Measurements of the UV radiation (Blue, Violet, UVA and UVB) falling on sea ice in McMurdo Sound, quantification of sea ice algae and the effect of snow thickness on the transmissivity of sea ice to UV radiation

The weather during the recording period was overcast with snow and blizzards but the monitors were run throughout this period and accumulated data on UVA, UVB and UV radiation levels under overcast conditions. The amount of algae growing in the area around the ice was simultaneously quantified. A two wavelength detector measured the amount of light at different locations on a circle of about 1m radius.

The detectors were sensitive to red and green wavelengths. Algae absorb radiation strongly in the green, so the relative intensity in these two bands should indicate the amount of algae present. The effect of various thicknesses of snowfall on the UV transmission through to the sea ice algae below the ice was measured using samples cut from snow drifts.