Modeling interannual variability of water isotopes

with sea surface temperatures of the period 1950–1994 and with stable water isotopes H2 18O and HDO explicitly included in the water cycle, was performed to examine interannual to decadal variations of the isotopic composition of precipitation in Greenland and Antarctica. The analyses focus on the Summit region, central Greenland, and the Law Dome region, East Antarctica, respectively. Simulation results reveal that about one third of the simulated variability in H2 18O can be explained by simultaneous changes of the surface temperature at the precipitation sites. Other climate variables influencing the isotope signal are identified by multiple linear regression, and the results show that the H2 18O record in central Greenland integrates the climatic history of a broader region. For the Law Dome region in Antarctica the H2 18O record appears to be mainly related to climate changes at the precipitation site only. For the deuterium excess a clear influence of climate condition at two distinct regions of the Indian Ocean on the simulated deuterium excess record of th