scholarly journals CO<sub>2</sub>-flux measurements above the Baltic Sea at two heights: flux gradients in the surface layer?

2015 ◽  
Vol 7 (2) ◽  
pp. 311-317 ◽  
Author(s):  
A. Lammert ◽  
F. Ament
Keyword(s):  
Baltic Sea ◽  
Eddy Covariance ◽  
Latent Heat ◽  
Co2 Flux ◽  
The Baltic Sea ◽  
Near Surface ◽  
Constant Flux ◽  
Flux Measurements ◽  
Flux Layer ◽  
The Baltic

Abstract. The estimation of CO2 exchange between the ocean and the atmosphere is essential to understand the global carbon cycle. The eddy-covariance technique offers a very direct approach to observe these fluxes. The turbulent CO2 flux is measured, as well as the sensible and latent heat flux and the momentum flux, a few meters above the ocean in the atmosphere. Assuming a constant-flux layer in the near-surface part of the atmospheric boundary layer, this flux equals the exchange flux between ocean and atmosphere. The purpose of this paper is the comparison of long-term flux measurements at two different heights above the Baltic Sea to investigate this assumption. The results are based on a 1.5-year record of quality-controlled eddy-covariance measurements. Concerning the flux of momentum and of sensible and latent heat, the constant-flux layer theory can be confirmed because flux differences between the two heights are insignificantly small more than 95 % of the time. In contrast, significant differences, which are larger than the measurement error, occur in the CO2 flux about 35 % of the time. Data used for this paper are published at http://doi.pangaea.de/10.1594/PANGAEA.808714.

scholarly journals CO<sub>2</sub>-flux measurements above the Baltic Sea at two heights: flux gradients in the surface layer

2015 ◽  
Vol 8 (2) ◽  
pp. 587-601
Author(s):  
A. Lammert ◽  
F. Ament
Keyword(s):  
Baltic Sea ◽  
Eddy Covariance ◽  
Latent Heat ◽  
Co2 Flux ◽  
The Baltic Sea ◽  
Near Surface ◽  
Constant Flux ◽  
Flux Measurements ◽  
Flux Layer ◽  
The Baltic

Abstract. The estimation of CO2 exchange between the ocean and the atmosphere is essential to understand the global carbon cycle. The eddy-covariance technique offers a very direct approach to observe these fluxes. The turbulent CO2 flux is measured as well as the sensible and latent heat flux and the momentum flux, a few meters above the ocean in the atmosphere. Assuming a constant-flux layer in the near surface part of the atmospheric boundary, this flux equals the exchange flux between ocean and atmosphere. The goal of this paper is the comparison of long-term flux measurements at two different heights above the Baltic Sea due to this assumption. The results are based on an one-and-a-half year record of quality controlled eddy covariance measurements. Concerning the flux of momentum and of sensible and latent heat, the constant-flux layer theory can be validated because flux gradients between the two heights are more than 95 % of the time insignificantly small. In contrast, significant gradients, which are larger than the measurement error, occur for the CO2 flux in nearly 35 % of the time. Data, used for this paper are published at http://doi.pangaea.de/10.1594/PANGAEA.808714.

scholarly journals Temporal and Spatial variation of Contribution from Ship Emissions to the concentration and deposition of air pollutants in the Baltic Sea

2016 ◽  
Author(s):  
Karin Haglund ◽  
Björn Claremar ◽  
Anna Rutgersson
Keyword(s):  
Atmospheric Deposition ◽  
Baltic Sea ◽  
Dry Deposition ◽  
Air Pollutants ◽  
Wet Deposition ◽  
Sulphur Content ◽  
The Baltic Sea ◽  
Near Surface ◽  
Baltic Sea Region ◽  
The Baltic

