Dynamical connections between large marine ecosystems of austral South America based on numerical simulations

The Humboldt Large Marine Ecosystem (HLME) and Patagonian Large Marine Ecosystem (PLME) are the two largest marine ecosystems in the Southern Hemisphere and are respectively located along the Pacific and Atlantic coasts of southern South America. This work investigates the exchange between these two LMEs and its seasonal and interannual variability by employing numerical model results and offline particle-tracking algorithms. Our analysis suggests a general poleward transport on the southern region of the HLME, a well-defined flux from the Pacific to the Atlantic, and equatorward transport on the PLME.Lagrangian simulations show that the majority of the southern PS waters originate from the upper layer in the southeast South Pacific (<200 m), mainly from the southern Chile and Cape Horn shelves. The exchange takes place through the Le Maire Strait, Magellan Strait, and the shelf break. These inflows amount to a net northeastward transport of 0.88 Sv at 51∘ S in the southern PLME. The transport across the Magellan Strait is small (0.1 Sv), but due to its relatively low salinity it greatly impacts the density and surface circulation of the coastal waters of the southern PLME. The water masses flowing into the Malvinas Embayment eventually reach the PLME through the Malvinas Shelf and occupy the outer part of the shelf. The seasonal and interannual variability of the transport are also addressed. On the southern PLME, the interannual variability of the shelf exchange is partly explained by the large-scale wind variability, which in turn is partly associated with the Southern Annular Mode (SAM) index (r=0.52).Fil: Guihou, Karen. Ministerio de Defensa. Armada Argentina. Servicio de Hidrografía Naval. Departamento Oceanografía; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Piola, Alberto Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Ministerio de Defensa. Armada Argentina. Servicio de Hidrografía Naval. Departamento Oceanografía; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias de la Atmósfera y los Océanos; Argentina. Instituto Franco-Argentino sobre Estudios del Clima y sus Impactos; ArgentinaFil: Palma, Elbio Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; ArgentinaFil: Chidichimo, María Paz. Ministerio de Defensa. Armada Argentina. Servicio de Hidrografía Naval. Departamento Oceanografía; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Franco-Argentino sobre Estudios del Clima y sus Impactos; Argentin

The UKC2 regional coupled environmental prediction system

It is hypothesized that more accurate prediction and warning of natural hazards, such as of the impacts of severe weather mediated through various components of the environment, require a more integrated Earth System approach to forecasting. This hypothesis can be explored using regional coupled prediction systems, in which the known interactions and feedbacks between different physical and biogeochemical components of the environment across sky, sea and land can be simulated. Such systems are becoming increasingly common research tools. This paper describes the development of the UKC2 regional coupled research system, which has been delivered under the UK Environmental Prediction Prototype project. This provides the first implementation of an atmosphere–land–ocean–wave modelling system focussed on the United Kingdom and surrounding seas at km-scale resolution. The UKC2 coupled system incorporates models of the atmosphere (Met Office Unified Model), land surface with river routing (JULES), shelf-sea ocean (NEMO) and ocean waves (WAVEWATCH III). These components are coupled, via OASIS3-MCT libraries, at unprecedentedly high resolution across the UK within a north-western European regional domain. A research framework has been established to explore the representation of feedback processes in coupled and uncoupled modes, providing a new research tool for UK environmental science. This paper documents the technical design and implementation of UKC2, along with the associated evaluation framework. An analysis of new results comparing the output of the coupled UKC2 system with relevant forced control simulations for six contrasting case studies of 5-day duration is presented. Results demonstrate that performance can be achieved with the UKC2 system that is at least comparable to its component control simulations. For some cases, improvements in air temperature, sea surface temperature, wind speed, significant wave height and mean wave period highlight the potential benefits of coupling between environmental model components. Results also illustrate that the coupling itself is not sufficient to address all known model issues. Priorities for future development of the UK Environmental Prediction framework and component systems are discussed

Study of the Northern Current dynamics in the Toulon region, using modelling, in-situ observations and satellite data.

