Noise rectification in quasigeostrophic forced turbulence

We study the appearance of large scale mean motion sustained by stochastic forcing on a rotating fluid (in the quasigeostrophic approximation) flowing over topography. As in other noise rectification phenomena, the effect requires nonlinearity and absence of detailed balance to occur. By application of an analytical coarse graining procedure we identify the physical mechanism producing such effect: It is a forcing coming from the small scales that manifests in a change in the effective viscosity operator and in the effective noise statistical properties.Comment: 4 pages revtex, including 5 figures. Related material at http://www.imedea.uib.es/Nonlinear and http://www.imedea.uib.es/Oceanography Figure 4 replaced by a slightly better on

Mesoscale subduction at the Almeria-Oran front. Part 1: ageostrophic flow

This paper presents a detailed diagnostic analysis of hydrographic and current meter data from three, rapidly repeated, fine-scale surveys of the Almeria-Oran front. Instability of the frontal boundary, between surface waters of Atlantic and Mediterranean origin, is shown to provide a mechanism for significant heat transfer from the surface layers to the deep ocean in winter. The data were collected during the second observational phase of the EU funded OMEGA project on RRS Discovery cruise 224 during December 1996. High resolution hydrographic measurements using the towed undulating CTD vehicle, SeaSoar,. traced the subduction of Mediterranean Surface Water across the Almeria-Oran front. This subduction is shown to result from a significant baroclinic component to the instability of the frontal jet. The Q-vector formulation of the omega equation is combined with a scale analysis to quantitatively diagnose vertical transport resulting from mesoscale ageostrophic circulation. The analyses are presented and discussed in the presence of satellite and airborne remotely sensed data; which provide the basis for a thorough and novel approach to the determination of observational error

Coupled atmosphere-ocean-wave simulations of a storm event over the Gulf of Lion and Balearic Sea

Author Posting. © American Geophysical Union, 2012. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 117 (2012): C09019, doi:10.1029/2012JC007924.The coastal areas of the North-Western Mediterranean Sea are one of the most challenging places for ocean forecasting. This region is exposed to severe storms events that are of short duration. During these events, significant air-sea interactions, strong winds and large sea-state can have catastrophic consequences in the coastal areas. To investigate these air-sea interactions and the oceanic response to such events, we implemented the Coupled Ocean-Atmosphere-Wave-Sediment Transport Modeling System simulating a severe storm in the Mediterranean Sea that occurred in May 2010. During this event, wind speed reached up to 25 m.s−1 inducing significant sea surface cooling (up to 2°C) over the Gulf of Lion (GoL) and along the storm track, and generating surface waves with a significant height of 6 m. It is shown that the event, associated with a cyclogenesis between the Balearic Islands and the GoL, is relatively well reproduced by the coupled system. A surface heat budget analysis showed that ocean vertical mixing was a major contributor to the cooling tendency along the storm track and in the GoL where turbulent heat fluxes also played an important role. Sensitivity experiments on the ocean-atmosphere coupling suggested that the coupled system is sensitive to the momentum flux parameterization as well as air-sea and air-wave coupling. Comparisons with available atmospheric and oceanic observations showed that the use of the fully coupled system provides the most skillful simulation, illustrating the benefit of using a fully coupled ocean-atmosphere–wave model for the assessment of these storm events.This work has been partially supported by MyOcean2 EU funded project 283367 whose support is gratefully acknowledged.2013-03-1

Fueling Plankton Production By a Meandering Frontal Jet: A Case Study For The Alboran Sea (Western Mediterranean)

A three dimensional biophysical model is employed to investigate the biological impacts of a meandering frontal jet for which the Alboran Sea of the Western Mediterranean is considered as a case study. The jet is characterized by relatively low density Atlantic water mass issuing from the Gibraltar Strait within the upper 100 m. It flows eastward as a highly nonlinear meandering current around the western and the eastern anticyclonic gyres prior to its attachment to the North African shelf/slope topography of the Algerian basin. Its inherent nonlinearity leads to the development of strong ageostrophic cross-frontal circulation that supplies nutrients into the nutrient-starved euphotic layer and stimulates an effective phytoplankton growth along the jet. The production intensity is strongest in the western basin and decreases eastwards with the gradual weakening of the jet. The stronger production intensity at the subsurface levels suggests the Alboran Sea is likely more productive than envisaged by the satellite chlorophyll data. The Mediterranean water mass away from the jet as well as the interior of the western and eastern anticyclonic gyres remain poorly productive.JRC.H.1-Water Resource

The potential of serum neurofilament as biomarker for multiple sclerosis

Biomarcadores; Neurofilamento; Respuesta a la terapiaBiomarkers; Neurofilament; Therapy responseBiomarcadors; Neurofilament; Resposta a la teràpiaMultiple sclerosis is a highly heterogeneous disease, and the detection of neuroaxonal damage as well as its quantification is a critical step for patients. Blood-based serum neurofilament light chain (sNfL) is currently under close investigation as an easily accessible biomarker of prognosis and treatment response in patients with multiple sclerosis. There is abundant evidence that sNfL levels reflect ongoing inflammatory-driven neuroaxonal damage (e.g. relapses or MRI disease activity) and that sNfL levels predict disease activity over the next few years. In contrast, the association of sNfL with long-term clinical outcomes or its ability to reflect slow, diffuse neurodegenerative damage in multiple sclerosis is less clear. However, early results from real-world cohorts and clinical trials using sNfL as a marker of treatment response in multiple sclerosis are encouraging. Importantly, clinical algorithms should now be developed that incorporate the routine use of sNfL to guide individualized clinical decision-making in people with multiple sclerosis, together with additional fluid biomarkers and clinical and MRI measures. Here, we propose specific clinical scenarios where implementing sNfL measures may be of utility, including, among others: initial diagnosis, first treatment choice, surveillance of subclinical disease activity and guidance of therapy selection.This work was supported by the German Research Council (DFG, CRC-TR-128 to F.Z. and S.B.), Hertie-Stiftung (myLab to S.B.), the Progressive Multiple Sclerosis Alliance (PMSA, BRAVEinMS PA-1604-08492 to F.Z.), and the German Federal Ministry of Education and Research (BMBF, VIP+ HaltMS to F.Z.)

Updated Dissemination and Exploitation Plan

Dissemination of project’s results and engagement with stakeholders towards a sustained results’ exploitation are intrinsically evolving. The vision of the project’s dissemination at the start of it should evolve as the activities progress. This plan presents an update on the EuroSea dissemination plans as seen a year after the kick-off