1
|
Liu X, Li X, Shi F, Wang Z, Liu M, Zhang X, Zhang Z. Thermal structure regulates the dynamics of carbon dioxide flux in alpine saline lake on the Qinghai-Tibet Plateau, China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 931:172700. [PMID: 38657815 DOI: 10.1016/j.scitotenv.2024.172700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Revised: 04/20/2024] [Accepted: 04/21/2024] [Indexed: 04/26/2024]
Abstract
Thermal stratification and mixing play important roles in the physicochemical composition of lakes and affect the geochemical cycle. However, the regulation of lake carbon exchange at the water-air interface by seasonal thermal structures remains unclear, especially for alpine saline lake on the Qinghai-Tibet Plateau (QTP). Based on continuous field sampling, carbon dioxide flux (FCO2) at the water-air interface in Qinghai Lake during the ice-free period was quantitatively analyzed by thin boundary layer model, as well as the driving factors of the change in FCO2 at the water-air interface. The findings revealed that the FCO2 was -22.16 ± 11.73 mmol m-2d-1 during the stratification period, and - 45.32 ± 29.67 mmol m-2d-1 during the mixing period. We found that thermal stratification limits the matter-energy exchange between the upper and bottom water columns, and carbonate precipitation results in a higher FCO2 than during mixing stage. However, the mixing process reduces the limiting effect of thermal stratification. During the carbonate process, water with higher salinity and pH at the bottom of the water column enters the upper part of the water column, reducing the partial pressure of carbon dioxide (pCO2) in the water column and causing the absorption of CO2 by the lake. Thermal stratification affects the vertical material-energy exchange and atmospheric CO2 uptake of lake. The present study further explains the possible underlying regulation of CO2 uptake in saline lake on the QTP involving the varied thermal structure.
Collapse
Affiliation(s)
- Xin Liu
- State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China; School of Natural Resources, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China
| | - Xiaoyan Li
- State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China; School of Natural Resources, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China; Academy of Plateau Science and Sustainability, Qinghai Normal University, Xining 810016, China; College of Geographical Sciences, Qinghai Normal University, Xining 810016, China.
| | - Fangzhong Shi
- State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China; School of Natural Resources, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China; Research and Development Center for Watershed Environmental Eco-Engineering, Beijing Normal University at Zhuhai, Zhuhai 519085, China
| | - Zhigang Wang
- State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China; School of Natural Resources, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China
| | - Menglin Liu
- College of Geographical Sciences, Qinghai Normal University, Xining 810016, China
| | - Xia Zhang
- State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China; School of Natural Resources, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China
| | - Zhanfei Zhang
- State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China; School of Natural Resources, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China
| |
Collapse
|
2
|
Rahlff J, Wietz M, Giebel HA, Bayfield O, Nilsson E, Bergström K, Kieft K, Anantharaman K, Ribas-Ribas M, Schweitzer HD, Wurl O, Hoetzinger M, Antson A, Holmfeldt K. Ecogenomics and cultivation reveal distinctive viral-bacterial communities in the surface microlayer of a Baltic Sea slick. ISME COMMUNICATIONS 2023; 3:97. [PMID: 37723220 PMCID: PMC10507051 DOI: 10.1038/s43705-023-00307-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Accepted: 09/06/2023] [Indexed: 09/20/2023]
Abstract
Visible surface films, termed slicks, can extensively cover freshwater and marine ecosystems, with coastal regions being particularly susceptible to their presence. The sea-surface microlayer (SML), the upper 1-mm at the air-water interface in slicks (herein slick SML) harbors a distinctive bacterial community, but generally little is known about SML viruses. Using flow cytometry, metagenomics, and cultivation, we characterized viruses and bacteria in a brackish slick SML in comparison to non-slick SML as well as seawater below slick and non-slick areas (subsurface water = SSW). Size-fractionated filtration of all samples distinguished viral attachment to hosts and particles. The slick SML contained higher abundances of virus-like particles, prokaryotic cells, and dissolved organic carbon compared to non-slick SML and SSW. The community of 428 viral operational taxonomic units (vOTUs), 426 predicted as lytic, distinctly differed across all size fractions in the slick SML compared to non-slick SML and SSW. Specific metabolic profiles of bacterial metagenome-assembled genomes and isolates in the slick SML included a prevalence of genes encoding motility and carbohydrate-active enzymes (CAZymes). Several vOTUs were enriched in slick SML, and many virus variants were associated with particles. Nine vOTUs were only found in slick SML, six of them being targeted by slick SML-specific clustered-regularly interspaced short palindromic repeats (CRISPR) spacers likely originating from Gammaproteobacteria. Moreover, isolation of three previously unknown lytic phages for Alishewanella sp. and Pseudoalteromonas tunicata, abundant and actively replicating slick SML bacteria, suggests that viral activity in slicks contributes to biogeochemical cycling in coastal ecosystems.