L’objectif général de cette thèse est de contribuer à l’avancement de la connaissance de la variabilité du Courant Nord Méditerranéen (CN) et de ses interactions avec la dynamique côtière, en s’appuyant principalement sur une configuration numérique réaliste à haute résolution de la façade méditerranéenne française, basée sur le modèle de circulation océanique NEMO et nommée GLAZUR64.La validation de cette configuration avec toutes les observations disponibles sur la période d'étude (CTD, gliders, ARGO, radar HF, ADCP, altimétrie et SST satellite) a permis d'évaluer le réalisme des simulations et leur paramétrisation, et de montrer l'apport de la haute-résolution par rapport aux configurations de bassin au 1/12° utilisées aux frontières de GLAZUR64.Enfin, l'utilisation d'un forçage océanique opérationnel a permis d'utiliser une simulation en complément des données d'une campagne en mer, pour l'étude ciblée d'un tourbillon anticyclonique associé à un méandre du CN au large de Toulon, en avril 2011 [Guihou et al., 2013].The main objective of this work is to improve our knowledge of the Northern Mediterrranean Current (NC) variability and its interactions with coastal dynamics, using high-resolution modelling of the North-Western Mediterranean Sea, based on the NEMO code and nammed GLAZUR64.The configuration has been validated using all available observations for the period of study (CTD, gliders, ARGO, HF radar, ADCP, satellite altimetry and SST), in order to assess the realism of the simulations and their parameterisations. The contribution of the high-resolution for the simulation of the mesoscale dynamics, compared to 1/12° configurations used at the boundaries is shown.Finally, the use of an operationnal oceanic boundary forcing allowed us to use a combined data-model approach to study the generation and advection of an anticyclonic eddy trapped at the coast and associated to a NC meander, flowing off Toulon in April 2011 [Guihou et al., 2013]

Étude de la dynamique du Courant Nord au large de Toulon, à l’aide de modèle, observations in-situ et données satellites

The main objective of this work is to improve our knowledge of the Northern Mediterrranean Current (NC) variability and its interactions with coastal dynamics, using high-resolution modelling of the North-Western Mediterranean Sea, based on the NEMO code and nammed GLAZUR64.The configuration has been validated using all available observations for the period of study (CTD, gliders, ARGO, HF radar, ADCP, satellite altimetry and SST), in order to assess the realism of the simulations and their parameterisations. The contribution of the high-resolution for the simulation of the mesoscale dynamics, compared to 1/12° configurations used at the boundaries is shown.Finally, the use of an operationnal oceanic boundary forcing allowed us to use a combined data-model approach to study the generation and advection of an anticyclonic eddy trapped at the coast and associated to a NC meander, flowing off Toulon in April 2011 [Guihou et al., 2013].L’objectif général de cette thèse est de contribuer à l’avancement de la connaissance de la variabilité du Courant Nord Méditerranéen (CN) et de ses interactions avec la dynamique côtière, en s’appuyant principalement sur une configuration numérique réaliste à haute résolution de la façade méditerranéenne française, basée sur le modèle de circulation océanique NEMO et nommée GLAZUR64.La validation de cette configuration avec toutes les observations disponibles sur la période d'étude (CTD, gliders, ARGO, radar HF, ADCP, altimétrie et SST satellite) a permis d'évaluer le réalisme des simulations et leur paramétrisation, et de montrer l'apport de la haute-résolution par rapport aux configurations de bassin au 1/12° utilisées aux frontières de GLAZUR64.Enfin, l'utilisation d'un forçage océanique opérationnel a permis d'utiliser une simulation en complément des données d'une campagne en mer, pour l'étude ciblée d'un tourbillon anticyclonique associé à un méandre du CN au large de Toulon, en avril 2011 [Guihou et al., 2013]

Étude de la dynamique du Courant Nord au large de Toulon, à l'aide de modèle, observations in-situ et données satellites

L objectif général de cette thèse est de contribuer à l avancement de la connaissance de la variabilité du Courant Nord Méditerranéen (CN) et de ses interactions avec la dynamique côtière, en s appuyant principalement sur une configuration numérique réaliste à haute résolution de la façade méditerranéenne française, basée sur le modèle de circulation océanique NEMO et nommée GLAZUR64.La validation de cette configuration avec toutes les observations disponibles sur la période d'étude (CTD, gliders, ARGO, radar HF, ADCP, altimétrie et SST satellite) a permis d'évaluer le réalisme des simulations et leur paramétrisation, et de montrer l'apport de la haute-résolution par rapport aux configurations de bassin au 1/12 utilisées aux frontières de GLAZUR64.Enfin, l'utilisation d'un forçage océanique opérationnel a permis d'utiliser une simulation en complément des données d'une campagne en mer, pour l'étude ciblée d'un tourbillon anticyclonique associé à un méandre du CN au large de Toulon, en avril 2011 [Guihou et al., 2013].The main objective of this work is to improve our knowledge of the Northern Mediterrranean Current (NC) variability and its interactions with coastal dynamics, using high-resolution modelling of the North-Western Mediterranean Sea, based on the NEMO code and nammed GLAZUR64.The configuration has been validated using all available observations for the period of study (CTD, gliders, ARGO, HF radar, ADCP, satellite altimetry and SST), in order to assess the realism of the simulations and their parameterisations. The contribution of the high-resolution for the simulation of the mesoscale dynamics, compared to 1/12 configurations used at the boundaries is shown.Finally, the use of an operationnal oceanic boundary forcing allowed us to use a combined data-model approach to study the generation and advection of an anticyclonic eddy trapped at the coast and associated to a NC meander, flowing off Toulon in April 2011 [Guihou et al., 2013].TOULON-Bibliotheque electronique (830629901) / SudocSudocFranceF

