Bingham
Frederick
Bingham
Frederick
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ArticleIntraseasonal variability of surface salinity in the eastern tropical pacific associated with mesoscale eddies.(American Geophysical Union, 2019-03-28) Hasson, Audrey ; Farrar, J. Thomas ; Boutin, Jacqueline ; Bingham, Frederick ; Lee, TongStrong variability in sea surface salinity (SSS) in the Eastern Tropical Pacific (ETPac) on intraseasonal to interannual timescales was studied using data from the Soil Moisture and Ocean Salinity, Soil Moisture Active Passive, and Aquarius satellite missions. A zonal wave number‐frequency spectral analysis of SSS reveals a dominant timescale of 50–180 days and spatial scale of 8°–20° of longitude with a distinct seasonal cycle and interannual variability. This intraseasonal SSS signal is detailed in the study of 19 individual ETPac eddies over 2010–2016 identified by their sea level anomalies, propagating westward at a speed of about 17 cm/s. ETPac eddies trap and advect water in their core westward up to 40° of longitude away from the coast. The SSS signatures of these eddies, with an average anomaly of 0.5‐pss magnitude difference from ambient values, enable the study of their dynamics and the mixing of their core waters with the surroundings. Three categories of eddies were identified according to the location where they were first tracked: (1) in the Gulf of Tehuantepec, (2) in the Gulf of Papagayo, and (3) in the open ocean near 100°W–12°N. They all traveled westward near 10°N latitude. Category 3 is of particular interest, as eddies seeded in the Gulf of Tehuantepec grew substantially in the vicinity of the Clipperton Fracture Zone rise and in a region where the mean zonal currents have anticyclonic shear. The evolution of the SSS signature associated with the eddies indicates the importance of mixing to their dissipation.
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ArticleFrom salty to fresh—salinity processes in the Upper-ocean Regional Study-2 (SPURS-2) : diagnosing the physics of a rainfall-dominated salinity minimum(The Oceanography Society, 2015-03) Schmitt, Raymond W. ; Asher, William E. ; Bingham, Frederick ; Carton, James A. ; Centurioni, Luca R. ; Farrar, J. Thomas ; Gordon, Arnold L. ; Hodges, Benjamin A. ; Jessup, Andrew T. ; Kessler, William S. ; Rainville, Luc ; Shcherbina, Andrey Y.One of the notable features of the global ocean is that the salinity of the North Atlantic is about 1 psu higher than that of the North Pacific. This contrast is thought to be due to one of the large asymmetries in the global water cycle: the transport of water vapor by the trade winds across Central America and the lack of any comparable transport into the Atlantic from the Sahara Desert. Net evaporation serves to maintain high Atlantic salinities, and net precipitation lowers those in the Pacific. Because the effects on upper-ocean physics are markedly different in the evaporating and precipitating regimes, the next phase of research in the Salinity Processes in the Upper-ocean Regional Study (SPURS) must address a high rainfall region. It seemed especially appropriate to focus on the eastern tropical Pacific that is freshened by the water vapor carried from the Atlantic. In a sense, the SPURS-2 Pacific region will be looking at the downstream fate of the freshwater carried out of the SPURS-1 North Atlantic region. Rainfall tends to lower surface density and thus inhibit vertical mixing, leading to quite different physical structure and dynamics in the upper ocean. Here, we discuss the motivations for the location of SPURS-2 and the scientific questions we hope to address.
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ArticleSea surface salinity seasonal variability in the tropics from satellites, gridded in situ products and mooring observations(MDPI, 2020-12-31) Bingham, Frederick ; Brodnitz, Susannah ; Yu, LisanSatellite observations of sea surface salinity (SSS) have been validated in a number of instances using different forms of in situ data, including Argo floats, moorings and gridded in situ products. Since one of the most energetic time scales of variability of SSS is seasonal, it is important to know if satellites and gridded in situ products are observing the seasonal variability correctly. In this study we validate the seasonal SSS from satellite and gridded in situ products using observations from moorings in the global tropical moored buoy array. We utilize six different satellite products, and two different gridded in situ products. For each product we have computed seasonal harmonics, including amplitude, phase and fraction of variance (R2). These quantities are mapped for each product and for the moorings. We also do comparisons of amplitude, phase and R2 between moorings and all the satellite and gridded in situ products. Taking the mooring observations as ground truth, we find general good agreement between them and the satellite and gridded in situ products, with near zero bias in phase and amplitude and small root mean square differences. Tables are presented with these quantities for each product quantifying the degree of agreement.
