About the CASLab
The physical environment at the CASLab
Where is the CASLab?
The CASLab is located close to the Weddell Sea coast. As the coast effectively forms a promontory at this point, the CASLab is exposed to the Weddell Sea in three directions. The surrounding area is flat and snow-covered with the nearest rock outcrops roughly 200 km away.
Sea ice/open water influence
During the summer months, an open water lead, that can be several tens of kilometers wide, extends along the ice front. During the winter, open water leads form regularly when the prevailing easterly winds force sea ice offshore. In particular, Precious Bay, to the south west of Halley, is normally ice free during winter and spring such that air arriving at Halley from this direction (the secondary wind-rose maximum) is likely to have had contact with open water.
At Halley, the sun stays permanently above the horizon from November 2nd to February 9th, and permanently below the horizon from April 30th to August 13th. Prior to sun-up and after sun-down, scattered light can be observed at Halley for several hours around solar noon.
Annual wind speed and temperatures
Wind speeds at Halley vary considerably through the year from very calm conditions to storms (mainly in winter/spring) gusting to 25 ms-1. Annual temperatures at the Halley CASLab range from just below 0°C in summer to around −45°C in winter.
CASLab site information/access
The CASLab was commissioned in 2003 at BAS’s Halley V station (75°35′S, 26°34′W). It operated successfully for five years before a temporary suspension during the construction of the new Halley VI station. In January 2012, the CASLab was installed at its new location at Halley VI (75°35′S, 26°10′W). The new site is some 20 km from Halley V, and has effectively identical environmental conditions.
The CASLab sits approximately 30 m above sea level on the floating Brunt Ice shelf in the Atlantic sector of coastal Antarctica.
Access to the laboratory is on foot or by ski — vehicle access is limited to a few occasions each year for delivery of equipment.