Abstract. The shipping sector contributes significantly to increasing emissions of air pollutants. In order to achieve sustainable shipping, primarily through new regulations and techniques, greater knowledge of dispersion and deposition of air pollutants is required. Regional model calculations of the dispersion and deposition of sulphur, nitrogen and particulate matter from the international maritime sector in the Baltic Sea and the North Sea have been made for the years 2009 to 2013. In some areas in the Baltic Sea region the contribution of sulphur dioxide, nitrogen oxide and nitrogen dioxide from international shipping represented up to 80 % of the total near surface concentration of the pollutants. Contributions from shipping of PM2,5 and PM10 were calculated to a maximum of 21 % and 13 % respectively. The contribution of wet deposition of sulphur from shipping was maximum 29 % of the total wet deposition, and for dry deposition the contribution from shipping was maximum 84 %. The highest percentage contribution of wet deposition of nitrogen from shipping reached 28 % and for dry deposition 47 %. The highest concentrations and deposition of the pollutants in the study were found near large ports and shipping lanes. High concentrations were also found over larger areas at sea and over land where many people are exposed. With enhanced regulations for sulphur content in maritime fuel, the cleaning of exhausts through scrubbers has become a possible economic solution. Wet scrubbers meet the air quality criteria but their consequences for the marine environment are largely unknown. The resulting potential of future acidification in the Baltic Sea, both from atmospheric deposition and from open-loop scrubber water along the shipping lanes, based on different assumptions about sulphur content in fuel and scrubber usage has been assessed. Shipping is expected to increase globally and in the Baltic Sea region, deposition of sulphur due to shipping will depend on traffic density, emission regulations and technology choices for the emission controls. To evaluate future changes scenarios are developed considering the amount of scrubber technology used. The increase in deposition for the different scenarios differs slightly for the basins in the Baltic Sea. The proportion of ocean acidifying sulphur from ships increases when taking scrubber water into account and the major reason to increasing acidifying nitrogen from ships are due to increasing ship traffic. This study also generates a database of scenarios for atmospheric deposition and scrubber exhaust from the period 2011 to 2050.

scholarly journals Sea Ice Concentration Analyses for the Baltic Sea and Their Impact on Numerical Weather Prediction

2006 ◽  
Vol 45 (7) ◽  
pp. 982-994 ◽  
Author(s):  
Matthias Drusch
Keyword(s):  
Heat Flux ◽  
Sea Ice ◽  
Baltic Sea ◽  
Latent Heat ◽  
Latent Heat Flux ◽  
The Baltic Sea ◽  
Sea Ice Concentration ◽  
Sea Ice Extent ◽  
Ice Concentration ◽  
The Baltic

Abstract Sea ice concentration plays a fundamental role in the exchange of water and energy between the ocean and the atmosphere. Global real-time datasets of sea ice concentration are based on satellite observations, which do not necessarily resolve small-scale patterns or coastal features. In this study, the global National Centers for Environmental Prediction (NCEP) 0.5° sea ice concentration dataset is compared with a regional high-resolution analysis for the Baltic Sea produced 2 times per week by the Swedish Meteorological and Hydrological Institute (SMHI). In general, the NCEP dataset exhibits less spatial and temporal variability during the winter of 2003/04. Because of the coarse resolution of the NCEP dataset, ice extent is generally larger than in the SMHI analysis. Mean sea ice concentrations derived from both datasets are in reasonable agreement during the ice-growing and ice-melting periods in January and April, respectively. For February and March, during which the sea ice extent is largest, mean sea ice concentrations are lower in the NCEP dataset relative to the SMHI product. Ten-day weather forecasts based on the NCEP sea ice concentrations and the SMHI dataset have been performed, and they were compared on the local, regional, and continental scales. Turbulent surface fluxes have been analyzed based on 24-h forecasts. The differences in sea ice extent during the ice-growing period in January cause mean differences of up to 30 W m−2 for sensible heat flux and 20 W m−2 for latent heat flux in parts of the Gulf of Bothnia and the Gulf of Finland. The comparison between spatially aggregated fluxes yields differences of up to 36 and 20 W m−2 for sensible and latent heat flux, respectively. The differences in turbulent fluxes result in different planetary boundary height and structure. Even the forecast cloud cover changes by up to 40% locally.

