Ice-mounted masts as platforms for micro-me- teorological measurements on glaciers Michael Winkler 1 , Rainer Prinz 1 , Lindsey Nicholson 1 , Nicolas Cullen 2 , Christophe Kinnard 3 1 Centre for Climate and Cryosphere, University of Innsbruck, Austria 2 Department of Geography, University of Otago, New Zealand 3 Centro de Estudios Avanzados en Zonas Áridas (CEAZA), La Serena, Chile Introduction Automated measurements of meteorological variables on glaciers are nec- essary for surface energy and mass balance studies. Typically, the instru- ments are mounted on tripods that are placed on the ice without addi- tional securing devices (e.g. guy wires). We take the opportunity here to describe an alternative method, that involves using segmented masts that are drilled vertically into ice or snow covered glacial surfaces (Fig. 1). The presented system (or a version of it) was tested at the following sites: Kersten Glacier (Kilimanjaro, TZ), Lewis Glacier (Mt. Kenya, KE), Glaciar Shallap (Cordillera Blanca, PE), Glaciar Cerro Tapado (Coquimbo region, CL), Glaciar Guanaco, Glaciar Ortigas, Glaciarete Toro (all 3 sites Atacama region, CL), Brewster Glacier (NZ), and at various sites in Greenland. Ice-mounted segmented mast design The masts consist of aluminium (or steel) tube segments, each ca. 1- 1.5 m long (l in Fig. 1A) with an outer diameter of ca. 50 mm and a wall thickness of ca. 4 mm. The segments are connected to each other through ca. 20 - 30 cm tubes with outer diameters equal to the inner diameter of the segments. They are fixed to both consecutive segments by high quality countersunk-head screws (Fig. 1B). The combined mast is put into a hole drilled by an ice auger 1 or steam drill. The depth of the bore hole (L in Fig. 1A) very much depends on the ablation rate between consecutive maintenance visits; at least 1.5 m of mast should always be encased by ice. It is valuable to drill a second mast (Fig. 1A) to avoid turning of the whole station that can e.g. be caused by wind in the case that the mast is temporarily not frozen into the host ice and to block the bottom ends of the tube with a plug to prevent the mast from sinking into the ice under its own weight (Fig. 1C). If a standard weather station tower must be used, the uppermost tube of the segmented mast can be equipped with a plate on top of which the standard mast can be mounted (Fig. 1E). This has proved to be a stable structure, but care should be taken concerning the color and size of the 1 48 mm outer diameter masts work e.g. perfectly with 51 mm Kovacs® ice augers. 88