Collapse
Affiliation(s)
- Janina Rahlff
- Centre for Ecology and Evolution in Microbial Model Systems (EEMiS), Department of Biology and Environmental Science, Linnaeus University, Kalmar, Sweden.
| | - Matthias Wietz
- Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
- Max Planck Institute for Marine Microbiology, Bremen, Germany
| | - Helge-Ansgar Giebel
- Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl von Ossietzky University of Oldenburg, Oldenburg, Germany
- Center for Marine Sensors (ZfMarS), Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl von Ossietzky University of Oldenburg, Wilhelmshaven, Germany
| | - Oliver Bayfield
- York Structural Biology Laboratory, Department of Chemistry, University of York, York, UK
| | - Emelie Nilsson
- Centre for Ecology and Evolution in Microbial Model Systems (EEMiS), Department of Biology and Environmental Science, Linnaeus University, Kalmar, Sweden
| | - Kristofer Bergström
- Centre for Ecology and Evolution in Microbial Model Systems (EEMiS), Department of Biology and Environmental Science, Linnaeus University, Kalmar, Sweden
| | - Kristopher Kieft
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, USA
| | | | - Mariana Ribas-Ribas
- Center of Marine Sensors (ZfMarS), Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl von Ossietzky University of Oldenburg, Wilhelmshaven, Germany
| | | | - Oliver Wurl
- Center of Marine Sensors (ZfMarS), Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl von Ossietzky University of Oldenburg, Wilhelmshaven, Germany
| | - Matthias Hoetzinger
- Centre for Ecology and Evolution in Microbial Model Systems (EEMiS), Department of Biology and Environmental Science, Linnaeus University, Kalmar, Sweden
| | - Alfred Antson
- York Structural Biology Laboratory, Department of Chemistry, University of York, York, UK
| | - Karin Holmfeldt
- Centre for Ecology and Evolution in Microbial Model Systems (EEMiS), Department of Biology and Environmental Science, Linnaeus University, Kalmar, Sweden
| |
Collapse
|
3
|
Nichol JE, Antonarakis AS, Nazeer M. Monitoring the Sea Surface Microlayer (SML) on Sentinel images. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 872:162218. [PMID: 36796692 DOI: 10.1016/j.scitotenv.2023.162218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 01/21/2023] [Accepted: 02/09/2023] [Indexed: 06/18/2023]
Abstract
Slicks on the sea surface are usually related to oil spills, algal blooms or organic runoff around coastlines. An extensive network of slicks extending across the English Channel is seen on Sentinel 1 and Sentinel 2 images and are identified as comprising a film of natural surfactant material within the sea surface microlayer (SML). As the SML represents the interface between ocean and atmosphere, controlling the vital exchange of gases and aerosols, identification of the slicks on images can add a new dimension to climate modelling. Current models use primary productivity often combined with wind speed, but quantifying the global extent of surface films spatially and temporally is difficult due to their patchy nature. The slicks are shown to be visible on Sentinel 2 optical images affected by sun glint, due to the wave dampening effect of the surfactants. On a Sentinel 1 SAR image of the same day, they can be identified using the VV polarised band. The paper investigates the nature and spectral properties of the slicks in relation to sun glint, and evaluates the performance of chlorophyll-a, floating algae and floating debris indices on the slick-affected areas. No index was able to distinguish slicks from non-slick areas as successfully as the original sun glint image. This image was used to devise a tentative Surfactant Index (SI) which indicates over 40 % of the study area covered by slicks. As ocean sensors have lower spatial resolution and are generally designed to avoid sun glint, Sentinel 1 SAR may offer a useful alternative for monitoring the global spatial extent of surface films, until dedicated sensors and algorithms can be developed.
