Present-day sea level rise and variability: observations, causes and coastal impacts
David Salas Y Melia
Goneri Le Cozannet
(Jet Propulsion Laboratory)
Observed sea level from satellite altimetry over 1993-2010 (blue solid curve). Thermal expansion (red curve; mean value based on temperature data from Levitus et al., 2009; Ishii and Kimoto, 2009). Contribution from Greenland and Antarctica (cyan curves) and glaciers (green curve). The black curve represents the total land ice contribution while the blue dotted curve represents the total climatic contribution (sum of thermal expansion and land ice).
The objective of this research is to:
- measure with the highest accuracy the global mean sea level evolution over the altimetry era and its regional variability using multi satellite altimetry (including Jason-3 and AltiKa altimetry data when available),
- contribute to the validation/calibration of the Jason-3 and AltiKa altimetry missions,
- compute 2-D sea level time series since 1950 using EOF-based reconstructions,
- estimate the climatic contributions (thermal expansion, glacier and ice sheet mass balances and land water storage changes) to the global mean sea level rise over the altimetry era,
- study the causes of the regional variability in sea level changes (i.e., steric changes and quasi-static effects due to Glacial Isostatic Adjustment -GIA- of the solid Earth to last deglaciation and response to present-day mass redistributions) with a focus on the Indian Ocean and North Atlantic/Arctic regions,
- study the forcing factors at the origin of the regional variability (wind stress and heat/mass flux changes),
- develop detection/attribution studies (i.e., try to answer the question: are the spatial patterns observed during the altimetry era and second-half of the 20th century due only to natural variability of the climate system or do they already contain the fingerprint of the anthropogenic forcing?), and finally
- estimate the total sea level changes (i.e., the sum of the global mean rise plus regional variability plus vertical crustal motions) since 1950 along a few selected coastlines and at island sites, with focus on areas considered as particularly vulnerable.