Nouméa: a new multi-mission calibration and validation site for past and future altimetry missions?
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Published:2023-08-22
Issue:4
Volume:19
Page:1277-1314
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ISSN:1812-0792
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Container-title:Ocean Science
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language:en
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Short-container-title:Ocean Sci.
Author:
Chupin Clémence, Ballu Valérie, Testut LaurentORCID, Tranchant Yann-TredenORCID, Aucan JérômeORCID
Abstract
Abstract. Today, monitoring the evolution of sea level in coastal
areas is of importance, since almost 11 % of the world's population
lives
in low-lying areas. Reducing uncertainties in sea level estimates requires
a
better understanding of both altimetry measurements and local sea level
dynamics. In New Caledonia, the Nouméa lagoon is an example of this
challenge, as altimetry, coastal tide gauge, and vertical land motions
from global navigation satellite systems (GNSSs) do not provide consistent
information. The GEOCEAN-NC 2019 field campaign addresses this issue with
deployments of in situ instruments in the lagoon (GNSS buoy,
pressure gauge, etc.),
with a particular focus on the crossover of one Jason-series track and two
Sentinel-3A missions tracks. In this study, we propose a method to
virtually
transfer the Nouméa tide gauge at the altimetry crossover point, using
in situ data
from the field campaign. Following the philosophy of calibration and validation (Cal/Val) studies, we
derive absolute altimeter bias time series over the entire Jason and
Sentinel-3A periods. Overall, our estimated altimeter mean biases are
slightly larger by 1–2 cm compared to Corsica and Bass Strait results,
with
inter-mission biases in line with those of Bass Strait site. Uncertainties
still remain regarding the determination of our vertical datum, only
constrained by the three days of the GNSS buoy deployment. With our method,
we are able to re-analyse about 20 years of altimetry observations and
derive a linear trend of −0.2 ± 0.1 mm yr−1 over the bias time series.
Compared to previous studies, we do not find any significant uplift in the
area, which is more consistent with the observations of inland permanent
GNSS stations. These results support the idea of developing Cal/Val
activities in the lagoon, which is already the subject of several
experiments for the scientific calibration phase of the SWOT wide-swath
altimetry mission.
Funder
Centre National d’Etudes Spatiales Centre National de la Recherche Scientifique Ministère de l'Enseignement Supérieur et de la Recherche
Publisher
Copernicus GmbH
Subject
Cell Biology,Developmental Biology,Embryology,Anatomy
Reference74 articles.
1. Ablain, M., Cazenave, A., Valladeau, G., and Guinehut, S.: A new assessment
of the error budget of global mean sea level rate estimated by satellite
altimetry over 1993–2008, Ocean Sci., 5, 193–201,
https://doi.org/10.5194/os-5-193-2009, 2009. 2. Ablain, M., Meyssignac, B., Zawadzki, L., Jugier, R., Ribes, A., Spada, G.,
Benveniste, J., Cazenave, A., and Picot, N.: Uncertainty in satellite
estimates of global mean sea-level changes, trend and acceleration, Earth
Syst. Sci. Data, 11, 1189–1202, https://doi.org/10.5194/essd-11-1189-2019,
2019. 3. Andersen, O. B. and Scharroo, R.: Range and Geophysical Corrections in
Coastal Regions: And Implications for Mean Sea Surface Determination, in:
Coastal Altimetry, edited by: Vignudelli, S., Kostianoy, A. G., Cipollini,
P., and Benveniste, J., Springer Berlin Heidelberg, Berlin, Heidelberg,
103–145, https://doi.org/10.1007/978-3-642-12796-0_5, 2011. 4. André, G., Miguez, B. M., Ballu, V., Testut, L., and Wöppelmann, G.:
Measuring sea level with gps-equipped buoys: a multi-instruments experiment
at Aix Island, Int. Hydrogr. Rev.,
26–38, https://journals.lib.unb.ca/index.php/ihr/article/view/22826/26514 (last access: 20 July 2023), 2013. 5. Aucan, J., Merrifield, M. A., and Pouvreau, N.: Historical Sea Level in the
South Pacific from Rescued Archives, Geodetic Measurements, and Satellite
Altimetry, Pure Appl. Geophys., 174, 3813–3823,
https://doi.org/10.1007/s00024-017-1648-1, 2017a.
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