GLORIA

GEOMAR Library Ocean Research Information Access

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
Document type
Keywords
Publisher
Language
Years
  • 1
    facet.materialart.
    Unknown
    Eddy covariance observations of CO2, latent heat, and sensible heat fluxes at the Spiekeroog Coastal Observatory (2023)
    PANGAEA
    Details
    Publication Date: 2023-10-07
    Description: Observations of vertical fluxes of CO2, latent heat, and sensible heat were made at the Spiekeroog Coastal Observatory in the German Wadden Sea between 1.1.2021 and 28.12.2022. Measurements were made with an eddy covariance (EC) system consisting of a sonic anemometer (Gill Windmaster) and infrared gas analyzer (Li-7200), and processed in EddyPro according to standard methods. This dataset was gathered for the purpose of investigating the drivers of air-sea fluxes, but includes observations of fluxes influenced by the nearby Spiekeroog island, which may also be of interest. Identification of land vs sea fluxes can be made with a flux footprint analysis and by screening according to wind direction.
    Keywords: Carbon dioxide, density; Carbon dioxide, flux; Carbon dioxide mixing ratio; Carbon dioxide mixing ratio, variance; Carbon Storage in German Coastal Seas - Stability, Vulnerability and Perspectives for Manageability; Carbostore; DATE/TIME; Day of the year; Eddy Covariance System; equipped with a sonic anemometer, Gill Windmaster, and infrared gas analyzer, Li-7200; Friction velocity; German Bight, North Sea; Heat, flux, sensible; HEIGHT above ground; Helmholtz-Zentrum Hereon; Hereon; Momentum, flux; Monin-Obukhov-length; Monin-Obukhov stability; Monitoring station; MONS; Quality flag, carbon dioxide, flux; Quality flag, heat, flux, sensible; Quality flag, momentum flux; Quality flag according to Mauder and Foken, 2004; Spiekeroog_TSS; Temperature, air; Time of day; Turbulence kinetic energy; Wind direction; Wind speed; Wind speed, along-wind, rotated, mean; Wind speed, cross-wind, rotated, mean; Wind speed, maximum; Wind speed, vertical, rotated, mean
    Type: Dataset
    Format: text/tab-separated-values, 123878 data points
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    DATA PANGAEA
  • 2
    facet.materialart.
    Unknown
    Water temperature control on CO2 flux and evaporation over a subtropical seagrass meadow revealed by atmospheric eddy covariance (2021)
    John Wiley & Sons, Inc. | Hoboken, USA
    Details
    Publication Date: 2021-07-01
    Description: Subtropical seagrass meadows play a major role in the coastal carbon cycle, but the nature of air–water CO2 exchanges over these ecosystems is still poorly understood. The complex physical forcing of air–water exchange in coastal waters challenges our ability to quantify bulk exchanges of CO2 and water (evaporation), emphasizing the need for direct measurements. We describe the first direct measurements of evaporation and CO2 flux over a calcifying seagrass meadow near Bob Allen Keys, Florida. Over the 78‐d study, CO2 emissions were 36% greater during the day than at night, and the site was a net CO2 source to the atmosphere of 0.27 ± 0.17 μmol m−2 s−1 (x̅ ± standard deviation). A quarter (23%) of the diurnal variability in CO2 flux was caused by the effect of changing water temperature on gas solubility. Furthermore, evaporation rates were ~ 10 times greater than precipitation, causing a 14% increase in salinity, a potential precursor of seagrass die‐offs. Evaporation rates were not correlated with solar radiation, but instead with air–water temperature gradient and wind shear. We also confirm the role of convective forcing on night‐time enhancement and day‐time suppression of gas transfer. At this site, temperature trends are regulated by solar heating, combined with shallow water depth and relatively consistent air temperature. Our findings indicate that evaporation and air–water CO2 exchange over shallow, tropical, and subtropical seagrass ecosystems may be fundamentally different than in submerged vegetated environments elsewhere, in part due to the complex physical forcing of coastal air–sea gas transfer.
    Description: Deutscher Akademischer Austauschdienst http://dx.doi.org/10.13039/501100001655
    Description: National Science Foundation http://dx.doi.org/10.13039/100000001
    Keywords: 551.5 ; Florida ; Bob Allen Keys ; seagrass meadows ; air–water CO2 exchanges ; biometeorological measurements
    Type: article
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    CITATION GEO-LEO
  • 3
    facet.materialart.
