scholarly journals Uncertainty of Aquarius sea surface salinity retrieved under rainy conditions and its implication on the water cycle study

2014 ◽  
Vol 119 (8) ◽  
pp. 4821-4839 ◽  
Author(s):  
Wenqing Tang ◽  
Simon H. Yueh ◽  
Alexander G. Fore ◽  
Akiko Hayashi ◽  
Tong Lee ◽  
...  
Keyword(s):  
Water Cycle ◽  
Sea Surface ◽  
Sea Surface Salinity ◽  
Surface Salinity

scholarly journals End-to-End Simulation of WCOM IMI Sea Surface Salinity Retrieval

2019 ◽  
Vol 11 (3) ◽  
pp. 217 ◽  
Author(s):  
Yan Li ◽  
Hao Liu ◽  
Aili Zhang
Keyword(s):  
Water Cycle ◽  
Earth Science ◽  
Global Climate ◽  
Microwave Radiometer ◽  
Sea Surface ◽  
Sea Surface Salinity ◽  
Surface Salinity ◽  
Open Sea ◽  
End To End ◽  
Change Intensity

The Water Cycle Observation Mission (WCOM) is an Earth science mission focused on the observation of the water cycle global climate change intensity through three different payloads. WCOM’s main payload is an interferometric microwave imager (IMI). IMI is a tri-frequency, one-dimensional aperture synthesis microwave radiometer operating at the L-, S-, and C-bands to perform measurements of soil moisture and ocean salinity. Focusing on sea surface salinity (SSS), an end-to-end simulator of WCOM/IMI has been realized and tested on climatological data. Results indicate a general agreement between original and retrieved SSS, with a single measurement root mean square error of 0.26 psu and with an orbital measurement of 0.17 psu in open sea. In accordance with previous studies, good results are obtained in open sea, while strong contamination is observed in coastal areas.

scholarly journals Comparison of Distributional Statistics of Aquarius and Argo Sea Surface Salinity Measurements

2016 ◽  
Vol 33 (1) ◽  
pp. 103-118 ◽  
Author(s):  
Elizabeth Mannshardt ◽  
Katarina Sucic ◽  
Montserrat Fuentes ◽  
Frederick M. Bingham
Keyword(s):  
Ocean Circulation ◽  
Hydrological Cycle ◽  
Water Cycle ◽  
Ocean Basin ◽  
Sea Surface ◽  
Sea Surface Salinity ◽  
Time And Space ◽  
Surface Salinity ◽  
Statistical Validation ◽  
Earth’S Climate

AbstractSalinity is an indicator of the interaction between ocean circulation and the global water cycle, which in turn affects the regulation of the earth’s climate. To thoroughly understand sea surface salinity’s connection to processes that define the hydrological cycle, such as surface forcing and ocean mixing, there is need for proper validation of remotely sensed salinity products with independent measurements, beyond central tendencies, across the entire distribution of salinity. Because of its fine spatial and temporal coverage, Aquarius presents an ideal measurement system for fully characterizing the distribution and properties of sea surface salinity. Using the first 33 months of Aquarius, version 3.0, level 2 sea surface salinity data, both central tendencies and distributional quantile characteristics across time and space are investigated, and a statistical validation of Aquarius measurements with Argo in situ observations is conducted. Several aspects are considered, including regional characteristics and temporal agreement, as well as seasonal differences by ocean basin and hemisphere. Regional studies examine the time and space scales of variability through time series comparisons and an analysis of quantile properties. Results indicate that there are significant differences between the tails of their respective distributions, especially the lower tail. The Aquarius data show longer, fatter lower tails, indicating higher probability to sample low-salinity events. There is also evidence of differences in measurement variation between Aquarius and Argo. These results are seen across seasons, ocean basins, hemispheres, and regions.

scholarly journals Global Analysis of Coastal Gradients of Sea Surface Salinity

2021 ◽  
Vol 13 (13) ◽  
pp. 2507
Author(s):  
Alina N. Dossa ◽  
Gaël Alory ◽  
Alex Costa da Silva ◽  
Adeola M. Dahunsi ◽  
Arnaud Bertrand
Keyword(s):  
Soil Moisture ◽  
Water Cycle ◽  
Global Analysis ◽  
Sea Surface ◽  
Sea Surface Salinity ◽  
Coastal Processes ◽  
In Situ Observation ◽  
Surface Salinity ◽  
Ocean Salinity ◽  
Satellite Missions

