Project: EC | MEDSEA (265103), UKRI | NSFGEO-NERC An unexpected... (NE/N011708/1), MZOS | Mechanism of long-term ch... (098-0982705-2731), EC | SEACELLS (670390), UKRI | GW4+ - a consortium of ex... (NE/L002434/1)
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.
From 2003 to 2013, the Ancona section of CNR-IRBIM (formerly part of CNR-Institute of Marine Science) runned the “Fishery Observing System” (FOS) program aimed at using Italian fishing vessels as Vessels Of Opportunity (VOOs) for the collection of scientifically useful datasets (Falco et al. 2007). Some commercial fishing vessels, targetting small pelagic species in the northern and central Adriatic Sea, were equipped with an integrated system for the collection of information on catches, position of the fishing operation, depth and water temperature during the haul, producing a great amount of data that demonstrated to be helpful both for oceanographic and fishery biology purposes (Carpi et al. 2015; Aydoğdu et a. 2016; Sparnocchia et al. 2016; Lucchetti et al. 2018). In 2012, thanks to the participation to some national and international projects (e.g. SSD-Pesca, EU-FP7 JERICO etc.), CNR started the development of a new modular “Fishery & Oceanography Observing System” (FOOS; Patti et al. 2013). New sensors for oceanographic and meteorological data allow nowadays the FOOS to collect more parameters, with higher accuracy and to send them directly to a data center in near real time (Martinelli et al. 2016; Sparnocchia et al. 2017). Furthermore, the FOOS is a multifunction system able to collect various kind of data from the fishing operations and also to send back to the fishermen useful information (e.g. weather and sea forecasts, etc.) through an electronic logbook with an ad hoc software embedded. The new FOOS installed on various kind of fishing vessels targetting different resources, allowed a spatial extension of the monitored areas in the Mediterranean Sea (Patti et al. 2013). CNR-IRBIM implemented the “AdriFOOS” observational system, by installing the FOOS on some commercial fishing boats operating in the Adriatic Sea. Since then the datacenter based in Ancona receives daily data sets of environmental parameters collected along the water column and close to the sea bottom (eg. temperature, salinity, etc.), together with GPS haul tracks, catch amounts per haul, target species sizes and weather information. Some temperature and salinity measurements acquired by the FOOS in the Adriatic Sea from January 2014 to March 2015 were published within the JERICO project and some oxygen and fluorescence profiles obtained in 2017 within the NEXOS project. The dataset here presented contains 14803 depth/temperature profiles collected by 10 vessels of the AdriFOOS fleet in the period 2012-2020. All the profiles were subjected to quality control.Data are flagged according the L20 (SEADATANET MEASURAND QUALIFIER FLAGS).
Although it has been demonstrated that the speed and magnitude of the recent Arctic sea ice decline is unprecedented for the past 1450 years, few records are available to provide a paleoclimate context for Arctic sea ice extent. Bromine enrichment in ice cores has been suggested to indicate the extent of newly formed sea ice areas. Despite the similarities among sea ice indicators and ice core bromine enrichment records, uncertainties still exist regarding the quantitative linkages between bromine reactive chemistry and the first-year sea ice surfaces. Here we present a 120 000-year record of bromine enrichment from the RECAP (REnland ice CAP) ice core, coastal east Greenland, and interpret it as a record of first-year sea ice. We compare it to existing sea ice records from marine cores and tentatively reconstruct past sea ice conditions in the North Atlantic as far north as the Fram Strait (50–85∘ N). Our interpretation implies that during the last deglaciation, the transition from multi-year to first-year sea ice started at ∼17.5 ka, synchronously with sea ice reductions observed in the eastern Nordic Seas and with the increase in North Atlantic ocean temperature. First-year sea ice reached its maximum at 12.4–11.8 ka during the Younger Dryas, after which open-water conditions started to dominate, consistent with sea ice records from the eastern Nordic Seas and the North Icelandic shelf. Our results show that over the last 120 000 years, multi-year sea ice extent was greatest during Marine Isotope Stage (MIS) 2 and possibly during MIS 4, with more extended first-year sea ice during MIS 3 and MIS 5. Sea ice extent during the Holocene (MIS 1) has been less than at any time in the last 120 000 years.
