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Measurements of cell size, cell density, nutrient concentration and genotype composition in a long-term experiment (182 days) with the marine phytoplankton species Chaetoceros affinis and Emiliania huxleyi, each consisting of nine genotypes. The species were cultivated together at three different nutrient regimes (10 N, 20 N, 30 N) with increasing nitrate supply in a semi-continuous batch cycle system. The genotype composition of both species was assessed after 49, 91, and 182 days using microsatellites. In a short-term experiment cell size and density of nine Chaetoceros affinis genotypes separately were measured after 7 days growth at seven nitrate levels (2.5, 5, 7.5, 12.5, 20, 30, and 45 μmol L−1 N).

Microplastics are substrates for microbial activity and can influence biomass production. This has potentially important implications at the sea-surface microlayer, the marine boundary layer that controls gas exchange with the atmosphere and where biologically produced organic compounds can accumulate. In the present study, we used large scale mesocosms (filled with 3 m3 of seawater) to simulate future ocean scenarios. We explored microbial organic matter dynamics in the sea-surface microlayer in the presence and absence of microplastic contamination of the underlying water. Our study shows that microplastics increased both biomass production and enrichment of particulate carbohydrates and proteins in the sea-surface microlayer. Importantly, this resulted in a 3% reduction in the concentration of dissolved CO2 in the underlying water. This reduction suggests direct and indirect impacts of microplastic pollution on the marine uptake of CO2, by modifying the biogenic composition of the sea’s boundary layer with the atmosphere.

As part of the Model Intercomparison Project on the climatic response to Volcanic forcing (VolMIP), several climate modeling centers performed a coordinated pre-study experiment with interactive stratospheric aerosol models simulating the volcanic aerosol cloud from an eruption resembling the 1815 Mt. Tambora eruption (VolMIP-Tambora ISA ensemble). The pre-study provided the ancillary ability to assess intermodel diversity in the radiative forcing for a large stratospheric-injecting equatorial eruption when the volcanic aerosol cloud is simulated interactively. An initial analysis of the VolMIP-Tambora ISA ensemble showed large disparities between models in the stratospheric global mean aerosol optical depth (AOD). In this study, we now show that stratospheric global mean AOD differences among the participating models are primarily due to differences in aerosol size, which we track here by effective radius. We identify specific physical and chemical processes that are missing in some models and/or parameterized differently between models, which are together causing the differences in effective radius. In particular, our analysis indicates that interactively tracking hydroxyl radical (OH) chemistry following a large volcanic injection of sulfur dioxide (SO2) is an important factor in allowing for the timescale for sulfate formation to be properly simulated. In addition, depending on the timescale of sulfate formation, there can be a large difference in effective radius and subsequently AOD that results from whether the SO2 is injected in a single model grid cell near the location of the volcanic eruption, or whether it is injected as a longitudinally averaged band around the Earth.

Coccolithophores are globally important marine calcifying phytoplankton that utilize a haplo-diplontic life cycle. The haplo-diplontic life cycle allows coccolithophores to divide in both life cycle phases and potentially expands coccolithophore niche volume. Research has, however, to date largely overlooked the life cycle of coccolithophores and has instead focused on the diploid life cycle phase of coccolithophores. Through the synthesis and analysis of global scanning electron microscopy (SEM) coccolithophore abundance data (n=2534), we find that calcified haploid coccolithophores generally constitute a minor component of the total coccolithophore abundance (≈ 2 %–15 % depending on season). However, using case studies in the Atlantic Ocean and Mediterranean Sea, we show that, depending on environmental conditions, calcifying haploid coccolithophores can be significant contributors to the coccolithophore standing stock (up to ≈30 %). Furthermore, using hypervolumes to quantify the niche of coccolithophores, we illustrate that the haploid and diploid life cycle phases inhabit contrasting niches and that on average this allows coccolithophores to expand their niche by ≈18.8 %, with a range of 3 %–76 % for individual species. Our results highlight that future coccolithophore research should consider both life cycle stages, as omission of the haploid life cycle phase in current research limits our understanding of coccolithophore ecology. Our results furthermore suggest a different response to nutrient limitation and stratification, which may be of relevance for further climate scenarios. Our compilation highlights the spatial and temporal sparsity of SEM measurements and the need for new molecular techniques to identify uncalcified haploid coccolithophores. Our work also emphasizes the need for further work on the carbonate chemistry niche of the coccolithophore life cycle.

The applications are designed for High Frequency Radar (HFR) data management according to the European HFR node processing workflow, thus generating aggregated radial and total velocity files in netCDF format according to the European standard data and metadata model for near real time HFR current data. These applications implement the periodic temporal aggregation of the datasets and the related CDI metadata to be distributed via SeaDataCloud. These applications are designed for the centralized run at the EU HFR Node.

