The 2026 Ocean Salinity Science and Technology Meeting convened 19–21 May 2026 at the Applied Physics Laboratory, University of Washington, Seattle, WA, USA. The meeting was held primarily in person, with limited options for remote participation. It was attended by approximately 50 international researchers, about 35 in person and 15 online, and featured roughly 46 oral presentations and 14 posters. The main goal of the meeting was to identify critical drivers for ocean salinity science, applications, and salinity measurement needs for the coming decade, with three organizing themes: the kickoff of NASA's FRESH (Fate of River Export and Surface Hydrology) Arctic field campaign and other field activities planned for Summer 2027; critical drivers for ocean salinity science and applications and the future need for high-resolution technologies; and recent ocean salinity science advances.
The meeting featured six different sessions that are detailed below, focusing on (1) the NASA's FRESH Arctic campaign focused on the Colville River system and the Beaufort Sea, and adjacent Arctic field activities also planned for Summer 2027; (2) Arctic processes; (3) Mission, sensors, and retrievals; (4) Open Ocean Processes; (5) Salinity products and Cal/Val; (6) Coastal Ocean processes and biogeochemistry. The meeting also featured wide-ranging discussion of priorities for the coming decade.
AgendaSMOS and SMAP continue to provide excellent SSS observation products at a 50-100 km resolution with weekly revisit. The continuity of SSS measurements is planned through the ESA Copernicus CIMR mission. CryoRad (a candidate for ESA Earth Explorer 12) is currently competing to pilot sensitive SSS measurements with wide bandwidth receivers over a narrow swath which could contribute measurements in the polar regions. However, there is no agency-backed, explicit path forward for significantly improved products in either revisit or spatial resolution. Observations at higher spatial resolution would be of particular interest for coastal applications (e.g. ocean-land hydrologic exchanges, aquaculture) and to study sub-mesoscale ocean energetics (Vinogradova et al. 2019).
Kim, S.-H., Jung, S., Jang, E., and Im, J. [19-May-26]. Sea surface salinity (SSS) is a key variable for understanding ocean circulation, freshwater fluxes, and climate variability. Despite its importance, reliable monitoring remains challenging, particularly in coastal and low salinity regions where variability is strong. González-Gambau, V., Ruiz-Sebastián, A., Olmedo, E., Gabarró, C., Hernández-Macià, F.,. Claret, M., Arias, M., Onrubia, R., Nestoras, I., Jordão, A., Camps, A., Almirall, R., Grozea, I., Radulescu, A., Severin, S., Lopes, G., Barbosa, J.,. Boutin, J., and Vergely, J.L. [20-May-26].CryoRad is a candidate mission for the European Space Agency’s (ESA) Earth Explorer 12 programme that proposes the use of wideband radiometry (0.4–2 GHz) to significantly extend and enhance current L-band (1.4 GHz) observation capabilities. A primary objective of the mission is the retrieval of sea surface salinity (SSS) with unprecedented accuracy, with particular emphasis on polar oceans. Previous L-band missions such as SMOS, Aquarius, and SMAP have established 1.4 GHz as a key frequency for monitoring the global water cycle. However, the sensitivity of brightness temperature (TB) to salinity decreases significantly in cold waters, limiting the performance of L-band observations in high-latitude regions. The main technical advantage of CryoRad arises from the increased sensitivity to salinity at lower frequencies. In polar oceans, the sensitivity of TB to SSS is approximately three times higher at 0.4 GHz than at 1.4 GHz. This enhanced sensitivity is expected to reduce the uncertainty of salinity estimates in cold waters by nearly an order of magnitude, providing critical information for the study of ocean circulation and the impact of polar ice melting on the global climate system.
Durski, S.M., Jung, J., and Kurapov, A.L. [21-May-26].The lateral exchange of salinity between the shelf and interior ocean contributes to seasonal and interannual variability in both environments. But because the flux is often primarily through cross-isobath eddying motions, quantification of the processes is challenging.
