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Momarsat 2022 cruise report: summary of dives and operations, and position of moorings and observation infrastructures and sampling locations

The tropical Angolan upwelling system is a highly productive ecosystem with a distinct seasonal cycle in surface temperature and primary production. The lowest sea surface temperature, strongest cross-shore temperature gradient, and maximum productivity occur in austral winter when seasonally prevailing upwelling favorable winds are weakest. A multi cruise dataset of microstructure profiles collected between 2013 and 2022 in the tropical Angolan upwelling system was used to analyze the importance of mixing for cooling of the mixed layer. The data were collected during six cruises on board of the R/V Meteor. The results show that cooling due to turbulent heat fluxes at the base of the mixed layer is an important cooling term. This turbulent cooling, that is strongest in shallow shelf regions, is capable of explaining the observed negative cross-shore temperature gradient.

Three high resolution multicore records have been collected at three sites in the western Mediterranean with a MC400-Multicorer system during the MedSeA cruise (Mediterranean Sea Acidification in a changing climate) on 2 May to 2 June 2013 onboard the R/V Angeles Álvarino. Core MedSeA-S3-c1 was retrieved in the Alboran basin (Lat. 36.0746° N, Long. 04.11040° W) at a water depth of 1137 m, with a core length of 33 cm. Core MedSeA-S23-c1 was recovered at a water depth of 1156 m in the Balearic basin offshore Barcelona (Lat. 41.1121° N, Long. 2.38200° E) with a core length of 43 cm. MedSeA-S7-c2 was collected at the Strait of Sicily (Lat. 37.7080° N, Long. 12.40553° E) at a water depth of 263 m, with a core length of 46.5 cm. All three cores have been analyzed for changes in size normalized weight (SNW) and stable carbon isotopes (δ13C), measured in planktic foraminiferal clacite shells of the two species Globigerina bulloides and Globigerinoides elongatus. Boron (δ11B) isotopes have been measured in tests of Globigerinoides elongatus at the Alboran site, and in Globigerinoides ruber albus at the Strait of Sicily. Complementary data for the Strait of Sicily record has been obtained, including a 210Pb based age depth model, sea surface temperatures (SST), alkenone concentrations and planktic foraminiferal assemblage changes. The Strait of Sicily record (MedSeA-S7-c2) covers around the last 200 a, describing environmental changes throughout the Industrial Era (IE) at high temporal resolution. The Alboran (MedSeA-S3-c1) and Balearic Sea (MedSeA-S23-c1) records spanning the last about 1 ka at lower temporal resolution, displaying oceanographic changes throughout the transition from the pre-industrial era to present, as discussed in (Pallacks et al., 2021; doi:10.1016/j.gloplacha.2021.103549). Data has been collected to investigate the response of marine calcifiers to the combined effects of climate change stressors on decadal to centennial timescales, caused by anthropogenic CO2 emissions.

A pesar del gran interés ecológico y económico que tiene el mero (Epinephelus marginatus), y el importante esfuerzo investigador realizado desde los años 90, no se han definido las condiciones para su óptimo engorde en cautividad. En general, las mejores condiciones de cultivo son las que proporcionan un ambiente similar al existente en el medio natural, y en el mero, estas condiciones estarían relacionadas con sus hábitos sedentarios, que al ocupar cuevas en el fondo, le permitiría destinar gran parte de la energía adquirida a crecimiento. Las diferentes condiciones de cultivo ensayadas en este estudio muestran que la presencia de refugios (CR) no mejoró el engorde respecto al cultivo sin refugios (SR), mientras que el grupo cultivado en jaula (JAU) mostró el menor peso medio a lo largo del estudio, con 123,1±67,5 g a los 645 días de edad (DDE), frente a SR y CR, que fueron similares, pero con una mayor dispersión en los peces CR (151,6±42,3 g y 164,7±84,6 g, respectivamente). El aumento del diámetro del refugio (225 DDE) y la retirada de la jaula (400 DDE) mejoraron los parámetros de engorde, aumentando el peso un 62% frente al 29% del periodo previo, y un 47% a 530 DDE respecto al 12% del periodo previo, respectivamente, pero no disminuyó la dispersión. La falta de refugios no perjudicó el engorde respecto a su presencia, mientras que el cultivo en jaula requiere un suministro de alimento mejorado.

El cultivo de Seriola dumerili constituye una opción a la diversificación y crecimiento de la producción de peces marinos, que aprovecharía, además, los sistemas de producción e instalaciones en el mar comúnmente usadas para especies como Sparus aurata. Sin embargo, este crecimiento podría estar amenazado por las patologías especificas e inespecíficas de ambas especies, principalmente las causadas por ectoparásitos. Este estudio muestra, en grupos de dorada (GD), seriola (GS) y dorada y seriola juntas (GDS-GSD), una evolución estable del número de huevos de Zeuxapta seriolae (GS: 35±10, y GDS-GSD: 67±24) y de Sparicotyle chrysophrii (GD: 59±10, y GDS-GSD: 22±4), mientras que los huevos de Neobebedenia melleni colectados en GS (2483±364) y GDS-GSD (3168±474) fueron entre un 15 y 20% más altos que en GD (508±100). No se encontraron diferencias en el hematocrito, glucosa, proteína, colesterol y triglicéridos de cada especie cultivada sola o de forma conjunta durante el estudio, pero los niveles de glucosa plasmática en seriola fueron un 50% más altos, y el colesterol un 30% más bajo que en la dorada.

