Spatio-temporal variation in microclimate, the surface energy balance and ablation over a cirque glacier

Climatic processes, operating at a range of scales, drive energy fluxes at the glacier surface which control meltwater generation and ultimately runof f. Nevertheless, to date, most glacier microclimate research has been both temporally (short-term) and spatially (single station) restricted. This pap er addresses this knowledge gap by reporting on a detailed, empirical study which characterizes spatio-temporal variations in and linkages between gla cier microclimate, surface energy and mass exchanges within a small glacier ized cirque (Taillon Glacier, French Pyrenees) over two melt seasons. Data collected at five automatic weather stations (AWSs) and over ablation stake networks suggest that topoclimates, altitude and transient snowline positi on primarily determine the distribution of glacier energy receipt and, in t urn, snow- and ice-melt patterns. Generally net radiation is the dominant e nergy source, followed by sensible heat, while latent heat is an energy sin k. However, the magnitude and partitioning of energy balance terms, and con sequently ablation, vary across the glacier both seasonally and with prevai ling weather conditions. Importantly, this paper demonstrates that such mon itoring programmes are required to truly represent and provide a sound basi s for modelling glacier energy and mass-balances in both space and time. Co pyright (C) 2000 Royal Meteorological Society.