fresh water
; acceleration
; Article
; deglaciation
; global mean sea level rise
; Indian Ocean
; priority journal
; salinity
; sea level rise
; sensitivity analysis
; tide
英文摘要:
The rate at which global mean sea level (GMSL) rose during the 20th century is uncertain, with little consensus between various reconstructions that indicate rates of rise ranging from 1.3 to 2 mm•y-1. Here we present a 20th-century GMSL reconstruction computed using an area-weighting technique for averaging tide gauge records that both incorporates up-to-date observations of vertical land motion (VLM) and corrections for local geoid changes resulting from ice melting and terrestrial freshwater storage and allows for the identification of possible differences compared with earlier attempts. Our reconstructed GMSL trend of 1.1 ± 0.3 mm•y-1 (1s) before 1990 falls below previous estimates, whereas our estimate of 3.1 ± 1.4 mm•y-1 from 1993 to 2012 is consistent with independent estimates from satellite altimetry, leading to overall acceleration larger than previously suggested. This feature is geographically dominated by the Indian Ocean-Southern Pacific region, marking a transition from lower-than-average rates before 1990 toward unprecedented high rates in recent decades. We demonstrate that VLM corrections, area weighting, and our use of a common reference datum for tide gauges may explain the lower rates compared with earlier GMSL estimates in approximately equal proportion. The trends and multidecadal variability of our GMSL curve also compare well to the sum of individual contributions obtained from historical outputs of the Coupled Model Intercomparison Project Phase 5. This, in turn, increases our confidence in process-based projections presented in the Fifth Assessment Report of the Intergovernmental Panel on Climate Change.
Dangendorf, S., Research Institute for Water and Environment, University of Siegen, Siegen, 57076, Germany; Marcos, M., Instituto Mediterráneo de Estudios Avanzados (IMEDEA), CSIC, Esporles, E-07190, Spain; Wöppelmann, G., Littoral Environnement et Sociétés (LIENSs), Universite de la Rochelle-CNRS, La-Rochelle, 17000, France; Conrad, C.P., Centre for Earth Evolution and Dynamics, University of Oslo, Oslo, NO-0315, Norway; Frederikse, T., Department of Geoscience and Remote Sensing, Delft University of Technology, Delft, 2628CN, Netherlands; Riva, R., Department of Geoscience and Remote Sensing, Delft University of Technology, Delft, 2628CN, Netherlands
Recommended Citation:
Dangendorf S.,Marcos M.,Wöppelmann G.,et al. Reassessment of 20th century global mean sea level rise[J]. Proceedings of the National Academy of Sciences of the United States of America,2017-01-01,114(23)