http://hdl.handle.net/2122/159 Sat, 25 May 2013 11:35:38 GMT 2013-05-25T11:35:38Z http://hdl.handle.net/2122/8665 Title: The Deep Sea and Sub-Seafloor Frontier Authors: Kopf, A.; MARUM, Univ. Bremen Leobener Strasse 28359 Bremen, Germany; Camerlenghi, A.; Istituto Nazionale di Oceanografia e di Geofisica Sperimentale (OGS), Trieste; Canals, M.; Departament d’Estratigrafia, Paleontologia i Geociències Marines de la Facultat de Geologia de la Universitat de Barcelona; Ferdelman, T.; Department of Biogeochemistry at the Max-Plank-Institute for Marine Microbiology, University of Bremen; Mevel, C.; Institut de Physique du Globe de Paris; Pälike, H.; The National Oceanography Centre, University of Southampton; Roest, W.; Unitè Gèosciences Marines Laboratoire Gèophysique et Gèodynamique Centre Bretagne - ZI de la Pointe du Diable - CS 10070 - 29280 Plouzané; Ask, M.; Rock Mechanics and Mining Engineering, 2006, Luleå University of Technology, Sweden; Barker-Jørgensen, B.; MPI for Marine Microbiology Celsiusstr. 1 D-28359 Bremen Germany; Boetius, A.; HGF-MPG Group for Deep Sea Ecology and Technology, Max Planck Institute for Marine Microbiology Celsiusstr. 1, 28359 Bremen, Germany; De Santis, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Früh-Green, G.; Inst. f. Geochemie und Petrologie, NW E 76.2, Clausiusstrasse 25, 8092 Zuerich Abstract: The deep sea and its sub-seafloor contain a vast reservoir of physical, mineral and biological resources that are rapidly coming into the window of exploitation. Assessing the opportunities and the risks involved requires a serious commitment to excellent deep sea research. There are numerous areas in this field in which Europe has cutting-edge technological potential. These include drilling and monitoring technology in the field of renewable energies such as geothermal, offshore wind and seafloor resources. Scientific ocean drilling will continue to play a valuable role, for example in the exploration of resource opportunities, in obtaining estimates for ecosystem and Earth climate sensitivity, or in improving understanding about the controlling factors governing processes and recurrence intervals of submarine geohazards. In Europe, there is also the scientific expertise needed to define a framework for policymakers for environmental protection measures and to carry out ecological impact assessments before, during and after commercial exploitation. Taking up these societal challenges will strengthen European scientific and educational networks and promote the development of world-class technology and industrial leadership. Sat, 31 Dec 2011 23:00:00 GMT http://hdl.handle.net/2122/8665 2011-12-31T23:00:00Z http://hdl.handle.net/2122/8195 Title: Impacts of natural and anthropogenic climate variations on North Pacific plankton in an Earth System Model Authors: Patara, L.; CMCC; Vichi, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Masina, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia Abstract: The impacts of natural atmospheric variability and anthropogenic climate change on the spatial distribution, seasonality, structure, and productivity of North Pacific plankton groups are investigated by means of an Earth System Model (ESM) that contains a plankton model with variable stoichiometry. The ESM is forced with observed greenhouse gases for the 20th century and with the Intergovernmental Panel on Climate Change A1B Emission Scenario for the 21st century. The impacts of the two main modes of variability – connected with the Aleutian Low (AL) strength and with the North Pacific Oscillation (NPO) – are considered. When the AL is strong, primary productivity and chlorophyll concentrations are higher in the central Pacific, the seasonality of plankton is enhanced, and the classical grazing chain is stimulated, whereas in the Alaskan Gyre the model simulates a chlorophyll decrease and a shift toward smaller phytoplankton species. A stronger NPO increases productivity and chlorophyll concentration at ∼45°N. In the anthropogenic climate change scenario, simulated sea surface temperature is 4 °C higher with respect to contemporary conditions, leading to reduced mixing and nutrient supply at middle-subpolar latitudes. The seasonal phytoplankton bloom