Sea surface salinity (SSS) is a key variable for ocean–atmosphere interactions and the water cycle. Due to its climatic importance, increasing efforts have been made for its global in situ observation, and dedicated satellite missions have been launched more recently to allow homogeneous coverage at higher resolution. Cross-shore SSS gradients can bear the signature of different coastal processes such as river plumes, upwelling or boundary currents, as we illustrate in a few regions. However, satellites performances are questionable in coastal regions. Here, we assess the skill of four gridded products derived from the Soil Moisture Ocean Salinity (SMOS) and Soil Moisture Active Passive (SMAP) satellites and the GLORYS global model reanalysis at capturing cross-shore SSS gradients in coastal bands up to 300 km wide. These products are compared with thermosalinography (TSG) measurements, which provide continuous data from the open ocean to the coast along ship tracks. The comparison shows various skills from one product to the other, decreasing as the coast gets closer. The bias in reproducing coastal SSS gradients is unrelated to how the SSS biases evolve with the distance to the coast. Despite limited skill, satellite products generally agree better with collocated TSG data than a global reanalysis and show a large range of coastal SSS gradients with different signs. Moreover, satellites reveal a global dominance of coastal freshening, primarily related to river runoff over shelves. This work shows a great potential of SSS remote sensing to monitor coastal processes, which would, however, require a jump in the resolution of future SSS satellite missions to be fully exploited.

scholarly journals Sea Surface Salinity Observations from Space with the SMOS Satellite: A New Means to Monitor the Marine Branch of the Water Cycle

2013 ◽  
Vol 35 (3) ◽  
pp. 681-722 ◽  
Author(s):  
Nicolas Reul ◽  
Severine Fournier ◽  
Jaqueline Boutin ◽  
Olga Hernandez ◽  
Christophe Maes ◽  
...  
Keyword(s):  
Water Cycle ◽  
Sea Surface ◽  
Sea Surface Salinity ◽  
Surface Salinity ◽  
Smos Satellite

Le Service national d'observation de la salinité de surface de la mer : 50 ans de mesures océaniques globales

2020 ◽  
pp. 029
Author(s):  
Gaël Alory ◽  
Philippe Téchiné ◽  
Thierry Delcroix ◽  
Denis Diverrès ◽  
David Varillon ◽  
...  
Keyword(s):  
New Caledonia ◽  
Water Cycle ◽  
Global Scale ◽  
Ocean Dynamics ◽  
Sea Surface ◽  
Sea Surface Salinity ◽  
Global Network ◽  
Time Data ◽  
Surface Salinity ◽  
Ocean Atmosphere

La salinité de surface de la mer (SSS : Sea Surface Salinity) influence la dynamique océanique et porte la signature du cycle de l'eau à l'interface océan-atmosphère. Pour mieux comprendre ses variations, le Service national d'observation SSS (SNO SSS) du Laboratoire d'études en géophysique et océanographie spatiales (Legos, Toulouse) gère un réseau global de navires d'opportunité équipés de thermosalinographes, initié il y a 50 ans. La maintenance des instruments est effectuée aux ports de Nouméa et du Havre par l'Institut de recherche pour le développement (IRD). Les données sont transmises en temps réel pour la surveillance des instruments et l'océanographie opérationnelle. Après correction des dérives instrumentales en temps différé, les données sont mises à disposition de la communauté scientifique internationale, et permettent d'étudier des processus océaniques et climatiques d'échelle régionale à globale, ou de valider modèles et données satellitaires. Sea Surface Salinity (SSS) affects the ocean dynamics and bears the signature of the water cycle at the ocean-atmosphere interface. To better understand its variations, the French SSS Observation Service from the Laboratory for Studies in Geophysics and Spatial Oceanography (LEGOS, Toulouse, France) manages a global network of voluntary observing ships equipped with thermosalinographs (TSG), initiated 50 years ago. The instruments are regularly serviced at harbour calls in New Caledonia and mainland France by the French National Research Institute for Sustainable Development (IRD). Data are transmitted in real time for instrument monitoring and operational oceanography. After correction of instrumental drifts in delayed time, data are freely distributed to the international research community, and used for process-oriented climate studies from regional to global scale, or for validation of models and satellite data.

scholarly journals Matchup Characteristics of Sea Surface Salinity Using a High-Resolution Ocean Model

2021 ◽  
Vol 13 (15) ◽  
pp. 2995
Author(s):  
Frederick M. Bingham ◽  
Severine Fournier ◽  
Susannah Brodnitz ◽  
Karly Ulfsax ◽  
Hong Zhang
Keyword(s):  
High Resolution ◽  
Time Window ◽  
Single Point ◽  
Ocean Model ◽  
Sea Surface ◽  
Sea Surface Salinity ◽  
Surface Salinity ◽  
Argo Floats ◽  
Statistical Measures ◽  
Salinity Difference