scholarly journals Measurement of Air-Sea Methane Fluxes in the Baltic Sea Using the Eddy Covariance Method

2019 ◽  
Vol 7 ◽  
Author(s):  
Lucía Gutiérrez-Loza ◽  
Marcus B. Wallin ◽  
Erik Sahlée ◽  
Erik Nilsson ◽  
Hermann W. Bange ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Eddy Covariance ◽  
The Baltic Sea ◽  
Eddy Covariance Method ◽  
Methane Fluxes ◽  
The Baltic

Addressing the effects of bottom trawling on benthic processes using experimental and field studies in the Baltic Sea

2020 ◽  
Author(s):  
Claudia Morys ◽  
Martin Jakobsson ◽  
Mattias Sköld ◽  
Pere Masqué ◽  
Volker Brüchert ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Field Experiments ◽  
Biogeochemical Cycling ◽  
Field Studies ◽  
The Baltic Sea ◽  
Bottom Trawling ◽  
Flux Measurements ◽  
The Baltic ◽  
Benthic Ecosystems ◽  
The Impact

&lt;p&gt;Bottom trawling is one of the most important anthropogenic disturbances affecting marine ecosystems and there has been increased attention to its impacts on seabed habitats as well as the structure and functioning of benthic ecosystems. The impact of bottom trawling is well-known with regard to benthic organisms. However, we still have a poor understanding of its effects on bentho-pelagic coupling and biogeochemical cycling in the sediment. In the Baltic Sea, the study area of the present investigation, there is a particular lack of data.&lt;br&gt;Here, we present new results from field experiments to quantify changes in sediment properties, macrofauna and biogeochemical cycling after the passage of a benthic dredge. To put the results in a broader context, a field survey was conducted in six areas of different commercial trawling intensities in the Bornholm Basin. Acoustic geophysical mapping, isotope profiling, functional categorization of macrofauna and sediment-water nutrient and oxygen flux measurements were used to evaluate the physical disturbance of the seabed. Preliminary results suggest a range of ecological, biogeochemical and physical impacts of trawling in the Baltic Sea, with implications for benthic ecosystem functioning.&lt;/p&gt;

scholarly journals Sensitivity of the air–sea CO<sub>2</sub> exchange in the Baltic Sea and Danish inner waters to atmospheric short term variability

2014 ◽  
Vol 11 (12) ◽  
pp. 16993-17042
Author(s):  
A. S. Lansø ◽  
J. Bendtsen ◽  
J. H. Christensen ◽  
L. L. Sørensen ◽  
H. Chen ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Co2 Flux ◽  
Co2 Concentration ◽  
Co2 Exchange ◽  
Atmospheric Co2 ◽  
The Baltic Sea ◽  
Short Term ◽  
Transfer Velocity ◽  
The Baltic ◽  
Short Term Variability

