Continuous real-time analysis, at 30 sec intervals, of precipitation at an Australian tropical location revealed extreme and rapidly changing δ¹⁸O and δD values related to variations in moisture source areas, transport paths and precipitation histories. The range of δ¹⁸O (−19.6 to +2.6 ‰) and δD (−140 to +13 ‰) values from 5948 measurements of nine rain events over 15 days during an 8 month period at a single location was comparable to the range measured in 1532 monthly samples from all seven Australian GNIP stations from 1962–2002. Extreme variations in δ¹⁸O (−8.7 to −19.6 ‰) and δD (−54 to −140 ‰) were recorded within a single four-hour 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 © 2012 John Wiley & Sons, Ltd.