AWS 5 and AWS 6 were given a new mast extension system, which should considerably simplify AWS maintenance in the future. Photo: Uwe Raffalski.

AWS 5 and AWS 6 were given a new mast extension system, which should considerably simplify AWS maintenance in the future. Photo: Uwe Raffalski.

Aim of the work

Since 1997/98 IMAU has been operating Automatic Weather Stations (AWS) in western Dronning Maud Land, of which one is situated close to Wasa (AWS 5) and one near Svea (AWS 6). The data from these stations have a very wide range of applications, from model validation, energy balance and mass balance calculations to supporting logistic operations. Funding for the operation of the AWS is secured until 2012. There are advanced plans for detailed meteorological measurements at the site of AWS 5 in 2006/07, in close collaboration with SWEDARP/Swedish Polar Research Secretariat and Stockholm University. As part of that experiment the AWS will be equipped with sensors for year-round eddycorrelation measurements. It is expected that data from AWS 5 and 6 will be available on GTS (Global Telecommunication System, used by weather forecasters to collect meteorological data from around the world) for weather forecasting and logistical purposes from November 2005 onwards. For several years already, the ARGOS receiver at McMurdo station has enabled online publication of the AWS data on the Antarctic AWS website of the University of Wisconsin.

Fieldwork in 2004/05

In the field season of 2004/05, AWS 5 near Wasa and AWS 6 near Svea were visited by IMAU technician Marcel Portanger, supported by personnel and vehicles from the Swedish Polar Research Secretariat (picture). Memory modules were exchanged, battery packs replaced and the mast system was replaced, allowing for easier mast extension in the future. Where necessary, sensors were replaced and snow temperature sensors were brought to the surface.

Some results

AWS 5 and AWS 6 are the most reliable IMAU AWS, because they experience persistent katabatic wind, which prevents ice accretion. As a result, nearly continuous measurements are now available since the beginning of 1998, i.e. covering more than 7 years. The figure shows the newest logger data of wind speed and temperature (hourly means are stored). A very long-lasting strong wind event occurred in May 2004, associated with high temperatures. Both at AWS 5 and 6, -40°C is occasionally reached, but only for short periods of time. The spring of 2004 was colder than the year before.

IMAU-AWS locations in western Dronning Maud Land, Antarctica

Wind speed (above) and temperature (below) at AWS 5 and 6 during the year preceding the 2004/05 fieldwork.

Data availability

The AWS data are available for research purposes free of charge (certain conditions apply when data are used in publications, contact Michiel van den Broeke). Those interested to work with the data should contact Michiel van den Broeke or Carleen Reijmer.

Acknowledgments

We thank all those involved in the 2004/05 maintenance of AWS 5 and 6, especially those that supported the fieldwork.