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On-going ocean acidification and increasing availability of high-frequency pH data have stimulated interest to understand seasonal pH dynamics in surface waters. Here we show that it is possible to accurately reproduce observed pH values by combining seasonal changes in temperature (T), dissolved inorganic carbon (DIC), and total alkalinity (TA) from three time series stations with novel pH sensitivity factors. Moreover, we quantify the separate contributions of T, DIC, and TA changes to winter-to-summertime differences in pH, which are in the ranges of −0.0334 to −0.1237, 0.0178 to 0.1169, and −0.0063 to 0.0234, respectively. The effects of DIC and temperature are therefore largely compensatory, and are slightly tempered by changes in TA. Whereas temperature principally drives pH seasonality in low-latitude to midlatitude systems, winter-to-summer DIC changes are most important at high latitudes. This work highlights the potential of pH sensitivity factors as a tool for quantifying the driving mechanisms behind pH changes.

In Indonesia, flyingfish are abundant and distributed in Makassar Strait, Flores Sea, Banda Sea, Sulawesi Sea, Maluku Sea, Arafura, Northern Sea of Papua, and Halmahera. The aims of this study were to analyse and describe the characteristics of flyingfish habitat, based on oceanographic conditions and eggs catches, and to visualize the variability in spatial and temporal patterns of predicted potential spawning grounds. The research was conducted in Fak-Fak and adjacent seas in the Indonesian Fisheries Area WPP 715, from 130°−134° E and 2°S−5° S. Data were collected during 2018 for selected months: June, July, August and September. Remote sensing data used in this study included chlorophyll-a concentration (Chl-a) OCI-Algorithm, Sea Surface Temperature (SST) 11μ daytime, Absolute Dynamic Topography (ADT), Significant Wave Height and Ocean Surface Current (meridian and zonal components). Fishery data were collected from fishermen’s GPS units, and through participatory mapping. Based on the mapping of fishing locations of flyingfish fishermen, there were four locations where fishing frequency was high. The potential fishing grounds were approximately 5-40 miles from mainland of Fak-Fak. Chlorophyll-a concentration in Fak-Fak waters ranged from 0.201–2.13 mg/m3. The temperature was estimated to be in the range of 27-31°C, with an average temperature of 27.1°C. ADT only changed by 0.01 cm in height each month with a range between 0.88–1.02 cm. Wind was one of the driving forces of geostrophic current. The waves reached a peak in August, with heights ranging from 0.70 to 1.6 metre. Flyingfish were predominantly found in oceanic zones.

Kim, K.; Shin, J.; Kim, K.Y., and Ryu, J.H., 2019. Long-term trend of green and golden tide in the eastern Yellow Sea. In: Jung, H.-S.; Lee, S.; Ryu, J.-H., and Cui, T. (eds.), Advances in Remote Sensing and Geoscience Information Systems of Coastal Environments. Journal of Coastal Research, Special Issue No. 90, pp. 317-323. Coconut Creek (Florida), ISSN 0749-0208.Since 2008, floating green tides (Ulva sp.) have been occurring continuously in the Yellow Sea (YS), and after 2013 floating golden tides (Sargassum sp.) have also occurred. The distribution, areal coverage, and migration of floating green tides have been actively studied, but most research has focused only on the western YS. Little is known about the floating golden tides in the eastern YS. The purpose of this study was to determine the long-term distribution of floating green and golden tides in the eastern YS using Geostationary Ocean Color Imager (GOCI), Moderate Resolution Imaging Spectroradiometer (MODIS), and Landsat satellite images from 2008 to 2017. In addition, the migration of floating macroalgae with Global Hybrid Coordinate Ocean Model (HYCOM) surface current data were compared. Green tides were observed in 2008, 2009, 2011, 2015, and 2016 in the eastern YS. From a satellite image backtracking analysis, it was confirmed that the green tides observed in the eastern YS were supplied from the western YS. When the maximum areal coverage of green tide was compared between the eastern and western YS, the coverage in the eastern YS was found to be about 4 % of that of the western YS. However, in 2011, the largest amount of floating macroalgae was found in the eastern YS and it accounted for about 45 % of the amount in the western part of the YS. In the eastern YS, floating golden tides were found in 2013, 2015, 2016, and 2017, with the largest amount of floating macroalgae occurring in 2017. Although there were no long-term golden tide data for the western YS, such that it was not compared to the areal coverage of the eastern YS, it was confirmed that the amount of golden tide supplied to the eastern YS gradually increased. A comparison between the migration of floating macroalgae and HYCOM surface current data suggested that the migration and flow directions were not identical, and were considerably affected by surface ocean currents during their passage into the eastern YS. From this study, the long-term distribution and changes in areal coverage of green and golden tides in the eastern YS were obtained for the first time. This information will be useful for understanding the long-term patterns of green and golden tides, and provides basic data for predicting the occurrence and migration of floating macroalgae.

Research on the sediment distribution based on types of grain size in the Cirebon and Demak waters has been conducted. The purposes of this research were to analyze the pattern of sediment distribution based on types of sediment grain size associated with the ocean surface current and rainfall patterns. The research was conducted in January, February, and March 2017 in the waters of Cirebon and Demak. Primary data used in this research was seabed sediment data, while secondary data included daily surface current data from HYCOM (HYbrid Coordinate Ocean Model) with resolution 0.080 and rainfall data. Sediment samples were taken by purposive sampling method at three point stations from each location. Sediment samples were analysed using wet sieving method at Marine Geology Laboratory of Diponegoro University, Semarang. The results showed that sediment texture in the Cirebon and Demak waters were dominated by sand, silt, and clay. The type of sediment in Demak waters was dominated by sand, whereas in the Cirebon region Was dominated by sandy silt. The pattern of sediment distribution was generally parallel to the coastline. Current velocity affected the sediment distribution, where larger types of sedimentary grains were found in areas with higher current velocities. Demak waters with strong current velocity was dominated by sand originating from various sources in the oceans which are carried by the currents and deposited on the coast. Cirebon waters with weaker current velocity and higher rainfall was dominated by sandy silt originating from the rivers that flow into the sea.

