Recent Publications

Weekly Highlighted Publication

Culprit of the Eastern Pacific Double-ITCZ Bias in the NCAR CESM1.2

Impact:
In summary, the oversimulated convection in the northern ITCZ region and Central America in boreal winter may result in biases in the surface wind fields in tropical northeastern Pacific in the atmospheric model, which favor the cooling of ocean mixed layer through the enhancement of latent heat flux and Ekman upwelling. Once the atmospheric model is coupled to the ocean model, these biases are passed into the ocean model and result in a severe cold bias of SST in the northern ITCZ region. The overly cold SST bias persists in the subsequent spring, leading to the suppression of convection in the northern ITCZ region. The enhanced low-level cross-equatorial northerly wind strengthens the wind convergence south of the equator and transports abundant water vapor to the convergence zone, strengthening the southern ITCZ convection. All these processes lead to the disappearance of northern ITCZ and the enhancement of southern ITCZ in boreal spring, forming a seasonally alternating type of double-ITCZ bias.

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  • Abstract Summary:

    As part of a broad-scale study of the biogeography of rocky reefs in the Gulf of California, Mexico (GOC), we collected a continuous 1-yr temperature time series at similar to 5 m water depth at 16 sites spanning 5 degrees of latitude and similar to 700 km along the western boundary of the basin. Throughout the region, thermal conditions were most variable in summer with fluctuations concentrated at diurnal and semi-diurnal frequencies,...

  • Garcon V., Karstensen J, Palacz A., Telszewski M., Lara T.A, Breitburg D., Chavez F., Coelho P., Cornejo-D'Ottone M., Santos C. et al..  2019.  Multidisciplinary observing in the world ocean's oxygen minimum zone regions: From climate to fish - The VOICE Initiative. 6
    Abstract Summary:

    Multidisciplinary ocean observing activities provide critical ocean information to satisfy ever-changing socioeconomic needs and require coordinated implementation. The upper oxycline (transition between high and low oxygen waters) is fundamentally important for the ecosystem structure and can be a useful proxy for multiple observing objectives connected to eastern boundary systems (EBSs) that neighbor oxygen minimum zones (OMZs). The...

  • Franks PJS, Garwood J.C, Ouimet M., Cortes J., Musgrave R.C, Lucas A.J.  2019.  Stokes drift of plankton in linear internal waves: Cross-shore transport of neutrally buoyant and depth-keeping organisms.
    Abstract Summary:

    The meroplanktonic larvae of many invertebrate and vertebrate species rely on physical transport to move them across the shelf to their adult habitats. One potential mechanism for cross-shore larval transport is Stokes drift in internal waves. Here, we develop theory to quantify the Stokes velocities of neutrally buoyant and depth-keeping organisms in linear internal waves in shallow water. We apply the analyses to theoretical and measured...

  • Lampe R.H, Wang S., Cassar N., Marchetti A..  2019.  Strategies among phytoplankton in response to alleviation of nutrient stress in a subtropical gyre. 13:2984-2997.
    Abstract Summary:

    Despite generally low primary productivity and diatom abundances in oligotrophic subtropical gyres, the North Atlantic Subtropical Gyre (NASG) exhibits significant diatom-driven carbon export on an annual basis. Subsurface pulses of nutrients likely fuel brief episodes of diatom growth, but the exact mechanisms utilized by diatoms in response to these nutrient injections remain understudied within near-natural settings. Here we simulated...

  • Abstract Summary:

    As the proportion of the human population living in cities continues to increase, understanding the factors affecting urban biodiversity is crucial to enhancing conservation efforts, urban ecosystem function, and human wellbeing. Here we present the results of the first comparative study of belowground invertebrate communities in urban soils (lawns and biofilters) and remnant patches of native coastal sage scrub (CSS) in a semi-arid urban...

  • Abstract Summary:

    An oceanographic survey around the South Shetland Islands (SSI) and the South Orkney Islands (SOI) was conducted during January 2007 and February 2008, respectively, as part of the United States Antarctic Marine Living Resources (AMLR) program ecosystems surveys. At 27 stations, concentrations of dissolved labile Fe (DFe) and total acid leachable (unfiltered, TaLFe) iron (Fe) were measured in the upper 200 m (including coastal and oceanic...

