Seasonal change of steric sea level in the GIN seas

2011 ◽  
Vol 10 (1) ◽  
pp. 16-22 ◽  
Author(s):  
Lei Li ◽  
Huijuan Wang ◽  
Ruili Sun
Keyword(s):  
Sea Level ◽  
Seasonal Change ◽  
Steric Sea Level ◽  
Gin Seas

scholarly journals Consistency of the current global ocean observing systems from an Argo perspective

Ocean Science ◽  
2014 ◽  
Vol 10 (3) ◽  
pp. 547-557 ◽  
Author(s):  
K. von Schuckmann ◽  
J.-B. Sallée ◽  
D. Chambers ◽  
P.-Y. Le Traon ◽  
C. Cabanes ◽  
...  
Keyword(s):  
Sea Level ◽  
Heat Content ◽  
Deep Ocean ◽  
Global Ocean ◽  
Regional Variability ◽  
Tropical Ocean ◽  
Steric Sea Level ◽  
Ocean Observing ◽  
Ocean Observing Systems ◽  
Observing Systems

Abstract. Variations in the world's ocean heat storage and its associated volume changes are a key factor to gauge global warming and to assess the earth's energy and sea level budget. Estimating global ocean heat content (GOHC) and global steric sea level (GSSL) with temperature/salinity data from the Argo network reveals a positive change of 0.5 ± 0.1 W m−2 (applied to the surface area of the ocean) and 0.5 ± 0.1 mm year−1 during the years 2005 to 2012, averaged between 60° S and 60° N and the 10–1500 m depth layer. In this study, we present an intercomparison of three global ocean observing systems: the Argo network, satellite gravimetry from GRACE and satellite altimetry. Their consistency is investigated from an Argo perspective at global and regional scales during the period 2005–2010. Although we can close the recent global ocean sea level budget within uncertainties, sampling inconsistencies need to be corrected for an accurate global budget due to systematic biases in GOHC and GSSL in the Tropical Ocean. Our findings show that the area around the Tropical Asian Archipelago (TAA) is important to closing the global sea level budget on interannual to decadal timescales, pointing out that the steric estimate from Argo is biased low, as the current mapping methods are insufficient to recover the steric signal in the TAA region. Both the large regional variability and the uncertainties in the current observing system prevent us from extracting indirect information regarding deep-ocean changes. This emphasizes the importance of continuing sustained effort in measuring the deep ocean from ship platforms and by beginning a much needed automated deep-Argo network.

scholarly journals Steric Sea-level Variations Inferred from Combined Topex/Poseidon Altimetry and GRACE Gravimetry

2007 ◽  
Vol 164 (4) ◽  
pp. 721-731 ◽  
Author(s):  
D. García ◽  
G. Ramillien ◽  
A. Lombard ◽  
A. Cazenave
Keyword(s):  
Sea Level ◽  
Steric Sea Level ◽  
Sea Level Variations

Steric sea level changes estimated from historical ocean subsurface temperature and salinity analyses

2006 ◽  
Vol 62 (2) ◽  
pp. 155-170 ◽  
Author(s):  
Masayoshi Ishii ◽  
Masahide Kimoto ◽  
Kenji Sakamoto ◽  
Sin-Iti Iwasaki
Keyword(s):  
Sea Level ◽  
Subsurface Temperature ◽  
Sea Level Changes ◽  
Steric Sea Level

scholarly journals Contribution of buoyancy fluxes to tropical Pacific sea level variability

2021 ◽  
Author(s):  
Patrick Wagner ◽  
Markus Scheinert ◽  
Claus W. Böning
Keyword(s):  
Sea Level ◽  
Fresh Water ◽  
Wind Stress ◽  
Tropical Pacific ◽  
Water Fluxes ◽  
Sea Level Variability ◽  
Steric Sea Level ◽  
Enso Events ◽  
Stress Changes ◽  
The Tropical Pacific

Abstract. Regional anomalies of steric sea level are either due to redistribution of heat and freshwater anomalies or due to ocean-atmosphere buoyancy fluxes. Interannual to decadal variability in sea level across the tropical Pacific is mainly due to steric variations driven by wind stress anomalies. The importance of air--sea buoyancy fluxes is less clear. We use a global, eddy permitting ocean model and a series of sensitivity experiments with quasi-climatological momentum and buoyancy fluxes to identify the contribution of buoyancy fluxes for interannual to decadal sea level variability in the tropical Pacific. We find their contribution on interannual timescales to be strongest in the central tropical Pacific at around 10° latitude in both hemispheres and also relevant in the very east of the tropical domain. Buoyancy flux forced anomalies are in phase with variations driven by wind stress changes but their effect on the prevailing anomalies and the importance of heat and fresh water fluxes vary locally. In the eastern tropical basin interannual sea level variability is amplified by anomalous heat fluxes, while the importance of fresh water fluxes is small and neither has any impact on decadal timescales. In the western tropical Pacific the variability on interannual and decadal timescales is dampened by both, heat and freshwater fluxes. The mechanism involves westward propagating Rossby waves that are triggered during ENSO events by anomalous buoyancy fluxes in the central tropical Pacific and counteract the prevailing sea level anomalies once they reach the western part of the basin.

Closing the global mean sea level budget from altimetry, GRACE/GRACE Follow-On and Argo data (2005-present)

2021 ◽  
Author(s):  
Anne Barnoud ◽  
Anny Cazenave ◽  
Julia Pfeffer ◽  
Michaël Ablain ◽  
Adrien Guérou ◽  
...  
Keyword(s):  
Sea Level ◽  
Systematic Bias ◽  
Satellite Mission ◽  
Argo Data ◽  
Steric Sea Level ◽  
Mean Sea Level ◽  
Ocean Mass ◽  
Salinity Data ◽  
Global Mean Sea Level ◽  
Global Mean

<p>Change in the global mean sea level (GMSL) is the sum of changes in the global mean steric sea level and global mean ocean mass. Over the 1993-2016 period, the GMSL budget was found to be closed, as shown by many independent studies. However, non-closure of the sea level budget after 2016 has been recently reported when using altimetry, Argo and GRACE/GRACE Follow-On data (Chen et al., GRL, 2020). This non-closure may result from errors in one or more components of the sea level budget (altimetry-based GMSL, Argo-based steric sea level or GRACE-based ocean mass). In this study, we investigated possible sources of errors affecting atlimetry and Argo data used to assess closure of the GMSL budget. Concerning altimetry data, we compared the wet tropospheric correction (WTC) applied to Jason-3 data (the reference satellite mission used for the GMSL computation since 2016) with that from the SARAL/AltiKa mission, and found no systematic bias between the radiometer measurements from these two missions. Besides, preliminary comparisons of GMSL trends (using the WTC ECMWF model) between different missions do not suggest discrepancies larger than 0.4 mm/yr over 2016-present. While further analyses are still needed, we find unlikely that non-closure of the sea level budget results from errors of the altimetry system. Concerning Argo data, since 2016, salinity data from different processing groups display strong discrepancies, likely due to instrumental problems and data editing issues. Good agreement is found between all available Argo-based thermosteric products. Given that the halosteric component should be negligible in global average, we re-examined the sea level budget since 2016 using only the thermosteric component and found significant improvement in the budget closure, although it is not yet fully closed. This suggests that the observed discrepancies in the Argo-based halosteric component largely contribute to the non-closure of the GMSL budget in the recent years.</p>

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