• Alory, G., and Coauthors, 2015: The French contribution to the voluntary observing ships network of sea surface salinity. Deep-Sea Res. I, 105, 118, https://doi.org/10.1016/j.dsr.2015.08.005.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Argo, 2019: Argo float data and metadata from Global Data Assembly Centre (Argo GDAC). SEANOE, accessed 1 January 2019, https://doi.org/10.17882/42182.

    • Crossref
    • Export Citation
  • Asher, W. E., A. T. Jessup, R. Branch, and D. Clark, 2014a: Observations of rain-induced near surface salinity anomalies. J. Geophys. Res. Oceans, 119, 54835500, https://doi.org/10.1002/2014JC009954.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Asher, W. E., A. T. Jessup, and D. Clark, 2014b: Stable near-surface ocean salinity stratifications due to evaporation observed during STRASSE. J. Geophys. Res. Oceans, 119, 32193233, https://doi.org/10.1002/2014JC009808.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Backhaus, J. O., and J. Kämpf, 1999: Simulations of sub-mesoscale oceanic convection and ice–ocean interactions in the Greenland Sea. Deep-Sea Res. II, 46, 14271455, https://doi.org/10.1016/S0967-0645(99)00029-6.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Bakker, D., and Coauthors, 2016: A multi-decade record of high quality fCO2 data in version 3 of the Surface Ocean CO2 Atlas (SOCAT). Earth Syst. Sci. Data, 8, 383413, https://doi.org/10.5194/essd-8-383-2016.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Belkin, I. M., and J. E. O’Reilly, 2009: An algorithm for oceanic front detection in chlorophyll and SST satellite imagery. J. Mar. Syst., 78, 319326, https://doi.org/10.1016/j.jmarsys.2008.11.018.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Boccaletti, G., R. Ferrari, and B. Fox-Kemper, 2007: Mixed layer instabilities and restratification. J. Phys. Oceanogr., 37, 22282250, https://doi.org/10.1175/JPO3101.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Bosse, A., P. Testor, L. Mortier, L. Prieur, V. Taillandier, F. d’Ortenzio, and L. Coppola, 2015: Spreading of Levantine Intermediate Waters by submesoscale coherent vortices in the northwestern Mediterranean Sea as observed with gliders. J. Geophys. Res. Oceans, 120, 15991622, https://doi.org/10.1002/2014JC010263.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Boutin, J., and Coauthors, 2016: Satellite and in situ salinity: Understanding near-surface stratification and sub-footprint variability. Bull. Amer. Meteor. Soc., 97, 13911407, https://doi.org/10.1175/BAMS-D-15-00032.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Boutin, J., and Coauthors, 2018: New SMOS sea surface salinity with reduced systematic errors and improved variability. Remote Sens. Environ., 214, 115134, https://doi.org/10.1016/j.rse.2018.05.022.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Boutin, J., N. Martin, G. Reverdin, S. Morisset, X. Yin, L. Centurioni, and N. Reul, 2014: Sea surface salinity under rain cells: SMOS satellite and in situ drifters observations. J. Geophys. Res. Oceans, 119, 55335545, https://doi.org/10.1002/2014JC010070.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Brando, V., and Coauthors, 2015: High-resolution satellite turbidity and sea surface temperature observations of river plume interactions during a significant flood event. Ocean Sci., 11, 909920, https://doi.org/10.5194/os-11-909-2015.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Capet, X., J. C. McWilliams, M. J. Molemaker, and A. Shchepetkin, 2008: Mesoscale to submesoscale transition in the California Current System. Part I: Flow structure, eddy flux, and observational tests. J. Phys. Oceanogr., 38, 2943, https://doi.org/10.1175/2007JPO3671.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • CATDS, 2017: CATDS-PDC L3OS 2Q - Debiased daily valid ocean salinity values product from SMOS satellite. CATDS (CNES, IFREMER, LOCEAN, ACRI), accessed 10 April 2018, https://doi.org/10.12770/12dba510-cd71-4d4f-9fc1-9cc027d128b0.