  • Gallo N.D, Drenkard E., Thompson A.R, Weber E.D, Wilson-Vandenberg D., McClatchie S., Koslow JA, Semmens B.X.  2019.  Bridging from monitoring to solutions-based thinking: Lessons from CalCOFI for understanding and adapting to marine climate change impacts. 6
    Abstract Summary:

    Multidisciplinary, integrated ocean observing programs provide critical data for monitoring the effects of climate change on marine ecosystems. California Cooperative Oceanic Fisheries Investigations (CalCOFI) samples along the US West Coast and is one of the world's longest-running and most comprehensive time series, with hydrographic and biological data collected since 1949. The pairing of ecological and physical measurements across this...

  • Spydell M.S, Feddersen F, MacMahan J..  2019.  The effect of drifter GPS errors on estimates of submesoscale vorticity. 36:2101-2119.
    Abstract Summary:

    Differential kinematic flow properties (DKP), such as vertical vorticity, have been estimated from surface drifters. However, previous DKP error estimates were a posteriori and did not include correlated errors across drifters. To accurately estimate submesoscale (<= 1 km) DKPs from drifters, errors must be better understood. Here, the a priori vorticity standard error is derived that depends upon the number of drifters in the cluster, the...

  • Stephens BM, Wankel SD, J. Beman M, Rabines AJ, Allen AE, Aluwihare LI.  2019.  Euphotic zone nitrification in the California Current Ecosystem.
    Abstract Summary:

    Nitrification, the microbial conversion of ammonium to nitrite then to nitrate, occurs throughout the oceanic water column, yet the environmental factors influencing the production of nitrate in the euphotic zone (EZ) remain unclear. In this study, the natural abundances of N and O isotopes (δ15N and δ18O, respectively) in nitrate were used in an existing model framework to quantify nitrate contributed by EZ nitrification in the California...

  • Stephens B.M, Wankel S.D, Beman J.M, Rabines A.J, Allen A.E, Aluwihare LI.  2019.  Euphotic zone nitrification in the California Current Ecosystem.
    Abstract Summary:

    Nitrification, the microbial conversion of ammonium to nitrite then to nitrate, occurs throughout the oceanic water column, yet the environmental factors influencing the production of nitrate in the euphotic zone (EZ) remain unclear. In this study, the natural abundances of N and O isotopes (delta N-15 and delta O-18, respectively) in nitrate were used in an existing model framework to quantify nitrate contributed by EZ nitrification in the...

  • Woodworth P.L, Melet A., Marcos M., Ray R.D, Woppelmann G., Sasaki Y.N, Cirano M., Hibbert A., Huthnance J.M, Monserrat S. et al..  2019.  Forcing factors affecting sea level changes at the coast. 40:1351-1397.
    Abstract Summary:

    We review the characteristics of sea level variability at the coast focussing on how it differs from the variability in the nearby deep ocean. Sea level variability occurs on all timescales, with processes at higher frequencies tending to have a larger magnitude at the coast due to resonance and other dynamics. In the case of some processes, such as the tides, the presence of the coast and the shallow waters of the shelves results in the...

  • Rogers J.S, Rayson M.D, Ko D.S, Winters KB, Fringer O.B.  2019.  A framework for seamless one-way nesting of internal wave-resolving ocean models. 143
    Abstract Summary:

    To resolve nonlinear internal wave motions in regional domains, we propose a one-way ocean model nesting framework in which a nonhydrostatic model is nested within a regional model. The nesting scheme produces internal tides that propagate freely into and out of the nonhydrostatic model domain with no reflections while nudging the low-frequency motions. We demonstrate the method with idealized test cases and a field-scale simulation of the...

  • Hell M.C, Cornelle B.D, Gille ST, Miller AJ, Bromirski PD.  2019.  Identifying ocean swell generation events from Ross Ice Shelf seismic data. 36:2171-2189.
    Abstract Summary:

    Strong surface winds under extratropical cyclones exert intense surface stresses on the ocean that lead to upper-ocean mixing, intensified heat fluxes, and the generation of waves, that, over time, lead to swell waves (longer than 10-s period) that travel long distances. Because low-frequency swell propagates faster than high-frequency swell, the frequency dependence of swell arrival times at a measurement site can be used to infer the...