Collapse
Affiliation(s)
- Janet E Nichol
- Department of Geography, School of Global Studies, University of Sussex, Brighton BN19RH, UK.
| | - Alexander S Antonarakis
- Department of Geography, School of Global Studies, University of Sussex, Brighton BN19RH, UK
| | - Majid Nazeer
- Department of Land Surveying and Geo-Informatics, The Hong Kong Polytechnic University, Hong Kong; Research Institute for Land and Space, The Hong Kong Polytechnic University, Hong Kong
| |
Collapse
|
4
|
Penezić A, Wang X, Perrier S, George C, Frka S. Interfacial photochemistry of marine diatom lipids: Abiotic production of volatile organic compounds and new particle formation. CHEMOSPHERE 2023; 313:137510. [PMID: 36495976 DOI: 10.1016/j.chemosphere.2022.137510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 11/29/2022] [Accepted: 12/06/2022] [Indexed: 06/17/2023]
Abstract
The global importance of abiotic oceanic production of volatile organic compounds (VOCs) still presents a source of high uncertainties related to secondary organic aerosol (SOA) formation. A better understanding of the photochemistry occurring at the ocean-atmosphere interface is particularly important in that regard, as it covers >70% of the Earth's surface. In this work, we focused on the photochemical VOCs production at the air-water interface containing organic material from authentic culture of marine diatom Chaetoceros pseudocurvisetus. Abiotic VOCs production upon irradiation of material originating from total phytoplankton culture as well as the fraction containing only dissolved material was monitored by means of PTR-ToF-MS. Furthermore, isolated dissolved lipid fraction was investigated after its deposition at the air-water interface. All samples acted as a source of VOCs, producing saturated oxygenated compounds such as aldehydes and ketones, as well as unsaturated and functionalized compounds. Additionally, a significant increase in surfactant activity following irradiation experiments observed for all samples implied biogenic material photo-transformation at the air-water interface. The highest VOCs flux normalized per gram of carbon originated from lipid material, and the produced VOCs were introduced into an atmospheric simulation chamber, where particle formation was observed after its gas-phase ozonolysis. This work clearly demonstrates abiotic production of VOCs from phytoplankton derived organic material upon irradiation, facilitated by its presence at the air/water interface, with significant potential for affecting the global climate as a precursor of particle formation.
Collapse
Affiliation(s)
- Abra Penezić
- Division for Marine and Environmental Research, Ruđer Bošković Institute, Zagreb, Croatia.
| | - Xinke Wang
- Université Lyon, Université Claude Bernard Lyon 1 CNRS, IRCELYON, Villeurbanne, France; Now at Department of Chemistry, University of California, Irvine, CA, 92697-2025, USA
| | - Sebastien Perrier
- Université Lyon, Université Claude Bernard Lyon 1 CNRS, IRCELYON, Villeurbanne, France
| | - Christian George
- Université Lyon, Université Claude Bernard Lyon 1 CNRS, IRCELYON, Villeurbanne, France
| | - Sanja Frka
- Division for Marine and Environmental Research, Ruđer Bošković Institute, Zagreb, Croatia.