is reduced and occurs one month earlier, the flow of carbon to the microbial loop is enhanced, and phytoplanktonic stoichiometry is nutrient-depleted. Primary productivity is enhanced at subpolar latitudes, due to increased ice-free regions and possibly to temperature-related photosynthesis stimulation. This study highlights that natural climate variability may act alternatively to strengthen or to weaken the human-induced impacts, and that in the next decades it will be difficult to distinguish between internal and external climate forcing on North Pacific plankton groups. Sat, 31 Dec 2011 23:00:00 GMT http://hdl.handle.net/2122/8195 2011-12-31T23:00:00Z http://hdl.handle.net/2122/8194 Title: Sensitivity of a marine coupled physical biogeochemical model to time resolution, integration scheme and time splitting method Authors: Butenschön, M.; University of Bologna; Zavatarelli, M.; University of Bologna; Vichi, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia Abstract: Coupled marine biogeochemical models are composed of a hydrodynamic component with a transport model for the ecological state variables and a model for the biogeochemical dynamics. The combination of these components involves the implementation of a numerical coupling method, that performs the spatial–temporal integration of the combined system, introducing an additional source of error to the system (splitting error). In this article we demonstrate the sensitivity of a comparatively complex 1D hydrodynamical biogeochemical model to the coupling method, showing that for an inadequate choice of the coupling method, the splitting error may dominate the numerical error of the system. It is demonstrated that for this type of system the tracer transport time scale clearly dominates over the scale of the biogeochemical processes, that maybe computed on significantly coarser time scales. In between the implemented coupling schemes Operator Splitting and Source Splitting, the Source Splitting method inserting the biogeochemical rates into the transport tracer integration is to be preferred for these type of models. Sat, 31 Dec 2011 23:00:00 GMT http://hdl.handle.net/2122/8194 2011-12-31T23:00:00Z http://hdl.handle.net/2122/8193 Title: Global response to solar radiation absorbed by phytoplankton in a coupled climate model Authors: Patara, L.; CMCC; Vichi, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Masina, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Fogli, P. G.; CMCC; Manzini, E.; MPI Abstract: The global climate response to solar radiation absorbed by phytoplankton is investigated by performing multi-century simulations with a coupled ocean–atmosphere-biogeochemistry model. The absorption of solar radiation by phytoplankton increases radiative heating in the near-surface ocean and raises sea surface temperature (SST) by overall ~0.5°C. The resulting increase in evaporation enhances specific atmospheric humidity by 2–5%, thereby increasing the Earth’s greenhouse effect and the atmospheric temperatures. The Hadley Cell exhibits a weakening and poleward expansion, therefore reducing cloudiness at subtropical-middle latitudes and increasing it at tropical latitudes except near the Equator. Higher SST at polar latitudes reduces sea ice cover and albedo, thereby increasing the high-latitude ocean absorption of solar radiation. Changes in the atmospheric baroclinicity cause a poleward intensification of mid-latitude westerly winds in both hemispheres. As a result, the North Atlantic Ocean meridional overturning circulation extends more northward, and the equatorward Ekman transport is enhanced in the Southern Ocean. The combination of local and dynamical processes decreases upper-ocean heat content in the Tropics and in the subpolar Southern Ocean, and increases it at middle latitudes. This study highlights the relevance of coupled ocean–atmosphere processes in the global climate response to phytoplankton solar absorption. Given that simulated impacts of phytoplankton on physical climate are within the range of natural climate variability, this study suggests the importance of phytoplankton as an internal constituent of the Earth’s climate and its potential role in participating in its long-term climate adjustments. Sat, 