An autonomous system using isotope dilution as its core method has been developed to obtain high-frequency measurements of dissolved inorganic carbon (DIC) concentrations in the surface ocean. This system accurately mixes a seawater sample and a 13C-labeled sodium bicarbonate solution (spike). The mixed solution is then acidified and sent through a gas permeable membrane contactor. CO2 derived from DIC in the mixture is extracted by a CO2-free gas stream, and is sent to a cavity ring-down spectrometer to analyze its 13C/12C ratio. [DIC] of the seawater can then be derived from the measured 13C/12C, the known mixing ratio and the [DI13C] of the spike. The method has been tested under a wide [DIC] range (1800–2300 µmol/kg) in the laboratory. It has also been deployed on a cruise that surveyed ocean waters to the south of Florida. At a sampling resolution of 4 min (15 samples per hour), the relative standard deviation of DIC determined from the laboratory tests and the field deployment is ± 0.07% and ± 0.09%, respectively. The accuracy of the method is better than 0.1% except where [DIC] varies faster than 5 µmol/kg per minute. Based on the laboratory and field evaluations, we conclude that this method can provide accurate underway [DIC] measurements at high resolution in most oceanic regions.

About 30% of the anthropogenically released CO2 is taken up by the oceans, which causes surface ocean pH to decrease and is commonly referred to as Ocean Acidification (OA). Foraminifera are one of the most abundant groups of marine calcifiers, estimated to precipitate ca. 50% of biogenic calcium carbonate in the open oceans. We have compiled the state of the art of OA effects on foraminifera, because the majority of OA research on this group was published within the last 3 yr. Disparate responses of this important group of marine calcifiers to OA were reported, highlighting the importance of a process based understanding of OA effects on foraminifera. The benthic foraminifer Ammonia sp. was cultured using two carbonate chemistry manipulation approaches: While pH and carbonate ions where varied in one, pH was kept constant in the other while carbonate ion concentration varied. This allows the identification of teh parameter of the parameter of the carbonate system causing observed effects. This parameter identification is the first step towards a process based understanding. We argue that [CO32−] is the parameter affecting foraminiferal size normalized weights (SNW) and growth rates and based on the presented data we can confirm the strong potential of foraminiferal SNW as a [CO32−] proxy.

Here we estimate the importance of vertical eddy diffusion in removing perfluorooctanoic acid (PFOA) from the surface Ocean and assess its importance as a global sink. Measured water column profiles of PFOA were reproduced by assuming that vertical eddy diffusion in a 3-layer ocean model is the sole cause for the transport of PFOA to depth. The global oceanic sink due to eddy diffusion for PFOA is high, with accumulated removal fluxes over the last 40 years of 660 t, with the Atlantic Ocean accounting for 70% of the global oceanic sink. The global oceans have removed 13% of all PFOA produced to a depth greater than 100 m via vertical eddy diffusion; an additional 4% has been removed via deep water formation. The top 100 m of the surface oceans store another 21% of all PFOA produced (∼1100 t).

The vast majority of the marine environment consists of dark, cold, high-pressure environments into which microbes from the surface ocean are continuously transported by advection or by attachment to sinking particles. Little is known about how the low temperature and high pressure of the deep ocean affect the abundance and activity of surface organisms, in particular microbial eukaryotes. Cultures of two flagellate species, Cafeteria roenbergensis and Neobodo designis , both isolated from surface waters where they are considered cosmopolitan, were incubated in titanium chambers for one to two weeks under typical deep-sea temperature (2 °C) and pressure (50 MPa, representing 5000 m water depth). Samples were taken daily with minimal loss of pressure in the culture vessel, and flagellates were subsequently enumerated, along with prokaryotic prey when possible. The abundance of protists declined in all treatments, with a significantly greater rate of mortality under combined cold temperature and high pressure conditions than in the cold temperature-only conditions. However, 1.6 (SD = 3.8)% of C. roenbergensis and 10.0 (6.1)% of N. designis cells survived on average in the high pressure treatments, indicating that some fraction of sinking protists can survive transport to the deep ocean. In addition, after a period of acclimation, positive growth rates were measured in some cases, suggesting that surface-adapted flagellates cannot only survive under deep-sea conditions but are able to reproduce and potentially provide seed populations to cold, high-pressure environments.

The isotopic composition of dissolved O2 (17Δ) and the biological O2 saturation from O2 : Ar ratios were measured in the surface ocean during six cruises off the coast of southern California from November 2005 to August 2008 to determine rates of gross oxygen production (GOP), net oxygen production (NOP), and the NOP : GOP ratio (a measure of potential export efficiency). In the mixed layer, 17Δ of dissolved O2 (17Δdiss) ranged from 24 to 108 per meg and biological O2 saturation ranged from 101% to 113% for all regions and cruises. Mixed-layer 17Δ-GOP ranged from 49 ± 23 mmol O2 m−2 d−1 to 533 ± 185 mmol O2 m−2 d−1 with an annual mean for the California Cooperative Oceanic Fisheries Investigations (CalCOFI) grid of 151 ± 59 mmol O2 m−2 d−1. Mixed-layer O2 : Ar-NOP ranged from 8 ± 6 mmol O2 m−2 d−1 to 135 ± 31 mmol O2 m−2 d−1 with an annual mean of 25 ± 8 mmol O2 m−2 d−1, implying that the CalCOFI grid is autotrophic year-round. 17Δ-GOP estimates were consistently greater than on-deck incubation-based 14C-primary production (14C-PP) by a factor of 5.6 ± 0.4 and greater than satellite PP estimates by a factor of 3.5 ± 0.3 (mmol O2 : mmol C). The 17Δ-GOP to 14C-PP factor was twice the expected factor of 2.7 determined from comparisons of incubation-based 18O-GOP and 14C-PP. The annual mean NOP : GOP ratio was 0.16 ± 0.06, suggesting a potential export efficiency that is surprisingly similar to the open ocean using comparable methods.

