Impact of Pacific Ocean Variability on Global Mean Sea Level
Event: 2017 Ocean Surface Topography Science Team Meeting
Session: Science I: Climate data records for understanding the causes of global and regional sea level variability and change
Presentation type: Type Oral
The impact of interannual to decadal variability on sea level has been heavily investigated in recent years. Particular focus has been put on the relationship between the El Nino-Southern Oscillation (ENSO) and interannual variability in global mean sea level (GMSL). The positive correlation between well-known ENSO indices and detrended GMSL has led to the attribution of many of the rises and falls in global sea levels to ENSO, with an over-generalization of the relationship often following. Several studies have linked the effect of ENSO on GMSL primarily to the movement of water between ocean and land, while others have highlighted a significant steric contribution that adds to the mass-related signal. Here, we adopt a more general approach, avoiding an index-based approach to find coupled modes of variability in modern observations of the different components of sea level change. Using such an approach, the impact of Pacific Ocean climate variability on GMSL can be quantified and separated into steric and mass contributions. Furthermore, interannual variability associated with ENSO can be preliminarily separated from lower frequency variability often attributed to the Pacific Decadal Oscillation (PDO). Finally, closure is obtained in the global sea level budget on interannual to decadal timescales and used to explain the sharp recent increase in global sea level.