  • Costa J.AV, Freitas B.CB, Rosa G.M, Moraes L., Morais M.G, Mitchell B.G.  2019.  Operational and economic aspects of Spirulina-based biorefinery. 292
    Abstract Summary:

    Microalgae biorefinery systems have been extensively studied from the perspective of resources, energy expenditure, biofuel production potential, and high-added value products. The genus Spirulina (Arthrospira) stands out among the microalgae of commercial importance. It accounts for over 30% of biomass produced globally because of high protein concentration and, carotenoid and phycocyanin content. Spirulina cultivation can be used to reduce...

  • Abstract Summary:

    Abstract Microplastics (< 5 mm) have long been a concern in marine debris research, but quantifying the smallest microplastics (< 333 μm) has been hampered by appropriate collection methods, like net tows. We modified standard epifluorescence microscopy methods to develop a new technique to enumerate < 333 μm microplastics (mini-microplastics) from filtered surface seawater samples and salp stomach contents. This permitted us to...

  • Gove JM, Whitney J.L, McManus MA, Lecky J., Carvalho F.C, Lynch J.M, Li J.W, Neubauer P., Smith K.A, Phipps J.E et al..  2019.  Prey-size plastics are invading larval fish nurseries. 116:24143-24149.
    Abstract Summary:

    Life for many of the world's marine fish begins at the ocean surface. Ocean conditions dictate food availability and govern survivorship, yet little is known about the habitat preferences of larval fish during this highly vulnerable life-history stage. Here we show that surface slicks, a ubiquitous coastal ocean convergence feature, are important nurseries for larval fish from many ocean habitats at ecosystem scales. Slicks had higher...

  • Fish M.A, Wilson A.M, Ralph FM.  2019.  Atmospheric river families: Definition and associated synoptic conditions. 20:2091-2108.
    Abstract Summary:

    Atmospheric rivers (ARs) can cause flooding when they are strong and stall over an already wet watershed. While earlier studies emphasized the role of individual, long-duration ARs in triggering floods, it is not uncommon for floods to be associated with a series of ARs that strike in close succession. This study uses measurements from an atmospheric river observatory at Bodega Bay (BBY), in Northern California, to identify periods when...

  • Abstract Summary:

    The Southern Ocean and coastal Antarctica provide a variety of ecosystem services with benefits for humankind that are of regional and global importance. Despite being nearly uninhabited, increasing exploitation of natural resources, a growing human presence, and environmental change threaten the sustained provisioning of these services. Ecosystem service assessments have proven as a suitable tool to understand the relevance of ecosystems for...

  • Abstract Summary:

    Objectively determining the level of ecosystem model complexity necessary to achieve meaningful representations of biogeochemical cycles at different spatial and temporal scales is an outstanding issue in marine ecosystem modeling. As part of the development of a three-dimensional (3D) Regional Ocean Modelling System (ROMS) application for the northwest North Atlantic Ocean, we compare model results from three alternative ecosystem model...

  • Smith SR, Dupont CL, McCarthy JK, Broddrick JT, Oborník M, Horák A, Füssy Z, Cihlář J, Kleessen S, Zheng H et al..  2019.  Evolution and regulation of nitrogen flux through compartmentalized metabolic networks in a marine diatom. 10:4552.
    Abstract Summary:

    Diatoms outcompete other phytoplankton for nitrate, yet little is known about the mechanisms underpinning this ability. Genomes and genome-enabled studies have shown that diatoms possess unique features of nitrogen metabolism however, the implications for nutrient utilization and growth are poorly understood. Using a combination of transcriptomics, proteomics, metabolomics, fluxomics, and flux balance analysis to examine short-term shifts in...

  • Abstract Summary:

    Sinking particles transport organic carbon produced in the surface ocean to the ocean interior, leading to net storage of atmospheric CO2 in the deep ocean. The rapid growth of in situ imaging technology has the potential to revolutionize our understanding of particle flux attenuation in the ocean; however, estimating particle flux from particle size and abundance (measured directly by in situ cameras) is challenging. Sinking rates are...

  • Abstract Summary:

    The deep-sea benthos covers over 90% of seafloor area and hosts a great diversity of species which contribute toward essential ecosystem services. Evidence suggests that deep-seafloor assemblages are structured predominantly by their physical environment, yet knowledge of assemblage/environment relationships is limited. Here, we utilized a very large dataset of Northwest Atlantic Ocean continental slope peracarid crustacean assemblages as a...