31 Dec 2011 23:00:00 GMT http://hdl.handle.net/2122/8193 2011-12-31T23:00:00Z http://hdl.handle.net/2122/8168 Title: Process studies on the ecological coupling between sea ice algae and phytoplankton Authors: Tedesco, L.; Marine Research Centre, Finnish Environment Institute; Vichi, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Thomas, D.; Marine Research Centre, Finnish Environment Institute Abstract: The seasonal dynamics of pelagic and sea ice communities are closely related in ice-covered waters, however, modelling works that analyse such interactions are scarce. We use the Biogeochemical Flux Model in Sea Ice (BFM-SI) coupled to the pelagic Biogeochemical Flux Model (BFM) in a study area in Greenland to quantitatively investigate: (1) the significance of photoacclimation/photoadaptation strategies of autotrophs, (2) the fate of the sea ice biomass in case of algae seeding, algae aggregation and at different mixed layer depths and (3) the changes in community production under a climate change scenario. The results show that sea ice algae need to be both photoacclimated and photoadapted to the sea ice environment in order to grow, while phytoplankton may adopt different strategies for optimising their growth. The seeding of the phytoplankton bloom shows to be driven, both in timing and magnitude, by the viability of sea ice algae and by the degree of aggregation of algae released from the ice, which also affects the sinking rate to the sea floor. Under a mild climate change scenario (SRES B2, 2071–2090) the sea ice community is projected to be generally more productive, whereas phytoplankton growth will be reduced because the melt of sea ice will occur earlier in the season when light is less favourable to sustain the growth. While it is generally anticipated that the melting of multi-year ice in the Arctic Ocean will cause an increase in marine production, this study shows that seasonal ice-covered seas in the Northern hemisphere may actually be less productive and may shift to more oligotrophic conditions within the next 100 years. Sat, 31 Dec 2011 23:00:00 GMT http://hdl.handle.net/2122/8168 2011-12-31T23:00:00Z http://hdl.handle.net/2122/7625 Title: Impact of appendicularians on detritus and export fluxes: a model approach at Dyfamed site Authors: Berline, L.; LOB; Stemman, L.; LOB; Vichi, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Lombard, F.; LOPB; Gorsky, G.; LOB Abstract: So far, the role of appendicularians in the biogeochemical cycling of organic matter has been largely overlooked. Appendicularians represent only a fraction of total mesozooplankton biomass, however these ubiquitous zooplankters have very high filtration and growth rates compared to copepods, and produce numerous fecal pellets and filtering houses contributing to export production by aggregating small marine particles. To study their quantitative impact on biogeochemical flux, we have included this group in the biogeochemical flux model, using a recently developed ecophysiological model. One-dimensional annual simulations of the pelagic ecosystem including appendicularians were conducted with realistic surface forcing for the year 2000, using data from the DyFAMed open ocean station. The appendicularian grazing impact was generally low, but appendicularians increased detritus production by 8% and export production by 55% compared to a simulation without appendicularians. Therefore, current biogeochemical models lacking appendicularians probably under, or misestimate the detritus and export production by omitting the pathway from small-sized plankton to fast sinking detritus. Detritus production and export rates are 60% lower than the estimates from mesotrophic sites, showing that appendicularians’ role is lower but still significant in oligotrophic environments. The simulated annual export at 200 m exceeds sediment trap values by 44%, suggesting an intense degradation during the sinking of appendicularian detritus, supported by observations made at other sites. Thus, degradation and grazing of appendicularian detritus need better quantification if we are to accurately assess the role of appendicularia in export flux. Fri, 31 Dec 2010 23:00:00 GMT http://hdl.handle.net/2122/7625 