| |
Collapse
|
5
|
Alsante AN, Thornton DCO, Brooks SD. Ocean Aerobiology. Front Microbiol 2021; 12:764178. [PMID: 34777320 PMCID: PMC8586456 DOI: 10.3389/fmicb.2021.764178] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 09/27/2021] [Indexed: 12/12/2022] Open
Abstract
Ocean aerobiology is defined here as the study of biological particles of marine origin, including living organisms, present in the atmosphere and their role in ecological, biogeochemical, and climate processes. Hundreds of trillions of microorganisms are exchanged between ocean and atmosphere daily. Within a few days, tropospheric transport potentially disperses microorganisms over continents and between oceans. There is a need to better identify and quantify marine aerobiota, characterize the time spans and distances of marine microorganisms’ atmospheric transport, and determine whether microorganisms acclimate to atmospheric conditions and remain viable, or even grow. Exploring the atmosphere as a microbial habitat is fundamental for understanding the consequences of dispersal and will expand our knowledge of biodiversity, biogeography, and ecosystem connectivity across different marine environments. Marine organic matter is chemically transformed in the atmosphere, including remineralization back to CO2. The magnitude of these transformations is insignificant in the context of the annual marine carbon cycle, but may be a significant sink for marine recalcitrant organic matter over long (∼104 years) timescales. In addition, organic matter in sea spray aerosol plays a significant role in the Earth’s radiative budget by scattering solar radiation, and indirectly by affecting cloud properties. Marine organic matter is generally a poor source of cloud condensation nuclei (CCN), but a significant source of ice nucleating particles (INPs), affecting the formation of mixed-phase and ice clouds. This review will show that marine biogenic aerosol plays an impactful, but poorly constrained, role in marine ecosystems, biogeochemical processes, and the Earth’s climate system. Further work is needed to characterize the connectivity and feedbacks between the atmosphere and ocean ecosystems in order to integrate this complexity into Earth System models, facilitating future climate and biogeochemical predictions.
Collapse
Affiliation(s)
- Alyssa N Alsante
- Department of Oceanography, Texas A&M University, College Station, TX, United States
| | - Daniel C O Thornton
- Department of Oceanography, Texas A&M University, College Station, TX, United States
| | - Sarah D Brooks
- Department of Atmospheric Sciences, Texas A&M University, College Station, TX, United States
| |
Collapse
|
6
|
Zhang T, Li J, Pu J, Wu F. Physical and chemical control on CO 2 gas transfer velocities from a low-gradient subtropical stream. WATER RESEARCH 2021; 204:117564. [PMID: 34455157 DOI: 10.1016/j.watres.2021.117564] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 07/28/2021] [Accepted: 08/11/2021] [Indexed: 06/13/2023]
Abstract
CO2 exchanges across the water-air interface in rivers and lakes are currently believed to be responsible for the dominant share of global aquatic CO2 emissions. The gas transfer velocity (k600) is the key factor that constrains the CO2 fluxes. It is also the most problematic to establish because of its high spatial and temporal variability. Here, we have evaluated the seasonal and spatial dynamics in k600 values and their physical and chemical controlling processes by gas tracer and floating chamber (FC) methods in three reaches of a low-gradient stream channel (Guancun surface stream, 'GSS') in a karst terrain in subtropical southwestern China in December 2016 and March, July and September 2017. The k600 values were highly variable in space and time in this small stream. Physical processes, including the velocity of the stream and its slope, were found to control the variations of k600. The k600 values recorded in the dry season (March and December) were at minimal levels due to very slow flow and gentle slope, and were also affected by complexation in the solute-enriched waters. The characteristics high pH and low turbulence of gentle streams in carbonate karst areas are conducive to such complexation, which is of great significance in the limiting CO2 degassing in such regions. We have obtained the first k600 prediction model for small streams in subtropical karst regions. In conclusion, we present a comprehensive approach for predicting the k600 values in small channels by comparison of independent SF6 gas tracer and floating chamber methods.