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ArticleRevisiting the global patterns of seasonal cycle in sea surface salinity(American Geophysical Union, 2021-03-17) Yu, Lisan ; Bingham, Frederick ; Lee, Tong ; Dinnat, Emmanuel ; Fournier, Séverine ; Melnichenko, Oleg ; Tang, Wenqing ; Yueh, Simon H.Argo profiling floats and L-band passive microwave remote sensing have significantly improved the global sampling of sea surface salinity (SSS) in the past 15 years, allowing the study of the range of SSS seasonal variability using concurrent satellite and in situ platforms. Here, harmonic analysis was applied to four 0.25° satellite products and two 1° in situ products between 2016 and 2018 to determine seasonal harmonic patterns. The 0.25° World Ocean Atlas (WOA) version 2018 was referenced to help assess the harmonic patterns from a long-term perspective based on the 3-year period. The results show that annual harmonic is the most characteristic signal of the seasonal cycle, and semiannual harmonic is important in regions influenced by monsoon and major rivers. The percentage of the observed variance that can be explained by harmonic modes varies with products, with values ranging between 50% and 72% for annual harmonic and between 15% and 19% for semiannual harmonic. The large spread in the explained variance by the annual harmonic reflects the large disparity in nonseasonal variance (or noise) in the different products. Satellite products are capable of capturing sharp SSS features on meso- and frontal scales and the patterns agree well with the WOA 2018. These products are, however, subject to the impacts of radiometric noises and are algorithm dependent. The coarser-resolution in situ products may underrepresent the full range of high-frequency small scale SSS variability when data record is short, which may have enlarged the explained SSS variance by the annual harmonic.
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Working PaperReview of US GO-SHIP (Global Oceans Shipboard Hydrographic Investigations Program) An OCB and US CLIVAR Report(Woods Hole Oceanographic Institution, 2019-10) Bingham, Frederick ; Juranek, Laurie W. ; Mazloff, Matthew R. ; McKinley, Galen A. ; Nelson, Norman B. ; Wijffels, Susan E.The following document constitutes a review of the US GO-SHIP program, performed under the auspices of US Climate Variability and Predictability (CLIVAR) and Ocean Carbon Biogeochemistry (OCB) Programs. It is the product of an external review committee, charged and assembled by US CLIVAR and OCB with members who represent the interests of the programs and who are independent of US GO-SHIP support, which spent several months gathering input and drafting this report. The purpose of the review is to assess program planning, progress, and opportunities in collecting, providing, and synthesizing high quality hydrographic data to advance the scientific research goals of US CLIVAR and OCB.
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Technical ReportSubmesoscale Ocean Dynamics Experiment (S-MODE) Data Submission Report(Woods Hole Oceanographic Institution, 2024-04) Westbrook, Elizabeth ; Bingham, Frederick M. ; Brodnitz, Susannah ; Farrar, J. Thomas ; Rodríguez, Ernesto ; Zappa, ChristopherThis document reviews the sampling details of the S-MODE (Submesoscale Ocean Dynamics Experiment), a NASA-funded, EVS-3 (Earth Venture Suborbital-3), oceanographic field program. It describes what measurements were collected, when and with what instruments and platforms. For each measurement platform it gives simple plots showing the basic dataset, and describes the sampling in detail. S-MODE in situ and aircraft data are available from the PO.DAAC (Physical Oceanography Distributed Active Archive Center) landing page, and individual datasets are also available at the DOIs listed in the “Data Availability” section of this report.