Lee, T., and Wang, O. [20-May-26]. The fresh pool in the western tropical Pacific Ocean, characterized by low salinity, extends eastward during El Nino. This eastward extension is important to El Nino-Southern Oscillation (ENSO) cycle because it amplifies ocean-surface warming that triggers atmospheric convection, thereby providing feedback to the trade winds that drive the ocean currents. Sea surface salinity data from in-situ sensors and satellites have well characterized the eastward extension of the fresh pool. Boutin, J., Vergely, J.-L., Bertino, L., Macelloni, G., Brogioni, M., Dinnat, E., Kaleschke, L., Tonboe, R., Zhou, Y., Frery, L., and Drusch, M. [20-May-26].The salinity of polar oceans is undergoing significant changes due to sea ice melt and increased continental runoff, which have resulted in a decrease in sea surface salinity (SSS) across most regions of the Arctic Ocean, intensifying upper ocean stratification. In the Southern Ocean, changes in the extent and thickness of Antarctic sea ice are also striking, and are also linked to SSS changes. These shifts profoundly impact ocean circulation, the ocean's capacity to absorb atmospheric heat and carbon, and ultimately, Earth’s climate. However, current climate models struggle to accurately represent high-latitude water mass properties.
Parc, L., Bonjean, F., Boutin, J., Vergely, J.-L., Guimbard, S., and Rouffi, F. [19-May-26]. Sea Surface Salinity (SSS) is an Essential Climate Variable (ECV) that plays a key role in the global thermohaline circulation, the hydrological cycle as well as the upper-ocean carbonate system and air-sea exchanges. Owing to its global coverage, satellite-based remote sensing of SSS is a key tool for monitoring this ECV. Bonjean, F., Boutin, J., Vergely, J.L., Rouffi, F., Guimbard, S., Jouanno, J., Reul, N., Catany, R., and Sabia, R. [21-May-26]. This talk provides and overview the CCI+SSS (Climate Change Initiative + Sea Surface Salinity) project of the European Space Agency. Olmedo, E., Arias, M., Bergas-Ques, J., Cornes, R., González-Gambau, V., Hart-Davis, M., Juhl, M.-C., Kent, E., Mayer, M., Merchant, C., Müller, F., Oliva, R., Sagués, A., Riaz, A., Storto, A., Turiel, A., Winkelbauer, S., and Yang, C. [21-May-26].Accurate estimates of ocean surface heat fluxes (OSHF) are essential for assessing andimproving climate projections and supporting adaptation strategies, yet direct measurements are challenging, costly, and not feasible at global scales.
Anderson, J., Schanze, J.J., and Melnichenko, O. [19-May-26]. The Salinity Validation Data System (SVDS) was developed with the goal of providing a systematic estimation and assessment of satellite sea surface salinity over the global ocean. Using an in situ centered dataset matchup (±3.5 days, 50km), we evaluate, global, latitudinal, and regional biases, and assess satellite salinity data product errors. Thouvenin-Masson , C., and Jouanno, J. [21-May-26]. The Mississippi River delivers large volumes of freshwater (~18,000 m³/s) to the northern Gulf of Mexico, creating an extensive plume that affects the stratification of the upper ocean, its biogeochemical conditions and its coastal ecosystems. Misra, S., Akins, A., Brown, S., Ogut, M., Vandemark, D., Shellito, S., Fournier, S., Fenty, I., Lee, T., and Gierach, M. [20-May-26].Highly dynamic sea surface salinity (SSS) in coastal regions are critical to understand the ocean-land water cycle, marine ecosystem health, coastal circulation, as well as human economic impact. Similarly, SSS in high latitude regions are required to truly understand the interactions between the ocean, atmosphere, and cryosphere. Despite their importance, coastal and polar SSS remains one of the most under-sampled geophysical parameters.