International audience; The ability of pelagic copepods to remotely detect and encounter potential sexual partners is a critical issue in zooplankton ecology. In calanoid copepods, mate-finding behaviour involves either chemical or hydromechanical cues. Here, I first provide a detailed description of the three-dimensional swimming behaviour of Eurytemora affinis, males, non-ovigerous females and ovigerous females swimming freely in the absence of chemical and hydromechanical cues and discuss potential reasons for the discrepancies observed in the literature. I further demonstrate that E. affinis males modify their swimming behaviour in response to a diffuse background of pheromone concentrations, which can be thought of as an adaptation to increase the encounter rate and follow trail mimics containing female scent. I finally describe the mate-seeking behaviour of E. affinis and show how males swimming freely in a three-dimensional environment modify their direction of motion upon encountering the pheromone trails of females and subsequently follow female trails over distance and duration of nearly 15 cm and 36 s until they hydromechanically sense the female and lunge at her. The relevance of these results is discussed in the general framework of search pattern strategies and the relative contribution of chemical versus hydromechanical cues in relation to the turbulent nature of the surface ocean.

Sabine, C. L. et al., As a response to public demand for a well-documented, quality controlled, publically available, global surface ocean carbon dioxide (CO2) data set, the international marine carbon science community developed the Surface Ocean CO2 Atlas (SOCAT). The first SOCAT product is a collection of 6.3 million quality controlled surface CO2 data from the global oceans and coastal seas, spanning four decades (1968–2007). The SOCAT gridded data presented here is the second data product to come from the SOCAT project. Recognizing that some groups may have trouble working with millions of measurements, the SOCAT gridded product was generated to provide a robust, regularly spaced CO2 fugacity (fCO2) product with minimal spatial and temporal interpolation, which should be easier to work with for many applications. Gridded SOCAT is rich with information that has not been fully explored yet (e.g., regional differences in the seasonal cycles), but also contains biases and limitations that the user needs to recognize and address (e.g., local influences on values in some coastal regions)., SOCAT is promoted by IOCCP, the Sur- face Ocean Lower Atmosphere Study, and the Integrated Marine Biogeochemistry and Ecosystem Research program. Douglas Wallace (Dalhousie University, Canada and former SOLAS chair) has strongly encouraged SOCAT. Support has been received from the University of Bergen (Norway), the Bjerknes Centre for Cli- mate Research (Norway), the National Oceanic and Atmospheric Administration (United States), the University of Washington (United States), Oak Ridge National Laboratory (United States), the University of East Anglia (United Kingdom), PANGAEA – Data Publisher for Earth & Environmental data (Germany), the Alfred Wegener Institute for Polar and Marine Research (Ger- many), the Centre National de la Recherche Scientifique (France), the CarboOcean (Norway, GOCE 511176-1) and CarboChange (Norway, FP7 264879) projects of the European Union, the US National Science Foundation (United States, OCE-1068958), the international Scientific Committee on Oceanic Research (SCOR, United States, OCE-0938349), and the UK Ocean Acidification Research Programme (NE / H017046 / 1; funded by the Natural Environment Research Council, the Department for Energy and Climate Change and the Department for Environment, Food and Rural A ff airs). Support for SOCAT meetings has been received from IOCCP, IMBER, the European Cooperation in Science and Technology (COST) Action 735 (United Kingdom), Geomar (Germany), the National Institute for Environmental Studies (Japan), and the Commonwealth Scientific and Industrial Research Organisation (Australia).

Nitrite, a central intermediate in the marine nitrogen cycle, accumulates at the base of the sunlit surface ocean. Isotopic measurements suggest that ammonia oxidation is the primary source of nitrite in the primary nitrite maximum in the Arabian Sea.

International audience; A temporally and spatially resolved estimate of the global surface-ocean CO2 partial pressure field and the sea-air CO2 flux is presented, obtained by fitting a simple data-driven diagnostic model of ocean mixed-layer biogeochemistry to surface-ocean CO2 partial pressure data from the SOCAT v1.5 database. Results include seasonal, interannual, and short-term (daily) variations. In most regions, estimated seasonality is well constrained from the data, and compares well to the widely used monthly climatology by Takahashi et al. (2009). Comparison to independent data tentatively supports the slightly higher seasonal variations in our estimates in some areas. We also fitted the diagnostic model to atmospheric CO2 data. The results of this are less robust, but in those areas where atmospheric signals are not strongly influenced by land flux variability, their seasonality is nevertheless consistent with the results based on surface-ocean data. From a comparison with an independent seasonal climatology of surface-ocean nutrient concentration, the diagnostic model is shown to capture relevant surface-ocean biogeochemical processes reasonably well. Estimated interannual variations will be presented and discussed in a companion paper.

Ocean surface current radar is a Doppler radar to observe oceanographic information using the Bragg scattering resonance mechanism. In this paper, we consider angular resolution improvement of the radar. The radar employs an antenna array with FMICW operation, then it can resolve angular distribution by Digital Beam Forming (DBF) and distance by Fourier transform of the beat signal obtained by the FMICW radar. In order to obtain sufficient angular resolution, large array length or aperture with increasing the number of elements is needed, that is often difficult to realize in the HF/VHF ocean surface current radar. In this paper we propose to apply the Khatri-Rao (KR) product array processing to the radar. To verify effectiveness of the KR product array processing in angular resolution enhancement for the ocean surface current radar, we apply the KR product array to actual experimental data set of the radar, and show that the method is available to angular resolution enhancement and Doppler spectrum improvement.

