Changes in column inventories of carbon and oxygen in the Atlantic Ocean

Increasing concentrations of dissolved inorganic carbon (DIC) in the interior ocean are expected as a direct consequence of increasing concentrations of CO<sub>2</sub> in the atmosphere. This extra DIC is often referred to as anthropogenic carbon (C<sub>ant</sub>), and its inventory, or increase rate, in the interior ocean has previously been estimated by a multitude of observational approaches. Each of these methods is associated with hard to test assumptions since C<sub>ant</sub> cannot be directly observed. Results from a simpler concept with fewer assumptions applied to the Atlantic Ocean are reported on here using two large data collections of carbon relevant bottle data. The change in column inventory on decadal time scales, i.e. the storage rate, of DIC, respiration compensated DIC and oxygen is calculated for the Atlantic Ocean. We report storage rates and the confidence intervals of the mean trend at the 95% level (CI), reflecting the mean trend but not considering potential biasing effects of the spatial and temporal sampling. For the whole Atlantic Ocean the mean trends for DIC and oxygen are non-zero at the 95% confidence level: DIC: 0.86 (CI: 0.72–1.00) and oxygen: −0.24 (CI: −0.41–(−0.07)) mol m<sup>−2</sup> yr<sup>−1</sup>. For oxygen, the whole Atlantic trend is dominated by the subpolar North Atlantic, whereas for other regions the O<sub>2</sub> trends are not significant. The storage rates are similar to changes found by other studies, although with large uncertainty. For the subpolar North Atlantic the storage rates show significant temporal and regional variation of all variables. This seems to be due to variations in the prevalence of subsurface water masses with different DIC and oxygen concentrations leading to sometimes different signs of storage rates for DIC compared to published C<sub>ant</sub> estimates. This study suggest that accurate assessment of the uptake of CO<sub>2</sub> by the oceans will require accounting not only for processes that influence C<sub>ant</sub> but also additional processes that modify CO<sub>2</sub> storage

Lukion päättävän nuoren valmius tehdä koulutustaan ja uravalintaansa koskevia päätöksiä

Tiivistelmä. Tässä kandidaatintutkielmassa käsittelen nuoren valmiuksia tehdä koulutus- ja työuraansa koskevia valintoja, sekä tasa-arvon ongelmia korkeakoulutukseen hakeutumisessa. Opetus- ja kulttuuriministeriö aloittivat yhdessä korkeakoulujen kanssa hankkeen nopeuttaa korkeakouluun ja työelämään siirtymistä. Yhtenä hankkeen osa-alueena korkeakoulujen tulee kehittää opiskelijavalintoja niin, että vuoteen 2018 mennessä pitkää valmistautumista vaativista valintakokeista on luovuttu, ja vuoteen 2020 mennessä korkeakoulujen tulee lisätä suoravalintaa niin, että nykyistä merkittävästi suurempi osa hakijoista saa koulutuspaikan suoraan ylioppilastutkinnon arvosanojen perusteella. Tarkastelen kandidaatintutkielmassani, miten ylioppilastutkinnon painottaminen korkeakoulujen opiskelijavalinnassa siirtää painetta yhä aikaisempaan vaiheeseen nuoruutta, jolloin nuoren pitäisi jo lukion, tai jopa peruskoulun viimeisten luokkien aikana, pyrkiä tekemään koulutusalaansa ja sitä kautta uravalintaansa koskevia päätöksiä. Tarkastelen psykologisten teorioiden valossa, millaiset ovat nuorella valmiudet, jotta hän pystyisi näitä valintoja tehdä. Kandidaatintutkielmassani käsittelen lisäksi valintakokeiden muutosta ja miten se vaikuttaa eri taustaisten hakijoiden asemaan. Korkeakoulupaikoista on kova kilpailu, joten on ensiarvoisen tärkeää, että hakijat tulevat kohdelluksi tasa-arvoisesti. Toteutan kandidaatintutkielmani kirjallisuuskatsauksena. Johtopäätöksenä esitetään, että ylioppilastutkinnon arvosanojen painottaminen korkeakouluun haettaessa siirtää painetta tehdä ratkaisevia päätöksiä yhä aikaisempaan vaiheeseen. Nuoruudessa ajatuksen kehitys on vielä kesken ja tulevaisuus voidaan nähdä epävarmana, mutta paine tehdä tulevaisuuden kannalta merkittäviä valintoja on siirtymässä jo peruskoulun ylimmille luokille, sekä lukioon

