Extreme short-term stable isotope variability revealed by continuous rainwater analysis

The continuous real-time analysis, at 30-s intervals, of precipitation at an Australian tropical location revealed extreme and rapidly changing d18O and dD values related to variations in moisture source areas, transport paths and precipitation histories. The range of d18O (-19.6 parts per thousand to +2.6 parts per thousand) and dD (-140 parts per thousand to +13 parts per thousand) values from 5948 measurements of nine rain events over 15 days during an 8-month period at a single location was comparable with the range measured in 1532 monthly samples from all seven Australian Global Network of Isotopes in Precipitation stations from 1962 to 2002. Extreme variations in d18O (-8.7 parts per thousand to -19.6 parts per thousand) and dD (-54 parts per thousand to -140 parts per thousand) were recorded within a single 4-h period. Real-time stable isotope monitoring of precipitation at a high temporal resolution enables new and powerful tracer applications in climatology, hydrology, ecophysiology and palaeoclimatology. Copyright (c) 2012 John Wiley & Sons, Ltd.