Bottom trawling in the deep sea is one of the main drivers of sediment resuspension, eroding the seafloor and altering the content and composition of sedimentary organic matter (OM). The physical and biogeochemical impacts of bottom trawling were studied on the continental slope of the Gulf of Castellammare, Sicily (southwestern Mediterranean), through the analysis of two triplicate sediment cores collected at trawled and untrawled sites (∼550 m water depth) during the summer of 2016. Geochemical and sedimentological parameters (excess 210Pb, excess 234Th, 137Cs, dry bulk density, and grain size), elemental (organic carbon and nitrogen) and biochemical composition of sedimentary OM (proteins, carbohydrates, lipids), as well as its freshness (phytopigments) and degradation rates were determined in both coring locations. The untrawled site had a sedimentation rate of 0.15 cm yr−1 and presented a 6 cm thick surface mixed layer that contained siltier sediment with low excess 210Pb concentrations, possibly resulting from the resuspension, posterior advection, and eventual deposition of coarser and older sediment from adjacent trawling grounds. In contrast, the trawled site was eroded and presented compacted century-old sediment highly depleted in OM components, which were between 20 % and 60 % lower than those in the untrawled site. However, the upper 2 cm of the trawled site consisted of recently accumulated sediments enriched in excess 234Th, excess 210Pb, and phytopigments, while OM contents were similar to those from the untrawled core. This fresh sediment supported protein turnover rates of 0.025 d−1, which doubled those quantified in surface sediments of the untrawled site. The enhancement of remineralization rates in surface sediment of the trawled site was associated with the arrival of fresh particles on a chronically trawled deep-sea region that is generally deprived of OM. We conclude that the detrimental effects of bottom trawling can be temporarily and partially abated by the arrival of fresh and nutritionally rich OM, which stimulate the response of benthic communities. However, these ephemeral deposits are likely to be swiftly eroded due to the high trawling frequency over fishing grounds, highlighting the importance of establishing science-based management strategies to mitigate the impacts of bottom trawling.
The paper investigates the wintertime dynamics of the coastal northeastern Adriatic Sea and is based on numerical modelling and in situ data collected through field campaigns executed during the winter and spring of 2015. The data were collected with a variety of instruments and platforms (acoustic Doppler current profilers, conductivity–temperature–depth probes, glider, profiling float) and are accompanied by the atmosphere–ocean ALADIN/ROMS modelling system. The research focused on the dense-water formation (DWF), thermal changes, circulation, and water exchange between the coastal and open Adriatic. According to both observations and modelling results, dense waters are formed in the northeastern coastal Adriatic during cold bora outbreaks. However, the dense water formed in this coastal region has lower densities than the dense water formed in the open Adriatic due to lower salinities. Since the coastal area is deeper than the open Adriatic, the observations indicate (i) balanced inward–outward exchange at the deep connecting channels of denser waters coming from the open Adriatic DWF site and less-dense waters coming from the coastal region and (ii) outward flow of less-dense waters dominating in the intermediate and surface layers. The latter phenomenon was confirmed by the model, even if it significantly underestimates the currents and transports in the connecting channels. The median residence time of the coastal area is estimated to be approximately 20 days, indicating that the coastal area may be renewed relatively quickly by the open Adriatic waters. The data that were obtained represent a comprehensive marine dataset that can be used to calibrate atmospheric and oceanic numerical models and point to several interesting phenomena to be investigated in the future.
Diel vertical migration (DVM) is a survival strategy adopted by zooplankton that we investigated in the Corsica Channel using acoustic Doppler current profiler (ADCP) data from April 2014 to November 2016. The principal aim of the study is to characterize migration patterns and biomass temporal evolution of zooplankton along the water column. The ADCP measured vertical velocity and echo intensity in the water column range between about 70 and 390 m (the bottom depth is 443 m). During the investigated period, zooplanktonic biomass had a well-defined daily and seasonal cycle, with peaks occurring in late winter to spring (2015 and 2016) when the stratification of the water column is weaker. Zooplanktonic biomass temporal distribution in the whole water column is well correlated with biomass of primary producers, estimated with satellite data. Zooplanktonic blooming and non-blooming periods have been identified and studied separately. During the non-blooming period zooplanktonic biomass was most abundant in the upper and the deep layers, while during the blooming period the upper-layer maximum in zooplanktonic biomass disappeared and the deep layer with high zooplanktonic biomass became thicker. These two layers are likely to correspond to two different zooplanktonic communities. The evolution of zooplanktonic biomass is well correlated with chlorophyll, with phytoplankton biomass peaks preceding the upper-layer secondary production by a lag of about 3.5 weeks. Nocturnal DVM appears to be the main pattern during both periods, but reverse and twilight migration are also detected. Nocturnal DVM was more evident at mid-water than in the deep and the upper layers. DVM occurred with different intensities during blooming and non-blooming periods. One of the main outcomes is that the principal drivers for DVM are light intensity and stratification, but other factors, like the moon cycle and primary production, are also taken in consideration.
