February 21-26, 2016
New Orleans, LA USAhttps://agu.confex.com/agu/os16/meetingapp.cgi
The 2016 Ocean Sciences meeting covered topics in all areas of the ocean sciences discipline. More than 50 presentations and posters referenced Aquarius and/or ocean salinity. Content focused on data analysis, global observations, and trend evaluation. View the scientific program
Documents: 54Schanze, J. and Lagerloef, G.
[26-Feb-16]. With the recent advent of remotely sensed sea-surface salinity (SSS) data from missions such as Aquarius/SAC-D and Soil Moisture and Ocean Salinity (SMOS), it has become possible to compute sea surface density from these data in conjunction with existing remotely sensed sea surface temperature (SST) data. The International Thermodynamic Equation of Seawater - 2010 (TEOS-2010) is used with Aquarius SSS and the Aquarius ancillary SST product to compute sea surface density. Khodri, M., Friedman, A.R., and Reverdin, G.P.
[25-Feb-16]. We present a new record of observed sea surface salinity (SSS) data, which has been compiled and processed to provide improved spatial coverage for the period 1896-2013. We discuss the characteristics of this data set and how we group the data in time series in 23 sub-regions from 20°S to 70°N, away from shelves. Vinogradova, N.T., Ponte, R.M., Piecuch, C.G., and Little, C.M.
[25-Feb-16]. During the past two decades, most surface waters around Greenland ice sheet and in the Nordic Seas became significantly saltier. Here we assess what controls contemporary salinity changes by examining various terms of the salinity budget, including the dilution effect due to air-sea fluxes of freshwater, fluxes of salt due to sea ice formation/melting, and ocean fluxes of salinity associated with advective and diffusive processes. Tranchant, B., Greiner, E., and Lellouche, J.
[25-Feb-16]. SSS has been measured from space for the past 6 years with the SMOS and Aquarius missions. These two missions should have filled the gaps in the current in-situ network. Few data assimilation experiments have been realized. In this study, we propose to estimate and remove the large scale bias with the operational ocean forecasting system at 1/4°. Bingham, F., Busecke, J.J.M, Gordon, A.L., and Giulivi, C.F.
[24-Feb-16]. The surface salinity (SSS) in the eastern South Pacific study area is associated with high evaporation and surface Ekman convergence, weak variability and seasonality on the northern side, fluctuating size driven by changes in southward extent, mean surface currents flowing toward and through the feature from the north, and higher tendency for fresh anomalies on northern side. These characteristics highlight the role of mesoscale stirring and northward Ekman transport in the formation and maintenance of this prominent feature. Guzmán, G., Duque, E.M., Hoyos, C., and Cardona, Y.
[25-Feb-16]. At the Eastern Tropical Pacific between the Panama Bight and the Galapagos Island a large region of low sea surface salinity (SSS) that exhibits a strong seasonal cycle and distinct spatial pattern. The mechanisms controlling the spatial and temporal variability of the SSS at this region are far from being fully understood. So, this work aims to present a characterization of the interannual variability of SSS in the region delimited by 4°S-10°N and 100°W-75°W through satellite observations and numerical modeling. Reagan, J.R., Boyer , T., and Zweng, M.
[25-Feb-16]. Multiple studies have shown that long-term salinity trends are indicative of an amplification of the global hydrological cycle, with salty regions of the ocean becoming saltier, and fresh regions of the ocean becoming fresher. However, are these long-term salinity trends consistent over the entire period, or are they dominated by medium and short-term salinity variability? Tang, W., Yueh, S.H., Liu, W.T., Fore, A., and Hayashi, A.
[24-Feb-16]. This study aims to identify the influence of ocean processes on the freshwater exchange between air-sea interfaces, using Aquarius sea surface salinity. Durack, P.J., Gleckler, P.J., and Guilyardi, E.
[25-Feb-16]. Previous work has suggested that fresh ocean regions are becoming fresher, and salty regions saltier in part to a response to evaporation minus precipitation (E-P; water cycle) changes driven by a warming Earth. As long-term observational insights are limited, model simulations provide a novel method to assess and validate observed change estimates, and attribute the drivers of long-term change. Busecke, J.J.M., Abernathey, R.P., and Gordon, A.L.
[24-Feb-16]. Horizontal mixing by mesoscale eddies has been proposed to be a significant term of the mean surface freshwater budget in the North Atlantic sea surface salinity (SSS) maximum, balancing part of the excess evaporation in the subtropics. Here we present estimates of seasonal transformation rates in salinity coordinates due to mesoscale stirring. Rainville, L., Farrar, J.T., Lee, C., and Eriksen, C.C.