Isotopic evidence for biogenic molecular hydrogen production in the Atlantic Ocean

Oceans are a net source of molecular hydrogen (H2) to the atmosphere. The production of marine H2 is assumed to be mainly biological by N2 fixation, but photochemical pathways are also discussed. We present measurements of mole fraction and isotopic composition of dissolved and atmospheric H2 from the southern and northern Atlantic between 2008 and 2010. In total almost 400 samples were taken during five cruises along a transect between Punta Arenas (Chile) and Bremerhaven (Germany), as well as at the coast of Mauretania. The isotopic source signatures of dissolved H2 extracted from surface water are highly deuterium-depleted and correlate negatively with temperature, showing δD values of (−629 ± 54) ‰ for water temperatures at (27 ± 3) °C and (−249 ± 88) ‰ below (19 ± 1) °C. The results for warmer water masses are consistent with biological production of H2. This is the first time that marine H2 excess has been directly attributed to biological production by isotope measurements. However, the isotope values obtained in the colder water masses indicate that beside possible biological production a significant different source should be considered. The atmospheric measurements show distinct differences between both hemispheres as well as between seasons. Results from the global chemistry transport model TM5 reproduce the measured H2 mole fractions and isotopic composition well. The climatological global oceanic emissions from the GEMS database are in line with our data and previously published flux calculations. The good agreement between measurements and model results demonstrates that both the magnitude and the isotopic signature of the main components of the marine H2 cycle are in general adequately represented in current atmospheric models despite a proposed source different from biological production or a substantial underestimation of nitrogen fixation by several authors

Tracer Applications of Noble Gas Radionuclides in the Geosciences

The noble gas radionuclides, including 81Kr (half-life = 229,000 yr), 85Kr (11 yr), and 39Ar (269 yr), possess nearly ideal chemical and physical properties for studies of earth and environmental processes. Recent advances in Atom Trap Trace Analysis (ATTA), a laser-based atom counting method, have enabled routine measurements of the radiokrypton isotopes, as well as the demonstration of the ability to measure 39Ar in environmental samples. Here we provide an overview of the ATTA technique, and a survey of recent progress made in several laboratories worldwide. We review the application of noble gas radionuclides in the geosciences and discuss how ATTA can help advance these fields, specifically determination of groundwater residence times using 81Kr, 85Kr, and 39Ar; dating old glacial ice using 81Kr; and an 39Ar survey of the main water masses of the oceans, to study circulation pathways and estimate mean residence times. Other scientific questions involving deeper circulation of fluids in the Earth's crust and mantle also are within the scope of future applications. We conclude that the geoscience community would greatly benefit from an ATTA facility dedicated to this field, with instrumentation for routine measurements, as well as for research on further development of ATTA methods

Temporal nutrient dynamics in the Mediterranean Sea in response to anthropogenic inputs

The temporal dynamics of the concentrations of nitrate (N), phosphate (P), and the N: P ratio in the upper water column (200-600 m) of the Mediterranean (MED) Sea were investigated using observational data (similar to 123,100 data points) collected between 1985 and 2014. The studied variables were found to evolve similarly in the western and easternMED Sea. In both basins, the N concentration increased during the first part of the observational period (1985-1998), and the temporal trend of N was broadly consistent with the history of riverine and atmospheric nitrogen input from populated areas in Europe, with a lag period of 20 years. In subsequent years, the N concentration was high and relatively constant between 1998 and 2005, after which N decreased gradually, although the decreasing trend was indistinct in the western basin. In particular, the trend of constant then declining N after 1998 is consistent with the history of pollutant nitrogen emissions from the European continent, allowing a 20 year lag following the introduction of regulation of pollutant nitrogen in the 1970s. The three-phase temporal transition in P in both basins was more consistent with the riverine phosphorus input, with a lag period of 20 years. Our analysis indicates that the recent dynamics of N and P in the upper MED Sea has been sensitive to the dynamics of anthropogenic nitrogen and phosphorus input from atmospheric deposition and rivers.1132Ysciescopu

Supporting cross-domain system-level environmental and earth science

Answering the key challenges for society due to environmental issues like climate change, pollution and loss of biodiversity, and making the right decisions to tackle these in a cost-efficient and sustainable way requires scientific understanding of the Earth System. This scientific knowledge can then be used to inform the general public and policymakers. Scientific understanding starts with having available the right data, often in the form of observations. Research Infrastructures (RIs) exist to perform these observations in the required quality and to make the data available to first of all the researchers. In the current Big Data era, the increasing challenge is to provide the data in an interoperable and machine-readable and understandable form. The European RIs on environment formed a project cluster called ENVRI that tackles these issues. In this chapter, we introduce the societal relevance of the environmental data produced by the RIs and discuss the issues at hand in providing the relevant data according to the so-called FAIR principles

