scholarly journals Picophytoplankton biomass distribution in the global ocean

2012 ◽  
Vol 4 (1) ◽  
pp. 37-46 ◽  
Author(s):  
E. T. Buitenhuis ◽  
W. K. W. Li ◽  
D. Vaulot ◽  
M. W. Lomas ◽  
M. R. Landry ◽  
...  
Keyword(s):  
North Atlantic ◽  
World Ocean ◽  
Marine Phytoplankton ◽  
Global Ocean ◽  
Biomass Distribution ◽  
The North ◽  
Carbon Biomass ◽  
The World ◽  
Data Points ◽  
Data Coverage

Abstract. The smallest marine phytoplankton, collectively termed picophytoplankton, have been routinely enumerated by flow cytometry since the late 1980s during cruises throughout most of the world ocean. We compiled a database of 40 946 data points, with separate abundance entries for Prochlorococcus, Synechococcus and picoeukaryotes. We use average conversion factors for each of the three groups to convert the abundance data to carbon biomass. After gridding with 1° spacing, the database covers 2.4% of the ocean surface area, with the best data coverage in the North Atlantic, the South Pacific and North Indian basins, and at least some data in all other basins. The average picophytoplankton biomass is 12 ± 22 μg C l−1 or 1.9 g C m−2. We estimate a total global picophytoplankton biomass of 0.53–1.32 Pg C (17–39% Prochlorococcus, 12–15% Synechococcus and 49–69% picoeukaryotes), with an intermediate/best estimate of 0.74 Pg C. Future efforts in this area of research should focus on reporting calibrated cell size and collecting data in undersampled regions. http://doi.pangaea.de/10.1594/PANGAEA.777385

scholarly journals Picophytoplankton biomass distribution in the global ocean

2012 ◽  
Vol 5 (1) ◽  
pp. 221-242 ◽  
Author(s):  
E. T. Buitenhuis ◽  
W. K. W. Li ◽  
D. Vaulot ◽  
M. W. Lomas ◽  
M. Landry ◽  
...  
Keyword(s):  
North Atlantic ◽  
World Ocean ◽  
Marine Phytoplankton ◽  
Global Ocean ◽  
Biomass Distribution ◽  
The North ◽  
Carbon Biomass ◽  
The World ◽  
Data Points ◽  
Data Coverage

Abstract. The smallest marine phytoplankton, collectively termed picophytoplankton, have been routinely enumerated by flow cytometry since the late 1980s, during cruises throughout most of the world ocean. We compiled a database of 40 946 data points, with separate abundance entries for Prochlorococcus, Synechococcus and picoeukaryotes. We use average conversion factors for each of the three groups to convert the abundance data to carbon biomass. After gridding with 1° spacing, the database covers 2.4% of the ocean surface area, with the best data coverage in the North Atlantic, the South Pacific and North Indian basins. The average picophytoplankton biomass is 12 ± 22 μg C l−1 or 1.9 g C m−2. We estimate a total global picophytoplankton biomass of 0.53–0.74 Pg C (17–39% Prochlorococcus, 12–15% Synechococcus and 49–69% picoeukaryotes). Future efforts in this area of research should focus on reporting calibrated cell size, and collecting data in undersampled regions.

scholarly journals A global algorithm for estimating Absolute Salinity

Ocean Science ◽  
2012 ◽  
Vol 8 (6) ◽  
pp. 1123-1134 ◽  
Author(s):  
T. J. McDougall ◽  
D. R. Jackett ◽  
F. J. Millero ◽  
R. Pawlowicz ◽  
P. M. Barker
Keyword(s):  
Thermodynamic Properties ◽  
North Atlantic ◽  
World Ocean ◽  
Practical Method ◽  
Sea Salt ◽  
The North ◽  
Salinity Anomaly ◽  
The World ◽  
Standard Composition ◽  
The Absolute