[24-Feb-16]. Observations collected during the Salinity Processes Upper-ocean Regional Study (SPURS) field campaign in the subtropical Atlantic Ocean are used to identify and quantify the processes responsible for deepening the surface mixed layer in Winter, and restratification in the Spring and Summer. We also present an overview of the upcoming SPURS-2 campaign in the eastern equatorial Pacific. Zeng, L., Liu, W.T., Xue, H., Xiu, P., and Wang, D.
[24-Feb-16]. Newly available sea surface salinity (SSS) data from Aquarius together with in situ hydrographic data are used to explore the spatial and temporal characteristics of SSS in the South China Sea (SCS). Dean, C., Soloviev, A., and Helber, R.W.
[24-Feb-16]. Convective rains in tropical regions produce lenses of freshened water in the near surface layer of the ocean. These lenses are localized in space and typically involve both salinity and temperature anomalies. Dynamics of freshwater lenses can be linked to the formation of the barrier layer and fronts, thus influencing large scale processes and contributing to the salinity field in the Aquarius and SMOS satellite footprints. Fine, R., Willey, D., and Millero, F.
[24-Feb-16]. To document effects of ocean acidification it is important to have an understanding of the processes and parameters that influence alkalinity. Alkalinity is a gauge on the ability of seawater to neutralize acids. We use Aquarius satellite data, which allow unprecedented global mapping of surface total alkalinity as it correlates strongly with salinity and to a lesser extent with temperature. Melzer, B.A. and Subrahmanyam, B.
[24-Feb-16]. We studied the interannual and decadal variability of sea surface salinity variations in Oceanic subtopical Gyres using the Simple Ocean Data Assimilation reanalysis in five subtropical gyre locations from 1950-2010. Results indicated an average salinity increase of 0.12 psu in the subtropical gyres over the 61-year study, with the greatest increase occurring in the southern hemisphere gyres. Grodsky, S., Reul, N., Chapron, B., Bryan, F., and Carton, J.
[24-Feb-16]. Aquarius observations indicate that SSS in the shelf water north of the Gulf Stream (between 35N and 45N) experiences interannual variations with more than 1 psu difference between salty and fresh events. Longer JAMSTEC records confirm these SSS variations and show that they are positively correlated with interannual SST. Hasson, A.E.A., Lee, T., Bingham, F., Farrar, J.T., and Boutin, J.
[24-Feb-16]. As part of the effort in preparation for SPURS-2, we examine the dominant temporal and spatial scales of SSS around 10°N and 125°W using Aquarius and SMOS SSS measurements together with a 0.25°x0.25° resolution ECCO (Estimating the Circulation and Climate Experiment of the Ocean) ocean circulation model simulation. This study focuses on sub-seasonal variability. Reul, N., Guimbard, S., Chapron, B., and Maes, C.
[24-Feb-16]. The Eastern Pacific Fresh Pool (EPFP) is a large region of low Sea Surface Salinity (SSS) defined by SSS <34 that develop east of 180°W. Using five years of SMOS SSS and complementary satellite wind, rain, currents, sea surface temperature together with an historical ensemble of in situ products, the present study explores qualitatively the interannual dynamic of the freshpool zonal extent over the period 2010-2014. Kolodziejczyk, N. and Maes, C.
[24-Feb-16]. The horizontal thermohaline structure at the sea surface is investigated in the Indian Ocean at length scales from five to hundreds of kilometers, i.e. at submeso- to meso-scales. Lee, W., Kaihatu, J.M., Anis, A., and Li, D.
[25-Feb-16]. Hypersaline discharges from desalination plants in the Persian Gulf can potentially affect the environment of the Gulf, and the influence of the shamal winds from the north of the Gulf is not clear. In this study, the distribution of seasonal salinity and its variations due to the effect of the shamal, is investigated using the Delft3D-FLOW hydrodynamic model. Fournier, S., Gaultier, L., Vandemark, D.C., Salisbury, J., Lee, T. and Gierach, M.
[25-Feb-16]. Large rivers are important to marine biogeochemistry and air-sea interactions. The freshwater inputs associated with major river plumes modify the local and regional sea surface salinity (SSS) and in the mean time carry a large amount of organic and inorganic particulates into the ocean. With the launches of the NASA Aquarius/SAC-D missions and the ESA Soil Moisture and Ocean Salinity (SMOS), we are now able to use the low-resolution SSS observations in combination with altimetry and high-resolution ocean color observations to monitor the physical and biogeochemical properties of river plumes, such as the Amazon River, the focus of this study. Liu, W.T. and Xie, X.