Abstract. Minimising the uncertainties in estimates of air–sea CO2 exchange is an important step toward increasing the confidence in assessments of the CO2 cycle. Using an atmospheric transport model makes it possible to investigate the direct impact of atmospheric parameters on the air–sea CO2 flux along with its sensitivity to e.g. short-term temporal variability in wind speed, atmospheric mixing height and the atmospheric CO2 concentration. With this study the importance of high spatiotemporal resolution of atmospheric parameters for the air–sea CO2 flux is assessed for six sub-basins within the Baltic Sea and Danish inner waters. A new climatology of surface water partial pressure of CO2 (pCO2) has been developed for this coastal area based on available data from monitoring stations and underway pCO2 measuring systems. Parameterisations depending on wind speed were applied for the transfer velocity to calculate the air–sea CO2 flux. Two model simulations were conducted – one including short term variability in atmospheric CO2 (VAT), and one where it was not included (CAT). A seasonal cycle in the air–sea CO2 flux was found for both simulations for all sub-basins with uptake of CO2 in summer and release of CO2 to the atmosphere in winter. During the simulated period 2005–2010 the average annual net uptake of atmospheric CO2 for the Baltic Sea, Danish Straits and Kattegat was 287 and 471 Gg C yr-1 for the VAT and CAT simulations, respectively. The obtained difference of 184 Gg C yr-1 was found to be significant, and thus ignoring short term variability in atmospheric CO2 does have a sizeable effect on the air–sea CO2 exchange. The combination of the atmospheric model and the new pCO2 fields has also made it possible to make an estimate of the marine part of the Danish CO2 budget for the first time. A net annual uptake of 2613 Gg C yr-1 was found for the Danish waters. A large uncertainty is connected to the air–sea CO2 flux in particular caused by the transfer velocity parameterisation and the applied pCO2 climatology. However, the present study underlines the importance of including short term variability in the atmospheric CO2 concentration in future model studies of the air–sea exchange in order to minimise the uncertainty.

scholarly journals A new disjunct eddy-covariance system for BVOC flux measurements – validation on CO<sub>2</sub> and H<sub>2</sub>O fluxes

2012 ◽  
Vol 5 (12) ◽  
pp. 3119-3132 ◽  
Author(s):  
R. Baghi ◽  
P. Durand ◽  
C. Jambert ◽  
C. Jarnot ◽  
C. Delon ◽  
...  
Keyword(s):  
Eddy Covariance ◽  
Latent Heat ◽  
Linear Regression Analysis ◽  
Co2 Flux ◽  
Heat Fluxes ◽  
Sampling System ◽  
Field Campaign ◽  
Air Samples ◽  
Flux Measurements ◽  
Internal Pressures

Abstract. The disjunct eddy covariance (DEC) method is an interesting alternative to the conventional eddy covariance (EC) method because it allows the estimation of turbulent fluxes of species for which fast sensors are not available. We have developed and validated a new disjunct sampling system (called MEDEE). This system is built with chemically inert materials. Air samples are taken quickly and alternately in two cylindrical reservoirs, the internal pressures of which are regulated by a moving piston. The MEDEE system was designed to be operated either on the ground or aboard an aircraft. It is also compatible with most analysers since it transfers the air samples at a regulated pressure. To validate the system, DEC and EC measurements of CO2 and latent heat fluxes were performed concurrently during a field campaign. EC fluxes were first compared to simulated DEC (SDEC) fluxes and then to actual DEC fluxes. Both the simulated and actual DEC fluxes showed a good agreement with EC fluxes in terms of correlation. The determination coefficients (R2) were 0.93 and 0.91 for DEC and SDEC latent heat fluxes, respectively. For DEC and SDEC CO2 fluxes R2 was 0.69 in both cases. The conditions of low fluxes experienced during the campaign impaired the comparison of the different techniques especially for CO2 flux measurements. Linear regression analysis showed an 14% underestimation of DEC fluxes for both CO2 and latent heat compared to EC fluxes. A first field campaign, focusing on biogenic volatile organic compound (BVOC) emissions, was carried out to measure isoprene fluxes above a downy oak (Quercus Pubescens) forest in the south-east of France. The measured standard emission rate was in the lower range of reported values in earlier studies. Further analysis will be conducted through ground-based and airborne campaigns in the coming years.

