Mass-induced sea level variations in the Gulf of Carpentaria

Abstract

In this work, variations in mass-induced sea surface height (SSHmass, ocean bottom pressure) in the Gulf of Carpentaria are investigated on seasonal to decadal timescales using altimetry data, Gravity Recovery and Climate Experiment (GRACE) estimates, and steric sea surface height measurements derived from subsurface temperature and salinity analyses. Seasonal variability in gulf-mean SSHmass can be attributed to local wind forcing. On an interannual and decadal timescale, SSHmass is the dominant factor affecting total sea surface height, and is related to large-scale modes such as the El Nio Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO). Oceanic waves propagating from the western Pacific and the corresponding water exchange between the deep ocean and the shallow Gulf of Carpentaria, rather than local wind variability associated with climate modes, are responsible for the low-frequency variations in SSHmass in the gulf. Over 2003-2011, SSHmass rose at a rate of about 8.0 +/- A 1.5 mm/year, and the PDO accounted for about 65 % of gulf-scale mass variation