This paper creatively approaches the marine ecological disaster. A hypothetical dystopic scenario becomes the starting point for an artistic critique on the ongoing ecological catastrophe of the marine environment. Could the colonization of the sea by artificial electromechanical “organisms” constitute a solution to this ecological crisis, so that humans may continue contaminating the marine life undisturbed and without fear of ending up with an uninhabited and dead sea? This thesis revolves around this absurd question and articulates ecological concerns about the dystopic possibility of an irreversibly polluted marine world. This question is approached in purely artistic terms, through the preliminary study, design, and partial implementation of a series of autonomous electromechanical organisms that could colonize an ecologically damaged marine environment, as well as by means of an attempt to compose a submarine art installation where they could “live” and interact freely with one another as well as with other materials of natural or artificial origin. At a purely technical level, this paper discusses particular solutions to technical affairs, describes three electromechanical organisms and their operating principles, and presents draft three-dimensional representations of a possible submarine installation within an aquarium. Through the completion of the work, it was found that, employing various technologies, such ecological concerns can be indeed expressed by artistic means. Η παρούσα εργασία προσεγγίζει δημιουργικά την θαλάσσια οικολογική καταστροφή. Ένα υποθετικό δυστοπικό σενάριο γίνεται το εφαλτήριο μιας βασισμένης σε καλλιτεχνική έρευνα κριτικής για την οικολογική καταστροφή του θαλάσσιου περιβάλλοντος. Θα μπορούσε να επιλύσει την παρούσα οικολογική κρίση ο αποικισμός της θάλασσας από τεχνητούς ηλεκτρομηχανικούς οργανισμούς, ούτως ώστε να μπορεί ο άνθρωπος να συνεχίζει να μολύνει ανενόχλητα την θαλάσσια ζωή δίχως τον φόβο να μείνει η θάλασσα ακατοίκητη και νεκρή; Η πτυχιακή περιστρέφεται γύρω από αυτό το παράλογο ερώτημα και εκφράζει οικολογικές ανησυχίες αναφορικά με την δυστοπική πιθανότητα ενός μολυσμένου θαλάσσιου κόσμου. Το ερώτημα προσεγγίζεται σε καθαρά καλλιτεχνικούς όρους, μέσω προκαταρκτικής μελέτης, σχεδιασμού, και εν μέρη υλοποίησης σειράς αυτόνομων ηλεκτρομηχανικών θαλάσσιων «οργανισμών», που θα μπορούσαν να αποικίσουν ένα οικολογικά κατεστραμμένο θαλάσσιο περιβάλλον, καθώς και μέσω απόπειρας σύνθεσης υποβρύχιας καλλιτεχνικής εγκατάστασης όπου αυτοί οι οργανισμοί θα μπορούσαν να κατοικήσουν να διαδρούν ελεύθερα ο ένας με τον άλλον αλλά και με λοιπά ανόργανα στοιχεία. Σε καθαρά τεχνικό επίπεδο, η παρούσα εργασία συζητά επί μέρους λύσεις σε τεχνικά ζητήματα, περιγράφει τρεις ηλεκτρομηχανικούς «οργανισμούς» και τις αρχές λειτουργίας αυτών, και παρουσιάζει προσχέδια και τρισδιάστατες αναπαραστάσεις μιας πιθανής υποβρύχιας εγκατάστασης εντός ενυδρείου. Μέσα από την ολοκλήρωση της εργασίας διαπιστώθηκε πως μέσω διαφόρων τεχνολογιών μπορούν να εκφραστούν οι οικολογικές ανησυχίες της παρούσας πτυχιακής σε καλλιτεχνικό επίπεδο. Completed

Concentrations of magnesium (Mg), calcium (Ca) and chlorine (Cl) measured in the 2015 RECAP ice core by inductive coupled plasma mass spectroscopy (ICPMS) along the 120,000 year-record.

Concentrations of sodium (Na), bromine (Br), calcium (Ca), magnesium (Mg) and chlorine (Cl) measured in the 2015 RECAP ice core by inductive coupled plasma mass spectroscopy (ICPMS) along the 120,000 year-record, as well as the sea-salt sodium (ssNa) calculations are presented. In the 0-8 kyr b2015 section only the Br and Na series are presented, as 100-yr averages.

This Product User Manual describes the INSITU_GLO_UV_NRT_OBSERVATIONS_013_048 product distributed by the Copernicus Marine Service In Situ Thematic Assembly Centre (CMEMS INS-TAC): how it is built, what is the content, what data services are available to access them, and how to use the files. This product concerns four real-time datasets dedicated to near-surface currents measurements coming from two platform categories (Lagrangian surface drifters and High Frequency radars): drifter: near-surface zonal and meridional raw velocities measured by drifting buoys, wind & wind stress components, quality flags and metadada. These surface observations are part of the DBCP's Global Drifter Program (see Table 1) drifter_filt: near-surface zonal and meridional velocities and 3-day filtered (with a Lanczos filter) velocities measured by drifting buoys. All the platforms are gathered together and concatenated in concatenated daily files. radar_total: near-surface zonal and meridional raw velocities measured by High Frequency radars (HFR), standard deviation of near-surface zonal and meridional raw velocities, Geometrical Dilution of Precision (GDOP), quality flags and metadata. These surface observations are part of the European HF radar Network (see Mader et al, 2017 and Corgnati et al., 2018) radar_radial: near-surface zonal and meridional components of raw radial velocities measured by HFRs, magnitude and direction of near-surface zonal and meridional components of raw radial velocities (measured in the radial directions covered by each of the HFR stations), standard deviation of near-surface zonal and meridional components of raw radial velocities, quality flags and metadata. These surface observations are part of the European HF radar Network (see Mader et al, 2017 and Corgnati et al., 2018) Argo: ocean currents derived from the original trajectory data from Argo GDAC (Global Data Assembly Center). Deep current is calculated from floats drift at parking depth, surface current is calculated from float surface drift. The INS-TAC aims at providing a research and operational framework to develop and deliver in situ observations and derived products based on such observations, to address progressively global (GLO) but also regional needs either for monitoring, modelling or downstream service development.