Corrigendum to “Satellite derived euphotic depth in the Southern Ocean: Implications for primary production modeling” [Remote Sens. Environ. 137C (2013) 198−211]

The Southern Ocean is known to be the largest High Nutrient Low Chlorophyll (HNLC) area of the global ocean, where algal development is mainly limited by iron (Fe) deficiency, except in few naturally Fefertilized areas (e.g. around Kerguelen plateau). The availability of different nutrients is unevenly distributed in this area. Thus, northwards the polar front, nitrogen and phosphorus (N and P) concentrations are high, but the scarcity of silicon (Si) limits the growth of diatoms (HN-LSi-LC). Further North, the Southern Indian Ocean is characterized by macronutrient limitation and low primary production (LNLC).In these areas, atmospheric input could play a major role in the nutrient supply of primary producers. The main aim of this study is to assess the biological response of local phytoplankton communities to a deposition of two types of natural aerosols: desert dust and volcanic ash. Preliminary trace-metal clean laboratory experiments enabled us to quantify the abiotic dissolution of main macro- and micronutrients in dry and wet deposition mode of different natural aerosols of these types that yield us to choose Patagonia dust and ash from the Icelandic volcano Eyjafjallaj&#246;kull for our experiment at sea. We set up a series of on-board trace-metal clean microcosm experiments in the contrasted biogeochemical conditions of the South Indian Ocean and Southern Ocean with addition of realistic amounts of dust and ash of respectively 2 and 25 mg.L-1. Experiments ran over 48 hours to evaluate the triggered primary production and cell abundances. Primary production was estimated by 13C spike and biogenic Si (bSi) uptake rates were assessed by 30Si spike. Parallel experiments with nutrient addition (dFe, DIP, DIN and dSi) along with flux cytometry for estimation of pico- and nanophytoplankton cells enabled us to determine which element(s) dissolved from the aerosols was responsible for the enhanced algal growth. The highest CO2 fixation rate of 50 mg.m-3.day-1 was found at the natural Fe fertilized Kerguelen plateau station. Dust, ash and Fe addition triggered primary production, and CO2 fixation doubled in these treatments. We recorded an enrichment of b30Si, indicating an increase of Si uptake rate, mostly stimulated by Fe addition. At the different HNLC stations (high N - low Si and high N - high Si), Fe and aerosol addition induced as well increased CO2 fixation. In the northern LNLC stations, algal growth was stimulated by nitrogen addition as expected, but Fe, Si and aerosol addition also triggered a biological response from Synechococcus cyanobacteria and pico- and nanoeukaryotes. Noteworthy, in most experiments the two contrasted aerosol types (desert dust and volcanic ash) at particle charges which varied over more than an order of magnitude triggered very similar biological responses in all of the sampled areas, even with distinct elementary and mineral compositions (e.g. the Icelandic volcano ash is 64 % amorphous and contains roughly twice the amount of Fe, P, Mn and Zn compared to the Patagonian desert dust which is only 48 % amorphous).

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Antarctic marine primary production, biogeochemical carbon cycles and climatic change

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.1992.0149 ◽

1992 ◽

Vol 338 (1285) ◽

pp. 289-297 ◽

Cited By ~ 35

Keyword(s):

Climate Change ◽

Southern Ocean ◽

Primary Production ◽

Climatic Change ◽

Carbon Fixation ◽

Algal Growth ◽

Ice Cover ◽

Phytoplankton Production ◽

Numerical Predictions ◽

Model Predictions

In the Southern Ocean, inorganic macronutrients are very rarely depleted by phytoplankton growth. This has led to speculation on possible additional CO 2 drawdown in this region. However, the effects of climate change can only be predicted once the role of environmental and biotic factors limiting phytoplankton carbon fixation are understood. It is clear that the Southern Ocean is heterogeneous, and no single factor controls prim ary production overall. Ice cover and vertical mixing influence algal growth rates by m odulating radiance flux. Micronutrients, especially iron, may limit growth in some areas. Primary production is also suppressed by high removal rates of algal biomass. Grazing by zooplankton is the major factor determining magnitude and quality of vertical particle flux. Several of the physical controls on phytoplankton production are sensitive to climate change. Although it is impossible to make numerical predictions of future change on the basis of our present knowledge, qualitative assessments can be put forward on the basis of model predictions of climate change and known factors controlling prim ary production. Changes in water temperature and in windinduced mixing are likely to be slight and have little effect. Model predictions of changes in sea-ice cover vary widely, making prediction of biogeochemical effects impossible. Even if climatic change induces increased nutrient uptake, there are several reasons to suspect that carbon sequestration will be ineffective in comparison with continuing anthropogenic CO 2 emission.