  • Kline DI, Teneva L., Okamoto D.K, Schneider K., Caldeira K., Miard T., Chai A., Marker M., Dunbar R.B, Mitchell B.G et al..  2019.  Living coral tissue slows skeletal dissolution related to ocean acidification. 3:1438-1444.
    Abstract Summary:

    Climate change is causing major changes to marine ecosystems globally, with ocean acidification of particular concern for coral reefs. Using a 200 d in situ carbon dioxide enrichment study on Heron Island, Australia, we simulated future ocean acidification conditions, and found reduced pH led to a drastic decline in net calcification of living corals to no net growth, and accelerated disintegration of dead corals. Net calcification declined...

  • Gracia A., Levin L.A, Zea S..  2019.  Meio-epifaunal wood colonization in the vicinity of methane seeps.
    Abstract Summary:

    In deep-sea environments, plant remains of several origins are found, including branches, twigs, leaves, and wood pieces, among others. As most of the deep-sea bottoms are oligotrophic and nutrient-limited, plant remains provide an oasis of localized organic enrichment and a substrate for colonization. Sunken wood was suggested to play an important evolutionary role in the diversification of chemosynthetic ecosystems, possibly representing...

  • Abstract Summary:

    The mesopelagic (200-1000 m) separates the productive upper ocean from the deep ocean, yet little is known of its long-term dynamics despite recent research that suggests fishes of this zone likely dominate global fish biomass and contribute to the downward flux of carbon. Here we show that mesopelagic fishes dominate the otolith (ear bone) record in anoxic sediment layers of the Santa Barbara Basin over the past two millennia. Among these...

  • Sathyendranath S., Brewin R.JW, Brockmann C., Brotas V., Calton B., Chuprin A., Cipollini P., Couto A.B, Dingle J., Doerffer R. et al..  2019.  An ocean-colour time series for use in climate studies: The experience of the Ocean-Colour Climate Change Initiative (OC-CCI). 19
    Abstract Summary:

    Ocean colour is recognised as an Essential Climate Variable (ECV) by the Global Climate Observing System (GCOS); and spectrally-resolved water-leaving radiances (or remote-sensing reflectances) in the visible domain, and chlorophyll-a concentration are identified as required ECV products. Time series of the products at the global scale and at high spatial resolution, derived from ocean-colour data, are key to studying the dynamics of...

  • Coale TH, Moosburner M, Horák A, Oborník M, Barbeau KA, Allen AE.  2019.  Reduction-dependent siderophore assimilation in a model pennate diatom.
    Abstract Summary:

    Diatoms can access inorganic iron with remarkable efficiency, but this process is contingent on carbonate ion concentration. As ocean acidification reduces carbonate concentration, inorganic iron uptake may be discouraged in favor of carbonate-independent uptake. We report details of an iron assimilation process that needs no carbonate but requires exogenous compounds produced by cooccurring organisms. We show this process to be critical for...

  • Luo M, Gieskes J, Chen L, Scholten J, Pan B, Lin G, Chen D.  2019.  Sources, degradation, and transport of organic matter in the New Britain Shelf-Trench continuum, Papua New Guinea. 124:1680-1695.
    Abstract Summary:

    Abstract Hadal trenches are considered as depocenters for organic matter and hotspots for microbial diagenetic activity. Here, we explore the sources, degradation, and transport of organic matter in the shelf-trench continuum using seven short sediment cores collected along two transects with water depths ranging between 1,553 and 8,901 m in the New Britain Trench area, Papua New Guinea. Carbon isotopic compositions (δ13C) and radiocarbon...

  • Bortolus A., Adam P., Adams J.B, Ainouche M.L, Ayres D., Bertness M.D, Bouma T.J, Bruno J.F, Cacador I., Carlton J.T et al..  2019.  Supporting Spartina: Interdisciplinary perspective shows Spartina as a distinct solid genus.
    Abstract Summary:

    In 2014, a DNA-based phylogenetic study confirming the paraphyly of the grass subtribe Sporobolinae proposed the creation of a large monophyletic genus Sporobolus, including (among others) species previously included in the genera Spartina, Calamovilfa, and Sporobolus. Spartina species have contributed substantially (and continue contributing) to our knowledge in multiple disciplines, including ecology, evolutionary biology, molecular biology...