[24-Feb-16]. Using satellite data, we have characterized the influence of monsoon on the variation of surface salinity in the Bay of Bengal. Song, Y.T., Lee, T., Moon, J., Qu, T., and Yueh, S.H.
[25-Feb-16]. Using a recently developed ESSL (extended surface-salinity layer) model [Song et al., JGR, 2013], we have examined the near-surface salinity stratifications with emphasis on understanding of the dynamical processes that differ from one region to another. Li, L., Schmitt, R.W., Ummenhofer, C., and Karnauskas, K.B.
[24-Feb-16]. Water evaporating from the subtropical oceans sustains precipitation on land. Moisture exiting the ocean surface leaves an imprint on sea surface salinity (SSS). Thus, the question arises of whether variations in subtropical SSS can provide mechanistic insight into, and predictability of, terrestrial precipitation. Using a series of observational and reanalysis products, we provide evidence that springtime SSS in the subtropical North Atlantic is a robust, physically meaningful predictor of terrestrial precipitation during the subsequent monsoon season. Banks, C., Srokosz, M.A., Cipollini, P., Snaith, H.M., Blundell, J., Gommenginger, C., and Tzortzi, E.
[25-Feb-16]. The European Space Agency (ESA) Soil Moisture and Ocean Salinity (SMOS) satellite has provided sea surface salinity (SSS) data for over six years. It has been shown that the operational ESA Level 2 SSS data have significant spatially and temporally varying biases between measurements from ascending passes (SSSA; SMOS moving south to north) and descending passes (SSSD; SMOS moving southwards). The data used for this study were from two SMOS SSS climatologies one based on SSSA and the other from SSSD. These climatologies have been used to calculate salinity anomalies, which are shown to have significantly reduced the spatio-temporal biases. Meissner, T., Wentz, F.J., and Scott, J.P.
[25-Feb-16]. This presentation discusses the adaption of the Aquarius salinity retrieval algorithm to SMAP. It includes corrections for signals from the rough ocean surface, the atmosphere and ionosphere, cold space, galaxy, sun, moon as well as sidelobe and cross polarization effects from the SMAP antenna. Schmitt, R.W., Schanze, J.J., Li, L., and Ummenhofer, C.
[25-Feb-16]. The ocean has a much larger water cycle than the land, with global ocean evaporation of 13 Sverdrups being 10 times larger than the sum of all river flows. This disparity and the different dynamics of dry surfaces, have led to an unfortunate disconnect between terrestrial hydrologists and oceanographers. Here we show that there is in fact a close coupling between the water cycles of ocean and land. Lagerloef, G.
[24-Feb-16]. An important scientific goal for satellite salinity observations is to document oceanic climate trends and their link to changes in the water cycle. This study is a preliminary examination of multi-year sea surface salinity (SSS) trends from analyses of SMOS and Aquarius data, years 2010-2015 to assess the feasibility of monitoring such trends from satellite. Parard, G., Alvera-Azcarate, A., Barth, A., and Beckers, J.
[24-Feb-16]. Sea Surface Salinity (SSS) data from the Soil Moisture and Ocean Salinity (SMOS) mission is analysed over the North Atlantic ocean using DINEOF (Data Interpolating Empirical Orthogonal Functions). DINEOF is a technique that reconstructs missing data and removes noise by retaining only an optimal set of EOFs. Santos-Garcia, A., Jacob, M.M., Jones, L., and Asher, W.
[25-Feb-16]. This research addresses the effects of rainfall on Aquarius (AQ) and Soil Moisture Ocean Salinity (SMOS) satellite sea surface salinity (SSS) retrievals using a macro-scale Rain Impact Model (RIM) that predicts transient SSS stratification based upon the rain accumulation and ocean surface wind speed over the previous 24 hours. Boutin, J., Viltard, N., Supply, A., Martin, N., Vergely, J., Hénocq, C., and Reverdin, G.P.
[24-Feb-16]. The European Soil Moisture and Ocean Salinity (SMOS) satellite mission monitors sea surface salinity (SSS) over the global ocean for more than 5 years since 2010. The MADRAS microwave radiometer carried by the French (CNES) Indian (ISRO) satellite mission Megha-Tropiques sampled the 30° N-30° S region end of 2011 and in 2012, very complementary to other Global Precipitation Measurement (GPM) missions. Skliris, N., Zika, J.D., Nurser, A.J.G., Marsh, R. and Josey, S.A.