Despite the current high level of safety and the efforts to make passenger ships resilient to most fire and flooding scenarios, there are still gaps and challenges in the marine emergency response and ship evacuation processes. Those challenges arise from the fact that both processes are complex, multi-variable problems that rely on parameters involving not only people and technology but also procedural and managerial issues. SafePASS Project, funded under EU’s Horizon 2020 Research and Innovation Programme, is set to radically redefine the evacuation processes by introducing new equipment, expanding the capabilities of legacy systems on-board, proposing new Life-Saving Appliances and ship layouts, and challenging the current international regulations, hence reducing the uncertainty, and increasing the efficiency in all the stages of ship evacuation and abandonment process.

We combine consistently dated benthic carbon isotopic records distributed over the entire Atlantic Ocean with numerical simulations performed by a glacial configuration of the Norwegian Earth System Model with active ocean biogeochemistry, in order to interpret the observed Cibicides δ13C changes at the stadial-interstadial transition corresponding to the end of Heinrich Stadial 4 (HS4) in terms of ocean circulation and remineralization changes. We show that the marked increase in Cibicides δ13C observed at the end of HS4 between ~2000 and 4200 m in the Atlantic can be explained by changes in nutrient concentrations as simulated by the model in response to the halting of freshwater input in the high latitude glacial North Atlantic. Our model results show that this Cibicides δ13C signal is associated with changes in the ratio of southern-sourced (SSW) versus northern-sourced (NSW) water masses at the core sites, whereby SSW is replaced by NSW as a consequence of the resumption of deep water formation in the northern North Atlantic and Nordic Seas after the freshwater input is halted. Our results further suggest that the contribution of ocean circulation changes to this signal increases from ~40 % at 2000 m to ~80 % at 4000 m. Below ~4200 m, the model shows little ocean circulation change but an increase in remineralization across the transition marking the end of HS4. The simulated lower remineralization during stadials than interstadials is particularly pronounced in deep subantarctic sites, in agreement with the decrease in the export production of carbon to the deep Southern Ocean during stadials found in previous studies.

Tropospheric ozone (O3) concentrations depend on a combination of hemispheric, regional, and local-scale processes. Estimates of how much O3 is produced locally vs. transported from further afield are essential in air quality management and regulatory policies. Here, a tagged-ozone mechanism within the Weather Research and Forecasting model coupled with chemistry (WRF-Chem) is used to quantify the contributions to surface O3 in the UK from anthropogenic nitrogen oxide (NOx) emissions from inside and outside the UK during May–August 2015. The contribution of the different source regions to three regulatory O3 metrics is also examined. It is shown that model simulations predict the concentration and spatial distribution of surface O3 with a domain-wide mean bias of −3.7 ppbv. Anthropogenic NOx emissions from the UK and Europe account for 13 % and 16 %, respectively, of the monthly mean surface O3 in the UK, as the majority (71 %) of O3 originates from the hemispheric background. Hemispheric O3 contributes the most to concentrations in the north and the west of the UK with peaks in May, whereas European and UK contributions are most significant in the east, south-east, and London, i.e. the UK's most populated areas, intensifying towards June and July. Moreover, O3 from European sources is generally transported to the UK rather than produced in situ. It is demonstrated that more stringent emission controls over continental Europe, particularly in western Europe, would be necessary to improve the health-related metric MDA8 O3 above 50 and 60 ppbv. Emission controls over larger areas, such as the Northern Hemisphere, are instead required to lessen the impacts on ecosystems as quantified by the AOT40 metric.

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.

Greenland ice cores provide information about past climate. Few impurity records covering the past 2 decades exist from Greenland. Here we present results from six firn cores obtained during a 426 km long northern Greenland traverse made in 2015 between the NEEM and the EGRIP deep-drilling stations situated on the western side and eastern side of the Greenland ice sheet, respectively. The cores (9 to 14 m long) are analyzed for chemical impurities and cover time spans of 18 to 53 years (±3 years) depending on local snow accumulation that decreases from west to east. The high temporal resolution allows for annual layers and seasons to be resolved. Insoluble dust, ammonium, and calcium concentrations in the six firn cores overlap, and the seasonal cycles are also similar in timing and magnitude across sites, while peroxide (H2O2) and conductivity both have spatial variations, H2O2 driven by the accumulation pattern, and conductivity likely influenced by sea salt. Overall, we determine a rather constant dust flux over the period, but in the data from recent years (1998–2015) we identify an increase in large dust particles that we ascribe to an activation of local Greenland sources. We observe an expected increase in acidity and conductivity in the mid-1970s as a result of anthropogenic emissions, followed by a decrease due to mitigation. Several volcanic horizons identified in the conductivity and acidity records can be associated with eruptions in Iceland and in the Barents Sea region. From a composite ammonium record we obtain a robust forest fire proxy associated primarily with Canadian forest fires (R=0.49).