Abstract. The International Thermodynamic Equation of Seawater – 2010 has defined the thermodynamic properties of seawater in terms of a new salinity variable, Absolute Salinity, which takes into account the spatial variation of the composition of seawater. Absolute Salinity more accurately reflects the effects of the dissolved material in seawater on the thermodynamic properties (particularly density) than does Practical Salinity. When a seawater sample has standard composition (i.e. the ratios of the constituents of sea salt are the same as those of surface water of the North Atlantic), Practical Salinity can be used to accurately evaluate the thermodynamic properties of seawater. When seawater is not of standard composition, Practical Salinity alone is not sufficient and the Absolute Salinity Anomaly needs to be estimated; this anomaly is as large as 0.025 g kg−1 in the northernmost North Pacific. Here we provide an algorithm for estimating Absolute Salinity Anomaly for any location (x, y, p) in the world ocean. To develop this algorithm, we used the Absolute Salinity Anomaly that is found by comparing the density calculated from Practical Salinity to the density measured in the laboratory. These estimates of Absolute Salinity Anomaly however are limited to the number of available observations (namely 811). In order to provide a practical method that can be used at any location in the world ocean, we take advantage of approximate relationships between Absolute Salinity Anomaly and silicate concentrations (which are available globally).

scholarly journals Assimilation of Radiocarbon and Chlorofluorocarbon Data to Constrain Deep and Bottom Water Transports in the World Ocean

2007 ◽  
Vol 37 (2) ◽  
pp. 259-276 ◽  
Author(s):  
Reiner Schlitzer
Keyword(s):  
Southern Ocean ◽  
North Atlantic ◽  
Bottom Water ◽  
World Ocean ◽  
Weddell Sea ◽  
Global Ocean ◽  
Western Boundary ◽  
Boundary Current ◽  
The North ◽  
The North Atlantic

Abstract A coarse-resolution global model with time-invariant circulation is fitted to hydrographic and tracer data by means of the adjoint method. Radiocarbon and chlorofluorocarbon (CFC-11 and CFC-12) data are included to constrain deep and bottom water transport rates and spreading pathways as well as the strength of the global overturning circulation. It is shown that realistic global ocean distributions of hydrographic parameters and tracers can be obtained simultaneously. The model correctly reproduces the deep ocean radiocarbon field and the concentrations gradients between different basins. The spreading of CFC plumes in the deep and bottom waters is simulated in a realistic way, and the spatial extent as well as the temporal evolution of these plumes agrees well with observations. Radiocarbon and CFC observations place upper bounds on the northward transports of Antarctic Bottom Water (AABW) into the Pacific, Atlantic, and Indian Oceans. Long-term mean AABW transports larger than 5 Sv (Sv ≡ 106 m3 s−1) through the Vema and Hunter Channels in the South Atlantic and net AABW transports across 30°S into the Indian Ocean larger than 10 Sv are found to be incompatible with CFC data. The rates of equatorward deep and bottom water transports from the North Atlantic and Southern Ocean are of similar magnitude (15.7 Sv at 50°N and 17.9 Sv at 50°S). Deep and bottom water formation in the Southern Ocean occurs at multiple sites around the Antarctic continent and is not confined to the Weddell Sea. A CFC forecast based on the assumption of unchanged abyssal transports shows that by 2030 the entire deep west Atlantic exhibits CFC-11 concentrations larger than 0.1 pmol kg−1, while most of the deep Indian and Pacific Oceans remain CFC free. By 2020 the predicted CFC concentrations in the deep western boundary current (DWBC) in the North Atlantic exceed surface water concentrations and the vertical CFC gradients start to reverse.

scholarly journals Picoheterotroph (<i>Bacteria</i> and <i>Archaea</i>) biomass distribution in the global ocean

2012 ◽  
Vol 4 (1) ◽  
pp. 101-106 ◽  
Author(s):  
E. T. Buitenhuis ◽  
W. K. W. Li ◽  
M. W. Lomas ◽  
D. M. Karl ◽  
M. R. Landry ◽  
...  
Keyword(s):  
Conversion Factor ◽  
Open Ocean ◽  
Global Ocean ◽  
Biomass Distribution ◽  
Carbon Biomass ◽  
Flow Cytometric ◽  
Data Points ◽  
Ocean Measurements ◽  
The Tropics ◽  
Carbon Inventory

