The Decrease in Summer Surface Water Temperature with Altitude in Swiss Alpine Lakes: A Comparison with Air Temperature Lapse Rates

Using miniature thermistors with integrated data loggers, the decrease in summer lake surface water temperature (LSWT) with increasing altitude a.s.l. was investigated in 10 Swiss Alpine lakes located between 613 m a.s.l. and 2339 m a.s.l. The LSWTs exhibit essentially the same short-term structure as regional air temperature, but are about 3 to 5°C higher than the air temperature at the altitude of the lake. LSWTs decrease approximately linearly with increasing altitude at a rate slightly greater than the surface air temperature lapse rate. Diel variations in LSWT are large, implying that single water temperature measurements are un- likely to be representative of the mean. Local factors will affect LSWT more than they affect air temperature, possibly resulting in severe distortion of the empirical relationship between the two. Several implications for paleoclimate reconstruction studies result. (1) Paleolimnologically reconstructed LSWTs are likely to be higher than the air temperatures prevailing at the altitude of the lake. (2) Lakes used for paleoclimate reconstruction should be selected to minimize local effects on LSWT. (3) The calibration of organism-specific quantitative paleotemperature inference models should not be based on single water temperature measurements. (4) Consideration should be given to calibrating such models directly against air temperature rather than water temperature. (5) The primary climate effect on the aquatic biota of high-altitude lakes may be mediated by the timing of the ice cover.

Zoë Wicomb's Ghosts. Uncanny Translocations in David's Story and The One That Got Away

This essay analyses Zoë Wicomb's novel David's Story and her latest collection of short stories, The One That Got Away, through the lense of cosmopolitanism and Jacques Derrida's concept of ‘hauntology’. Wicomb is a cosmopolitan author in a very precise sense: an author who embeds locally specific stories in a complex intertextual, historical and transnational web of cross-references. As settings, characters and objects move between Scotland and South Africa, it appears that the histories of these countries are mutually haunted by each other. Uncanny encounters with the past, and with memorials and art objects that take on a spectral quality, evoke an increasing sense of disorientation on the part of protagonists and readers alike. Assumptions about place, history and identity are thus constantly undermined and reconfigured.