Jarugula, S., Fournier, S., Reager, J.T., and Pascolini-Campbell, M. [21-May-26]. This talk presents an overview of the findings from a NASA-funded project on global coastal salinity and its linkages to natural and human-driven changes in the hydrological cycle. Ocean sea surface salinity (SSS) has been demonstrated to be a powerful indicator for monitoring changes in the global water cycle. Small, J., Laurindo, L., and Thompson, L. [20-May-26].Recent work has shown that the drivers of the upper ocean temperature variability depend on time and spatial scales, with surface fluxes being more important for larger spatial scales (>O(100km)) and short (<14 days) timescales, while oceanic processes dominate at smaller spatial and longer time scales.
Bulusu, S., and Stamper, N. [20-May-26].Marine heatwaves (MHWs) have intensified in both frequency and magnitude worldwide, with especially pronounced impacts in western boundary current regions such as the Gulf Stream (GS). In these highly dynamic environments, variability in ocean circulation strongly shapes upper-ocean stratification and regulates the storage and redistribution of heat.
Meissner, T. [21-May-26]. NASA’s SMAP L-band radiometer has been supplying the scientific community with high quality ocean measurements of sea surface salinity (SSS) and wind speeds since 2015. Starting in 2023, there has been an increasing level of radio frequency interference (RFI) contaminating SMAP ocean observations which results in spurious retrieved SSS and wind speed values. Thomson, J. [19-May-26]. Overview of several previous, ongoing, and upcoming projects collecting observations of coastal plumes along the north slope of Alaska using drifting and moored assets. Sabia, R. [19-May-26]. Overview of ESA salinity science/technology including programmatic lines and scientific SSS achievements. Piliouras, A., Hines, C., and Ashik, S. [19-May-26]. This talk discusses research focusing on how Arctic deltas influence transport and storage of suspended sediments from the river to the ocean. Specifically implications for coastal turbidity, light attenuation, marine primary productivity, particulate nutrient transport, and small Arctic ocean basin where coasts are responsible for ~30% of primary production. Bergas-Ques, J., Olmedo, E., González-Gambau, V., Arias, M., Beszczynska-Möller, A., Gabarró, C, García-Espriu, A., Goszczko, I.,. Karcher, M., Karlsson, N.B., Kauker, F., Oliva, R., Piracha, A., Ruiz-Sebastián, A., Sabia, R., Sagués, A., Turiel, A., Umbert, M., Vrettou, A., and Wearing, M. [19-May-26].The Atlantic Meridional Overturning Circulation (AMOC) plays a central role in the climate system by transporting and redistributing heat to depth, thereby regulating the effective heat capacity of the ocean under global warming. Observations and projections indicate a potential decline of the AMOC in response to climate change, with far-reaching climate consequences. The Nordic Seas are a key region for the overturning circulation, as dense water formation north of the Greenland–Scotland Ridge feeds the lower limb of the AMOC.
Bingham, F., Schmidgall, C., Steele, M., and Jayne, S. [19-May-26]. This talk discusses preliminary results from floats deployed as part of the SASSIE project in the Beaufort Sea. Topics include what float observations can tell us about the role of salinity in the formation and/or melting of sea ice in late summer / early fall and observations of the breakdown of the shallow halocline and the upwelling of heat into the near surface. Tzortziou, M., and Mannino, A. [19-May-26]. This talk provides an overview of FORTE, a recently selected NASA Earth Venture Suborbital (EVS-4) Mission that will apply cutting edge ocean observing technologies and state of-the-art models to explore the remote and rapidly transforming ecosystem of the coastal Alaskan Arctic. Gaube, P., and Rowley, T. [19-May-26]. The Fate of River Export and Surface Hydrology (FRESH) Arctic team will address the following overarching question: How does freshwater move through the land-delta-ocean system and ultimately control the pathways that dictate the fate of freshwater in the Beaufort Sea? Kopec, B., Klein, E., and Welker, J. [19-May-26].Rapid warming has led to large inputs of surface runoff, precipitation, and glacial melt to the Arctic seas. These freshwater influxes affect ocean composition and circulation, which have widespread and varied impacts across the Arctic depending on the freshwater source. It is therefore important to delineate these different freshwater sources from one another, yet this delineation can be challenging using only physical oceanographic measurements (e.g., temperature, salinity).