Abstract. We compiled a database of 39 766 data points consisting of flow cytometric and microscopical measurements of picoheterotroph abundance, including both Bacteria and Archaea. After gridding with 1° spacing, the database covers 1.3% of the ocean surface. There are data covering all ocean basins and depths except the Southern Hemisphere below 350 m or from April until June. The average picoheterotroph biomass is 3.9 &amp;pm; 3.6 μg C l−1 with a 20-fold decrease between the surface and the deep sea. We estimate a total ocean inventory of about 1.3 × 1029 picoheterotroph cells. Surprisingly, the abundance in the coastal regions is the same as at the same depths in the open ocean. Using an average of published open ocean measurements for the conversion from abundance to carbon biomass of 9.1 fg cell−1, we calculate a picoheterotroph carbon inventory of about 1.2 Pg C. The main source of uncertainty in this inventory is the conversion factor from abundance to biomass. Picoheterotroph biomass is ~2 times higher in the tropics than in the polar oceans. doi:10.1594/PANGAEA.779142

scholarly journals A global diatom database – abundance, biovolume and biomass in the world ocean

2012 ◽  
Vol 5 (1) ◽  
pp. 147-185 ◽  
Author(s):  
K. Leblanc ◽  
J. Arístegui ◽  
L. Armand ◽  
P. Assmy ◽  
B. Beker ◽  
...  
Keyword(s):  
Marine Ecosystem ◽  
Sampling Site ◽  
World Ocean ◽  
The Arctic ◽  
Global Ocean ◽  
Order Estimate ◽  
Abundance Data ◽  
Marine Ecosystem Model ◽  
The World ◽  
Data Points

Abstract. Phytoplankton identification and abundance data are now commonly feeding plankton distribution databases worldwide. This study is a first attempt to compile the largest possible body of data available from different databases as well as from individual published or unpublished datasets regarding diatom distribution in the world ocean. The data obtained originate from time series studies as well as spatial studies. This effort is supported by the Marine Ecosystem Model Inter-Comparison Project (MAREMIP), which aims at building consistent datasets for the main Plankton Functional Types (PFT) in order to help validate biogeochemical ocean models by using carbon (C) biomass derived from abundance data. In this study we collected over 293 000 individual geo-referenced data points with diatom abundances from bottle and net sampling. Sampling site distribution was not homogeneous, with 58% of data in the Atlantic, 20% in the Arctic, 12% in the Pacific, 8% in the Indian and 1% in the Southern Ocean. A total of 136 different genera and 607 different species were identified after spell checking and name correction. Only a small fraction of these data were also documented for biovolumes and an even smaller fraction was converted to C biomass. As it is virtually impossible to reconstruct everyone's method for biovolume calculation, which is usually not indicated in the datasets, we decided to undertake the effort to document, for every distinct species, the minimum and maximum cell dimensions, and to convert all the available abundance data into biovolumes and C biomass using a single standardized method. Statistical correction of the database was also adopted to exclude potential outliers and suspicious data points. The final database contains 90 648 data points with converted C biomass. Diatom C biomass calculated from cell sizes spans over eight orders of magnitude. The mean diatom biomass for individual locations, dates and depths is 141.19 μg C l−1, while the median value is 11.16 μg C l−1. Regarding biomass distribution, 19% of data are in the range 0–1 μg C l−1, 29% in the range 1–10 μg C l−1, 31% in the range 10–100 μg C l−1, 18% in the range 100–1000 μg C l−1, and only 3% >1000 μg C l−1. Interestingly, less than 50 species contributed to >90% of global biomass, among which centric species were dominant. Thus, placing significant efforts on cell size measurements, process studies and C quota calculations on these species should considerably improve biomass estimates in the upcoming years. A first-order estimate of the diatom biomass for the global ocean ranges from 449 to 558 Tg C, which converts to 5 to 6 Tmol Si and to an average Si biomass turnover rate of 0.11 to 0.20 d−1. Link to the dataset: preliminary link http://doi.pangaea.de/10.1594/PANGAEA.777384.