A comparison of FerryBox data vs. monitoring data from research vessels for near surface waters of the Baltic Sea and the Kattegat

2016 ◽  
Vol 162 ◽  
pp. 98-111 ◽  
Author(s):  
B. Karlson ◽  
L.S. Andersson ◽  
S. Kaitala ◽  
J. Kronsell ◽  
M. Mohlin ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Surface Waters ◽  
Monitoring Data ◽  
The Baltic Sea ◽  
Near Surface ◽  
The Baltic

scholarly journals Sensitivity of the air–sea CO<sub>2</sub> exchange in the Baltic Sea and Danish inner waters to atmospheric short-term variability

2015 ◽  
Vol 12 (9) ◽  
pp. 2753-2772 ◽  
Author(s):  
A. S. Lansø ◽  
J. Bendtsen ◽  
J. H. Christensen ◽  
L. L. Sørensen ◽  
H. Chen ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Co2 Flux ◽  
Co2 Concentration ◽  
Co2 Exchange ◽  
Atmospheric Co2 ◽  
The Baltic Sea ◽  
Short Term ◽  
Transfer Velocity ◽  
The Baltic ◽  
Short Term Variability

Abstract. Minimising the uncertainties in estimates of air–sea CO2 exchange is an important step toward increasing the confidence in assessments of the CO2 cycle. Using an atmospheric transport model makes it possible to investigate the direct impact of atmospheric parameters on the air–sea CO2 flux along with its sensitivity to, for example, short-term temporal variability in wind speed, atmospheric mixing height and atmospheric CO2 concentration. With this study, the importance of high spatiotemporal resolution of atmospheric parameters for the air–sea CO2 flux is assessed for six sub-basins within the Baltic Sea and Danish inner waters. A new climatology of surface water partial pressure of CO2 (pCO2w) has been developed for this coastal area based on available data from monitoring stations and on-board pCO2w measuring systems. Parameterisations depending on wind speed were applied for the transfer velocity to calculate the air–sea CO2 flux. Two model simulations were conducted – one including short-term variability in atmospheric CO2 (VAT), and one where it was not included (CAT). A seasonal cycle in the air–sea CO2 flux was found for both simulations for all sub-basins with uptake of CO2 in summer and release of CO2 to the atmosphere in winter. During the simulated period 2005–2010, the average annual net uptake of atmospheric CO2 for the Baltic Sea, Danish straits and Kattegat was 287 and 471 Gg C yr−1 for the VAT and CAT simulations, respectively. The obtained difference of 184 Gg C yr−1 was found to be significant, and thus ignoring short-term variability in atmospheric CO2 does have a sizeable effect on the air–sea CO2 exchange. The combination of the atmospheric model and the new pCO2w fields has also made it possible to make an estimate of the marine part of the Danish CO2 budget for the first time. A net annual uptake of 2613 Gg C yr−1 was found for the Danish waters. A large uncertainty is connected to the air–sea CO2 flux in particular caused by the transfer velocity parameterisation and the applied pCO2w climatology. However, as a significant difference of 184 Gg C yr−1 is obtained between the VAT and CAT simulations, the present study underlines the importance of including short-term variability in atmospheric CO2 concentration in future model studies of the air–sea exchange in order to minimise the uncertainty.

Estimation of heat fluxes at the ocean-atmosphere interface in the south-western part of the Baltic Sea (2003—2016)

2019 ◽  
Vol 151 (4) ◽  
pp. 15-26
Author(s):  
V. F. Dubravin ◽  
M. V. Kapustina ◽  
Zh. I. Stont
Keyword(s):  
Baltic Sea ◽  
Latent Heat ◽  
Monitoring Network ◽  
Sampling Interval ◽  
Heat Fluxes ◽  
The Baltic Sea ◽  
Annual Variability ◽  
Daily Variability ◽  
The Baltic ◽  
Station Location

Based hydrometeorological data of the MARNET monitoring network, with the sampling interval of 1-hour, from 2003—2016, provided by the German Oceanographic Data Centre (BSH / DOD (M41)), the contributions of the irregular daily variability, the regular daily variability, the synoptic variability, the irregular intra-annual variability, the regular seasonal variability and the interannual component in the total temporal variability of the sensible and latent heat fluxes were estimated. The intra-annual and inter-annual variability of the specific contribution of the daily component of the sensible and latent heat fluxes are computed. It is shown that the structure of time variations of the fluxes in the southern part of the Baltic Sea depends on both, the station location and the nature of the flux itself.

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