[25-Feb-16]. Ocean salinity is an integrator of changes in the water cycle, reflecting the exchange of freshwater between the ocean and various components of the climate system. In this study we will use the water mass transformation framework to infer water cycle changes from salinity changes in observations and CMIP5 models. Chandanpurkar, H.A., Yeager, S.G., Reager, J.T., and Famiglietti, J.S.
[24-Feb-16]. Because of the challenges with traditional means of measuring discharge globally, effect of continental freshwater forcing on regional and global ocean processes remains highly uncertain. In this work, we provide regional analyses of discharge plumes of major river systems identified in Aquarius/SAC-D and SMOS SSS observations after removing the ocean evaporation minus precipitation (E-P) signal. Ren, L. and Bayler, E.
[25-Feb-16]. Comparing satellite sea-surface salinity (SSS) measurements and in situ observations reveals large-scale differences. What causes these differences? In this study, five boxes, sampling various oceanic regimes of the global ocean, provide insights on the relative performance of satellite SSS retrievals with respect to the influences of SST, precipitation and wind speed. Sommer, A., Reverdin, G.P., Kolodziejczyk, N., and Boutin, J.
[24-Feb-16]. Sea surface salinity (SSS) is investigated in the subtropical North Atlantic Ocean during the Subtropical Atlantic Surface Salinity Experiment Strasse/SPURS in August 2012 - September 2013. During this experiment, more than 100 drifters were deployed providing measurements of temperature, salinity and 15m depth currents. Melnichenko, O., Maimo, A.M.A., Maximenko, N.A., Hacker, P.W., and Potemra, J.T.
[24-Feb-16]. A persistent signature of transient mesoscale eddies in sea surface salinity (SSS) is revealed by analyzing the relationship between satellite SSS and sea surface height (SSH) variability. The SSS fields used in the study are Aquarius SSS optimum interpolation analysis recently developed at the University of Hawaii. Drushka, K. and Asher, W.
[24-Feb-16]. Fronts, eddies, filaments, upwelling, and freshwater input from rainfall, rivers, and ice-melt can all generate submesoscale to mesoscale variations in sea surface salinity. Knowledge about the horizontal variability of surface salinity is valuable for understanding ocean surface dynamical processes. Jacob, M.M., Santos-Garcia, A., and Jones, L.
[25-Feb-16]. Previous studies have demonstrated significant differences between satellite and in-situ salinity measurements during rain. In the presence of precipitation, salinity stratification exists near the sea surface, which nullifies the presumption of a well-mixed salinity. This paper describes the Rain Impact Model (RIM) that simulates the effects of rain accumulation on the SSS applied to SMAP. Li, B., Mehra, A., and Bayler, E.J.
[25-Feb-16]. Satellite sea-surface salinity (SSS) observations provide a new means for constraining an important state parameter in numerical ocean models. The benefits of assimilating satellite SSS observations include improved model surface density, near-surface convection, and thermohaline circulation. Alvera-Azcarate, A., Parard, G., Barth, A., and Beckers, J.
[24-Feb-16]. Sea surface salinity (SSS) has been measured by the Soil Moisture and Ocean Salinity (SMOS) satellite mission since 2010, providing unprecedented information about the spatial and temporal variability of salinity at the ocean surface. An analysis of daily SSS from the SMOS satellite mission using DINEOF (Data Interpolating Empirical Orthogonal Functions) is presented for the North Atlantic Ocean in 2013. Chi, N. and Lien, R.
[24-Feb-16]. The oceanic surface mixed layer salinity budget is evaluated during Madden-Julian Oscillation (MJO) events in the central equatorial Indian Ocean. As part of the DYNAMO field campaign (September 2011 - January 2012), three MJO events were recorded at two mooring sites (0S 79E and 1.5S 79E). Alory, G., Delcroix, T.C., Téchiné, P., Diverrès, D., Varillon, D., Cravatte, S.E., Gouriou, Y., Grelet, J., Jacquin, S., Kestenare, E., Maes, C., Morrow, R., Perrier, J., Reverdin, G.P., and Roubaud, F.
[25-Feb-16]. Sea Surface Salinity (SSS) is an essential climate variable that requires long term in situ observation. The French SSS Observation Service (SSS-OS) manages a network of Voluntary Observing Ships equipped with thermosalinographs (TSG). Levang, S. and Schmitt, R.W.