The main objective of this study was to model the contribution of shelf sediments in the Arctic Ocean to the total mass of neutral organic contaminants accumulated in the Arctic environment using a standardized emission scenario for sets of hypothetical chemicals and realistic emission estimates (1930-2100) for polychlorinated biphenyl congener 153 (PCB-153). Shelf sediments in the Arctic Ocean are shown to be important reservoirs for neutral organic chemicals across a wide range of partitioning properties, increasing the total mass in the surface compartments of the Arctic environment by up to 3.5-fold compared to simulations excluding this compartment. The relative change in total mass for hydrophobic organic chemicals with log air-water partition coefficients ≥0 was greater than for chemicals with properties similar to typical POPs. The long-term simulation of PCB-153 generated modeled concentrations in shelf sediments in reasonable agreement with available monitoring data and illustrate that the relative importance of shelf sediments in the Arctic Ocean for influencing surface ocean concentrations (and therefore exposure via the pelagic food web) is most pronounced once primary emissions are exhausted and secondary sources dominate. Additional monitoring and modeling work to better characterize the role of shelf sediments for contaminant fate is recommended.

We use isoprene and related field measurements from three different ocean data sets together with remotely sensed satellite data to model global marine isoprene emissions. We show that using monthly mean satellite-derived chl a concentrations to parameterize isoprene with a constant chl a normalized isoprene production rate underpredicts the measured oceanic isoprene concentration by a mean factor of 19 ± 12. Improving the model by using phytoplankton functional type dependent production values and by decreasing the bacterial degradation rate of isoprene in the water column results in only a slight underestimation (factor 1.7 ± 1.2). We calculate global isoprene emissions of 0.21 Tg C for 2014 using this improved model, which is twice the value calculated using the original model. Nonetheless, the sea-to-air fluxes have to be at least 1 order of magnitude higher to account for measured atmospheric isoprene mixing ratios. These findings suggest that there is at least one missing oceanic source of isoprene and, possibly, other unknown factors in the ocean or atmosphere influencing the atmospheric values. The discrepancy between calculated fluxes and atmospheric observations must be reconciled in order to fully understand the importance of marine-derived isoprene as a precursor to remote marine boundary layer particle formation.

The sinking flux of particulate organic carbon (POC) from the surface ocean is a central driver of ocean biogeochemical cycling, which is directly related to the integrated NPP through euphotic layer. Using the global NPP data (estimated by remote sensing model) and other relevant satellite-derived data, the sinking flux of POC was derived following different algorithms. In situ data was used to compare the accuracy of these algorithms and the best algorithm was chosen to derive the global POC flux over period 2003∼2012. Then, the estimated global POC flux data were applied to study the spatial and temporal distribution characteristic of POC flux. The average annual total global POC flux at the bottom of euphotic layer is about 9.7 Gt C for period of 2003∼2012.

Ocean upwelling pipes are used to upwell nutrient-rich deeper waters in order to fertilize the surface ocean. This article addresses whether international legal rules exist governing the deployment of ocean pipes and which states are entitled to exercise jurisdiction over these objects. Taking into account the need to avoid user conflicts and unauthorized deployment of upwelling pipes in marine areas under the jurisdiction of third states, the article advocates the development of nonbinding guidelines that would implement the general terms of the United Nations Convention on the Law of the Sea.

In this study, the quality of near-surface current forecasts from the FOAM ocean forecasting system is assessed using the trajectories of Lagrangian drifting buoys. A method is presented for deriving pseudo-Eulerian estimates of ocean currents from the positions of Surface Velocity Program drifters and the resulting data are compared to velocities observed by the global tropical moored buoy array. A quantitative analysis of the global FOAM velocities is performed for the period 2007 and 2008 using currents derived from over 3000 unique drifters (providing an average of 650 velocity observations per day). A potential bias is identified in the Southern Ocean which appears to be caused by wind-slip in the drifter dataset as a result of drogue loss. The drifter-derived currents are also used to show how the data assimilation scheme and a recent system upgrade impact upon the quality of FOAM current forecasts.

Summary Dimethylsulfide (DMS) is a climatically relevant trace gas produced and cycled by the surface ocean food web. Mechanisms driving intraannual variability in DMS production and dimethylsulfoniopropionate (DMSP) degradation in open-ocean, oligotrophic regions were investigated during a 10-month time-series at the Bermuda Atlantic Time-series Study site in the Sargasso Sea. Abundance and transcription of bacterial DMSP degradation genes, DMSP lyase enzyme activity, and DMS and DMSP concentrations, consumption rates and production rates were quantified over time and depth. This interdisciplinary data set was used to test current hypotheses of the role of light and carbon supply in regulating upper-ocean sulfur cycling. Findings supported UV-A-dependent phytoplankton DMS production. Bacterial DMSP degraders may also contribute significantly to DMS production when temperatures are elevated and UV-A dose is moderate, but may favour DMSP demethylation under low UV-A doses. Three groups of bacterial DMSP degraders with distinct intraannual variability were identified and niche differentiation was indicated. The combination of genetic and biochemical data suggest a modified ‘bacterial switch’ hypothesis where the prevalence of different bacterial DMSP degradation pathways is regulated by a complex set of factors including carbon supply, temperature and UV-A dose.

Two Dungeness crab trap tags and floats lost off the State of Oregon, USA during the 2006-2007 fishing season were recovered 4years later in the Northwestern Hawaiian Islands (NWHI): on Lisianski Island on July 15, 2010; and on Kure Atoll on December 10, 2010. This is the first documented recovery of marine debris from Oregon fisheries in the NWHI. We simulate the oceanic drift tracks of the derelict fishing gear with the Ocean Surface Current Simulator (OSCURS) model using estimated loss dates in Oregon based on interviews with the crab trap owners and known recovery sites and dates in the NWHI. These data confirm the US Pacific Northwest as a source of marine debris deposited in the NWHI and provide enhanced understanding of the oceanic drift pathways of marine debris in the North Pacific Ocean.

An explicit integro-differential equation formulation is derived for surface ocean waves with finite depth. The equation involves only 2D surface variables. For this equation, we establish the stability and existence of solutions, and explain the effect of depth on surface wave properties.