2010-12-31T23:00:00Z http://hdl.handle.net/2122/7104 Title: Societal need for improved understanding of climate change, anthropogenic impacts, and geo-hazard warning drive development of ocean observatories in European Seas Authors: Ruhl, H. A.; NOCS; Andrè, M.; UPC; Beranzoli, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Çagatay, M. N.; ITU; Colaço, A.; Univ. Azores; Cannat, M.; IPGP; Dañobeitia, J. J.; CSIC-UTM; Favali, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Géli, L.; IFREMER; Gillooly, M.; IMI; Greinert, J.; NIOZ; Hall, P. O. J.; Univ. Goteborg; Huber, R.; MARUM; Karstensen, J.; Univ. Kiel; Lampitt, R. S.; NOCS; Larkin, K. E.; NOCS; Lykousis, V.; HCMR; Mienert, J.; Univ. Tromsø; Miranda, J. M.; Univ. Lisboa; Person, R.; IFREMER; Priede, I. G.; Univ. Aberdeen; Puillat, I.; IFREMER; Thomsen, L.; Jacobs Univ. Bremen; Waldmann, C.; MARUM Abstract: Society’s needs for a network of in situ ocean observing systems cross many areas of earth and marine science. Here we review the science themes that benefit from data supplied from ocean observatories. Understanding from existing studies is fragmented to the extent that it lacks the coherent long-term monitoring needed to address questions at the scales essential to understand climate change and improve geo-hazard early warning. Data sets from the deep sea are particularly rare with long-term data available from only a few locations worldwide. These science areas have impacts on societal health and well-being and our awareness of ocean function in a shifting climate. Substantial efforts are underway to realise a network of open-ocean observatories around European Seas that will operate over multiple decades. Some systems are already collecting high-resolution data from surface, water column, seafloor, and sub-seafloor sensors linked to shore by satellite or cable connection in real or near-real time, along with samples and other data collected in a delayed mode. We expect that such observatories will contribute to answering major ocean science questions including: How can monitoring of factors such as seismic activity, pore fluid chemistry and pressure, and gas hydrate stability improve seismic, slope failure, and tsunami warning? What aspects of physical oceanography, biogeochemical cycling, and ecosystems will be most sensitive to climatic and anthropogenic change? What are natural versus anthropogenic changes? Most fundamentally, how are marine processes that occur at differing scales related? The development of ocean observatories provides a substantial opportunity for ocean science to evolve in Europe. Here we also describe some basic attributes of network design. Observatory networks provide the means to coordinate and integrate the collection of standardised data capable of bridging measurement scales across a dispersed area in European Seas adding needed certainty to estimates of future oceanic conditions. Observatory data can be analysed along with other data such as those from satellites, drifting floats, autonomous underwater vehicles, model analysis, and the known distribution and abundances of marine fauna in order to address some of the questions posed above. Standardised methods for information management are also becoming established to ensure better accessibility and traceability of these data sets and ultimately to increase their use for societal benefit. The connection of ocean observatory effort into larger frameworks including the Global Earth Observation System of Systems (GEOSS) and the Global Monitoring of Environment and Security (GMES) is integral to its success. It is in a greater integrated framework that the full potential of the component systems will be realised. Fri, 31 Dec 2010 23:00:00 GMT http://hdl.handle.net/2122/7104 2010-12-31T23:00:00Z http://hdl.handle.net/2122/6871 Title: Challenges of modeling depth-integrated marine primary productivity over multiple decades: A case study at BATS and HOT Authors: Saba, V.; VIMS; Friedrichs, M.A.M.; VIMS; et al.; including; Vichi, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia Abstract: The performance of 36 models (22 ocean color models and 14 biogeochemical ocean circulation models (BOGCMs)) that estimate depth-integrated marine net primary