[25-Feb-16]. The global water cycle is expected to intensify in a warming climate. To identify potential patterns and magnitudes of change, we analyze outputs from a high emissions scenario (RCP8.5) of the Coupled Model Intercomparison Project 5 (CMIP5) for evaporation (E), precipitation (P), atmospheric vapor transport (Q), and sea surface salinity (SSS) over the coming century. Yuan, X., Salama, S., and Su, Z.
[24-Feb-16]. Sea surface salinity data from both the Aquarius satellite and Argo float in the Indian Ocean are utilized to investigate sea surface salinity's role in South Asian Summer Monsoon. Davis, X.J. and Farrar, J.T.
[24-Feb-16]. This study examines the subtropical salinity maximum water, or Subtropical Underwater (STUW), in the subtropical regions of the North and South Atlantic, North and South Pacific and Indian Oceans. These salty water masses are important components of the upper-ocean overturning and global water cycle. Asher, W., Drushka, K., Jessup, A.T., and Clark, D.
[25-Feb-16]. Satellite-mounted microwave radiometers measure sea surface salinity (SSS) as an area-averaged quantity in the top centimeter of the ocean over the footprint of the instrument. If the horizontal variability in SSS is large inside this footprint, sub-grid-scale variability in SSS can affect comparison of the satellite-retrieved SSS with in situ measurements. Understanding the magnitude of horizontal variability in SSS over spatial scales that are relevant to the satellite measurements is therefore important. Tsontos, V. and Vazquez, J.
[25-Feb-16]. The Physical Oceanography Distributed Active Center (PO.DAAC) serves as the official NASA repository and distribution node for all Aquarius/SAC-D data products in close collaboration with the project. Here we report on the status of NASA salinity data holdings at PO.DAAC, the range of data services and access tools that we provide in support of the Aquarius mission and SPURS in-situ salinity datasets. Zhang, Y., Bayler, E., and Baker-Yeboah, S.
[25-Feb-16]. In this study, we compare the NCEI satellite binned Level-3 products to the JPL PODAAC official Aquarius and SMOS Barcelona Expert Center Level-3 SSS products. Also, we present a comparison of the NCEI Level-3 SSS product with the NOAA/NCEI World Ocean Atlas in situ gridded data. Results indicate consistency and a good match of NCEI-binned Level-3 SSS data with other datasets for open ocean areas, with some bias apparent in coastal and high-latitude regions. Menezes, V. and Phillips, H.
[25-Feb-16]. Subtropical salinity maximum regions are particularly important because the salty subtropical underwater (STW) is formed by subduction of surface waters in these areas. Anderson, J.E. and Riser, S.
[24-Feb-16]. The input of freshwater to the ocean through precipitation is an important component of the global hydrologic cycle. Using salinity as a proxy, satellites and the Argo array have provided new insights into the larger-scale, integrated responses of the ocean to rainfall. Bayler, E.J. and Ren, Li.
[25-Feb-16]. When employing satellite sea-surface salinity (SSS) observations in studies of observed and modeled ocean variability and change, assessments must consider the variability and uncertainty contained within the satellite SSS data that may or may not reflect physical processes. Lu, X., Fine, R.A., and Qu, T.
[24-Feb-16]. Developing a new understanding of the variability of temperature and salinity anomalies in South Pacific Tropical Water (SPTW) and their downstream impacts may possibly provide a mechanism for ENSO modulations. The anomalies of SPTW are examined using Argo data. Trafford, L.E.M., Gordon, A.L., Lee, T., and Giulivi, C.F.
[24-Feb-16]. The expansive archipelago stretching from Southeast Asia to Australia is comprised of a network of seas of varied dimensions. Freshwater enters the region through precipitation and river discharge, leaving a unique spatial and temporal thumbprint. Here we use Aquarius data to investigate the evolution of sea surface salinity in the Southeast Asian seas. Delcroix, T.C., Tchilibou, M.L., Alory, G., Arnault, S., and Reverdin, G.P.
[25-Feb-16]. This presentation focuses on the time-space variability of the low Sea Surface Salinity (SSS) waters extending zonally within 2N-12N in the Atlantic and Pacific and within 6S-16S in the western third of the Pacific. We further document long-term (1979-2009) meridional migrations of the E-P and SSS minima, especially in the SPCZ region, and discuss whether or not they are consistent with documented SST and wind stress trends.