GO-SHIP Repeat Hydrography Nutrient Manual: The Precise and Accurate Determination of Dissolved Inorganic Nutrients in Seawater, Using Continuous Flow Analysis Methods

The GO-SHIP nutrient manual covers all aspects of nutrient analysis from basic sample collection and storage, specifically for Continuous Flow analysis using an Auto-Analyzer, and describes some specific nutrient methods for Nitrate, Nitrite, Silicate, Phosphate and Ammonium that are in use by many laboratories carrying out at-sea analysis and repeat hydrography sections across the world. The focus is on segmented flow analyzers not flow injection analyzers. It also covers laboratory best practices including quality control and quality assurance (QC/QA) procedures to obtain the best results, and suggests protocols for the use of reference materials (RM) and certified reference materials (CRMs)

Consistency of cruise data of the CARINA database in the Atlantic sector of the Southern Ocean

Initially a North Atlantic project, the CARINA carbon synthesis was extended to include the Southern Ocean. Carbon and relevant hydrographic and geochemical ancillary data from cruises all across the Arctic Mediterranean Seas, Atlantic and Southern Ocean were released to the public and merged into a new database as part of the CARINA synthesis effort. Of a total of 188 cruises, 37 cruises are part of the Southern Ocean, including 11 from the Atlantic sector. The variables from all Southern Ocean cruises, including dissolved inorganic carbon (TCO2), total alkalinity, oxygen, nitrate, phosphate and silicate, were examined for cruise-to-cruise consistency in one collective effort. Seawater pH and chlorofluorocarbons (CFCs) are also part of the database, but the pH quality control (QC) is described in another Earth System Science Data publication, while the complexity of the Southern Ocean physics and biogeochemistry prevented a proper QC analysis of the CFCs. The area-specific procedures of quality control, including crossover analysis between stations and inversion analysis of all crossover data (i.e. secondary QC), are briefly described here for the Atlantic sector of the Southern Ocean. Data from an existing, quality controlled database (GLODAP) were used as a reference for our computations – however, the reference data were included into the analysis without applying the recommended GLODAP adjustments so the corrections could be independently verified. The outcome of this effort is an internally consistent, high-quality carbon data set for all cruises, including the reference cruises. The suggested corrections by the inversion analysis were allowed to vary within a fixed envelope, thus accounting for natural variability. The percentage of cruises adjusted ranged from 31% (for nitrate) to 54% (for phosphate) depending on the variable

The CARIMED (CARbon IN the MEDiterranean Sea) data synthesis initiative: overview and quality control procedures

posterIn this work we present the data synthesis project CARIMED (CARbon in the MEDiterranean Sea), we aim to create a uniformly formatted consistent quality controlled public database for carbon relevant variables from hydrographic cruises covering the whole water column and the different basins in the MedSea. Both primary and secondary quality control (QC) of the data has been performed following the experience gathered in CARINA and GLODAPv2. The motivation for this initiative stemmed from two CIESM (Mediterranean Science Commission) workshops, the first one in Menton (France) October 2008 (CIESM, 2008) focused on the impact of OA on biological, chemical and physical systems in the MedSea, and the second one in Supetar (Croatia) May 2011 (CIESM, 2012) focused on designing the Mediterranean Sea repeat hydrography program (MED-SHIP). The unresolved issues regarding the CO2 system in the MedSea were summarized in Malanotte-Rizzoli et al. (Oc Sc, 2014), one of them the temporal and spatial variability of the interior CO2 system, clearly justifies the need for CARIMED. Independently two projects focused on compiling CO2 water column data in the MedSea, an initiative within the EU MedSeA project (Gemayel et al., ESD 2015) called MEDICA (T. Lovato personal communication) and the one here presented lead by the Spanish IEO and partially funded by SanLeón-Bartolomé 's PhD project. We hope a product like this will be much welcome by the oceanographic community, both observationist and modellers, as it was the release of the Meteor cruise M84/3 data in CDIAC used in several publications (Palmieri et al., BG 2015; Cossarini et al., BG 2015; Hassoun et al., DSR 2015 & JWROS 2015; Lovato & Vichi, DSR 2015; Gemayel et al., ESD 2015)