    Unknown
    Parameterizing Air-Water Gas Exchange in the Shallow, Microtidal New River Estuary (2021)
    Details
    Publication Date: 2021-10-14
    Description: Estuarine CO2 emissions are important components of regional and global carbon budgets, but assessments of this flux are plagued by uncertainties associated with gas transfer velocity (k) parameterization. We combined direct eddy covariance measurements of CO2 flux with waterside pCO2 determinations to generate more reliable k parameterizations for use in small estuaries. When all data were aggregated, k was described well by a linear relationship with wind speed (U10), in a manner consistent with prior open ocean and estuarine k parameterizations. However, k was significantly greater at night and under low wind speed, and nighttime k was best predicted by a parabolic, rather than linear, relationship with U10. We explored the effect of waterside thermal convection but found only a weak correlation between convective scale and k. Hence, while convective forcing may be important at times, it appears that factors besides waterside thermal convection were likely responsible for the bulk of the observed nighttime enhancement in k. Regardless of source, we show that these day-night differences in k should be accounted for when CO2 emissions are assessed over short time scales or when pCO2 is constant and U10 varies. On the other hand, when temporal variability in pCO2 is large, it exerts greater control over CO2 fluxes than does k parameterization. In these cases, the use of a single k value or a simple linear relationship with U10 is often sufficient. This study provides important guidance for k parameterization in shallow or microtidal estuaries, especially when diel processes are considered.
    Keywords: 551 ; air-water CO2 exchange ; gas transfer velocity ; convective ; eddy covariance ; estuary ; gas exchange
    Language: English
    Type: map
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    CITATION GEO-LEO
  • 4
    facet.materialart.
    Unknown
    Parameterizing air-water gas exchange in the shallow, microtidal New River estuary (2019)
    American Geophysical Union
    Details
    Publication Date: 2022-10-20
    Description: © The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution-NonCommercial‐NoDerivs License. The definitive version was published in Van Dam, B. R., Edson, J. B., & Tobias, C. Parameterizing air-water gas exchange in the shallow, microtidal New River estuary. Journal of Geophysical Research-Biogeosciences, 124(7), (2019): 2351-2363, doi: 10.1029/2018JG004908.
    Description: Estuarine CO2 emissions are important components of regional and global carbon budgets, but assessments of this flux are plagued by uncertainties associated with gas transfer velocity (k) parameterization. We combined direct eddy covariance measurements of CO2 flux with waterside pCO2 determinations to generate more reliable k parameterizations for use in small estuaries. When all data were aggregated, k was described well by a linear relationship with wind speed (U10), in a manner consistent with prior open ocean and estuarine k parameterizations. However, k was significantly greater at night and under low wind speed, and nighttime k was best predicted by a parabolic, rather than linear, relationship with U10. We explored the effect of waterside thermal convection but found only a weak correlation between convective scale and k. Hence, while convective forcing may be important at times, it appears that factors besides waterside thermal convection were likely responsible for the bulk of the observed nighttime enhancement in k. Regardless of source, we show that these day‐night differences in k should be accounted for when CO2 emissions are assessed over short time scales or when pCO2 is constant and U10 varies. On the other hand, when temporal variability in pCO2 is large, it exerts greater control over CO2 fluxes than does k parameterization. In these cases, the use of a single k value or a simple linear relationship with U10 is often sufficient. This study provides important guidance for k parameterization in shallow or microtidal estuaries, especially when diel processes are considered.
    Description: We thank SERDP and DCERP for funding and support. Dennis Arbige assisted with EC tower construction, and Susan Cohen provided invaluable logistical support. I also thank Marc Alperin (UNC Chapel Hill) for his thoughtful guidance and encouragement with this project. All data sets for this manuscript are available at FigShare (https://doi.org/10.6084/m9.figshare.7276877.v1). Additional funding for this project was provided by DAAD (57429828) from funds of the German Federal Ministry of Education and Research (BMBF).
    Keywords: Air‐water CO2 exchange ; Gas transfer velocity ; Convective ; Eddy covariance ; Estuary ; Gas exchange
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    PAPER (OA)
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...