A 3D finite-volume integral boundary layer method for icing applications

A three-dimensional integral boundary layer code was developed to allow fast computations of boundary layer flows for the purpose of ice accretion modelling. The model is derived in this paper. It is based on a surface Finite-Volume approach. The unsteady equations of momentum deficit and kinetic energy deficit are solved until convergence is reached, preventing from specifying explicitly the stagnation point or separation line. A validation of the code is also presented in the present article. First, the 3D solver is cross-checked against a 2D solver on test cases of self-similar flows and on a NACA0012 configuration. The modelling of the effects of three-dimensionality is also assessed on a self-similar flow test-case. Moreover, the use of unstructured grids is also validated. Finally, an example of the use of the code for the computation of ice accretion is presented

Sea surface temperature and salinity seasonal changes in the western Solomon and Bismarck Seas

We analyze mean and seasonal change of Sea Surface Temperature (SST) and Salinity (SSS) in the Solomon and Bismarck Seas, using 1977-2009 in situ data collected from Voluntary Observing Ships. Covariability of these two variables with surface wind, altimeter-derived and model-derived horizontal currents, precipitation, and Sepik River discharge are examined. SST and SSS show large annual oscillations in the Solomon Sea, with the coldest and saltiest waters occurring in July/August mainly due to horizontal advection. In contrast, they show large semiannual oscillations in the Bismarck Sea. There, the coldest and saltiest waters happen in January/February, when the northwest monsoon winds drive coastal upwelling, and in July/August, when the New Guinea Coastal Current advects cold and high-salinity waters from the Solomon Sea through Vitiaz Strait. The low SSS values observed in April/May, stuck between the January/February and July/August SSS maxima, are further enhanced by the Sepik River discharge annual maximum. A high-resolution model strengthens the conclusions we derive from observations. The impacts of ENSO on SST and SSS are also discussed with, for instance, saltier-than-average and fresher-than-average waters during the 2002-2003 El Nino and 2007-2008 La Nina, respectively

Abnormal features of Macoma balthica (Bivalvia) in the Baltic Sea: alerting symptoms of environmental adversity?

Recent studies of the Baltic clam Macoma balthica (L.) from the southern Baltic (the Gulf of Gdansk) have revealed striking morphological, histological and cytogenetic features. Strong deformation of the shell, including elongation of the posterior end and the appearance of an easily visible flexure in this part, has been recorded. The population contribution of the deformed blunt shelled ("irregular") clams ranged from 0% to 65% and tended to increase with depth. The morphologically "irregular" clams had higher accumulated tissue concentrations of trace metals (As, Ag, Cd, Pb, Cu and Zn), indicating a different metal handling ability. Adverse conditions in deeper water regions of the Gulf (e.g. hypoxia, hydrogen sulphide, elevated bioavailability of contaminants) have been suggested as inducers of the phenotypical changes (morphological deformation) in part of the population and, in parallel, of the specific physiological adaptations that result in higher metal accumulation in the "irregular" clams. Cytogenetic and histological analyses showed the presence of tumours in gill cells and digestive system of the affected clams, the prevalence of disseminated neoplasia ranging from 0% to 94% depending on the site. The disease was manifested by a modified karyotype (i.e. an abnormal number and morphology of chromosomes), a higher activity of nucleolar organizer regions (AgNORs), and tissue lesions (enlarged cells, actively proliferative with pleomorphic nuclei). Bottom sediments showed acute toxi [KEYWORDS: Abnormal features; Macoma balthica; Southern Baltic sea; Environmental adversity]

The ‘Coral Bulker’ Fuel Oil Spill on the North Coast of Portugal: Spatial and Temporal Biomarker Responses in Mytilus galloprovincialis

In December 2000, the ship ‘Coral Bulker’ ran aground at the entrance of the port of Viana do Castelo (North–west coast of Portugal). A large amount of fuel oil was spilled and part of it reached the shore. To evaluate the spatial and temporal impact of this oil spill, a field study, and several laboratory toxicity tests were performed using Mytilus galloprovincialis as biological indicator of environmental contamination and the biomarkers glutathione S-transferases (GSTs) and acetylcholinesterase (AChE) as indicative criteria. Fifteen days after the oil spill, mussels collected at stations located near the ship presented higher and lower values of GSTs and AChE activity, respectively. These results, and those obtained in the laboratory toxicity tests, evidence that these biomarkers were sensitive indicators of exposure to this kind of pollution and were able to monitor a spatial impact of the oil spill of at least 10 km, confirming the higher level of contamination near the ship and a contamination gradient along the sampling stations. One year after the accident, such a contamination gradient was no longer evident. This study highlight the potential suitability of a biomarker approach for assessing spatial and temporal impacts of marine pollution accidents, such as fuel oil spills, suggesting the inclusion of these biomarkers in risk assessment studies, as cost-effective and early warning recognized tools. Major advantages and limitations of the biomarker approach used in this study are further discussed