A 1/24 degree resolution Mediterranean analysis and forecast modeling system for the Copernicus Marine Environment Monitoring Service

The Mediterranean Forecasting System (MFS) is a numerical ocean prediction system that operationally produces analyses, reanalyses and short-term forecasts of the main physical parameters for the entire Mediterranean Sea and its Atlantic Ocean adjacent areas. This work is specifically focused on the description and evaluation of the analysis and forecast modeling system that covers the analysis of the current situation and produces daily updates of the following 10 days forecast. The system has been recently upgraded in the framework of the Copernicus Marine Environment Monitoring Service (CMEMS) by increasing the grid resolution from 1/16o to 1/24o in the horizontal and from 72 to 141 vertical levels, by increasing the number of fresh water river inputs and by updating the data assimilation scheme. The model has a non-linear explicit free surface and it is forced by surface pressure, interactive heat, momentum and water fluxes at the air-sea interface. In order to validate the modeling system and to estimate the accuracy of the model products, a quality assessment is regularly performed including both pre-operational qualification and near real time (NRT) validation procedures. Pre-operational qualification activities focus on testing the improvements of the quality of the new system with respect to the previous version and relies on past simulation and historical data, while NRT validation activities aim at routinely and on-line providing the skill assessment of the model analysis and forecasts and relies on the NRT available observations. The focus of this work is to present the new operational modeling system and the skill assessment including comparison with independent (insitu coastal moorings) and quasi-independent (insitu vertical profiles and satellite) datasets.PublishedBergen, Norway3SR. AMBIENTE - Servizi e ricerca per la Societ

A 1/24° resolution Mediterranean physical analysis and forecasting system for the Copernicus Marine Environment Monitoring Service

This study describes a new model implementation for the Mediterranean Sea that has been achieved in the framework of the Copernicus Marine Environment Monitoring Service (CMEMS). The numerical ocean prediction system, that operationally produces analyses and forecasts of the main physical parameters for the entire Mediterranean Sea and its Atlantic Ocean adjacent areas, has been upgraded by increasing the grid resolution from 1/16o to 1/24o in the horizontal and from 72 to 141 unevenly spaced vertical levels, by increasing the number of fresh water river inputs and by updating the data assimilation scheme. The model has a non-linear explicit free surface and it is forced by surface pressure, interactive heat, momentum and water fluxes at the airsea interface. The focus of this work is to present the new modelling system which will become operational in the near future and the validation assessment including the comparison with an independent non assimilated dataset (coastal moorings) and quasi-independent (in situ vertical profiles and satellite) datasets. The results show that the higher resolution model is capable of representing most of the variability of the general circulation in the Mediterranean Sea, however some improvements need to be implemented in order to enhance the model ability in reproducing specific hydrodynamic features particularly the Sea Level Anomaly.PublishedBergen, Norway3SR. AMBIENTE - Servizi e ricerca per la Societ

The Copernicus Marine Service ocean forecasting system for the Mediterranean Sea

The Mediterranean Monitoring and Forecasting Center (MED-MFC) is part of the Copernicus Marine Environment and Monitoring Service (CMEMS) and provides regular and systematic information on the time-evolving Mediterranean Sea physical (including waves) and biogeochemical state. The systems consist of 3 components: 1) Med-Physics, a numerical ocean prediction systems, based on NEMO model, that operationally produces analyses, reanalysis and short term forecasts of the main physical parameters; 2) Med-Biogeochemistry, a biogeochemical analysis, reanalysis and forecasting system based on the Biogeochemical Flux Model (BFM) which provides information on chlorophyll, phosphate, nitrate, primary productivity, oxygen, phytoplankton biomass, pH and pCO2; 3) Med-Waves based on WAM model and providing analysis, forecast and reanalysis products for waves. The systems have been recently upgraded at a resolution of 1/24 degree in the horizontal and 141 vertical levels. The Med-Physics analysis and forecasting system is composed by the hydrodynamic model NEMO 2-way coupled with the third-generation wave model WaveWatchIII and forced by ECMWF atmospheric fields. The model solutions are corrected by the 3DVAR data assimilation system (3D variational scheme adapted to the oceanic assimilation problem) with a daily assimilation cycle of sea level anomaly and vertical profiles of temperature and salinity. The model has a non-linear explicit free surface and it is forced by surface pressure, interactive heat, momentum and water fluxes at the air-sea interface. The biogeochemical analysis and forecasts are produced by means of the MedBFM v2.1 modeling system (i.e. the physical-biogeochemical OGSTM-BFM model coupled with the 3DVARBIO assimilation scheme) forced by the outputs of the Med-Physics product. Seven days of analysis/hindcast and ten days of forecast are bi-weekly produced on Wednesday and on Saturday, with the assimilation of surface chlorophyll concentration from satellite observations. In-situ data are mainly used to estimate model uncertainty at different spatial scales. The Med-Waves modelling system is based on the WAM Cycle 4.5.4 wave model code. It consists of a wave model grid covering the Mediterranean Sea at a 1/24° horizontal resolution, nested to a North Atlantic grid at a 1/6° resolution. The system is forced by ECMWF winds at 1/8°. Refraction due to surface currents is accounted by the system which assimilates altimeter along-track significant wave height observations. On a daily basis, it provides 1-day analysis and 5-day forecast hourly wave parameters. Currently, wave buoy observations of significant wave height and mean wave period along with satellite observations are used to calibrate and validate the Med-waves modelling system.PublishedHalifax, Nova Scotia, Canada4A. Oceanografia e clim

