Extreme short-term stable isotope variability revealed by continuous rainwater analysis (original) (raw)

The continuous real-time analysis, at 30-s intervals, of precipitation at an Australian tropical location revealed extreme and rapidly changing d 18 O and dD values related to variations in moisture source areas, transport paths and precipitation histories. The range of d 18 O (À19.6% to +2.6%) and dD (À140% to +13%) 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 d 18 O (À8.7% to À19.6%) and dD (À54% to À140%) 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.