University of Tasmania, Australia

Solar irradiance and Antarctic benthic communities

Level: MSc/PhD

Sea-bed communities are commonly used as a measure of anthropogenic impacts in the marine environment. To identify impacts it is first necessary to understand the range of natural variability that can occur. Light availability is a major factor in determining the characteristics of sea-bed communities and in the Antarctic, light reaching the sea bed is highly influenced by sea ice cover. This project would look to build a statistical model of light availability at the sea-bed, using a software package such as R or Matlab. The model will contribute to a better understanding of the spatial distributions of benthic communities in East Antarctica.

The model would be developed in two phases. The first phase would identify which physical parameters are relevant and feasible to model, and then develop a model of the available light at the sea bed given these parameters. The relevant parameter list might include time of year, latitude, cloud cover, sea ice cover, snow thickness over sea ice, water depth, and optical properties of the atmosphere and water column. The processes involved with many of these parameters are fairly well understood and existing work would be re-used for these parts of the model.  Some of these processes are modelled by equations that require locality-specific constants to be estimated; these may need to be estimated for the Casey region.

The second modelling phase would seek to provide a predictive model of light availability in the Casey region. This would involve coupling the above work with either a predictive spatio-temporal GIS model of the relevant physical parameters (sea ice cover, snow thickness, etc), or with observations of these parameters obtained from direct measurement or remote sensed techniques. The GIS approach is likely to provide better spatial resolution, but require more detailed modelling in order to obtain satisfactory results. The scope of the project (Masters/PhD) and the progress of the student would determine which of these options would be taken.

Nominal supervisors: Jonny Stark, Ben Raymond