The Southern Ocean biogeochemical divide

  title={The Southern Ocean biogeochemical divide},
  author={I. Marinov and Anand Gnanadesikan and J. R. Toggweiler and Jorge L. Sarmiento},
Modelling studies have demonstrated that the nutrient and carbon cycles in the Southern Ocean play a central role in setting the air–sea balance of CO2 and global biological production. Box model studies first pointed out that an increase in nutrient utilization in the high latitudes results in a strong decrease in the atmospheric carbon dioxide partial pressure (pCO2). This early research led to two important ideas: high latitude regions are more important in determining atmospheric pCO2 than… 
Strong sensitivity of Southern Ocean carbon uptake and nutrient cycling to wind stirring
Here we test the hypothesis that winds have an important role in determining the rate of exchange of CO 2 between the atmosphere and ocean through wind stirring over the Southern Ocean. This is
Changing Biogeochemistry of the Southern Ocean and Its Ecosystem Implications
The Southern Ocean plays a critical role in regulating global climate as a major sink for atmospheric carbon dioxide (CO2), and in global ocean biogeochemistry by supplying nutrients to the global
Anthropogenic carbon and heat uptake by the ocean: Will the Southern Ocean remain a major sink?
Vertical exchange in the Southern Ocean between the atmosphere and the surface and deep ocean has a profound influence on the oceanic uptake of anthropogenic carbon and heat, as well as nutrient
Efficiency of small scale carbon mitigation by patch iron fertilization
Abstract. While nutrient depletion scenarios have long shown that the high-latitude High Nutrient Low Chlorophyll (HNLC) regions are the most effective for sequestering atmospheric carbon dioxide,
Seasonally different carbon flux changes in the Southern Ocean in response to the southern annular mode
In the annual mean, the upper ocean region south of the PF loses more carbon by additional export production than by the release of CO2 into the atmosphere, highlighting the role of the biological carbon pump in response to a positive SAM event.
Lowering of glacial atmospheric CO2 in response to changes in oceanic circulation and marine biogeochemistry
[1] We use an Earth system model of intermediate complexity, CLIMBER-2, to investigate what recent improvements in the representation of the physics and biology of the glacial ocean imply for the
Impact of oceanic circulation on biological carbon storage in the ocean and atmospheric pCO2
We use both theory and ocean biogeochemistry models to examine the role of the soft‐tissue biological pump in controlling atmospheric CO2. We demonstrate that atmospheric CO2 can be simply related to
Variability of primary production and air‐sea CO2 flux in the Southern Ocean
Biogeochemical cycling in the Southern Ocean (SO) plays a key role in the global sea‐air CO2balance and in the ocean anthropogenic carbon inventory (Ito et al., 2010; Khatiwala et al., 2009;
Anthropogenic carbon dioxide transport in the Southern Ocean driven by Ekman flow
A high-resolution ocean circulation and carbon cycle model is used to address the mechanisms controlling the Southern Ocean sink of anthropogenic CO2 and suggests intimate connections between oceanic carbon uptake and climate variability through the temporal variability of Ekman transport.
The changing roles of iron and vertical mixing in regulating nitrogen and silicon cycling in the Southern Ocean over the last glacial cycle
The Southern Ocean plays a critical role in the air-sea CO2 balance through biological and physical mechanisms. Vertical supply of deep waters returns nutrients and CO2 to the surface and stimulates


Three‐dimensional simulations of the impact of Southern Ocean nutrient depletion on atmospheric CO2 and ocean chemistry
Surface nutrient concentrations in the Southern Ocean are an important indicator of the atmosphere-ocean chemical balance that played a key role in ice-age reduction of atmospheric pC0, and would
Glacial/interglacial variations in atmospheric carbon dioxide
A version of the hypothesis that the whole-ocean reservoir of algal nutrients was larger during glacial times, strengthening the biological pump at low latitudes, where these nutrients are currently limiting is presented.
High-latitude controls of thermocline nutrients and low latitude biological productivity
The ocean's biological pump strips nutrients out of the surface waters and exports them into the thermocline and deep waters. If there were no return path of nutrients from deep waters, the
A new model for the role of the oceans in determining atmospheric PCO2
Recent ice-core measurements have revealed that the atmospheric CO2 level increased comparatively rapidly by about 70 p.p.m. at the end of the last ice age1. Here we present an ocean–atmosphere model
Interactions of the iron and phosphorus cycles: A three‐dimensional model study
We use an ocean circulation, biogeochemistry, and ecosystem model to explore the interactions between ocean circulation, macro‐ and micro‐nutrient supply to the euphotic layer, and biological
Estimates of the effect of Southern Ocean iron fertilization on atmospheric CO2 concentrations
IT has been suggested1–3 that fertilizing the ocean with iron might offset the continuing increase in atmospheric CO2 by enhancing the biological uptake of carbon, thereby decreasing the
The role of the southern ocean in uptake and storage of anthropogenic carbon dioxide
If global climate change reduces the density of surface waters in the Southern Ocean, isopycnal surfaces that now outcrop may become isolated from the atmosphere, tending to diminish Southern Ocean carbon uptake.
Variation of atmospheric CO2 by ventilation of the ocean's deepest water
A new box model for glacial-interglacial changes in atmospheric CO2 produces lower levels of atmospheric CO 2 without changes in biological production or nutrient chemistry. The model treats the
Rapid atmospheric CO2 variations and ocean circulation
Studies on air trapped in old polar ice1,2 have shown that during the last ice age, the atmospheric carbon dioxide concentration was probably significantly lower than during the Holocene—about 200
glacial-interglacial Co2 change : the iron hypothesis
Several explanations for the 200 to 280 ppm glacial/interglacial change in atmospheric CO2 concentrations deal with variations in southern ocean phytoplankton productivity and the related use or