A Probabilistic Method to Construct an Optimal Ice Chronology for Ice Cores

Accurate ice chronologies are needed for the interpretation of paleoclimate reconstructions inferred from ice cores. Several methods are used to provide chronological information: identification of dated horizons along the cores, synchronization to other dated paleoclimatic records, counting of annual layers or modelling of the ice flow. These methods are relevant for different parts of the core and enable to reach various levels of accuracy. We present a probabilistic approach based on inverse techniques which aims at building an optimal ice core chronology by using all the available chronological information. It consists in identifying the accumulation rate and the thinning function along the core 1) which are as close as possible to the flow model simulations and 2) so that the corresponding ice chronology is as close as possible to independent dating information. This probabilistic approach enables to evaluate confidence intervals on the optimal age scale as well as on the accumulation and the thinning estimates. We test the new method on the EPICA Dome C ice core. The necessary prior accumulation rate and thinning function as well as a set of dated horizons are provided by a previous work aiming at the EDC3 age scale reconstruction. We further discuss the sensitivity of the obtaincd optimal solution with respect to the necessary prior information. This probabilistic approach could be used in the future to build a common and optimal chronology for several ice cores simultaneously.III. Firn densification, close-off and chronolog

Orbital and millennial-scale features of atmospheric CH4 over the past 800,000 years

Atmospheric methane is an important greenhouse gas and a sensitive indicator of climate change and millennial-scale temperature variability. Its concentrations over the past 650,000 years have varied between ∼350 and ∼800 parts per 109 by volume (p.p.b.v.) during glacial and interglacial periods, respectively. In comparison, present-day methane levels of ∼1,770 p.p.b.v. have been reported. Insights into the external forcing factors and internal feedbacks controlling atmospheric methane are essential for predicting the methane budget in a warmer world. Here we present a detailed atmospheric methane record from the EPICA Dome C ice core that extends the history of this greenhouse gas to 800,000 yr before present. The average time resolution of the new data is ∼380 yr and permits the identification of orbital and millennial-scale features. Spectral analyses indicate that the long-term variability in atmospheric methane levels is dominated by ∼100,000 yr glacial-interglacial cycles up to ∼400,000 yr ago with an increasing contribution of the precessional component during the four more recent climatic cycles. We suggest that changes in the strength of tropical methane sources and sinks (wetlands, atmospheric oxidation), possibly influenced by changes in monsoon systems and the position of the intertropical convergence zone, controlled the atmospheric methane budget, with an additional source input during major terminations as the retreat of the northern ice sheet allowed higher methane emissions from extending periglacial wetlands. Millennial-scale changes in methane levels identified in our record as being associated with Antarctic isotope maxima events are indicative of ubiquitous millennial-scale temperature variability during the past eight glacial cycles. ©2008 Nature Publishing Group

Mediterranean Sea physics Analysis and Forecast (CMEMS MED-Currents 2015-2017)

The CMEMS Mediterranean Sea Physics Analysis and Forecast system comprises an Ocean General Circulation Model based on NEMO v3.6 and a variational data assimilation scheme (OceanVar) for temperature and salinity vertical profiles and satellite SLA along track data. The model has a 1/24\u2dauniform horizontal grid resolution and 141 unevenly spaced vertical levels. It spans the time period 2015-2017 and it is daily updated

From Observation to Information and Users: The Copernicus Marine Service Perspective