We conducted a survey of archaeal GDGT (glycerol dibiphytanyl glycerol tetraether) distributions in marine sediments deposited in a range of depositional settings. The focus was comparison of two pools presumed to have distinct geobiological significance, i.e. intact polar GDGTs (IP GDGTs) and core GDGTs (C GDGTs). The former pool has been suggested to be related to living communities of benthic archaea in marine sediments, while the latter is commonly interpreted to consist of molecular fossils from past planktonic archaeal communities that inhabited the surface ocean. Understanding the link between these two pools is important for assessment of the validity of current molecular proxies for sedimentary archaeal biomass and past sea surface temperatures. The relative distributions of GDGTs in the two pools in a core at a CH4 rich site in the Black Sea provide evidence for in situ production of glycosidic IP GDGTs and their subsequent degradation to corresponding C GDGTs on timescales that are short in geological terms. In addition, we monitored the relationship between the IP GDGT and C GDGT pools in a sample set from various ocean basins with subseafloor depth from a few cm to 320 m and 0 to 4 Myr in age. Notable differences between the two pools can be summarized as follows: the GDGT with acyclic biphytanes, GDGT-0, and its analogues with two and three cyclopentane moieties (GDGT-2 and -3) are generally more abundant in the pool of IP GDGTs, while crenarchaeol tends to be more abundant in the C GDGT pool. Consequently, the ring index is generally higher for the C GDGTs while TEX86, a molecular proxy ratio not considering the two major GDGTs, tends to be higher in the IP GDGT pool. These differences in the proportion of individual GDGTs in the two pools are probably due to in situ production of IP GDGTs with distributions differing from those of C GDGTs. Despite these differences, we observed significant correlation of these two ratios between the two pools. Specifically, in both pools TEX86 is high in sediments from warm oceanic regimes and low in cold regimes. We discuss these relationships and suggest that recycling of core GDGTs by benthic archaea is an important mechanism linking both molecular pools.

The VAMOS Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-REx) was a major field experiment conducted in spring of 2008 off southern Peru and northern Chile, aimed at better understanding the coupled climate systems of the southeast Pacific. Because of logistical constrains, the coastal area around 30° S was not sampled during VOCALS-REx. This area not only marks the poleward edge of the subtropical stratocumulus cloud regime (thus acting as a source of transient disturbances) but is also one of the most active upwelling centers and source of surface ocean kinetic energy along the Chilean coast. To fill such an observational gap, a small, brief, but highly focused field experiment was conducted in late spring 2009 in the near-shore region around 30° S. The Chilean Upwelling Experiment (CUpEx) was endorsed by VOCALS as a regional component. CUpEx included long-term monitoring, an intensive two-week field campaign and off-shore research flights. Our goal was to obtain an atmospheric/oceanic dataset with enough temporal and spatial coverage to be able to document (a) the mean diurnal cycles of the lower-troposphere and upper-ocean in a region of complex topography and coastline geometry, and (b) the ocean-atmosphere response to the rapid changes in coastal winds from strong, upwelling-favorable equatorward flow (southerly winds) to downwelling-favorable poleward flow (northerly winds). In this paper we describe the measurement platforms and sampling strategy, and provide an observational overview, highlighting some key mean-state and transient features.

The initial trigger of the atmospheric CO2 rise during Heinrich Stadial 1 (HS1: 14.5–17.5 kyr B.P.) remains elusive. We present a compilation of four paired surface and intermediate-depth foraminiferal δ13C records to test whether reduced biological pump efficiency led to the initial CO2 rise during the last deglaciation. Surface ocean δ13C decreased across HS1 while intermediate-depth δ13C increased, leading to a reduction in the upper ocean δ13C gradient. Our compilation also suggests the δ13C gradient increased during the Bolling-Allerod (12.9–14.5 kyr B.P.) and decreased during the Younger Dryas (YD: 11.7–12.9 kyr B.P.). The HS1 and YD data are consistent with reduced biological export of isotopically light carbon from the surface ocean and its remineralization at depth. Our results support the idea that a weaker Atlantic Meridional Overturning Circulation decreased biological pump efficiency by increasing the overall fraction of preformed nutrients in the global ocean, leading to an increase in atmospheric CO2.

A moored time-series sediment trap was deployed at the Korea Ocean Research and Development Institute Long-term Monitoring (KOMO) Station in the northeastern equatorial Pacific from July 2003 to June 2005. A weak El Nino event was recorded from June 2004 to February 2005, and normal conditions were observed in the remaining periods. The normal period was divided into two seasons based on the cycles of environmental properties in the surface ocean: cold (December–May) and warm (June–November) season. During the normal period, the total mass flux was 1.7 times higher in the cold season than in the warm season. Particularly, the CaCO3 flux was nearly three times higher in the cold season. The enhanced CaCO3 flux in the cold season was attributed to an increased foraminiferal flux, which may have influenced the seasonal variability of the total mass flux at the KOMO station. The enhanced foraminiferal flux during the cold season may have been caused by the environmental changes of the surface ocean in response to wind-driven mixing resulting in supply of subsurface nutrient-enriched water. Particle fluxes during the weak El Nino period were lower by 30% than those during the normal period, which was consistent with previous findings in the central and eastern equatorial Pacific.

A national high-frequency radar network has been created over the past 20 years or so that provides hourly 2-D ocean surface current velocity fields in near real time from a few kilometers offshore out to approximately 200 km. This preoperational network is made up of more than 100 radars from 30 different institutions. The Integrated Ocean Observing System efforts have supported the standards-based ingest and delivery of these velocity fields to a number of applications such as coastal search and rescue, oil spill response, water quality monitoring, and safe and efficient marine navigation. Thus, regardless of the operating institution or location of the radar systems, emergency response managers, and other users, can rely on a common source and means of obtaining and using the data. Details of the history, the physics, and the application of high-frequency radar are discussed with successes of the integrated network highlighted.

