Publication Date:
2024-02-14
Description:
Increased Greenland ice sheet melting has an impact on global mean and regional sea level rise and the ocean circulation. In this study, we explore whether Greenland melting signatures found in ocean model simulations are visible in observations from radar altimetry, satellite gravimetry and Argo floats. We have included Greenland freshwater flux (GF) in the global Finite‐Element‐Sea ice‐Ocean Model (FESOM) for the years 1993–2016. The reference run is computed by excluding Greenland freshwater input. These experiments are performed on a low resolution (ca. 24 km) and a high resolution (ca. 6 km) eddy‐permitting mesh. For comparison with the model experiments, we use different observational data, such as Argo floats, satellite observations, and reanalyses. We find that surface GF maps into signatures in temperature and salinity down to about 100 m in the surroundings of Greenland. The simulated melting signatures are particularly visible in steric heights in Baffin Bay and Davis Strait. Here, we find an improvement of the mean square error of up to 30% when including GF. For the Nordic part of the Nordic Seas, however, we find no improvement when including GF. We compare steric heights with reanalysis data and a new setup of the inversion method from gravimetric and altimetric satellite data. We cannot confirm that the GF signatures on variables such as temperature and salinity are visible in the observations on the time scales considered. However, we find that increased model resolution often causes larger improvements than occur due to including the simulated melting effect.
Description:
Plain Language Summary:
In recent years, Greenland's freshwater contribution to the ocean has increased due to the accelerated melting of its ice sheet and glaciers. In this study, we investigate the importance of this melting in reproducing the observed characteristics of the northern part of the North Atlantic Ocean in a numerical ocean model. To do that, we compare the results of two model simulations, one with and one without Greenland melt, with in situ observations or data from satellites. The inclusion of Greenland melt results in a better model representation of the ocean in terms of salinity, temperature, and sea level anomalies, especially in Baffin Bay on the west side of Greenland. We also discuss the role of a higher model resolution on the simulations in reproducing observations. Our study shows that progress in modeling how Greenland melt affects the nearby ocean is best achieved by improving model resolution so that small‐scale processes can be well represented.
Description:
Key Points:
Greenland freshwater flow yields distinct signatures in temperature and salinity within the upper 100 m.
Steric heights and sea level anomalies are sensitive to the Greenland freshwater intrusion especially in Baffin Bay.
Increasing the spatial model resolution improves the agreement with observations more than if only Greenland meltwater is included.
Description:
Bundesministerium für Bildung und Forschung
http://dx.doi.org/10.13039/501100002347
Description:
https://doi.org/10.5281/zenodo.6243822
Keywords:
ddc:551.46
;
ocean modeling
;
FESOM
;
Greenland freshwater discharge
;
ocean reanalysis
;
altimetry
Language:
English
Type:
doc-type:article
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