  • Piecuch C.G, Thompson P.R, Ponte R.M, Merrifield M.A, Hamlington B.D.  2019.  What caused recent shifts in tropical Pacific decadal sea-level trends?
    Abstract Summary:

    Satellite altimetry reveals substantial decadal variability in sea level zeta across the tropical Pacific during 1993-2015. An ocean state estimate that faithfully reproduces the observations is used to elucidate the origin of these low-frequency tropical Pacific zeta variations. Analysis of the hydrostatic equation reveals that recent decadal zeta changes in the tropical Pacific are mainly thermosteric in nature, related to changes in upper-...

  • Gaskell D.E, Ohman MD, Hull P.M.  2019.  Zooglider-based measurements of planktonic foraminifera in the California Current system. 49:390-404.
    Abstract Summary:

    Spines and rhizopodia play an important role in the feeding behavior, symbiont ecology, shell geochemistry, and density and drag of planktonic foraminifera. However, there are few empirical data on planktonic foraminifera in situ, and these delicate structures are disturbed on capture. Here, we report spine and rhizopod measurements from underwater images obtained in the California Current System near La Jolla, California by Zooglider, a new...

  • Kelly T.B, Davison P.C, Goericke R, Landry MR, Ohman MD, Stukel M.R.  2019.  The importance of mesozooplankton diel vertical migration for sustaining a mesopelagic food web. 6
    Abstract Summary:

    We used extensive ecological and biogeochemical measurements obtained from quasi-Lagrangian experiments during two California Current Ecosystem Long-Term Ecosystem Research cruises to analyze carbon fluxes between the epipelagic and mesopelagic zones using a linear inverse ecosystem model (LIEM). Measurement constraints on the model include C-14 primary productivity, dilution-based microzooplankton grazing rates, gut pigment-based...

  • Brandon JA, Jones W, Ohman MD.  2019.  Multidecadal increase in plastic particles in coastal ocean sediments. 5
    Abstract Summary:

    We analyzed coastal sediments of the Santa Barbara Basin, California, for historical changes in microplastic deposition using a box core that spanned 1834–2009. The sediment was visually sorted for plastic, and a subset was confirmed as plastic polymers via FTIR (Fourier transform infrared) spectroscopy. After correcting for contamination introduced during sample processing, we found an exponential increase in plastic deposition from 1945 to...

  • Abstract Summary:

    The eastern Fram Strait and area north of Svalbard, are influenced by the inflow of warm Atlantic water, which is high in nutrients and CO2, influencing the carbon flux into the Arctic Ocean. However, these estimates are mainly based on summer data and there is still doubt on the size of the net ocean Arctic CO2 sink. We use data on carbonate chemistry and nutrients from three cruises in 2014 in the CarbonBridge project (January, May, and...

  • Cazenave A., Hamlington B., Horwath M., Barletta V.R, Benveniste J., Chambers D., Doll P., Hogg A.E, Legeais J.F, Merrifield M. et al..  2019.  Observational requirements for long-term monitoring of the global mean sea level and its components over the altimetry era. 6
    Abstract Summary:

    Present-day global mean sea level rise is caused by ocean thermal expansion, ice mass loss from glaciers and ice sheets, as well as changes in terrestrial water storage. For that reason, sea level is one of the best indicators of climate change as it integrates the response of several components of the climate system to internal and external forcing factors. Monitoring the global mean sea level allows detecting changes (e.g., in trend or...

  • Mascioni M., Almandoz GO, Cefarelli AO, Cusick A., Ferrario ME, Vernet M.  2019.  Phytoplankton composition and bloom formation in unexplored nearshore waters of the western Antarctic Peninsula. 42:1859-1872.
    Abstract Summary:

    The western Antarctic Peninsula (WAP) is one of the most productive regions in the Southern Ocean. However, little is known about the phytoplankton composition in nearshore waters, in fjords and channels between 63 degrees and 67 degrees S, where Antarctic krill and baleen whales are conspicuous. This study represents the first attempt to describe spatial and temporal composition of the phytoplankton community (species, cell concentration,...