Nitrogen fixation in the surface ocean impacts global marine nitrogen bioavailability and thus microbial primary productivity. Until now, cyanobacterial populations have been viewed as the main suppliers of bioavailable nitrogen in this habitat. Although PCR amplicon surveys targeting the nitrogenase reductase gene have revealed the existence of diverse non-cyanobacterial diazotrophic populations, subsequent quantitative PCR surveys suggest that they generally occur in low abundance. Here, we use state-of-the-art metagenomic assembly and binning strategies to recover nearly one thousand non-redundant microbial population genomes from the TARA Oceans metagenomes. Among these, we provide the first genomic evidence for non-cyanobacterial diazotrophs inhabiting surface waters of the open ocean, which correspond to lineages within the Proteobacteria and, most strikingly, the Planctomycetes. Members of the latter phylum are prevalent in aquatic systems, but have never been linked to nitrogen fixation previously. Moreover, using genome-wide quantitative read recruitment, we demonstrate that the discovered diazotrophs were not only widespread but also remarkably abundant (up to 0.3% of metagenomic reads for a single population) in both the Pacific Ocean and the Atlantic Ocean northwest. Our results extend decades of PCR-based gene surveys, and substantiate the importance of heterotrophic bacteria in the fixation of nitrogen in the surface ocean.

In the version of this Article originally published, in the ‘Acknowledgements’ section the authors neglected to include the following text: “The Surface Ocean CO2 Atlas (SOCAT) is an international effort, endorsed by the International Ocean Carbon Coordination Project (IOCCP), the Surface Ocean Lower Atmosphere Study (SOLAS) and the Integrated Marine Biosphere Research (IMBeR) programme, to deliver a uniformly quality-controlled surface ocean CO2 database. The many researchers and funding agencies responsible for the collection of data and quality control are thanked for their contributions to SOCAT.” This has now been added in the online versions of the Article.

Iron is a key limiting micro-nutrient for marine primary productivity. It can be supplied to the ocean by atmospheric dust deposition. Volcanic ash deposition into the ocean represents another external and so far largely neglected source of iron. This study demonstrates strong evidence for natural fertilisation in the iron-limited oceanic area of the NE Pacific, induced by volcanic ash from the eruption of Kasatochi volcano in August 2008. Atmospheric and oceanic conditions were favourable to generate a massive phytoplankton bloom in the NE Pacific Ocean which for the first time establishes a causal connection between oceanic iron-fertilisation and volcanic ash supply.

Very short-lived halocarbons are significant sources of reactive halogen in the marine boundary layer, and likely in the upper troposphere and lower stratosphere. Quantifying ambient concentrations in the surface ocean and atmosphere is essential for understanding the atmospheric impact of these trace gas fluxes. Despite the body of literature increasing substantially over recent years, calibration issues complicate the comparison of results and limit the utility of building larger-scale databases that would enable further development of the science (e.g. sea-air flux quantification, model validation, etc.). With this in mind, thirty-one scientists from both atmospheric and oceanic halocarbon communities in eight nations gathered in London in February 2008 to discuss the scientific issues and plan an international effort toward developing common calibration scales (http://tinyurl.com/c9cg58). Here, we discuss the outputs from this meeting, suggest the compounds that should be targeted initially, identify opportunities for beginning calibration and comparison efforts, and make recommendations for ways to improve the comparability of previous and future measurements.

We report radiocarbon measurements of dissolved inorganic carbon (DIC) in surface water samples collected daily during 12 cruises to Station M in the northeast Pacific off central California. Individual surface Δ14C values ranged from 22‰ to 70‰ over 10 yr. Variability of average cruise values is highest during winter likely due to increased mixing. A general decrease of Δ14C values was observed at a rate of about 3‰ per year between 1994 and 2004, about half of that in atmospheric CO2 during this period (Levin and Kromer 2004). The Δ14C results ranged from 2–18‰ during individual cruises and were often significantly larger than the total uncertainty for individual measurements (±3.9‰). This indicates that a single Δ14C result from a surface site is not sufficient to capture the true variability of Δ14C in the surface ocean.

The aim of the work presented here was to detect BrO in the marine boundary layer over the Eastern North-Atlantic by Multi AXis-Differential Optical Absorption Spectroscopy (MAX-DOAS) of scattered sunlight. With this technique, information about the concentration and the vertical profile of trace gases in the atmosphere can be gained. BrO can be formed in the marine atmosphere by degradation of biogenic organohalogens or by oxidation of bromide in sea salt aerosol. BrO influences the chemistry in marine air in many ways, e.g. since it catalytically destroys ozone, changes the NO2/NO-ratio as well as the OH/HO2-ratio and oxidises DMS. However, the abundance and the significance of BrO in the marine atmosphere is not yet fully understood. We report on data collected during a ship cruise, which took place along the West African Coast in February 2007, within the framework of the Surface Ocean PRocesses in the ANthropocene project (SOPRAN). Tropospheric BrO could be detected during this cruise at peak mixing ratios of (10.2±3.7) ppt at an assumed layer height of 1 km on 18 February 2007. Furthermore, it was found that the mean BrO concentrations increased when cruising close to the African Coast suggesting that at least part of the BrO might have originated from there.

This study implements the assimilation of sea surface temperature (SST) data acquired by passive microwave remote sensing to a high-resolution, primitive-equation ocean model. The aim was to improve a forecasting tool capable of predicting the surface ocean processes linked to the air–sea interactions at sub-mesoscale level using one-way coupled, atmosphere–ocean modelling. An assimilation scheme based on a Newtonian relaxation scheme was fine-tuned to improve the forecasting skill of the ocean model. The ocean model was driven by predicted, synchronous air–sea fluxes derived by an overlying atmosphere model, remotely sensed SST and lateral boundary conditions derived from its previous run. The estimation of the model forecasting error was based on statistical and spatial comparison with remotely sensed observations. The optimal nudging coefficient was found to be 5 × 10−4 for 12 hours, giving a mean bias of −0.07°C. Forecast validation was done against calibrated AVHRR scenes using a new approach to cali...

