Modeling the modern marine δ30Si distribution

  title={Modeling the modern marine $\delta$30Si distribution},
  author={Ben C. Reynolds},
  journal={Global Biogeochemical Cycles},
  • B. Reynolds
  • Published 1 June 2009
  • Environmental Science
  • Global Biogeochemical Cycles
The silicon isotopic composition of opal sediments can be used as a proxy for past Si utilization, and hence paleoproductivity for a fixed ocean circulation. Interpretation of this Si utilization proxy is limited by our understanding of the present marine Si isotope distribution. Observations show significant isotopic variations is silicic acid between deep‐water masses that are not captured by a previous global climate model (GCM). Here, simple box models of the global oceans for the Si cycle… 
Simulating the modern δ30Si distribution in the oceans and in marine sediments
The δ30Si of biogenic silica ( δ30SiBSi ) in marine sediments is a promising proxy for the reconstruction of silicic acid utilization by diatoms in the geological past. The application of this proxy,
Heavy silicon isotopic composition of silicic acid and biogenic silica in Arctic waters over the Beaufort shelf and the Canada Basin
The silicon isotopic composition of silicic acid (δ30Si(OH)4) and biogenic silica (δ30Si‐bSiO2) were measured for the first time in marine Arctic waters from the Mackenzie River delta to the deep
Mechanistic understanding of the marine biogeochemical proxy d30Si: A modeling approach
The stable silicon isotopic composition d30Si of silicic acid and of biogenic opal is used as a proxy for investigating the marine silicon cycle and silicic acid utilization by diatoms both at
Southern Ocean control of silicon stable isotope distribution in the deep Atlantic Ocean
The fractionation of silicon (Si) stable isotopes by biological activity in the surface ocean makes the stable isotope composition of silicon (δ30Si) dissolved in seawater a sensitive tracer of the
Silicon Isotopes in an EMIC's Ocean: Sensitivity to Runoff, Iron Supply, and Climate
The isotopic composition of Si in biogenic silica (BSi), such as opal buried in the oceans' sediments, has changed over time. Paleorecords suggest that the isotopic composition, described in terms of
Silicon pool dynamics and biogenic silica export in the Southern Ocean inferred from Si-isotopes
Silicon isotopic signatures ( 30 Si) of water col- umn silicic acid (Si(OH)4) were measured in the Southern Ocean, along a meridional transect from South Africa (Sub- tropical Zone) down to 57 S


Control mechanisms for the oceanic distribution of silicon isotopes
Marine diatoms take up silicic acid for the buildup of their opaline shells and discriminate against the heavier silicon isotope. For the first time, the overall oceanic distribution of silicon
Silicon isotope fractionation during nutrient utilization in the North Pacific
Relevance of silicon isotopes to Si‐nutrient utilization and Si‐source assessment in Antarctic waters
We analyzed δ29Si of dissolved silicate for eight water column profiles across the Southern Ocean (south of Australia in spring 2001) from the Seasonal Ice Zone (SIZ) north to the Subantarctic Zone
Deep ocean biogeochemistry of silicic acid and nitrate
Observations of silicic acid and nitrate along the lower branch of the global conveyor belt circulation show that silicic acid accumulation by diatom opal dissolution occurs at 6.4 times the rate of
Biological fractionation of silicon isotopes in Southern Ocean surface waters
The fractionation of silicon isotopes by diatoms during silicification (i.e., opaline cell wall formation) provides a new tool for paleoceanographic studies of the silicon cycle. Here we examine the
The distribution of 13C of ΣCO2 in the world oceans
The δ15N of nitrate in the Southern Ocean: Nitrogen cycling and circulation in the ocean interior
We report analyses of the nitrogen isotopic composition of nitrate in the eastern Indian and Pacific sectors of the Southern Ocean. In this paper, we focus on the subsurface data as well as data from
Sensitivity of silicon isotopes to whole-ocean changes in the silica cycle
The annual production of biogenic silica in the Antarctic Ocean
A first look at the distribution of the stable isotopes of silicon in natural waters