    • Crossref
    • Export Citation
  • Cayula, J.-F., and P. Cornillon, 1992: Edge detection algorithm for SST images. J. Atmos. Oceanic Technol., 9, 6780, https://doi.org/10.1175/1520-0426(1992)009<0067:EDAFSI>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • D’Asaro, E., C. Lee, L. Rainville, R. Harcourt, and L. Thomas, 2011: Enhanced turbulence and energy dissipation at ocean fronts. Science, 332, 318322, https://doi.org/10.1126/science.1201515.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Delcroix, T., and M. McPhaden, 2002: Interannual sea surface salinity and temperature changes in the western Pacific warm pool during 1992–2000. J. Geophys. Res., 107, 8002, https://doi.org/10.1029/2001JC000862.

    • Search Google Scholar
    • Export Citation
  • Delcroix, T., M. J. McPhaden, A. Dessier, and Y. Gouriou, 2005: Time and space scales for sea surface salinity in the tropical oceans. Deep-Sea Res. I, 52, 787813, https://doi.org/10.1016/j.dsr.2004.11.012.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Desprès, A., G. Reverdin, and F. d’Ovidio, 2011a: Mechanisms and spatial variability of mesoscale frontogenesis in the northwestern subpolar gyre. Ocean Modell., 39, 97113, https://doi.org/10.1016/j.ocemod.2010.12.005.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Desprès, A., G. Reverdin, and F. d’Ovidio, 2011b: Summertime modification of surface fronts in the North Atlantic subpolar gyre. J. Geophys. Res., 116, C10003, https://doi.org/10.1029/2011JC006950.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Drucker, R., and S. C. Riser, 2014: Validation of Aquarius sea surface salinity with Argo: Analysis of error due to depth of measurement and vertical salinity stratification. J. Geophys. Res. Oceans, 119, 46264637, https://doi.org/10.1002/2014JC010045.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Drushka, K., W. E. Asher, B. Ward, and K. Walesby, 2016: Understanding the formation and evolution of rain-formed fresh lenses at the ocean surface. J. Geophys. Res. Oceans, 121, 26732689, https://doi.org/10.1002/2015JC011527.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Fahrbach, E., G. Rohardt, and R. Sieger, 2007: 25 years of Polarstern hydrography (1982–2007). WDC-MARE Rep. 5, 88 pp., https://doi.org/10.2312/wdc-mare.2007.5.

    • Crossref
    • Export Citation
  • Fore, A. G., S. H. Yueh, W. Tang, B. W. Stiles, and A. K. Hayashi, 2016: Combined active/passive retrievals of ocean vector wind and sea surface salinity with SMAP. IEEE Trans. Geosci. Remote Sens., 54, 73967404, https://doi.org/10.1109/TGRS.2016.2601486.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Gaillard, F., D. Diverres, S. Jacquin, Y. Gouriou, J. Grelet, M. LeMenn, J. Tassel, and G. Reverdin, 2015: Sea Surface Salinity from French Research Vessels: Delayed mode dataset (updated annually). Subset used: 2001–2013. SEANOE, accessed 15 March 2018, http://doi.org/z79.

  • Henocq, C., J. Boutin, G. Reverdin, F. Petitcolin, S. Arnault, and P. Lattes, 2010: Vertical variability of near-surface salinity in the tropics: Consequences for L-band radiometer calibration and validation. J. Atmos. Oceanic Technol., 27, 192209, https://doi.org/10.1175/2009JTECHO670.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Hosegood, P., M. C. Gregg, and M. H. Alford, 2006: Sub-mesoscale lateral density structure in the oceanic surface mixed layer. Geophys. Res. Lett., 33, L22604, https://doi.org/10.1029/2006GL026797.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Hosegood, P., M. Gregg, and M. Alford, 2008: Restratification of the surface mixed layer with submesoscale lateral density gradients: Diagnosing the importance of the horizontal dimension. J. Phys. Oceanogr., 38, 24382460, https://doi.org/10.1175/2008JPO3843.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • JAMSTEC, 2016: Data and Sample Research System for Whole Cruise Information in Japan Agency for Marine-Earth Science and Technology (DARWIN). Accessed 1 November 2016, http://www.godac.jamstec.go.jp/darwin/.