The massive amount of impact-generated atmospheric CO2at the Cretaceous-Palaeogene boundary (KPB) would have accumulated globally in the surface ocean, leading to acidification and CaCO3undersaturation. These chemical changes would have caused a crisis of biocalcification of calcareous plankton and enhanced dissolution of their shells; these factors together may have played a crucial role in forming the biogenic calcite-poor KPB spherule layers observed at numerous oceanic sites and marine (now on land) sites in Europe and Africa. Experimental data and observations indicate that the deposition spherule layer probably lasted only a few decades at most.

Measurements of the efficiency of photosystem (PS) II have become widespread in bio- logical oceanography, and various forms are used to assess the 'health' of marine phytoplankton and to help estimate primary productivity. Absolute values of PS II efficiency depend to some extent on the measuring system, but changes in PS II efficiency are most commonly interpreted in terms of cel- lular acclimations to changing irradiance (including photoacclimation and photoinhibition) and nutri- ent availability (especially N and Fe). Recent measurements of phytoplankton viability in the surface ocean have revealed that in many regions phytoplankton assemblages may contain large proportions of dead cells. The effect of these dead cells on apparent PS II efficiency is largely unknown. By mix- ing live and dead cells and measuring PS II efficiency, we show that the presence of photosyntheti- cally non-functional (dead) cells has surprisingly little effect; in a number of species, mixtures in which 50% of the cells were dead had values of 0.5, similar to values often found in natural assem- blages. A simple model indicates that the non-linear nature of the fluorescence ratio is responsible for this unexpected result. We conclude that relatively high values of PS II efficiency cannot be used as evidence of low mortality. Our findings highlight the need for more information on the physiological status of both eukaryotic and prokaryotic microalgae in nature.

A climatological mean distribution for the surface water pCO2 over the global oceans in non-El Nino conditions has been constructed with spatial resolution of 4°(latitude) x 5°(longitude) for a reference year 2000 based upon about 3 million measurements of surface water pCO2 obtained from 1970 to 2007. The database used for this study is about 3 times larger than the 0.94 million used for our earlier paper [Takahashi et al., 2002. Global sea-air CO2 flux based on climatological surface ocean pCO2, and seasonal biological and temperature effects. Deep-Sea Res. 11, 49, 1601-1622]. A time-trend analysis using deseasonalized surface water pCO2 data in portions of the North Atlantic, North and South Pacific and Southern Oceans (which cover about 27% of the global ocean areas) indicates that the surface water pCO2 over these oceanic areas has increased on average at a mean rate of 1.5 µatm y-1 with basin-specific rates varying between 1.2 +/- 0.5 and 2.1 +/- 0.4 µatm y-1. A global ocean database for a single reference year 2000 is assembled using this mean rate for correcting observations made in different years to the reference year. The observations made during El Nino periods in the equatorial Pacific and those made in coastal zones are excluded from the database. Seasonal changes in the surface water pCO2 and the sea-air pCO2 difference over four climatic zones in the Atlantic, Pacific, Indian and Southern Oceans are presented. Over the Southern Ocean seasonal ice zone, the seasonality is complex. Although it cannot be thoroughly documented due to the limited extent of observations, seasonal changes in pCO2 are approximated by using the data for under-ice waters during austral winter and those for the marginal ice and ice-free zones. The net air-sea CO2 flux is estimated using the sea-air pCO2 difference and the air-sea gas transfer rate that is parameterized as a function of (wind speed)2 with a scaling factor of 0.26. This is estimated by inverting the bomb 14C data using Ocean General Circulation models and the 1979-2005 NCEP-DOE AMIP-II Reanalysis (R-2) wind speed data. The equatorial Pacific (14°N-14°S) is the major source for atmospheric CO2, emitting about +0.48 Pg-C y-1, and the temperate oceans between 14° and 50° in the both hemispheres are the major sink zones with an uptake flux of -0.70 Pg-C y-1 for the northern and -1.05 Pg-C y-1 for the southern zone. The high-latitude North Atlantic, including the Nordic Seas and portion of the Arctic Sea, is the most intense CO2 sink area on the basis of per unit area, with a mean of -2.5 tons-C month-1 km-2. This is due to the combination of the low pCO2 in seawater and high gas exchange rates. In the ice-free zone of the Southern Ocean (50°-62°S), the mean annual flux is small (-0.06 Pg-C y-1) because of a cancellation of the summer uptake v flux with the winter release Of CO2 caused by deepwater upwelling. The annual mean for the contemporary net v uptake flux over the global oceans is estimated to be -1.6+/-0.9 Pg-C y-1, which includes an undersampling correction to the direct estimate of -1.4+/-0.7 Pg-C y-1. Taking the pre-industrial steady-state ocean source of 0.4+/-0.2 Pg-C y-1 into account, the total ocean uptake flux including the anthropogenic CO2 is estimated to be -2.0+/- 1.0 Pg-C y-1 in 2000.

This paper presents radiocarbon results from modern South Pacific corals from the Marquesas Islands, Vanuatu, Papua New Guinea (PNG), and Easter Island. All of the measurements are from pre-bomb Porites corals that lived during the 1940s and 1950s. The data reflect subannual to multiannual surface ocean 14C variability and allow for precise, unambiguous reservoir age determinations. The results are compared with published values from other coral records throughout the South Pacific, with striking consistency. By comparisons with other published values, we identify 3 South Pacific regions with uniform pre-bomb reservoir ages (1945 to 1955). These are 1) the Central Equatorial South Pacific (361.6 ± 8.2 14C yr, 2 σ); 2) the Western Equatorial South Pacific (322.1 ± 8.6 14C yr, 2 σ); and 3) the subtropical Pacific (266.8 ± 13.8 14C yr, 2 σ). The question of how much, and how fast, South Pacific reservoir ages might have varied in the past is addressed by examining a published record from a Pleistocene coral from Vanuatu that lived over a 700-yr period during the Younger Dryas. The average reservoir age at that time was larger than today, by ~150 yr, and exhibited reservoir age variability on a decadal timescale not seen in modern times. Measured paleo-reservoir ages increase sharply in this record by as many as 300 14C yr in 3 decades. These increases are punctuated by smaller reservoir age decreases, on the order of 150 yr. This reservoir age variability provides a rare picture of active ocean ventilation and ocean-atmosphere exchange at the close of the Pleistocene.