The Copernicus Marine Environment Monitoring Service (CMEMS) provides regular and systematic reference information on the physical and biogeochemical ocean and sea-ice state for the global ocean and the European regional seas. CMEMS serves a wide range of users (more than 15,000 users are now registered to the service) and applications. Observations are a fundamental pillar of the CMEMS value-added chain that goes from observation to information and users. Observations are used by CMEMS Thematic Assembly Centres (TACs) to derive high-level data products and by CMEMS Monitoring and Forecasting Centres (MFCs) to validate and constrain their global and regional ocean analysis and forecasting systems. This paper presents an overview of CMEMS, its evolution, and how the value of in situ and satellite observations is increased through the generation of high-level products ready to be used by downstream applications and services. The complementary nature of satellite and in situ observations is highlighted. Long-term perspectives for the development of CMEMS are described and implications for the evolution of the in situ and satellite observing systems are outlined. Results from Observing System Evaluations (OSEs) and Observing System Simulation Experiments (OSSEs) illustrate the high dependencies of CMEMS systems on observations. Finally future CMEMS requirements for both satellite and in situ observations are detailed

Deficiency or inhibition of oxygen sensor Phd1 induces hypoxia tolerance by reprogramming basal metabolism.

HIF prolyl hydroxylases (PHD1-3) are oxygen sensors that regulate the stability of the hypoxia-inducible factors (HIFs) in an oxygen-dependent manner. Here, we show that loss of Phd1 lowers oxygen consumption in skeletal muscle by reprogramming glucose metabolism from oxidative to more anaerobic ATP production through activation of a Pparalpha pathway. This metabolic adaptation to oxygen conservation impairs oxidative muscle performance in healthy conditions, but it provides acute protection of myofibers against lethal ischemia. Hypoxia tolerance is not due to HIF-dependent angiogenesis, erythropoiesis or vasodilation, but rather to reduced generation of oxidative stress, which allows Phd1-deficient myofibers to preserve mitochondrial respiration. Hypoxia tolerance relies primarily on Hif-2alpha and was not observed in heterozygous Phd2-deficient or homozygous Phd3-deficient mice. Of medical importance, conditional knockdown of Phd1 also rapidly induces hypoxia tolerance. These findings delineate a new role of Phd1 in hypoxia tolerance and offer new treatment perspectives for disorders characterized by oxidative stress

Copernicus marine service ocean state report

The oceans regulate our weather and climate from global to regional scales. They absorb over 90% of accumulated heat in the climate system (IPCC Citation2013) and over a quarter of the anthropogenic carbon dioxide (Le Quéré et al. Citation2016). They provide nearly half of the world’s oxygen. Most of our rain and drinking water is ultimately regulated by the sea. The oceans provide food and energy and are an important source of the planet's biodiversity and ecosystem services. They are vital conduits for trade and transportation and many economic activities depend on them (OECD Citation2016). Our oceans are, however, under threat due to climate change and other human induced activities and it is vital to develop much better, sustainable and science-based reporting and management approaches (UN Citation2017). Better management of our oceans requires long-term, continuous and state-of-the art monitoring of the oceans from physics to ecosystems and global to local scales. The Copernicus Marine Environment Monitoring Service (CMEMS) has been set up to address these challenges at European level. Mercator Ocean was tasked in 2014 by the European Union under a delegation agreement to implement the operational phase of the service from 2015 to 2021 (CMEMS Citation2014). The CMEMS now provides regular and systematic reference information on the physical state, variability and dynamics of the ocean, ice and marine ecosystems for the global ocean and the European regional seas (Figure 0.1; CMEMS Citation2016). This capacity encompasses the description of the current situation (analysis), the prediction of the situation 10 days ahead (forecast), and the provision of consistent retrospective data records for recent years (reprocessing and reanalysis). CMEMS provides a sustainable response to European user needs in four areas of benefits: (i) maritime safety, (ii) marine resources, (iii) coastal and marine environment and (iv) weather, seasonal forecast and climate. Figure 0.1. CMEMS geographical areas on the map are for: 1 – Global Ocean; 2 – Arctic Ocean from 62°N to North Pole; 3 – Baltic Sea, which includes the whole Baltic Sea including Kattegat at 57.5°N from 10.5°E to 12.0°E; 4 – European North-West Shelf Sea, which includes part of the North East Atlantic Ocean from 48°N to 62°N and from 20°W to 13°E. The border with the Baltic Sea is situated in the Kattegat Strait at 57.5°N from 10.5°E.to 12.0°E; 5 – Iberia-Biscay-Ireland Regional Seas, which includes part of the North East Atlantic Ocean from 26 to 48°N and 20°W to the coast. The border with the Mediterranean Sea is situated in the Gibraltar Strait at 5.61°W; 6 – Mediterranean Sea, which includes the whole Mediterranean Sea until the Gibraltar Strait at 5.61°W and the Dardanelles Strait; 7 – Black Sea, which includes the whole Black Sea until the Bosporus Strait