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Meridional asymmetric distribution of the primary production in the Atlantic Sector of the Southern Ocean in the austral spring and summer

Oceanology ◽

10.1134/s0001437012050050 ◽

2012 ◽

Vol 52 (5) ◽

pp. 623-634 ◽

Cited By ~ 4

Author(s):

A. B. Demidov ◽

S. A. Mosharov ◽

V. I. Gagarin

Keyword(s):

Southern Ocean ◽

Primary Production ◽

Asymmetric Distribution ◽

Austral Spring ◽

Atlantic Sector

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Organic carbon fluxes in the Atlantic and the Southern Ocean: relationship to primary production compiled from satellite radiometer data

Deep Sea Research Part II Topical Studies in Oceanography ◽

10.1016/s0967-0645(00)00013-8 ◽

2000 ◽

Vol 47 (9-11) ◽

pp. 1961-1997 ◽

Cited By ~ 77

Author(s):

G Fischer ◽

V Ratmeyer ◽

G Wefer

Keyword(s):

Organic Carbon ◽

Southern Ocean ◽

Primary Production ◽

Carbon Fluxes ◽

Organic Carbon Fluxes

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Deriving maximal light use efficiency from coordinated flux measurements and satellite data for regional gross primary production modeling

Remote Sensing of Environment ◽

10.1016/j.rse.2010.05.001 ◽

2010 ◽

Vol 114 (10) ◽

pp. 2248-2258 ◽

Cited By ~ 49

Author(s):

Hesong Wang ◽

Gensuo Jia ◽

Congbin Fu ◽

Jinming Feng ◽

Tianbao Zhao ◽

...

Keyword(s):

Primary Production ◽

Satellite Data ◽

Gross Primary Production ◽

Light Use Efficiency ◽

Flux Measurements ◽

Use Efficiency ◽

Production Modeling

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Explicit silicate cycling in the Kiel Marine Biogeochemistry Model, version 3 (KMBM3) embedded in the UVic ESCM version 2.9

10.5194/gmd-2020-235 ◽

2020 ◽

Author(s):

Karin Kvale ◽

David P. Keller ◽

Wolfgang Koeve ◽

Katrin J. Meissner ◽

Chris Somes ◽

...

Keyword(s):

Southern Ocean ◽

Primary Production ◽

Large Scale ◽

Climate Model ◽

Net Primary Production ◽

Coupled Model ◽

Co2 Concentration ◽

Ecosystem Model ◽

New Model ◽

Fully Coupled

Abstract. We describe and test a new model of biological marine silicate cycling, implemented in the University of Victoria Earth System Climate Model (UVic ESCM) version 2.9. This new model adds diatoms, which are a key aspect of the biological carbon pump, to an existing ecosystem model. The new model performs well against important ocean biogeochemical indicators and captures the large-scale features of the marine silica cycle. Furthermore it is computationally efficient, allowing both fully-coupled, long-timescale transient simulations, as well as "offline" transport matrix spinups. We assess the fully-coupled model against modern ocean observations, the historical record since 1960, and a business-as-usual atmospheric CO2 forcing to the year 2300. The model simulates a global decline in net primary production (NPP) of 1.3 % having occurred since the 1960s, with the strongest declines in the tropics, northern mid-latitudes, and Southern Ocean. The simulated global decline in NPP reverses after the year 2100 (forced by the extended RCP CO2 concentration scenario), and NPP returns to pre-industrial rates by 2300. This recovery is dominated by increasing primary production in the Southern Ocean, mostly by calcifying phytoplankton. Large increases in calcifying phytoplankton in the Southern Ocean offset a decline in the low latitudes, producing a global net calcite export in 2300 that varies only slightly from pre-industrial rates. Diatoms migrate southward in our simulations, following the receding Antarctic ice front, but are out-competed by calcifiers across most of their pre-industrial Southern Ocean habitat. Global opal export production thus drops to 50 % of its pre-industrial value by 2300. Model nutrients phosphate, silicate, and nitrate build up along the Southern Ocean particle export pathway, but dissolved iron (for which ocean sources are held constant) increases in the upper ocean. This different behaviour of iron is attributed to a reduction of low-latitude NPP (and consequently, a reduction in both uptake and export and particle, including calcite, scavenging), an increase in seawater temperatures (raising the solubility of particle forms), and stratification that "traps" the iron near the surface. These results are meant to serve as a baseline for sensitivity assessments to be undertaken with this model in the future.

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