productivity (NPP) was assessed by comparing their output to in situ 14C data at the Bermuda Atlantic Time series Study (BATS) and the Hawaii Ocean Time series (HOT) over nearly two decades. Specifically, skill was assessed based on the models' ability to estimate the observed mean, variability, and trends of NPP. At both sites, more than 90% of the models underestimated mean NPP, with the average bias of the BOGCMs being nearly twice that of the ocean color models. However, the difference in overall skill between the best BOGCM and the best ocean color model at each site was not significant. Between 1989 and 2007, in situ NPP at BATS and HOT increased by an average of nearly 2% per year and was positively correlated to the North Pacific Gyre Oscillation index. The majority of ocean color models produced in situ NPP trends that were closer to the observed trends when chlorophyll-a was derived from high-performance liquid chromatography (HPLC), rather than fluorometric or SeaWiFS data. However, this was a function of time such that average trend magnitude was more accurately estimated over longer time periods. Among BOGCMs, only two individual models successfully produced an increasing NPP trend (one model at each site). We caution against the use of models to assess multiannual changes in NPP over short time periods. Ocean color model estimates of NPP trends could improve if more high quality HPLC chlorophyll-a time series were available Thu, 31 Dec 2009 23:00:00 GMT http://hdl.handle.net/2122/6871 2009-12-31T23:00:00Z http://hdl.handle.net/2122/6870 Title: A dynamic Biologically-Active Layer for numerical studies of the sea ice ecosystem. Authors: Tedesco, L.; CMCC; Vichi, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Haapala, J.; FMI; Stipa, T.; FMI Abstract: This work introduces a novel approach for the modelling and coupling of sea ice biology to sea ice physics. The central concept of the coupling is the definition of the Biologically Active Layer, which is the time-varying fraction of sea ice that is connected to the ocean via brine pockets and channels, and acts as a rich habitat for many microorganisms. A simple but comprehensive physical model of the sea ice thermohalodynamics is coupled to a novel sea ice microalgal model of growth in the framework of the Biogeochemical Flux Model. The physical model provides the key physical properties of the Biologically Active Layer and the biological model simulates the physiological and ecological response of the algal community to the physical environment. Numerical simulations of chl-a were compared with observations at two different ice stations, in the Baltic and off the coast of Greenland, showing that this new coupling structure is sufficiently generic to represent well the temporal and spatial distribution of sea ice algae during the whole ice season at both sites. This model implementation and coupling structure is viable as a new component of General Circulation Models, allowing for estimates of the role and importance of sea ice biology in the local and global carbon cycle. Thu, 31 Dec 2009 23:00:00 GMT http://hdl.handle.net/2122/6870 2009-12-31T23:00:00Z http://hdl.handle.net/2122/6175 Title: The Ligurian Sea: present status, problems and perspectives Authors: Cattaneo Vietti, R.; Dip.Te.Ris. Università degli Studi di Genova, Genoa, Italy; Albertelli, G.; Dip.Te.Ris. Università degli Studi di Genova, Genoa, Italy; Aliani, S.; CNR- ISMAR, La Spezia, Italy; Bava, S.; Area Marina Protetta di Portofino, Portofino, Italy; Bavestrello, G.; Università degli Studi di Ancona, Ancona, Italy; Benedetti Cecchi, L.; Dipartimento di Biologia, Università degli Studi di Pisa, Pisa, Italy; Bianchi, C. N.; Dip.Te.Ris. Università degli Studi di Genova, Genoa, Italy; Bozzo, E.; Dip.Te.Ris. Università degli Studi di Genova, Genoa, Italy; Capello, M.; Dip.Te.Ris. Università degli Studi di Genova, Genoa, Italy; Castellano, M.; Dip.Te.Ris. Università degli Studi di Genova, Genoa, Italy; Cerrano, C.; Dip.Te.Ris. Università degli Studi di Genova, Genoa, Italy; Chiantore, M.; Dip.Te.Ris. Università degli Studi di Genova, Genoa, Italy; Corradi, N.; Dip.Te.Ris. Università degli Studi di Genova, Genoa, Italy; Cocito, S.; ENEA, Santa Teresa, La