Local δ¹⁸O and δ²H variability in UK rainfall

Abstract. Rainfall collected twice weekly from 3 nearby UK stations between November 2004 and October 2006 allows local differences in δ¹⁸O and δ²H to be observed. Local gradients in δ¹⁸O_p appear to be of the same order of magnitude as national trends, suggesting the spatial δ¹⁸O_p picture is more complicated than the one currently available from sparse GNIP coverage. Comparing data from this study with previous work we find that average δ¹⁸O_p has changed in the UK over the last 20 years concurrent with an average temperature increase although inter-annual controls on the values remain seasonal temperature and the amount of precipitation in each rain event. Climate-isotope relationships observed from the weekly data do not explain the observed decadal scale shifts.