  • Gaidarenko O., Sathoff C., Staub K., Huesemann M.H, Vernet M, Hildebrand M.  2019.  Timing is everything: Diel metabolic and physiological changes in the diatom Cyclotella cryptica grown in simulated outdoor conditions. 42
    Abstract Summary:

    Microalgal cultures grown on a light-dark cycle experience diel patterns in metabolic and physiological processes, including cell cycle synchronization, but the implications for productivity in terms of biomass and commercially-appealing molecules are not commonly appreciated. Despite a long history of diel response studies, only recently have photobioreactor technology advances enabled the use of sinusoidal light and temperature to more...

  • Vernet M, Geibert W., Hoppema M., Brown P.J, Haas C., Hellmer H.H, Jokat W., Jullion L., Mazloff M., Bakker D.CE et al..  2019.  The Weddell Gyre, Southern Ocean: Present knowledge and future challenges. 57:623-708.
    Abstract Summary:

    The Weddell Gyre (WG) is one of the main oceanographic features of the Southern Ocean south of the Antarctic Circumpolar Current which plays an influential role in global ocean circulation as well as gas exchange with the atmosphere. We review the state-of-the art knowledge concerning the WG from an interdisciplinary perspective, uncovering critical aspects needed to understand this system's role in shaping the future evolution of oceanic...

  • Kenitz K.M, Visser A.W, Ohman MD, Landry MR, Andersen K.H.  2019.  Community trait distribution across environmental gradients. 22:968-980.
    Abstract Summary:

    Variability in community composition is often attributed to underlying differences in physical environments. However, predator-prey interactions can play an equally important role in structuring communities. Although environmental differences select for different species assemblages, less is known about their impacts on trait compositions. We develop a trait-based analysis of plankton communities of the southern California Current System...

  • Winters KB, Ulloa H.N, Wuest A., Bouffard D..  2019.  Energetics of radiatively heated ice-covered lakes. 46:8913-8925.
    Abstract Summary:

    We derive the mechanical energy budget for shallow, ice-covered lakes energized by penetrative solar radiation. Radiation increases the available and background components of the potential energy at different rates. Available potential energy drives under-ice motion, including diurnally active turbulence in a near-surface convective mixing layer. Heat loss at the ice-water interface depletes background potential energy at a rate that depends...

  • Jiang M., Measures C.I, Barbeau K.A, Charette MA, Gille ST, Hatta M., Kahru M, Mitchell B.G, Garabato A.CN, Reiss C et al..  2019.  Fe sources and transport from the Antarctic Peninsula shelf to the southern Scotia Sea. 150
    Abstract Summary:

    The Antarctic Peninsula (AP) shelf is an important source of dissolved iron (Fe) to the upper ocean in the southern Scotia Sea, one of the most productive regions of the Southern Ocean. Here we present results from a four-year (2003-2006) numerical simulation using a regional coupled physical-biogeochemical model to assess the Fe sources and transport on the AP shelf and toward the southern Scotia Sea. The model was validated with a suite of...

  • Ellen J.S, Graff C.A, Ohman MD.  2019.  Improving plankton image classification using context metadata. 17:439-461.
    Abstract Summary:

    Advances in both hardware and software are enabling rapid proliferation of in situ plankton imaging methods, requiring more effective machine learning approaches to image classification. Deep Learning methods, such as convolutional neural networks (CNNs), show marked improvement over traditional feature-based supervised machine learning algorithms, but require careful optimization of hyperparameters and adequate training sets. Here, we...

  • Prend C.J, Gille ST, Talley LD, Mitchell B.G, Rosso I., Mazloff MR.  2019.  Physical drivers of phytoplankton bloom initiation in the Southern Ocean's Scotia Sea. 124:5811-5826.
    Abstract Summary:

    The Scotia Sea is the site of one of the largest spring phytoplankton blooms in the Southern Ocean. Past studies suggest that shelf-iron inputs are responsible for the high productivity in this region, but the physical mechanisms that initiate and sustain the bloom are not well understood. Analysis of profiling float data from 2002 to 2017 shows that the Scotia Sea has an unusually shallow mixed-layer depth during the transition from winter...