Feng, D., and Devkota, P. [19-May-26]. River widths and water surface elevation (WSE) measured by satellites (e.g., Landsat and SWOT) provide essential information for river discharge estimation. We developed a physics-based modeling-data assimilation framework to assimilate satellite–derived discharge into hydrological model simulations, which significantly improved the accuracy of the discharge estimates. Yu, L. [19-May-26]. This talk focuses on four main themes (1) How salinity’s role changes with scale, i.e., from tracing the water cycle to shaping frontal density gradients; (2) salinity-driven frontal dynamics near O(10 km) and our ability to resolve it by current satellite salinity; (3) submesoscale thermohaline front types and their implications for vertical exchange, productivity, carbon cycling, and Earth system model fidelity; (4) the missing dimension O(10–20 km) SSS may add to SWOT, SST, and PACE observations of ocean fronts. Dolan, W. [19-May-26]. This talk explores the movement of water and sediment through lake-rich Arctic and boreal deltas with a specific focus on how lake connectivity to the channel network controls which lakes store and attenuate riverine floodwater and sediment, how much is stored in these delta lakes, and how long the flood water stays in the delta. Steele, M., Dickinson, S., Thomson, J., Zhang, J., and Bingham, F. [19-May-26]. We present preliminary results from our analysis of three years of microSWIFT buoy deployments in the Alaskan Arctic i.e. the Bering, Chukchi, and Beaufort Seas. These small buoys measure ocean surface waves, surface currents, SST, and SSS. Vinogradova-Shiffer, N. [19-May-26]. Overview of NASA Physical Oceanography Programs are discussed along with research opportunities and organizational updates. deCharon, A. [19-May-26]. The collection of “NASA Salinity” StoryMaps continues to grow with 10 being added over the past year or so. These popular features are based on research publications, topics of interest to salinity scientists (e.g., RFI, sea ice contamination), and new programs such as FRESH Arctic. Alory, G., Gouzenes, Y., Martin, G., Téchiné, P., Ngakala, R., Diverrès, D., Jacquin, S., Bachelier, C., Khvorostyanov, D., and Reverdin, G. [21-May-26]. The French Sea Surface Salinity (SSS) Observation Service is the main provider of thermosalinograph (TSG) observations from ships of opportunity at global scale, in real time (RT) for operational oceanography and in delayed time (DT) for research. Boutin, J., Vergely, J.L., Bonjean, F., Khvorostyanov, D., Guimbard, S., and Tarot, S. [19-May-26].The Ocean Salinity Center of Expertise for CATDS (CATDS CEC-OS) works at improving methodologies for SMOS mapped sea surface salinities, that are next implemented in the near real time CATDS processing chain (CATDS-CPDC). In this poster, we present recent updates in the global and Arctic CATDS fields.
Schmidgall, C., Gaube, P., Shcherbina, A., Steele, M., and Thomson, J. [19-May-26]. Under anthropogenic climate change, the Arctic Ocean is experiencing significant declines in sea ice extent and shifts in seasonality, impacting ocean dynamics, Arctic ecosystems and communities, and global climate. Grodsky, S. [19-May-26]. The Chukchi Sea is an Arctic marginal sea with a slightly saltier mixed layer than the surrounding open Arctic waters by a few practical salinity units. This higher salinity results from the influx of warm, salty Pacific water through the Bering Strait, suggesting that changes in properties of this inflow could affect the thermohaline characteristics of the Chukchi Sea. Schmitt, R., and Zhang, J. [20-May-26].The key role of diapycnal mixing in maintaining the meridional overturning circulation (MOC) has long been clear (Munk, 1966). Scaling analysis and numerical models show that if mixing is represented by a constant eddy diffusivity K, then the amplitude of the MOC is proportional to K^2/3 (Zhang, Schmitt, and Huang, 1999).
