) only (pCO2w = 1.23 AOU + 43 S), reproduced the seasonality of pCO2w in surface water reasonably well. Based on our pCO2, salinity, and temperature data set, we attempted to separate processes changing total inorganic carbon concentrations (CT) by using an alkalinity-salinity relation for the area. The contribution of CO2 gas exchange and mixing were calculated and from this the biological turnover was deduced to reveal the calculated CT changes. The net annual uptake of CO2 in the central Arkona Sea was estimated to be about 1.5 Tg (1.5·1012 g) which was approximately balanced by a net oxygen release considering the uncertainties of the flux calculations. Near-coast CO2 emission due to episodic upwelling partly compensated the uptake of the central part of the Arkona Sea reducing the overall magnitude of the CO2 uptake.

KW - Air-sea gas exchange

KW - Annual cycle

KW - Baltic Sea

KW - Carbon dioxide

KW - Oxygen

UR - https://www.scopus.com/pages/publications/33746391409

U2 - 10.1016/j.marchem.2006.03.004

DO - 10.1016/j.marchem.2006.03.004

M3 - Article

AN - SCOPUS:33746391409

SN - 0304-4203

VL - 101

SP - 220

EP - 232

JO - Marine Chemistry

JF - Marine Chemistry

IS - 3-4

ER -