Global Sea Level Budget Assessment by World Climate Research Programme

Global mean sea level is an integral of changes occurring in the climate system in response to unforced climate variability as well as natural and anthropogenic forcing factors. Its temporal evolution allows detecting changes (e.g., acceleration) in one or more components. Study of the sea level budget provides constraints on missing or poorly known contributions, such as the unsurveyed deep ocean or the still uncertain land water component. In the context of the World Climate Research Programme Grand Challenge entitled “Regional Sea Level and Coastal Impacts”, an international effort involving the sea level community worldwide has been recently initiated with the objective of assessing the various data sets used to estimate components of the sea level budget during the altimetry era (1993 to present). These data sets are based on the combination of a broad range of space-based and in situ observations, model estimates and algorithms. Evaluating their quality, quantifying uncertainties and identifying sources of discrepancies between component estimates is extremely useful for various applications in climate research. This effort involves several tens of scientists from about sixty research teams/institutions worldwide (www.wcrp-climate.org/grand-challenges/gc-sea-level). The results presented in this paper are a synthesis of the first assessment performed during 2017-2018. We present estimates of the altimetry-based global mean sea level (average rate of 3.1 +/- 0.3 mm/yr and acceleration of 0.1 mm/yr2 over 1993-present), as well as of the different components of the sea level budget. We further examine closure of the sea level budget, comparing the observed global mean sea level with the sum of components. Ocean thermal expansion, glaciers, Greenland and Antarctica contribute by 42%, 21%, 15% and 8% to the global mean sea level over the 1993-present. We also study the sea level budget over 2005-present, using GRACE-based ocean mass estimates instead of sum of individual mass components. Results show closure of the sea level budget within 0.3 mm/yr. Substantial uncertainty remains for the land water storage component, as shown in examining individual mass contributions to sea level.How to cite: Cazenave Anny, Meyssignac Benoit, Palanisamy Hindumathi (2018). Global Sea Level Budget Assessment by World Climate Research Programme. SEANOE. https://doi.org/10.17882/54854. In addition to properly cite this dataset, it would be appreciated that the following work(s) be cited too, when using this dataset in a publication : Cazenave Anny, Meyssignac Benoit, Ablain Michael, Balmaseda Magdalena, Bamber Jonathan, Barletta Valentina, Beckley Brian, Benveniste Jerome, Berthier Etienne, Blazquez Alejandro, Boyer Tim, Caceres Denise, Chambers Don, Champollion Nicolas, Chao Ben, Chen Jianli, Cheng Lijing, Church John A., Chuter Stephen, Cogley J. Graham, Dangendorf Soenke, Desbruyeres Damien, Doell Petra, Domingues Catia, Falk Ulrike, Famiglietti James, Fenoglio-Marc Luciana, Forsberg Rene, Galassi Gaia, Gardner Alex, Groh Andreas, Hamlington Benjamin, Hogg Anna, Horwath Martin, Humphrey Vincent, Husson Laurent, Ishii Masayoshi, Jaeggi Adrian, Jevrejeva Svetlana, Johnson Gregory, Kolodziejczyk Nicolas, Kusche Juergen, Lambeck Kurt, Landerer Felix, Leclercq Paul, Legresy Benoit, Leuliette Eric, Llovel William, Longuevergne Laurent, Loomis Bryant D., Luthcke Scott B., Marcos Marta, Marzeion Ben, Merchant Chris, Merrifield Mark, Milne Glenn, Mitchum Gary, Mohajerani Yara, Monier Maeva, Monselesan Didier, Nerem Steve, Palanisamy Hindumathi, Paul Frank, Perez Begona, Piecuch Christopher G., Ponte Rui M., Purkey Sarah G., Reager John T., Rietbroek Roelof, Rignot Eric, Riva Riccardo, Roemmich Dean H., Sorensen Louise Sandberg, Sasgen Ingo, Schrama E. J. O., Seneviratne Sonia I., Shum C. K., Spada Giorgio, Stammer Detlef, Van De Wal Roderic, Velicogna Isabella, von Schuckmann Karina, Wada Yoshihide, Wang Yiguo, Watson Christopher, Wiese David, Wijffels Susan, Westaway Richard, Woppelmann Guy, Wouters Bert (2018). Global sea-level budget 1993-present. Earth System Science Data, 10(3), 1551-1590. Publisher's official version : https://doi.org/10.5194/essd-10-1551-201