Monthly resolved biannual precipitation oxygen isoscape for Switzerland

Abstract

Stable oxygen isotope composition of atmospheric precipitation (δ¹⁸O_p) was scrutinized from 39 stations distributed over Switzerland and its border zone. Monthly amount-weighted δ¹⁸O_p values averaged over the 1995–2000 period showed the expected strong linear altitude dependence (−0.15–−0.22 ‰/100 m) only during the summer season (May–September). Steeper gradients (~ −0.51–−0.59 ‰/100 m) were observed for winter months over a low elevation belt, while hardly any altitudinal difference was seen for high elevation stations. This dichotomy could be explained by the characteristically shallower vertical atmospheric mixing height during winter season. Grids and isotope distribution maps of the monthly δ¹⁸O_p have been calculated for 1995–1996 when the station network was the densest. The adopted interpolation method took into account both the variable mixing heights and the seasonal differences in isotopic lapse rates and combined them with residual kriging. The presented dataset allow point estimation of δ¹⁸O_p with monthly resolution. According to the test calculations this biannual dataset can be extended to recent years and back to 1992 with maintained fidelity and with a reduced station-set even back to 1983 at the expense of faded reliability over some parts of Switzerland. There is even a good chance to reach back to the seventies for the Swiss Plateau

Timing and nature of the penultimate deglaciation in a high alpine stalagmite from Switzerland

“…Because d 18 O of modern precipitation in Switzerland is strongly governed by air temperature (Schürch et al, 2003;Kern et al, 2013), the distinct positive shift in the MF-3 d 18 O profile is most likely related to an increase in air temperature above Schafsloch…”