Experimental set-up

We installed the automated aerosol sampler inside a 20’ container. Because winter temperatures at Kohnen were frequently below -70°C and the needed electronic components (data logger, electric pumps and control units for solar panels and wind turbine) as well as batteries were generally susceptible to malfunction below -50°C, we took special care to abate minimum temperature amplitudes. This was attained by setting up a polyurethane foam insulated deep freeze chamber with stainless steel lamination inside the container. Additionally, we deployed about 1200 kg of liquid water to further buffer temperature fluctuations.

The operating aerosol sampler has continuous power consumption between 5-7 W at 12 VDC. Electric power was supplied by solar panels and a wind turbine. Wind turbine and solar panels were backed up with 1070 Ah nickel-cadmium batteries which have proven to be operative down to -50°C. This ensured a continuous sampling and minimized outages due to wind velocities below around 3 m/s during polar night, when the power supply relies entirely on the wind turbine.