Spezia, Italy; Cutroneo, L.; Dip.Te.Ris. Università degli Studi di Genova, Genoa, Italy; Diviacco, G.; Regione Liguria, Genoa, Italy; Fabiano, M.; Dip.Te.Ris. Università degli Studi di Genova, Genoa, Italy; Faimali, M.; CNR-ISMAR, Genoa, Italy; Ferrari, M.; Dip.Te.Ris. Università degli Studi di Genova, Genoa, Italy; Gasparini, G. P.; CNR- ISMAR, La Spezia, Italy; Locritani, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Mangialajo, L.; Dip.Te.Ris. Università degli Studi di Genova, Genoa, Italy; Marin, V.; Dip.Te.Ris. Università degli Studi di Genova, Genoa, Italy; Moreno, M.; Dip.Te.Ris. Università degli Studi di Genova, Genoa, Italy; Morri, C.; Dip.Te.Ris. Università degli Studi di Genova, Genoa, Italy; Orsi Relini, L.; Dip.Te.Ris. Università degli Studi di Genova, Genoa, Italy; Pane, L.; Dipartimento di Biologia, Università degli Studi di Genova, Genoa, Italy; Paoli, C.; Dip.Te.Ris. Università degli Studi di Genova, Genoa, Italy; Petrillo, M.; Dip.Te.Ris. Università degli Studi di Genova, Genoa, Italy; Povero, P.; Dip.Te.Ris. Università degli Studi di Genova, Genoa, Italy; Pronzato, R.; Dip.Te.Ris. Università degli Studi di Genova, Genoa, Italy; Relini, G.; Dip.Te.Ris. Università degli Studi di Genova, Genoa, Italy; Santangelo, G.; Dipartimento di Biologia, Università degli Studi di Pisa, Pisa, Italy; Tucci, S.; Dip.Te.Ris. Università degli Studi di Genova, Genoa, Italy; Tunesi, L.; ISPRA, Rome, Italy; Vacchi, M.; ISPRA, Rome, Italy; Vassallo, P.; Dip.Te.Ris. Università degli Studi di Genova, Genoa, Italy; Vezzulli, L.; Dipartimento di Biologia, Università degli Studi di Genova, Genoa, Italy; Wurtz, M.; Dipartimento di Biologia, Università degli Studi di Genova, Genoa, Italy Abstract: The Ligurian Sea is a deep basin in the northernmost sector of the western Mediterranean which shows peculiar hydrodynamic and meteo-oceanographic features. The coasts of the Ligurian Sea are among the most urbanised and industrialised along the Italian coastline: the main causes of disturbance being littoral urban development and harbour activities, the building of littoral rail- and highways, and the presence of several polluted discharges. This review, by evaluating the huge scientific output published in the last three decades, describes and discusses the most important geological, hydrological and biological characteristics of the Ligurian Sea.We show that this regional sea has largely been investigated in terms of its geological and structural evolution, as well as in terms of the sedimentation dynamics of the littoral and deep bottoms, with particular attention to the sedimentation balance of the beaches and their erosive processes.We report that the prevalent hydrodynamic and meteo-oceanographic conditions favour a continuous exchange of coastal water masses, and that the seasonal and interannual dynamics of water masses can effects the local climate, with direct and indirect consequences on fish and benthic communities documented in the last decade. We stress that although recent studies offer good knowledge of the distribution of coastal benthic communities, only scant information is available for the whole continental shelf, the submarine canyons and the rocky bathyal bottoms. Our meta-analysis reveals that significant fishing activities are monitored, but also that certain sectors of the biological resource are suffering, and suggests the set up of appropriate management measures. The Ligurian Sea hosts a number of Marine Protected Areas (MPAs) of high relevance, while the institution of the Whale Sanctuary completes the protection policy of the Regione Liguria. Our meta-analysis points out the need for long-term studies, based primarily on the analysis of those areas of the Ligurian Sea that have been little investigated to date. Finally, only properly addressed studies, using experimental approaches and along appropriate spatial and temporal scales, might allow us to understand the functioning of the Ligurian marine ecosystems, evaluate their health conditions and the dynamics of the main variables that affect the distribution of the single species (including species of high economic value) and benthic communities. Mon, 31 May 2010 22:00:00 GMT http://hdl.handle.net/2122/6175 2010-05-31T22:00:00Z