Collapse
Affiliation(s)
- Tao Zhang
- Chongqing Key Laboratory of Surface Process and Environment Remote Sensing in the Three Gorges Reservoir Area, School of Geography and Tourism Science, Chongqing Normal University, Chongqing 401331, China; Key Laboratory of Karst Dynamics, MNR & Guangxi, Institute of Karst Geology, Chinese Academy of Geological Sciences, Guilin 541004, China
| | - Jianhong Li
- Key Laboratory of Karst Dynamics, MNR & Guangxi, Institute of Karst Geology, Chinese Academy of Geological Sciences, Guilin 541004, China
| | - Junbing Pu
- Chongqing Key Laboratory of Surface Process and Environment Remote Sensing in the Three Gorges Reservoir Area, School of Geography and Tourism Science, Chongqing Normal University, Chongqing 401331, China; Key Laboratory of Karst Dynamics, MNR & Guangxi, Institute of Karst Geology, Chinese Academy of Geological Sciences, Guilin 541004, China.
| | - Feihong Wu
- Key Laboratory of Karst Dynamics, MNR & Guangxi, Institute of Karst Geology, Chinese Academy of Geological Sciences, Guilin 541004, China
| |
Collapse
|
7
|
Yang M, Smyth TJ, Kitidis V, Brown IJ, Wohl C, Yelland MJ, Bell TG. Natural variability in air-sea gas transfer efficiency of CO 2. Sci Rep 2021; 11:13584. [PMID: 34193883 PMCID: PMC8245487 DOI: 10.1038/s41598-021-92947-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 06/18/2021] [Indexed: 11/29/2022] Open
Abstract
The flux of CO2 between the atmosphere and the ocean is often estimated as the air–sea gas concentration difference multiplied by the gas transfer velocity (K660). The first order driver for K660 over the ocean is wind through its influence on near surface hydrodynamics. However, field observations have shown substantial variability in the wind speed dependencies of K660. In this study we measured K660 with the eddy covariance technique during a ~ 11,000 km long Southern Ocean transect. In parallel, we made a novel measurement of the gas transfer efficiency (GTE) based on partial equilibration of CO2 using a Segmented Flow Coil Equilibrator system. GTE varied by 20% during the transect, was distinct in different water masses, and related to K660. At a moderate wind speed of 7 m s−1, K660 associated with high GTE exceeded K660 with low GTE by 30% in the mean. The sensitivity of K660 towards GTE was stronger at lower wind speeds and weaker at higher wind speeds. Naturally-occurring organics in seawater, some of which are surface active, may be the cause of the variability in GTE and in K660. Neglecting these variations could result in biases in the computed air–sea CO2 fluxes.
Collapse
Affiliation(s)
- Mingxi Yang
- Plymouth Marine Laboratory, Prospect Place, Plymouth, UK.
| | | | | | - Ian J Brown
- Plymouth Marine Laboratory, Prospect Place, Plymouth, UK
| | - Charel Wohl
- Plymouth Marine Laboratory, Prospect Place, Plymouth, UK
| | | | - Thomas G Bell
- Plymouth Marine Laboratory, Prospect Place, Plymouth, UK
| |
Collapse
|
8
|
Coupling Vortical Bulk Flows to the Air–Water Interface: From Putting Oil on Troubled Waters to Surfactants on Protein Solutions. FLUIDS 2021. [DOI: 10.3390/fluids6060198] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The air–water interface in flowing systems remains a challenge to model, even in cases where the interface is essentially flat. This is because even though each side is governed by the Navier–Stokes equations, the stress balance which provides the boundary conditions for the equations involves properties associated with surfactants that are inevitably present at the air–water interface. Aside from challenges in measuring interfacial properties, either intrinsic or flow-dependent, the two-way coupling of bulk and interfacial flows is non-trivial, even for very simple flow geometries. Here, we present an overview of the physics associated with surfactant monolayers of flowing liquid and describe how the monolayer affects the bulk flow and how the monolayer is transported and deformed by the bulk flow. The emphasis is primarily on cylindrical flow geometries, and both Newtonian and non-Newtonian interfacial responses are considered. We consider interfacial flows that are solenoidal as well as those where the surface velocity is not divergence free.
