Pan-derived isotopic composition of atmospheric water vapour and its variability in northern Canada

Isotope mass balance of evaporation pans is a practical method for detecting and quantifying temporal variations in the isotopic composition of atmospheric moisture ( δ A), as demonstrated during summer in continental arctic and subarctic regions of Canada. Variability of δ A, an atmospheric characteristic determined by air-mass origin and history, is a potentially useful tracer of synoptic atmospheric variations, and is an important control on isotopic behaviour of open-water bodies during surface–atmosphere exchange and evaporation. Flux-weighted δ A estimation using class A evaporation pans may be a practical alternative to precipitation or direct vapour sampling in dry climates, and is well-suited to short-term isotope mass balance investigations of shallow lakes.