Sea surface salinity (SSS) satellite measurements are validated using in situ observations usually made by surfacing Argo floats. Validation statistics are computed using matched values of SSS from satellites and floats. This study explores how the matchup process is done using a high-resolution numerical ocean model, the MITgcm. One year of model output is sampled as if the Aquarius and Soil Moisture Active Passive (SMAP) satellites flew over it and Argo floats popped up into it. Statistical measures of mismatch between satellite and float are computed, RMS difference (RMSD) and bias. The bias is small, less than 0.002 in absolute value, but negative with float values being greater than satellites. RMSD is computed using an “all salinity difference” method that averages level 2 satellite observations within a given time and space window for comparison with Argo floats. RMSD values range from 0.08 to 0.18 depending on the space–time window and the satellite. This range gives an estimate of the representation error inherent in comparing single point Argo floats to area-average satellite values. The study has implications for future SSS satellite missions and the need to specify how errors are computed to gauge the total accuracy of retrieved SSS values.

scholarly journals Sea Surface Salinity Response to Tropical Cyclones Based on Satellite Observations

2021 ◽  
Vol 13 (3) ◽  
pp. 420
Author(s):  
Jingru Sun ◽  
Gabriel Vecchi ◽  
Brian Soden
Keyword(s):  
Tropical Cyclones ◽  
Sea Surface ◽  
Sea Surface Salinity ◽  
Surface Salinity ◽  
Translation Speed ◽  
Salinity Stratification ◽  
Left Hand ◽  
In Situ Data ◽  
Salinity Response ◽  
The Right

Multi-year records of satellite remote sensing of sea surface salinity (SSS) provide an opportunity to investigate the climatological characteristics of the SSS response to tropical cyclones (TCs). In this study, the influence of TC winds, rainfall and preexisting ocean stratification on SSS evolution is examined with multiple satellite-based and in-situ data. Global storm-centered composites indicate that TCs act to initially freshen the ocean surface (due to precipitation), and subsequently salinify the surface, largely through vertical ocean processes (mixing and upwelling), although regional hydrography can lead to local departure from this behavior. On average, on the day a TC passes, a strong SSS decrease is observed. The fresh anomaly is subsequently replaced by a net surface salinification, which persists for weeks. This salinification is larger on the right (left)-hand side of the storm motion in the Northern (Southern) Hemisphere, consistent with the location of stronger turbulent mixing. The influence of TC intensity and translation speed on the ocean response is also examined. Despite having greater precipitation, stronger TCs tend to produce longer-lasting, stronger and deeper salinification especially on the right-hand side of the storm motion. Faster moving TCs are found to have slightly weaker freshening with larger area coverage during the passage, but comparable salinification after the passage. The ocean haline response in four basins with different climatological salinity stratification reveals a significant impact of vertical stratification on the salinity response during and after the passage of TCs.

scholarly journals Using Saildrones to Validate Arctic Sea-Surface Salinity from the SMAP Satellite and from Ocean Models

2021 ◽  
Vol 13 (5) ◽  
pp. 831
Author(s):  
Jorge Vazquez-Cuervo ◽  
Chelle Gentemann ◽  
Wenqing Tang ◽  
Dustin Carroll ◽  
Hong Zhang ◽  
...  
Keyword(s):  
Arctic Ocean ◽  
Sea Surface ◽  
Sea Surface Salinity ◽  
The Arctic ◽  
Future Research ◽  
Surface Salinity ◽  
Cold Temperatures ◽  
Yukon River ◽  
Arctic Sea ◽  
The Arctic Ocean

The Arctic Ocean is one of the most important and challenging regions to observe—it experiences the largest changes from climate warming, and at the same time is one of the most difficult to sample because of sea ice and extreme cold temperatures. Two NASA-sponsored deployments of the Saildrone vehicle provided a unique opportunity for validating sea-surface salinity (SSS) derived from three separate products that use data from the Soil Moisture Active Passive (SMAP) satellite. To examine possible issues in resolving mesoscale-to-submesoscale variability, comparisons were also made with two versions of the Estimating the Circulation and Climate of the Ocean (ECCO) model (Carroll, D; Menmenlis, D; Zhang, H.). The results indicate that the three SMAP products resolve the runoff signal associated with the Yukon River, with high correlation between SMAP products and Saildrone SSS. Spectral slopes, overall, replicate the −2.0 slopes associated with mesoscale-submesoscale variability. Statistically significant spatial coherences exist for all products, with peaks close to 100 km. Based on these encouraging results, future research should focus on improving derivations of satellite-derived SSS in the Arctic Ocean and integrating model results to complement remote sensing observations.

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