Collapse
|
9
|
Sensitivity of Modeled CO2 Air–Sea Flux in a Coastal Environment to Surface Temperature Gradients, Surfactants, and Satellite Data Assimilation. REMOTE SENSING 2020. [DOI: 10.3390/rs12122038] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This work evaluates the sensitivity of CO2 air–sea gas exchange in a coastal site to four different model system configurations of the 1D coupled hydrodynamic–ecosystem model GOTM–ERSEM, towards identifying critical dynamics of relevance when specifically addressing quantification of air–sea CO2 exchange. The European Sea Regional Ecosystem Model (ERSEM) is a biomass and functional group-based biogeochemical model that includes a comprehensive carbonate system and explicitly simulates the production of dissolved organic carbon, dissolved inorganic carbon and organic matter. The model was implemented at the coastal station L4 (4 nm south of Plymouth, 50°15.00’N, 4°13.02’W, depth of 51 m). The model performance was evaluated using more than 1500 hydrological and biochemical observations routinely collected at L4 through the Western Coastal Observatory activities of 2008–2009. In addition to a reference simulation (A), we ran three distinct experiments to investigate the sensitivity of the carbonate system and modeled air–sea fluxes to (B) the sea-surface temperature (SST) diurnal cycle and thus also the near-surface vertical gradients, (C) biological suppression of gas exchange and (D) data assimilation using satellite Earth observation data. The reference simulation captures well the physical environment (simulated SST has a correlation with observations equal to 0.94 with a p > 0.95). Overall, the model captures the seasonal signal in most biogeochemical variables including the air–sea flux of CO2 and primary production and can capture some of the intra-seasonal variability and short-lived blooms. The model correctly reproduces the seasonality of nutrients (correlation > 0.80 for silicate, nitrate and phosphate), surface chlorophyll-a (correlation > 0.43) and total biomass (correlation > 0.7) in a two year run for 2008–2009. The model simulates well the concentration of DIC, pH and in-water partial pressure of CO2 (pCO2) with correlations between 0.4–0.5. The model result suggest that L4 is a weak net source of CO2 (0.3–1.8 molCm−2 year−1). The results of the three sensitivity experiments indicate that both resolving the temperature profile near the surface and assimilation of surface chlorophyll-a significantly impact the skill of simulating the biogeochemistry at L4 and all of the carbonate chemistry related variables. These results indicate that our forecasting ability of CO2 air–sea flux in shelf seas environments and their impact in climate modeling should consider both model refinements as means of reducing uncertainties and errors in any future climate projections.
Collapse
|
10
|
Mustaffa NIH, Ribas-Ribas M, Banko-Kubis HM, Wurl O. Global reduction of in situ CO 2 transfer velocity by natural surfactants in the sea-surface microlayer. Proc Math Phys Eng Sci 2020; 476:20190763. [PMID: 32201480 PMCID: PMC7069489 DOI: 10.1098/rspa.2019.0763] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 12/18/2019] [Indexed: 11/17/2022] Open
Abstract
For decades, the effect of surfactants in the sea-surface microlayer (SML) on gas transfer velocity (k) has been recognized; however, it has not been quantified under natural conditions due to missing coherent data on in situ k of carbon dioxide (CO2) and characterization of the SML. Moreover, a sea-surface phenomenon of wave-dampening, known as slicks, has been observed frequently in the ocean and potentially reduces the transfer of climate-relevant gases between the ocean and atmosphere. Therefore, this study aims to quantify the effect of natural surfactant and slicks on the in situ k of CO2. A catamaran, Sea Surface Scanner (S3), was deployed to sample the SML and corresponding underlying water, and a drifting buoy with a floating chamber was deployed to measure the in situ k of CO2. We found a significant 23% reduction of k above surfactant concentrations of 200 µg Teq l-1, which were common in the SML except for the Western Pacific. We conclude that an error of approximately 20% in CO2 fluxes for the Western Pacific is induced by applying wind-based parametrization not developed in low surfactant regimes. Furthermore, we observed an additional 62% reduction in natural slicks, reducing global CO2 fluxes by 19% considering known frequency of slick coverage. From our observation, we identified surfactant concentrations with two different end-members which lead to an error in global CO2 flux estimation if ignored.