This work evaluates whether an accurate calculation of the entire CO2 system in the northern North Atlantic can be carried out using a combination of in situ fugacity of CO2 (fCO2) and ancillary data often measured on Voluntary Observing Ships (VOS), i.e., sea surface temperature (SST) and sea surface salinity (SSS), as well as nitrate (NO3−). Two approaches are tested: (I) determination of At from SSS and then calculating Ct from measured fCO2 and estimated At; and (II) determination of Ct from SSS, SST, and NO3− and then calculating At from measured fCO2 and estimated Ct. The optimal approach was found to be determination of At from SSS and then calculating Ct from measured fCO2 and estimated At. This allowed At to be determined with a mean bias of −1.8 µmol kg−1 and root mean square (rms) deviation 6.2 µmol kg−1 and then Ct to be calculated with a mean bias of −1.0 µmol kg−1 and standard error of calculation of 7.4 µmol kg−1, as validated using independent data sets.

Analysis of bomb generated radiocarbon ( 14 C) changes in a red abalone, Haliotis rufescens Swainson shell was used to evaluate age-at-length relationships derived from data from a previous multiyear, multisite tag-recapture study. Shell carbonate was extracted from four successive growth trajectory locations in a single shell with a maximum shell length of 251 mm. Extraction locations were based on Von Bertalanffy growth function (VBGF) predictions and chosen to span the initial rise of the 14 C-bomb pulse that is known to have occurred in surface ocean waters during 1958 ±1 y in the northeast Pacific. The close temporal correspondence of the red abalone sample series to regional D 14 C records demonstrated the utility of the technique for validating age-at-length relationships for the red abalone. The findings provided support for a mean VBGF derived age of 32 y (range 30-33 y) for the specimen; however, the analysis of 14 C data indicated that the specimen could be older.

One method for minimizing climate change is to capture CO2 from power plants and inject it into the deep ocean, thus reducing the magnitude and rate of change of CO2 concentration in the atmosphere and the surface ocean. Many discharge options are possible, with varied mixing and retention characteristics. The ocean's capacity is vast, and mathematical models suggest that injected CO2 could remain sequestered for several hundred years. While theoretical and laboratory studies support the viability of ocean storage, field experiments are necessary to realistically evaluate the environmental impact.

Coastal upwelling regions have been identified as sites of enhanced CH4 emissions to the atmosphere. The coastal upwelling area off Mauritania (NW Africa) is one of the most biologically productive regions of the world's ocean but its CH4 emissions have not been quantified so far. More than 1000 measurements of atmospheric and dissolved CH4 in the surface layer in the upwelling area off Mauritania were performed as part of the German SOPRAN (Surface Ocean Processes in the Anthropocene) study during two cruises in March/April 2005 (P320/1) and February 2007 (P348). During P348 enhanced CH4 saturations of up to 200% were found close to the coast and were associated with upwelling of South Atlantic Central Water. An area-weighted, seasonally adjusted estimate yielded overall annual CH4 emissions in the range from 1.6 to 2.9 Gg CH4. Thus the upwelling area off Mauritania represents a regional hot spot of CH4 emissions but seems to be of minor importance for the global oceanic CH4 emissions.

Rainwater hydrophobic extractable dissolved organic matter (EDOM) contains ligand(s) that completely prevent Fe(II) oxidation for at least 4 h after rain is mixed with seawater. The EDOM Fe(II) complex is at least of comparable strength to the ferrozine complex, indicating that this rainwater Fe(II) ligand is among the strongest Fe(II) ligands ever observed in natural waters. In addition to the strong class of ligands that prevent oxidation, rainwater EDOM also contains weaker Fe(II) ligands that slow oxidation of Fe(II) in seawater. Rainwater EDOM is not a single molecule but rather a complex mixture of relatively hydrophobic compounds, even in marine rain with minimal continental influence. When EDOM from the nearby Cape Fear River was extracted using the same method as for rainwater, the river EDOM could not prevent or even slow the oxidation of Fe(II) on mixing with seawater. Therefore, rainwater EDOM is fundamentally different than surface-water EDOM with respect to the strength of Fe(II) ligands. The stability of EDOM complexed Fe(II) most likely affects the bioavailability of rainwater-derived Fe in the surface ocean because the length of time atmospherically deposited Fe remains dissolved in seawater is critical to its role as a phytoplankton nutrient.

We report radiocarbon measurements of dissolved inorganic carbon (DIC) in surface water samples collected daily during cruises to the central North Pacific, the Sargasso Sea and the Southern Ocean. The ranges of Δ14C measurements for each cruise (11-30‰) were larger than the total uncertainty (7.8‰, 2-sigma) of the measurements. The variability is attributed to changes in the upper water mass that took place at each site over a two to four week period. These results indicate that variability of surface Δ14C values is larger than the analytical precision, because of patchiness that exists in the DIC Δ14C signature of the surface ocean. This additional variability can affect estimates of geochemical parameters such as the air-sea CO2 exchange rate using radiocarbon. © 2008 Elsevier B.V. All rights reserved.

Over a range of trophic conditions in the ocean, we argue that variations in productivity are more closely related to variations in phytoplankton absorption than to variations in the chlorophyll-a (Chl-a) concentration. Our analysis suggests that environmental variability is expressed through the absorption properties of phytoplankton pigments rather than their quantity, and that productivity normalized to absorption is relatively invariant in the world ocean. The relationship between primary productivity and phytoplankton absorption makes possible a more direct approach to the estimation of ocean productivity from satellite sensors.