  • Sanz-Martin M., Vernet M, Cape M.R, Mesa E., Delgado-Huertas A., Reigstad M., Wassmann P., Duarte C.M.  2019.  Relationship between carbon- and oxygen-based primary productivity in the Arctic Ocean, Svalbard Archipelago. 6
    Abstract Summary:

    Phytoplankton contribute half of the primary production (PP) in the biosphere and are the major source of energy for the Arctic Ocean ecosystem. While PP measurements are therefore fundamental to our understanding of marine biogeochemical cycling, the extent to which current methods provide a definitive estimate of this process remains uncertain given differences in their underlying approaches, and assumptions. This is especially the case in...

  • Chen Z., Bromirski PD, Gerstoft P, Stephen R.A, Lee W.S, Yun S., Olinger S.D, Aster R.C, Wiens D.A, Nyblade A.A.  2019.  Ross Ice shelf Icequakes Associated With Ocean Gravity Wave Activity. 46:8893-8902.
    Abstract Summary:

    Gravity waves impacting ice shelves illicit a suite of responses that can affect ice shelf integrity. Broadband seismometers deployed on the Ross Ice Shelf, complemented by a near-icefront seafloor hydrophone, establish the association of strong icequake activity with ocean gravity wave amplitudes (A(G)) below 0.04 Hz. The Ross Ice Shelf-front seismic vertical displacement amplitudes (A(SV)) are well correlated with A(G), allowing estimating...

  • Ray R.D, Merrifield M.A.  2019.  The semiannual and 4.4-year modulations of extreme high tides. 124:5907-5922.
    Abstract Summary:

    In most places extreme high tides undergo a clear seasonal variation. It is well known that semidiurnal tides tend to peak during equinox seasons, and diurnals during solstice seasons. This is a consequence of the solar and lunar declinations, which when large maximize diurnal tides at the expense of semidiurnals. The semiannual range modulation of tidal extremes for a pure semidiurnal tide is determined mainly by the amplitude of the K-2...

  • Ludka B.C, Guza RT, O'Reilly W.C, Merrifield M.A, Flick RE, Bak A.S, Hesser T., Bucciarelli R., Olfe C., Woodward B. et al..  2019.  Sixteen years of bathymetry and waves at San Diego beaches. 6
    Abstract Summary:

    Sustained, quantitative observations of nearshore waves and sand levels are essential for testing beach evolution models, but comprehensive datasets are relatively rare. We document beach profiles and concurrent waves monitored at three southern California beaches during 2001-2016. The beaches include offshore reefs, lagoon mouths, hard substrates, and cobble and sandy (medium-grained) sediments. The data span two energetic El Nino winters...

  • Abstract Summary:

    Despite generally low primary productivity and diatom abundances in oligotrophic subtropical gyres, the North Atlantic Subtropical Gyre (NASG) exhibits significant diatom-driven carbon export on an annual basis. Subsurface pulses of nutrients likely fuel brief episodes of diatom growth, but the exact mechanisms utilized by diatoms in response to these nutrient injections remain understudied within near-natural settings. Here we simulated...

  • Valente A., Sathyendranath S., Brotas V., Groom S., Grant M., Taberner M., Antoine D., Arnone R., Balch W.M, Barker K. et al..  2019.  A compilation of global bio-optical in situ data for ocean-colour satellite applications - version two. 11:1037-1068.
    Abstract Summary:

    A global compilation of in situ data is useful to evaluate the quality of ocean-colour satellite data records. Here we describe the data compiled for the validation of the ocean-colour products from the ESA Ocean Colour Climate Change Initiative (OC-CCI). The data were acquired from several sources (including, inter alia, MOBY, BOUSSOLE, AERONET-OC, SeaBASS, NOMAD, MERMAID, AMT, ICES, HOT and GeP&CO) and span the period from 1997 to 2018...

  • Kolody B.C, McCrow J.P, L. Allen Z, Aylward F.O, Fontanez K.M, Moustafa A., Moniruzzaman M., Chavez F.P, Scholin C.A, Allen EE et al..  2019.  Diel transcriptional response of a California Current plankton microbiome to light, low iron, and enduring viral infection.
    Abstract Summary:

    Phytoplankton and associated microbial communities provide organic carbon to oceanic food webs and drive ecosystem dynamics. However, capturing those dynamics is challenging. Here, an in situ, semi-Lagrangian, robotic sampler profiled pelagic microbes at 4 h intervals over ~2.6 days in North Pacific high-nutrient, low-chlorophyll waters. We report on the community structure and transcriptional dynamics of microbes in an operationally large...