  • Kerr, Y. H., and Coauthors, 2010: The SMOS mission: New tool for monitoring key elements of the global water cycle. Proc. IEEE, 98, 666687, https://doi.org/10.1109/JPROC.2010.2043032.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Klein, P., and Coauthors, 2015: Mesoscale/sub-mesoscale dynamics in the upper ocean. CNES–NASA, https://swot.jpl.nasa.gov/documents.htm.

  • Kolodziejczyk, N., G. Reverdin, J. Boutin, and O. Hernandez, 2015: Observation of the surface horizontal thermohaline variability at mesoscale to submesoscale in the north-eastern subtropical Atlantic Ocean. J. Geophys. Res. Oceans, 120, 25882600, https://doi.org/10.1002/2014JC010455.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Lagerloef, G., and Coauthors, 2010: Resolving the global surface salinity field and variations by blending satellite and in situ observations. Proceedings of OceanObs'09: Sustained Ocean Observations and Information for Society, J. Hall, D. E. Harrison, and D. Stammer, Eds., IOC/UNESCO, 11 pp., https://archimer.ifremer.fr/doc/00071/18216/.

  • Lapeyre, G., and P. Klein, 2006: Dynamics of the upper oceanic layers in terms of surface quasigeostrophy theory. J. Phys. Oceanogr., 36, 165176, https://doi.org/10.1175/JPO2840.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Legal, C., P. Klein, A.-M. Treguier, and J. Paillet, 2007: Diagnosis of the vertical motions in a mesoscale stirring region. J. Phys. Oceanogr., 37, 14131424, https://doi.org/10.1175/JPO3053.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Lévy, M., P. Klein, and A.-M. Treguier, 2001: Impact of sub-mesoscale physics on production and subduction of phytoplankton in an oligotrophic regime. J. Mar. Res., 59, 535565, https://doi.org/10.1357/002224001762842181.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Lindstrom, E. J., J. B. Edson, J. J. Schanze, and A. Y. Shcherbina, 2019: SPURS-2: Second Salinity Processes in the Upper-ocean Regional Study—The Eastern Equatorial Pacific Experiment. Oceanography, 32 (2), 1519, https://doi.org/10.5670/oceanog.2019.207.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • MacKinnon, J. A., and Coauthors, 2016: A tale of two spicy seas. Oceanography, 29 (2), 5061, https://doi.org/10.5670/oceanog.2016.38.

  • Maes, C., B. Dewitte, J. Sudre, V. Garçon, and D. Varillon, 2013: Small-scale features of temperature and salinity surface fields in the Coral Sea. J. Geophys. Res. Oceans, 118, 54265438, https://doi.org/10.1002/jgrc.20344.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Manucharyan, G. E., and A. F. Thompson, 2017: Submesoscale sea ice-ocean interactions in marginal ice zones. J. Geophys. Res. Oceans, 122, 94559475, https://doi.org/10.1002/2017JC012895.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Meissner, T., L. Ricciardulli, and F. J. Wentz, 2017: Capability of the SMAP mission to measure ocean surface winds in storms. Bull. Amer. Meteor. Soc., 98, 1660–1677, https://doi.org/10.1175/BAMS-D-16-0052.1.

    • Crossref
    • Export Citation
  • Meissner, T., F. Wentz, and D. Le Vine, 2018: The salinity retrieval algorithms for the NASA Aquarius Version 5 and SMAP Version 3 releases. Remote Sens., 10, 1121, https://doi.org/10.3390/rs10071121.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Menemenlis, D., C. Hill, G. Forget, C. H. B. Nelson, B. Ciotti, and A. Chaudhuri, 2014: Global llcXXXX simulations with tides. ECCO meeting presentation, http://ecco2.org/meetings/2014/Jan_MIT/presentations/ThursdayPM/05_menemenlis.pdf.

