Australian water mass variations from GRACE data linked to Indo-Pacific climate variability

Time-variable gravity data from the Gravity Recovery And Climate Experiment (GRACE) mission are used to 22 study total water content over Australia for the period 2002-2010. A time-varying annual signal explains 61% 23 of the variance of the data, in good agreement with two independent estimates of the same quantity from 24 hydrological models. Water mass content variations across Australia are linked to Pacific and Indian Ocean 25 variability, associated with El Niño-Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD), 26 respectively.From1989,positive(negative)IODphaseswererelatedtoanomalouslylow(high)precipitation 27 in southeastern Australia, associated with a reduced (enhanced) tropical moisture flux. In particular, the 28 sustained water mass content reduction over central and southern regions of Australia during the period 29 2006-2008 is associated with three consecutive positive IOD events. Acknowledgments: We thank the research project for emergent groups from the University of Alicante, GRE10-13.