Abstract: Charge-Coupled Device (CCD) and Array Pixel Sensors (APS) can be used to image radiation-induced energy deposition. The high sensitivity of depleted silicon to ionizing radiation constitutes an opportunity to investigate radiation effects while it is a nuisance to astronomer activities. CCD and APS provide a better combination of spatial and intensity resolution for radiation events than other available types of detector. This paper proposes to analyze radiation events observed in the CCD camera and more specifically analyses of charge deposition spectra and spatially extensive events. Measurements were performed in the Pic du Midi from 2011 to 2015 and in the Concordia Antarctica station since 2018. Coupled transport models (i.e. particle transport and charge transport in semiconductors) allow investigating contributions to charge collection spectra as a function of the particle nature, i.e. neutron, proton and muon. Coupled measurements and simulations allow to access to the detected secondary CR flux and the charge deposition pattern. Results showed that high charge level events seen on atmospheric sites can be considered as hadronic component (mainly neutrons and protons) while low charge levels and punctual events are induced by muons which are able to generate up to 3 fC in the CCD camera. Hence, thanks to double level of measurement sites, muon discrimination from other secondary particles has been investigated. Cross-comparison analyses based on CCD and neutron spectrometers operated in both station/observatory investigate secondary CR dynamic.

Abstract: Fisheries modify prey availability for marine predators by extracting resources but also by providing them with new feeding opportunities. Among these, depredation, which occurs when predators feed on fish caught on fishing gear, is a behavior developed by many species as a way to acquire food through limited foraging effort. However, the extent to which depredated resources from fisheries contribute to the energetic requirements and affect the demography of depredating individuals is unknown. We investigated the contribution of Patagonian toothfish Dissostichus eleginoides depredated on longlines to the energetic requirements of killer whales Orcinus orca around the Crozet Islands (southern Indian Ocean) over the period 2007-2018. Our results indicate that during days when depredation occurred, depredating individuals fulfilled on average 94.1% of their daily energetic requirements with depredated toothfish. However, the contribution varied from 1.2 to 13.3% of the monthly energetic requirements and from 2.4 to 8.8% of the yearly energetic requirements of the total population. Together, these findings suggest that intake of depredated toothfish can be substantial at a fine scale (daily and individually), potentially leading to temporary provisioning effects and changes in predation pressures. These effects become minor (<10%), however, when considering the full population over a whole year. The contribution of depredated fish to the annual energetic requirements of the population has increased in recent years, likely due to larger fishing quotas and greater opportunities for whales to depredate, which stresses the importance of accounting for depredation in ecosystem-based management of fishing activity.

Abstract: The accurate prediction of tides is vital for the operation of many industries, early warning of coastal flooding and scientific understanding of ocean processes. In this paper, we describe the creation method of a global dataset of tidal harmonics using NEMO (Nucleus for European Modelling of the Ocean) for the first time and an offline objective analysis scheme. Data are assimilated as part of a post-processing step, reducing the computational resources required. A reduced ensemble of tidal harmonics is generated, where each member is run for a shorter period of time than a central background state. This ensemble is used to estimate a single background covariance state, which is used for analysis. Output is validated using an ensemble of objective analyses. For each ensemble member, random selections of observations are omitted and validation is performed at these locations. Improvements in both Mean Absolute Error (MAE) and correlation coefficients (R2) are seen across all 6 of the largest diurnal and semi-diurnal constituents. MAEs in amplitude and phase are reduced by up to 78% and 89%, respectively, and correlations by as much as 0.14. In addition, the majority of locations (between 70 and 80%) see significant improvement.