Guimbard, S., Reul, N., Herlédan, S., El Khoury Hanna, Z., Alory, G., Schanze, J., Anderson, J., Díez-García, R., Sabia, R., and Scipal, K. [19-May-26]. The Pilot-Mission Exploitation Platform (Pi-MEP) for salinity (https://www.salinity-pimep.org/) is an initiative originally meant to support and widen the uptake of ESA Soil Moisture and Ocean Salinity (SMOS) mission data over the ocean. Since its beginning in 2017, the project aims at setting up a computational web-based platform focusing on satellite sea surface salinity data validation, supporting also process studies over the ocean. González-Gambau, V., García-Espriu, A., Gabarró, C., Sánchez-Urrea, M., González-Haro, C., López-López, A., Umbert, M., Hoareau, N., de Andrés, E., Turiel, A., and Olmedo, E. [19-May-26]. Monitoring freshwater fluxes in polar regions is essential for understanding how global warming affects sea-ice melt and influences global ocean circulation. These rapid environmental changes demand continuous monitoring; however, the extreme conditions in polar regions make sustained in situ observations particularly challenging. Melnichenko, O., Hacker, P., Meissner, T., Wentz, F., Schanze, J., and Anderson, J. [21-May-26]. This presentation provides an update on version 3.0 of the Multi-Mission Sea Surface Salinity Optimum Interpolation (OISSS) analysis. OISSS applies Optimum Interpolation (OI) to integrate SSS observations from the Aquarius/SAC-D, SMAP and SMOS satellite missions, producing weekly SSS fields at 0.25° x 0.25° spatial resolution from 2011 to the present. Mollenhauer, G., Juhls, B., Henkel, S., and Gutjahr, M. [19-May-26]. Overview of the upcoming Beau PAIR Expedition June to September 2027 and research priorities. Zahn, M., Fournier, S., Fenty, I., Steele, M., Wood, M., and Gaube, P. [19-May-26]. The Mackenzie River is the largest North American source of freshwater into the Arctic Ocean and discharges warm water in the spring that initiates coastal sea ice melt. However, the influence of its freshwater discharge on fall sea ice advance has not been investigated. In the Arctic, ocean salinity is a primary control on upper ocean stratification and therefore modulates vertical heat exchange and sea ice formation. Shutler, J.D., and Ford, D.J. [21-May-26]. This presentation discusses how salinity understanding, expertise, and advances in sensing (in situ and in space) are critical for supporting ocean carbon assessments. Gaube, P. [19-May-26]. This talk provides an overview and update of the NASA SASSIE project Hu, S., Liu, S., and McPhaden, M. [20-May-26]. Classic El Niño-Southern Oscillation (ENSO) theories do not account for the influence of ocean salinity variations. With ocean reanalysis products, we have identified a robust boreal spring western Pacific salinity pattern that can boost El Niño amplitude. Climate models that capture this salinity-El Niño connection tend to simulate a stronger ENSO. Zahn, M., Wood, M., Fenty, I., and Fournier, S. [19-May-26]. This poster describes the the high-resolution pan-Arctic coupled sea ice-ocean model developed from the ECCO project in support of the NASA SASSIE campaign. Lee, C., Giglio, D., Subramanian, A.C., Han, W., Capotondi, A., Du, D., and Molod, A. [20-May-26].Upper-ocean stratification depends jointly on temperature and salinity, yet sea surface salinity (SSS) remains comparatively weakly constrained in many coupled data assimilation (DA) systems.
