Regional Variability of the 20th century sea level rise from Ocean-Atmosphere Coupled Climate Models
Event: 2014 Ocean Surface Topography Science Team Meeting
Session: Science Results from Satellite Altimetry: Regional and basin-scale processes and sea level rise
Presentation type: Type Poster
Contribution: not provided
In this study we aim to estimate this 20th century regional sea level changes. We use historical runs of the CMIP5 (Coupled Model Intercomparison Project Phase 5) coupled climate models, which cover the period 1850-2005, and extend them until 2012 with the RCP8.5 run. With these simulations, we estimate the different contributors to the regional sea level changes since 1900. The ocean warming contribution is directly computed from the temperature and salinity outputs of the CMIP5 models while the mountain glaciers and the Greenland contributions are computed from offline models using the surface temperature and precipitations output of CMIP5 models. Concerning the landwater storage contribution, it is actually mainly of anthropogenic origin over the 20th century
(Ngoduc et al. 2005, Meyssignac et Cazenave 2012, IPCC AR5 2013) so it is not modeled in CMIP5 models, and we do not include them in this study. As a result, we present for each different contributors and for the sum of all, a map of associated sea level changes over the 20th century (average sea level changes over the period 1993-2012 with respect to the period 1860-1880). We then compare the models' results to observations. We show that over the altimetric era (1993-2012), the observed regional trends in sea level are not well reproduced by CMIP5 models. Large discrepancies are found in the tropical Pacific and seem to be due to a failure of CMIP5 models in reproducing the current regional trends in ocean warming.