Collapse
Affiliation(s)
- Nur Ili Hamizah Mustaffa
- Institute for Chemistry and Biology of the Marine Environment, Carl Von Ossietzky Universität Oldenburg, 26382 Wilhelmshaven, Germany
- Center for Marine Sensors, Institute for Chemistry and Biology of the Marine Environment, Carl von Ossietzky Universität Oldenburg, 26382 Wilhelmshaven, Germany
| | - Mariana Ribas-Ribas
- Center for Marine Sensors, Institute for Chemistry and Biology of the Marine Environment, Carl von Ossietzky Universität Oldenburg, 26382 Wilhelmshaven, Germany
| | - Hanne M. Banko-Kubis
- Center for Marine Sensors, Institute for Chemistry and Biology of the Marine Environment, Carl von Ossietzky Universität Oldenburg, 26382 Wilhelmshaven, Germany
| | - Oliver Wurl
- Center for Marine Sensors, Institute for Chemistry and Biology of the Marine Environment, Carl von Ossietzky Universität Oldenburg, 26382 Wilhelmshaven, Germany
| |
Collapse
|
11
|
Mustaffa NIH, Badewien TH, Ribas-Ribas M, Wurl O. High-resolution observations on enrichment processes in the sea-surface microlayer. Sci Rep 2018; 8:13122. [PMID: 30177725 PMCID: PMC6120901 DOI: 10.1038/s41598-018-31465-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 08/21/2018] [Indexed: 01/16/2023] Open
Abstract
For decades, researchers assumed that enrichment of dissolved organic matter (DOM) in the sea surface microlayer (SML) is solely controlled by changes in the DOM concentration at this uppermost thin boundary layer between the ocean and the atmosphere. We conducted high-resolution observations of fluorescent-DOM (FDOM) at 13 stations in the coastal and open Atlantic Ocean to understand the enrichment processes. Results show that FDOM enrichment in the SML varied between 0.8 and 2.0 (in comparison to the concentrations in the underlying water; ULW), and FDOM enrichment is a common feature of the SML despite the varied distances to the terrestrial sources. At six stations, the FDOM concentration in the SML was less variable over the sampling period (>5 h) compared to FDOM concentrations in the ULW characterized with sudden changes. Even so we observed slightly lower enrichments with increasing wind speeds and solar radiation, changes in ULW concentrations forced the enrichment to change. In addition, we found evidences for the occurrence of photochemical degradation of FDOM in near-shore SML with implications on coastal carbon cycling. Overall, the results show that the processes leading to the enrichment of DOM in the SML are more complex than previously assumed. Given the importance of the organic-rich SML as a diffusion layer in the air-sea exchange of climate-relevant gases and heat, understanding the layer's enrichment processes is crucial.
Collapse
Affiliation(s)
- Nur Ili Hamizah Mustaffa
- Institute for Chemistry and Biology of the Marine Environment, Carl Von Ossietzky Universität Oldenburg, 26382, Wilhelmshaven, Germany.
