scholarly journals GEOCENTRIC MEAN SEA LEVEL FIELDS AT THE GERMAN NORTH SEA AND BALTIC COAST

2018 ◽  
pp. 21
Author(s):  
Jessica Kelln ◽  
Sönke Dangendorf ◽  
Jürgen Jensen ◽  
Justus Patzke ◽  
Wolfgang Niemeier ◽  
...  
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Tide Gauge ◽  
Last Deglaciation ◽  
Mean Sea Level ◽  
Baltic Coast ◽  
Vertical Land Motion ◽  
Level Information ◽  
The Last Deglaciation ◽  
Global Mean Sea Level

Global mean sea level has risen over the 20th century (Hay et al. 2015; Dangendorf et al. 2017) and under sustained greenhouse gas emissions it is projected to further accelerate throughout the 21st century (Church et al. 2013) with large spatial variations, significantly threatening coastal communities. Locally the effects of geocentric (sometimes also referred to absolute) sea level rise can further be amplified by vertical land motion (VLM) due to natural adjustments of the solid earth to the melting of the large ice-sheets during the last deglaciation (GIA) or local anthropogenic interventions such as groundwater or gas withdrawal (e.g. Santamaría-Gómez et al. 2017). Both, the observed and projected geocentric sea level rise as well as VLM are critically important for coastal planning and engineering, since only their combined effect determines the total threat of coastal flooding at specific locations. Furthermore, due large spatial variability of sea level, information is required not only at isolated tide gauge (TG) locations but also along the coastline stretches in between.

scholarly journals Reassessment of 20th century global mean sea level rise

2017 ◽  
Vol 114 (23) ◽  
pp. 5946-5951 ◽  
Author(s):  
Sönke Dangendorf ◽  
Marta Marcos ◽  
Guy Wöppelmann ◽  
Clinton P. Conrad ◽  
Thomas Frederikse ◽  
...  
Keyword(s):  
Sea Level ◽  
20Th Century ◽  
Tide Gauge ◽  
Equal Proportion ◽  
Tide Gauge Records ◽  
Intergovernmental Panel ◽  
Mean Sea Level ◽  
Vertical Land Motion ◽  
Global Mean Sea Level ◽  
Global Mean

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 (1σ) 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.

scholarly journals A new assessment of global mean sea level from altimeters highlights a reduction of global trend from 2005 to 2008

2009 ◽  
Vol 6 (1) ◽  
pp. 31-56 ◽  
Author(s):  
M. Ablain ◽  
A. Cazenave ◽  
G. Valladeau ◽  
S. Guinehut
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Tide Gauge ◽  
Mean Sea Level ◽  
Error Budget ◽  
Isostatic Adjustment ◽  
Global Trend ◽  
Tide Gauge Measurements ◽  
Global Mean Sea Level ◽  
Global Mean

Abstract. A new error budget assessment of the global Mean Sea Level (MSL) determined by TOPEX/Poseidon and Jason-1 altimeter satellites between January 1993 and June 2008 is presented. We discuss all potential errors affecting the calculation of the global MSL rate. We also compare altimetry-based sea level with tide gauge measurements over the altimetric period. This allows us to provide a realistic error budget of the MSL rise measured by satellite altimetry. These new calculations highlight a reduction in the rate of sea level rise since 2005, by ~2 mm/yr. This represents a 60% reduction compared to the 3.3 mm/yr sea level rise (glacial isostatic adjustment correction applied) measured between 1993 and 2005. Since November 2005, MSL is accurately measured by a single satellite, Jason-1. However the error analysis performed here indicates that the recent reduction in MSL rate is real.

scholarly journals The imprints of contemporary mass redistribution on local sea level and vertical land motion observations

Solid Earth ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 1971-1987 ◽  
Author(s):  
Thomas Frederikse ◽  
Felix W. Landerer ◽  
Lambert Caron
Keyword(s):  
Sea Level ◽  
Tide Gauge ◽  
Tide Gauge Records ◽  
Mean Sea Level ◽  
Sea Floor ◽  
Vertical Land Motion ◽  
Mass Redistribution ◽  
Global Mean Sea Level ◽  
The Impact ◽  
Global Mean

Abstract. Observations from permanent Global Navigation Satellite System (GNSS) stations are commonly used to correct tide-gauge observations for vertical land motion (VLM). We combine GRACE (Gravity Recovery and Climate Experiment) observations and an ensemble of glacial isostatic adjustment (GIA) predictions to assess and evaluate the impact of solid-Earth deformation (SED) due to contemporary mass redistribution and GIA on VLM trends derived from GNSS stations. This mass redistribution causes relative sea-level (RSL) and SED patterns that not only vary in space but also exhibit large interannual variability signals. We find that for many stations, including stations in coastal locations, this deformation causes VLM trends on the order of 1 mm yr−1 or higher. In multiple regions, including the Amazon Basin and large parts of Australia, the SED trend flips sign between the first half and second half of the 15-year GRACE record. GNSS records often only span a few years, and due to these interannual variations SED causes substantial biases when the linear trends in these short records are extrapolated back in time. We propose a new method to avoid this potential bias in the VLM-corrected tide-gauge record: instead of correcting tide-gauge records for the observed VLM trend, we first remove the effects from GIA and contemporary mass redistributions from the VLM observations before computing the VLM trend. This procedure reduces the extrapolation bias induced by SED, and it also avoids the bias due to sea-floor deformation: SED includes net sea-floor deformation, which is ignored in global-mean sea-level reconstructions based on VLM-corrected tide-gauge data. We apply this method to 8166 GNSS stations. With this separation, we are able to explain a large fraction of the discrepancy between observed sea-level trends at multiple long tide-gauge records and the global-mean sea-level trend from recent reconstructions.