This time series has been collected by the Italian Consiglio Nazionale delle Ricerche (CNR) in a station located at about 3500 m depth in the central Tyrrhenian Sea (39° 46.85 N, 011° 53.00 E) over the period 2003-2016. The dataset contains 21 hydrological profiles (Pressure (dbar), Temperature (ITS-90, °C) and Salinity) performed on average every six months, with a lack of data in the period 2007-2010. The dataset is highly homogeneous in technical characteristics and quality, since the instrument used to collect most of the data is the same CTD probe (SBE911plus) and data quality procedures have been performed. The calibration of the probe was performed at the NATO-CMRE Centre of La Spezia up to 2014, and by the manufacturer (SeaBird) or by the Oceanographic Calibration Center of OGS in Trieste thereafter. To verify the post calibration performance of the probe, redundant sensors were often used for both temperature and salinity measurements, and on board salinity analysis of the water samples was performed using a Guideline Autosal or a Portasal salinometer. Raw data are post-processed and averaged at 1 dbar. Until 2014, the data were collected by the Italian R/V URANIA, those of 2015 by the Italian R/V MINERVA UNO, and those of 2016 by the Spanish R/V Angeles Alvarino. This is the longest time series (fourteen years) of temperature and salinity of thermohaline staircases due to double diffusion in the salt finger regime ever observed. Parameters included in the .csv data file: - Cruise name (Cruise) - Time as julian days (Time_julian day) - Latitude - Longitude - Pressure in dbar (Pressure_dbar) - Practical Salinity (Salinity) - Temperature ITS-90 in °C (Temperature_ITS-90_°C)
Project: EC | BlueBRIDGE (675680), EC | AGINFRA PLUS (731001)
The gCube Data Catalogue is a software component that provides facilities for: a) (meta)data publishing; b) vres' products publishing; c) making data products publicly available; d) enriching products of metadata to maximise their potential reuse and making them searchable (via title, tags etc) are based on the CKAN technology. The gcube-ckan-datacatalog Web Application allows to (a) show all the metadata available in the CKAN instance, as well as publish a new product, retrieve the list of organizations (i.e. Virtual Research Environments) to which the user belongs and his/her already published products.
A coordinated effort, based on observing system simulation experiments (OSSEs), has been carried out by four European ocean forecasting centers for the first time, in order to provide insights on the present and future design of the in situ Atlantic Ocean observing system from a monitoring and forecasting perspective. This multi-system approach is based on assimilating synthetic data sets, obtained by sub-sampling in space and time using an eddy-resolving unconstrained simulation, named the Nature Run. To assess the ability of a given Atlantic Ocean observing system to constrain the ocean model state, a set of assimilating experiments were performed using four global eddy-permitting systems. For each set of experiments, different designs of the in situ observing system were assimilated, such as implementing a global drifter array equipped with a thermistor chain down to 150 m depth or extending a part of the global Argo array in the deep ocean. While results from the four systems show similarities and differences, the comparison of the experiments with the Nature Run, generally demonstrates a positive impact of the different extra observation networks on the temperature and salinity fields. The spread of the multi-system simulations, combined with the sensitivity of each system to the evaluated observing networks, allowed us to discuss the robustness of the results and their dependence on the specific analysis system. By helping define and test future observing systems from an integrated observing system view, the present work is an initial step toward better-coordinated initiatives supporting the evolution of the ocean observing system and its integration within ocean monitoring and forecasting systems. Refereed 14.A Manual (incl. handbook, guide, cookbook etc) 2019-03-14