| | - Thomas H Badewien
- Institute for Chemistry and Biology of the Marine Environment, Carl Von Ossietzky Universität Oldenburg, 26382, Wilhelmshaven, Germany
| | - Mariana Ribas-Ribas
- Institute for Chemistry and Biology of the Marine Environment, Carl Von Ossietzky Universität Oldenburg, 26382, Wilhelmshaven, Germany
| | - Oliver Wurl
- Institute for Chemistry and Biology of the Marine Environment, Carl Von Ossietzky Universität Oldenburg, 26382, Wilhelmshaven, Germany
| |
Collapse
|
12
|
Zäncker B, Bracher A, Röttgers R, Engel A. Variations of the Organic Matter Composition in the Sea Surface Microlayer: A Comparison between Open Ocean, Coastal, and Upwelling Sites Off the Peruvian Coast. Front Microbiol 2017; 8:2369. [PMID: 29375483 PMCID: PMC5770621 DOI: 10.3389/fmicb.2017.02369] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 11/16/2017] [Indexed: 11/17/2022] Open
Abstract
The sea surface microlayer (SML) is the thin boundary layer between the ocean and the atmosphere, making it important for air-sea exchange processes. However, little is known about what controls organic matter composition in the SML. In particular, there are only few studies available on the differences of the SML of various oceanic systems. Here, we compared the organic matter and neuston species composition in the SML and the underlying water (ULW) at 11 stations with varying distance from the coast in the Peruvian upwelling regime, a system with high emissions of climate relevant trace gases, such as N2O and CO2. In the open ocean, organic carbon, and amino acids were highly enriched in the SML compared to the ULW. The enrichment decreased at the coastal stations and vanished in the upwelling regime. At the same time, the degradation of organic matter increased from the open ocean to the upwelling stations. This suggests that in the open ocean, upward transport processes or new production of organic matter within the SML are faster than degradation processes. Phytoplankton was generally not enriched in the SML, one group though, the Trichodesmium-like TrL (possibly containing Trichodesmium), were enriched in the open ocean but not in the upwelling region indicating that they find a favorable habitat in the open ocean SML. Our data show that the SML is a distinct habitat; its composition is more similar among different systems than between SML and ULW of a single station. Generally the enrichment of organic matter is assumed to be reduced when encountering low primary production and high wind speeds. However, our study shows the highest enrichments of organic matter in the open ocean which had the lowest primary production and the highest wind speeds.
Collapse
Affiliation(s)
- Birthe Zäncker
- RD Marine Biogeochemistry, GEOMAR-Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
| | - Astrid Bracher
- Phytooptics Group, Climate Sciences, Alfred-Wegener-Institute Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany.,Department of Physics and Electrical Engineering, Institute of Environmental Physics, University Bremen, Bremen, Germany
| | - Rüdiger Röttgers
- Remote Sensing, Institute for Coastal Research-Helmholtz Zentrum Geesthacht, Center for Materials and Coastal Research, Geesthacht, Germany
| | - Anja Engel
- RD Marine Biogeochemistry, GEOMAR-Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
| |
Collapse
|
13
|
Carpenter LJ, Nightingale PD. Chemistry and Release of Gases from the Surface Ocean. Chem Rev 2015; 115:4015-34. [DOI: 10.1021/cr5007123] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Lucy J. Carpenter
- Wolfson
Atmospheric Chemistry Laboratories, Department of Chemistry, University of York, York YO10 5DD, United Kingdom
| | - Philip D. Nightingale
- Plymouth Marine Laboratory, Prospect
Place, The Hoe, Plymouth PL1 3DH, United Kingdom
| |
Collapse
|
14
|
Transfer Across the Air-Sea Interface. OCEAN-ATMOSPHERE INTERACTIONS OF GASES AND PARTICLES 2014. [DOI: 10.1007/978-3-642-25643-1_2] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
|
15
|
Amazon River carbon dioxide outgassing fuelled by wetlands. Nature 2013; 505:395-8. [DOI: 10.1038/nature12797] [Citation(s) in RCA: 242] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Accepted: 10/25/2013] [Indexed: 11/08/2022]
|
16
|
Callaghan AH, Deane GB, Stokes MD, Ward B. Observed variation in the decay time of oceanic whitecap foam. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2012jc008147] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
17
|
|