  • NASA Aquarius Project, 2017: Aquarius official release level 2 sea surface salinity and wind speed data V5.0. PO.DAAC, accessed 11 November 2018 https://doi.org/10.5067/AQR50-2SOCS.

    • Crossref
    • Export Citation
  • Pietri, A., P. Testor, V. Echevin, A. Chaigneau, L. Mortier, G. Eldin, and C. Grados, 2013: Finescale vertical structure of the upwelling system off southern Peru as observed from glider data. J. Phys. Oceanogr., 43, 631646, https://doi.org/10.1175/JPO-D-12-035.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Ramachandran, S., and Coauthors, 2018: Submesoscale processes at shallow salinity fronts in the Bay of Bengal: Observations during the winter monsoon. J. Phys. Oceanogr., 48, 479509, https://doi.org/10.1175/JPO-D-16-0283.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Reverdin, G., S. Morisset, J. Boutin, and N. Martin, 2012: Rain-induced variability of near sea-surface T and S from drifter data. J. Geophys. Res., 117, C02032, https://doi.org/10.1029/2011JC007549.

    • Search Google Scholar
    • Export Citation
  • Roemmich, D., and J. Gilson, 2009: The 2004-2008 mean and annual cycle of temperature, salinity, and steric height in the global ocean from the Argo program. Prog. Oceanogr., 82, 81100, https://doi.org/10.1016/j.pocean.2009.03.004.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Rossby, T., 2001: Sustained ocean observations from merchant marine vessels. Mar. Technol. Soc. J., 35, 3842, https://doi.org/10.4031/002533201788057873.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Rudnick, D. L., and R. Ferrari, 1999: Compensation of horizontal temperature and salinity gradients in the ocean mixed layer. Science, 283, 526529, https://doi.org/10.1126/science.283.5401.526.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Rudnick, D. L., and J. P. Martin, 2002: On the horizontal density ratio in the upper ocean. Dyn. Atmos. Oceans, 36, 321, https://doi.org/10.1016/S0377-0265(02)00022-2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Sena Martins, M., N. Serra, and D. Stammer, 2015: Spatial and temporal scales of sea surface salinity variability in the Atlantic Ocean. J. Geophys. Res., 120, 43064323, https://doi.org/10.1002/2014JC010649.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Shcherbina, A. Y., E. A. D’Asaro, S. C. Riser, and W. S. Kessler, 2015: Variability and interleaving of upper-ocean water masses surrounding the North Atlantic salinity maximum. Oceanography, 28, 106113, https://doi.org/10.5670/oceanog.2015.12.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Smith, S., J. Rolph, K. Briggs, and M. Bourassa, 2009: Quality-Controlled Underway Oceanographic and Meteorological Data from the Center for Ocean-Atmospheric Predictions Center (COAPS)–Shipboard Automated Meteorological and Oceanographic System (SAMOS). NOAA/NCEI, accessed 1 September 2017, https://doi.org/10.7289/v5qj7f8r.

    • Crossref
    • Export Citation
  • Soloviev, A., and R. Lukas, 1997: Sharp frontal interfaces in the near-surface layer of the ocean in the western equatorial Pacific warm pool. J. Phys. Oceanogr., 27, 9991017, https://doi.org/10.1175/1520-0485(1997)027<0999:SFIITN>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Tang, W., S. H. Yueh, A. G. Fore, and A. Hayashi, 2014: Validation of Aquarius sea surface salinity with in situ measurements from Argo floats and moored buoys. J. Geophys. Res. Ocean, 119, 61716189, https://doi.org/10.1002/2014JC010101.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Tang, W., and Coauthors, 2017: Validating SMAP SSS with in situ measurements. Remote Sens. Environ., 200, 326340, https://doi.org/10.1016/j.rse.2017.08.021.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Thomas, L. N., A. Tandon, and A. Mahadevan, 2008: Submesoscale processes and dynamics. Ocean Modeling in an Eddying Regime, Geophys. Monogr., Vol. 177, Amer. Geophys. Union, 17–38.