scholarly journals Environmental control of marine phytoplankton stoichiometry in the North Atlantic Ocean

2021 ◽  
Vol 119 (1) ◽  
pp. e2114602118
Author(s):  
Boris Sauterey ◽  
Ben A. Ward
Keyword(s):  
North Atlantic ◽  
Nitrogen Availability ◽  
Environmental Control ◽  
Marine Phytoplankton ◽  
Global Ocean ◽  
Environmental Drivers ◽  
The North ◽  
Phytoplankton Communities ◽  
The North Atlantic ◽  
C:N Stoichiometry

The stoichiometric coupling of carbon to limiting nutrients in marine phytoplankton regulates the magnitude of biological carbon sequestration in the ocean. While clear links between plankton C:N ratios and environmental drivers have been identified, the nature and direction of these links, as well as their underlying physiological and ecological controls, remain uncertain. We show, with a well-constrained mechanistic model of plankton ecophysiology, that while nitrogen availability and temperature emerge as the main drivers of phytoplankton C:N stoichiometry in the North Atlantic, the biological mechanisms involved vary depending on the spatiotemporal scale and region considered. We find that phytoplankton C:N stoichiometry is overall controlled by nitrogen availability below 40° N, predominantly driven by ecoevolutionary shifts in the functional composition of the phytoplankton communities, while phytoplankton stoichiometric plasticity in response to dropping temperatures and increased grazing pressure dominates at higher latitudes. Our findings highlight the potential of “organisms-to-ecosystems” modeling approaches based on mechanistic models of plankton biology accounting for physiology, ecology, and trait evolution to explore and explain complex observational data and ultimately improve the predictions of global ocean models.

scholarly journals A global diatom database – abundance, biovolume and biomass in the world ocean

2012 ◽  
Vol 4 (1) ◽  
pp. 149-165 ◽  
Author(s):  
K. Leblanc ◽  
J. Arístegui ◽  
L. Armand ◽  
P. Assmy ◽  
B. Beker ◽  
...  
Keyword(s):  
Marine Ecosystem ◽  
Sampling Site ◽  
World Ocean ◽  
The Arctic ◽  
Global Ocean ◽  
Order Estimate ◽  
Abundance Data ◽  
Marine Ecosystem Model ◽  
The World ◽  
Data Points

Abstract. Phytoplankton identification and abundance data are now commonly feeding plankton distribution databases worldwide. This study is a first attempt to compile the largest possible body of data available from different databases as well as from individual published or unpublished datasets regarding diatom distribution in the world ocean. The data obtained originate from time series studies as well as spatial studies. This effort is supported by the Marine Ecosystem Model Inter-Comparison Project (MAREMIP), which aims at building consistent datasets for the main plankton functional types (PFTs) in order to help validate biogeochemical ocean models by using carbon (C) biomass derived from abundance data. In this study we collected over 293 000 individual geo-referenced data points with diatom abundances from bottle and net sampling. Sampling site distribution was not homogeneous, with 58% of data in the Atlantic, 20% in the Arctic, 12% in the Pacific, 8% in the Indian and 1% in the Southern Ocean. A total of 136 different genera and 607 different species were identified after spell checking and name correction. Only a small fraction of these data were also documented for biovolumes and an even smaller fraction was converted to C biomass. As it is virtually impossible to reconstruct everyone's method for biovolume calculation, which is usually not indicated in the datasets, we decided to undertake the effort to document, for every distinct species, the minimum and maximum cell dimensions, and to convert all the available abundance data into biovolumes and C biomass using a single standardized method. Statistical correction of the database was also adopted to exclude potential outliers and suspicious data points. The final database contains 90 648 data points with converted C biomass. Diatom C biomass calculated from cell sizes spans over eight orders of magnitude. The mean diatom biomass for individual locations, dates and depths is 141.19 μg C l−1, while the median value is 11.16 μg C l−1. Regarding biomass distribution, 19% of data are in the range 0–1 μg C l−1, 29% in the range 1–10 μg C l−1, 31% in the range 10–100 μg C l−1, 18% in the range 100–1000 μg C l−1, and only 3% > 1000 μg C l−1. Interestingly, less than 50 species contributed to > 90% of global biomass, among which centric species were dominant. Thus, placing significant efforts on cell size measurements, process studies and C quota calculations of these species should considerably improve biomass estimates in the upcoming years. A first-order estimate of the diatom biomass for the global ocean ranges from 444 to 582 Tg C, which converts to 3 to 4 Tmol Si and to an average Si biomass turnover rate of 0.15 to 0.19 d−1. Link to the dataset: doi:10.1594/PANGAEA.777384.