Liu, C., Kolodziejczyk, N., and Lique, C. [19-May-26]. Freshwater content (FWC) plays a central role in Arctic stratification, circulation, and sea-ice evolution, yet sustained basin-scale observations remain sparse due to limited in situ sampling. Satellite L-band sea surface salinity (SSS) products now provide multi-year surface coverage across much of the ice-free Arctic, offering new opportunities to infer vertically integrated freshwater variability. Menemenlis, D. [19-May-26]. Review of the new llc4320v2 Global-Ocean-Ice-River-Tides Simulation with a specific focus on how this new version resolves key issues found within the initial version. Reul, N., and Tenerelli, J. [20-May-26]. This talk provides an overview of the CIMR mission with a specific emphasis on details and limitations of SSS retrievals. Li, L., Zhang, P., and Schmitt, R.W. [20-May-26]. Atmospheric Rivers (ARs) are narrow moisture corridors that occupy less than 10% of the surface of the globe but are responsible for more than 90% of poleward moisture transport, and thus influences hydroclimate across the globe. The formation of ARs usually occurs within the warm sector in front of the leading cold front of an extratropical cyclone. Jung, J., Durski, S., and Kurapov, A. [19-May-26]. The Gulf of Anadyr (GA), which occupies the northwest portion of the broad eastern Bering Sea shelf exhibits complex salinity variability, due to the combined influences of river runoff, transport of salty basin water in the Anadyr Current and the mixed salinification and freshening effects of sea ice formation and melt from active seasonal polynyas. Kurapov, A., Durski, S., Khazaei, B., and Heidary, P. [21-May-26].SMOS and SMAP sea surface salinity (SSS) products, in-situ Argo and glider measurements, and outputs of a high-resolution regional ocean circulation model are used to understand near-surface salinity variability along the US West Coast and in the wider Northeast Pacific (NEP) region.
Khazaei, B., Kurapov, A., Durski, S., and Heidary, P. [19-May-26]. This poster examines seasonal and longer period variability in sea surface salinity along the coastal transition zone of the Northeastern Pacific region. Akins, A., Fore, A., and Yueh, S. [19-May-26].Accurate retrieval of SSS from L-band radiometer observations requires careful correction for the effects of wind stress and swell on the roughness of the ocean surface. This has been particularly challenging at high wind speeds due to limited sampling in sensor measurements used to determine surface roughness model functions (Yueh et al. 2013, 2016, Meissner et al. 2014).
Rodriguez-Fernandez, N., Anterrieu, E., Kerr, Y., Boutin, J., Herrmann, M., Rixen, T., Brandt, P., Corbari, C., Escorihuela, M., Iovino, D., Landschutzer, P., Merkouriadi, I., Roy, A., Scholze, M., Gonzalez, P., Richaume, P., Mialon, A., and Carayon, B. [20-May-26].Monitoring the dynamic evolution of the coastal ocean at the interfaces with the land, the atmosphere and the cryosphere, is key to understanding the present and future climate of the Earth, the impact of human-induced environmental perturbations and their effect on the marine ecosystems and the society.
Hao, L. [20-May-26]. This talk describes the performance of MICAP (Microwave Imager Combined Active and Passive) during its first year in orbit. Chaudhuri, D., D’Asaro, E.A., Sengupta, D., Thangaprakash,V.P., Farrar, J.T., Shroyer, E., Moum, J., Parida, C., and Kumar, B.K. [21-May-26]. Large river discharges and copious rainfall give rise to a shallow, fresh surface layer in parts of the equatorial ocean that mediates air-sea interaction. While the dynamical effects of freshwater are well known, the thermodynamic effects of specifically riverine input remain unclear.The concept of Fiduciary Reference Measurements (FRM) has emerged in recent years to describe in-situ measurements that closely resemble what is being sensed by satellite sensors. As satellite remote sensing of sea surface salinity (SSS) is still a comparatively young discipline compared to measurements such as sea surface temperature or ocean color, the last decade has provided rapid advances in our understanding of the variability of salinity within the footprint of a satellite sensor.
Jarugula, S., Lee, T., and Fournier, S. [19-May-26]. Argo measurements illustrate pronounced decadal variation of salinity in the southeast Indian Ocean (SEIO) that is coherent in the upper 70 m, with freshening during 2004–2010 followed by salinification during 2011–2019. Le Guillou, F., Chapron, B., and Rio, M.H. [21-May-26]. This talk is about reconstructing gridded maps (Level-4) from sparse satellite observations (Level-2/3). Specifically, the VarDyn tool - a physics-informed inversion tool for estimating gridded SSH, SST, and SSS fields from sparse satellite observations - is discussed.