Meteorological measurements

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27 February 2007

Our science activities can broadly be broken down into three categories – atmospherics, snow and ice measurements and oceanography. Lower atmosphere meteorological measurements form an important part of our climate monitoring.

We have a meteorological mast on the sea ice measuring temperature, wind speed and direction, air pressure and relative humidity. The objective is to better understand the thermal exchanges occurring between different air masses, hence the wind measurements are made at a height of 1, 2, 5 and 10 meters. On either side of the main mast we also have two smaller masts supporting sonic anemometers capable of measuring the wind direction in three dimensions.

At the base of the met mast is a data logger that automatically sends all data to a computer on board Tara via a cable on the ice. This data is then sent directly to scientists in Europe for analysis. Although the station operates autonomously once installed we have had to move, modify and reinstall it a number of times due to ice movement.

During the winter we have recorded a minimum temperature of -41˚C and a maximum of -5˚C. The average relative humidity is constant at around 80 percent and the average atmospheric pressure 1017 hpa (range 980 – 1033). The wind has been predominantly from the southwest with an average speed of 10 knots, although we have recorded gusts up to 60 knots.

Grant