scholarly journals Bacterial biomass distribution in the global ocean

2012 ◽  
Vol 5 (1) ◽  
pp. 301-315 ◽  
Author(s):  
E. T. Buitenhuis ◽  
W. K. W. Li ◽  
M. W. Lomas ◽  
D. M. Karl ◽  
M. R. Landry ◽  
...  
Keyword(s):  
Deep Sea ◽  
Bacterial Abundance ◽  
Conversion Factor ◽  
Bacterial Biomass ◽  
Global Ocean ◽  
Biomass Distribution ◽  
Carbon Biomass ◽  
Data Points ◽  
Ocean Measurements ◽  
Carbon Inventory

Abstract. We compiled a database of bacterial abundance of 39 766 data points. After gridding with 1° spacing, the database covers 1.3% of the ocean surface. There is data covering all ocean basins and depth except the Southern Hemisphere below 350 m or from April until June. The average bacterial biomass is 3.9 ± 3.6 μg l−1 with a 20-fold decrease between the surface and the deep sea. We estimate a total ocean inventory of about 1.3 × 1029 bacteria. Using an average of published open ocean measurements for the conversion from abundance to carbon biomass of 9.1 fg cell−1, we calculate a bacterial carbon inventory of about 1.2 Pg C. The main source of uncertainty in this inventory is the conversion factor from abundance to biomass. http://doi.pangaea.de/10.1594/PANGAEA.779142

Interannual to Decadal Changes in the ECCO Global Synthesis

2007 ◽  
Vol 37 (2) ◽  
pp. 313-337 ◽  
Author(s):  
A. Köhl ◽  
D. Stammer ◽  
B. Cornuelle
Keyword(s):  
Southern Ocean ◽  
Ocean Circulation ◽  
North Atlantic ◽  
General Circulation ◽  
World Ocean ◽  
Circulation Model ◽  
Sea Surface Height ◽  
Sea Surface ◽  
Global Ocean ◽  
The World

Abstract An estimate of the time-varying global ocean circulation for the period 1992–2002 was obtained by combining most of the World Ocean Circulation Experiment (WOCE) ocean datasets with a general circulation model on a 1° horizontal grid. The estimate exactly satisfies the model equations without artificial sources or sinks of momentum, heat, and freshwater. To bring the model into agreement with observations, its initial temperature and salinity conditions were permitted to change, as were the time-dependent surface fluxes of momentum, heat, and freshwater. The estimation of these “control variables” is largely consistent with accepted uncertainties in the hydrographic climatology and meteorological analyses. The estimated time-mean horizontal transports of volume, heat, and freshwater, which were largely underestimated in the previous 2° optimization performed by Stammer et al., have converged with time-independent estimates from box inversions over most parts of the World Ocean. Trends in the model’s heat content are 7% larger than those reported by Levitus and correspond to a global net heat uptake of about 1.1 W m−2 over the model domain. The associated model trend in sea surface height over the estimation period resembles the observations from Ocean Topography Experiment (TOPEX)/Poseidon over most of the global ocean. Sea surface height changes in the model are primarily steric but show contributions from mass redistributions from the subpolar North Atlantic Ocean and the Southern Ocean to the subtropical Pacific Ocean gyres. Steric contributions are primarily temperature based but are partly compensated by salt variation. However, the North Atlantic and the Southern Ocean reveal a clear contribution of salt to large-scale sea level variations.

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