Dissolved oxygen & oxygen saturation percentage (GBR4 BGC v3.1 baseline)
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Dissolved Oxygen
Concentration of oxygen.
Dissolved oxygen plays a pivotal role, driving multiple biogeochemical processes and influencing the balance of other elements like carbon, nitrogen, and phosphorus. The BGC model cycles carbon, nitrogen, phosphorous and oxygen through multiple phytoplankton, zooplankton, detritus and dissolved organic and inorganic forms in the water column and sediment layers.
The production (by photosynthesis) and consumption (by respiration and remineralisation) of dissolved oxygen is included in the model and, depending on prevailing concentrations, facilitates or inhibits the oxidation of ammonium to nitrate and its subsequent denitrification to dinitrogen gas which is then lost from the system.
More detail on how oxygen levels were modelled can be found in Baird et al. (2020).
Oxygen saturation percentage
The saturation state of oxygen [O2]sat is determined as a function of temperature and salinity following Weiss (1970). It represents the maximum amount of the dissolved oxygen that the water can hold. It is used to calculate the amount of oxygen exchange in the sea-air boundary. If the oxygen saturation percentage is below 100% then oxygen will be absorbed from the atmosphere. If it is above 100% then oxygen will be out gased from the sea into the atmosphere.
Reference
Baird, M. E., Wild-Allen, K. A., Parslow, J., Mongin, M., Robson, B., Skerratt, J., Rizwi, F., Soja-Woźniak, M., Jones, E., Herzfeld, M., Margvelashvili, N., Andrewartha, J., Langlais, C., Adams, M. P., Cherukuru, N., Gustafsson, M., Hadley, S., Ralph, P. J., Rosebrock, U., … Steven, A. D. L. (2020). CSIRO Environmental Modelling Suite (EMS): scientific description of the optical and biogeochemical models (vB3p0). Geoscientific Model Development, 13(9), 4503–4553. https://doi.org/10.5194/gmd-13-4503-2020
Weiss, R.: The solubility of nitrogen, oxygen and argon in water and seawater, Deep Sea Res., 17, 721–735, 1970.
Source data
The videos/images on this page are based on the 4km eReefs BioGeoChemical model (v3.1) (GBR4_H2p0_B3p1_Cq3b_Dhnd) run with SOURCE Catchments using Baseline catchment conditions. Detailed information about the model can be found in the paper: CSIRO Environmental Modelling Suite (EMS): Scientific description of the optical and biogeochemical models (vB3p0). The raw model data is available from the NCI THREDDS server (daily, in curvilinear NetCDF format) and the aggregate data from the AIMS eReefs THREDDS server (daily, monthly, yearly, in in regular rectangular grid NetCDF format).
Data span
These results are based on a fixed time period (Dec 2010 - Apr 2019) hind-cast analysis developed for comparing changes in land practices. The river run off used to drive the BGC model were provided by the SOURCE Catchments modelling.