    • Crossref
    • Export Citation
  • Thompson, A. F., A. Lazar, C. Buckingham, A. C. Naveira Garabato, G. M. Damerell, and K. J. Heywood, 2016: Open-ocean submesoscale motions: A full seasonal cycle of mixed layer instabilities from gliders. J. Phys. Oceanogr., 46, 12851307, https://doi.org/10.1175/JPO-D-15-0170.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Vinogradova, N. T., and R. M. Ponte, 2013: Small-scale variability in sea surface salinity and implications for satellite-derived measurements. J. Atmos. Oceanic Technol., 30, 26892694, https://doi.org/10.1175/JTECH-D-13-00110.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 190 190 94
PDF Downloads 130 130 39

Global Patterns of Submesoscale Surface Salinity Variability

View More View Less
  • 1 Applied Physics Laboratory, University of Washington, Seattle, Washington
  • 2 Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California
© Get Permissions
Restricted access

Abstract

Surface salinity variability on O(1–10) km lateral scales (the submesoscale) generates density variability and thus has implications for submesoscale dynamics. Satellite salinity measurements represent a spatial average over horizontal scales of approximately 40–100 km but are compared to point measurements for validation, so submesoscale salinity variability also complicates validation of satellite salinities. Here, we combine several databases of historical thermosalinograph (TSG) measurements made from ships to globally characterize surface submesoscale salinity, temperature, and density variability. In river plumes; regions affected by ice melt or upwelling; and the Gulf Stream, South Atlantic, and Agulhas Currents, submesoscale surface salinity variability is large. In these regions, horizontal salinity variability appears to explain some of the differences between surface salinities from the Aquarius and SMOS satellites and salinities measured with Argo floats. In other words, apparent satellite errors in highly variable regions in fact arise because Argo point measurements do not represent spatially averaged satellite data. Salinity dominates over temperature in generating submesoscale surface density variability throughout the tropical rainbands, in river plumes, and in polar regions. Horizontal density fronts on 10-km scales tend to be compensated (salinity and temperature have opposing effects on density) throughout most of the global oceans, with the exception of the south Indian and southwest Pacific Oceans between 20° and 30°S, where fronts tend to be anticompensated.

© 2019 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).

Corresponding author: Kyla Drushka, kdrushka@apl.uw.edu

Abstract

Surface salinity variability on O(1–10) km lateral scales (the submesoscale) generates density variability and thus has implications for submesoscale dynamics. Satellite salinity measurements represent a spatial average over horizontal scales of approximately 40–100 km but are compared to point measurements for validation, so submesoscale salinity variability also complicates validation of satellite salinities. Here, we combine several databases of historical thermosalinograph (TSG) measurements made from ships to globally characterize surface submesoscale salinity, temperature, and density variability. In river plumes; regions affected by ice melt or upwelling; and the Gulf Stream, South Atlantic, and Agulhas Currents, submesoscale surface salinity variability is large. In these regions, horizontal salinity variability appears to explain some of the differences between surface salinities from the Aquarius and SMOS satellites and salinities measured with Argo floats. In other words, apparent satellite errors in highly variable regions in fact arise because Argo point measurements do not represent spatially averaged satellite data. Salinity dominates over temperature in generating submesoscale surface density variability throughout the tropical rainbands, in river plumes, and in polar regions. Horizontal density fronts on 10-km scales tend to be compensated (salinity and temperature have opposing effects on density) throughout most of the global oceans, with the exception of the south Indian and southwest Pacific Oceans between 20° and 30°S, where fronts tend to be anticompensated.

© 2019 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).

Corresponding author: Kyla Drushka, kdrushka@apl.uw.edu
Save