scholarly journals Ocean mass, sterodynamic effects, and vertical land motion largely explain US coast relative sea level rise

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
T. C. Harvey ◽  
B. D. Hamlington ◽  
T. Frederikse ◽  
R. S. Nerem ◽  
C. G. Piecuch ◽  
...  
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Tide Gauge ◽  
Sea Level Changes ◽  
Relative Sea Level ◽  
Vertical Land Motion ◽  
Ocean Mass ◽  
Coastal Sea ◽  
Regional Sea Level ◽  
Global Mean Sea Level

AbstractRegional sea-level changes are caused by several physical processes that vary both in space and time. As a result of these processes, large regional departures from the long-term rate of global mean sea-level rise can occur. Identifying and understanding these processes at particular locations is the first step toward generating reliable projections and assisting in improved decision making. Here we quantify to what degree contemporary ocean mass change, sterodynamic effects, and vertical land motion influence sea-level rise observed by tide-gauge locations around the contiguous U.S. from 1993 to 2018. We are able to explain tide gauge-observed relative sea-level trends at 47 of 55 sampled locations. Locations where we cannot explain observed trends are potentially indicative of shortcomings in our coastal sea-level observational network or estimates of uncertainty.

scholarly journals A reconciled solution of Meltwater Pulse 1A sources using sea-level fingerprinting

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yucheng Lin ◽  
Fiona D. Hibbert ◽  
Pippa L. Whitehouse ◽  
Sarah A. Woodroffe ◽  
Anthony Purcell ◽  
...  
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Last Deglaciation ◽  
Considerable Uncertainty ◽  
Isostatic Adjustment ◽  
Geographically Distributed ◽  
The Last Deglaciation ◽  
Global Mean Sea Level ◽  
Global Sea Level ◽  
The Relationship

AbstractThe most rapid global sea-level rise event of the last deglaciation, Meltwater Pulse 1A (MWP-1A), occurred ∼14,650 years ago. Considerable uncertainty regarding the sources of meltwater limits understanding of the relationship between MWP-1A and the concurrent fast-changing climate. Here we present a data-driven inversion approach, using a glacio-isostatic adjustment model to invert for the sources of MWP-1A via sea-level constraints from six geographically distributed sites. The results suggest contributions from Antarctica, 1.3 m (0–5.9 m; 95% probability), Scandinavia, 4.6 m (3.2–6.4 m) and North America, 12.0 m (5.6–15.4 m), giving a global mean sea-level rise of 17.9 m (15.7–20.2 m) in 500 years. Only a North American dominant scenario successfully predicts the observed sea-level change across our six sites and an Antarctic dominant scenario is firmly refuted by Scottish isolation basin records. Our sea-level based results therefore reconcile with field-based ice-sheet reconstructions.

scholarly journals Are long tide gauge records in the wrong place to measure global mean sea level rise?

2016 ◽  
Vol 43 (19) ◽  
pp. 10,403-10,411 ◽  
Author(s):  
P. R. Thompson ◽  
B. D. Hamlington ◽  
F. W. Landerer ◽  
S. Adhikari
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Tide Gauge ◽  
Tide Gauge Records ◽  
Mean Sea Level ◽  
Global Mean Sea Level ◽  
Wrong Place ◽  
Global Mean

scholarly journals A new assessment of the error budget of global mean sea level rate estimated by satellite altimetry over 1993–2008

Ocean Science ◽  
2009 ◽  
Vol 5 (2) ◽  
pp. 193-201 ◽  
Author(s):  
M. Ablain ◽  
A. Cazenave ◽  
G. Valladeau ◽  
S. Guinehut
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Satellite Altimetry ◽  
Tide Gauge ◽  
Mean Sea Level ◽  
Error Budget ◽  
Isostatic Adjustment ◽  
Tide Gauge Measurements ◽  
Global Mean Sea Level ◽  
Global Mean

Abstract. A new error budget assessment of the global Mean Sea Level (MSL) determined by TOPEX/Poseidon and Jason-1 altimeter satellites between January 1993 and June 2008 is presented using last altimeter standards. We discuss all potential errors affecting the calculation of the global MSL rate. We also compare altimetry-based sea level with tide gauge measurements over the altimetric period. Applying a statistical approach, this allows us to provide a realistic error budget of the MSL rise measured by satellite altimetry. These new calculations highlight a reduction in the rate of sea level rise since 2005, by ~2 mm/yr. This represents a 60% reduction compared to the 3.3 mm/yr sea level rise (glacial isostatic adjustment correction applied) measured between 1993 and 2005. Since November 2005, MSL is accurately measured by a single satellite, Jason-1. However the error analysis performed here indicates that the recent reduction in MSL rate is real.

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