Modelling transport and stranding of jellyfish Pelagia noctiluca in the Ligurian Sea

Jellyfish bloom origins are generally sought in some biological response to the environment, leaving aside the role of transport patterns in redistributing existing populations. Here we use high resolution (1.25 km) ocean modelling to examine the role of transport in the onshore arrival and abundance of the pelagic stinging jellyfish Pelagia noctiluca on the Ligurian Sea coast. Jellyfish are modelled as Lagrangian particles with a 0-300m diel vertical migration typical of P. noctiluca. Over a year, onshore arrivals are not restricted to the summer period. Arrivals are concentrated at capes, but abundance can reach maxima in bays and in the lee of capes. Two factors impact jellyfish arrivals at the coast: the position of the Northern Current and the wind. A comparison of summer 2006 and available onshore jellyfish observations suggests a correct capture of the main stranding events by the model. These results have implications for understanding long term fluctuation

Modelling jellyfish Pelagia noctiluca transport and stranding in the Ligurian Sea

International audienceModelling jellyfish Pelagia noctiluca transport and stranding in the Ligurian Se

A case study of the mesoscale dynamics in the North-Western Mediterranean Sea: a combined data-model approach

The Northern current is the main circulation fea- ture of the North-Western Mediterranean Sea. While the large-scale to mesoscale variability of the northern current (NC) is well known and widely documented for the Lig- urian region, off Nice or along the Gulf of Lions shelf, few is known about the current instabilities and its associated mesoscale dynamics in the intermediate area, off Toulon. Here, we took advantage of an oceanographic cruise of opportunity, the start of a HF radar monitoring programme in the Toulon area and the availability of regular satellite sea surface temperature and chlorophyll a data, to evaluate the realism of a NEMO-based regional high-resolution model and the added value brought by HF radar. The combined analysis of a 1/64◦ configuration, named GLAZUR64, and of all data sets revealed the occurrence of an anticyclonic coastal trapped eddy, generated inside a NC meander and passing the Toulon area during the field campaign. We show that this anticyclonic eddy is advected downstream along the French Riviera up to the study region and dis- turbs the Northern current flow. This study aims to show the importance of combining observations and modelling when dealing with mesoscale processes, as well as the importance of high-resolution modelling

River Freshwater Contribution in Operational Ocean Models along the European Atlantic Façade: Impact of a New River Discharge Forcing Data on the CMEMS IBI Regional Model Solution

35 pages, 12 figures, 7 tables.-- Data Availability Statement: The following publicly available datasets were analyzed in this study: Model data: The CMEMS IBI MFC operational forecast product can be found in the CMEMS catalogue (IBI-MFC forecast analysis product: https://resources.marine.copernicus.eu/?option=com_csw&view=details&product_id=IBI_ANALYSISFORECAST_PHY_005_001 (accessed on 8 April 2021)); LAMBDA river data can be found in: http://www.cmems-lambda.eu/#data-portal (accessed on 8 April 2021); data from the different ocean model scenarios analyzed in the study can be available on request from the corresponding author. Observational data: The data from in-situ buoys, Argo floats and Recopesca can be found in the CMEMS catalogue (Insitu-TAC Near-Real-Time observational product: https://resources.marine.copernicus.eu/?option=com_csw&view=details&product_id=INSITU_IBI_NRT_OBSERVATIONS_013_033 (accessed on 8 April 2021)). The salinity data from SMOS (the low-resolution level 3 SSS product computed with smoothening spatial window of 50-km radius) can be found in the BEC public ftp catalogue: http://bec.icm.csic.es/bec-ftp-service/ (accessed on 8 April 2021); Finally, the INTECMAR and IPMA observational salinity datasets used in this study are 3rd Party Data, and restrictions are applied to their availability (contact with the institutions owner of these datasets would be required for access permission)River freshwater contribution in the European Atlantic margin and its influence on the sea salinity field are analyzed. The impacts of using a new river discharge database as part of the freshwater forcing in a regional ocean model are assessed. Ocean model scenarios, based on the CMEMS (Copernicus Marine Environment Monitoring Service) operational IBI-MFC (Iberia Biscay Ireland Monitoring Forecasting Centre) model set-up, are run to test different (observed, modeled and climatological) river and coastal freshwater forcing configurations throughout 2018. The modelled salinity fields are validated, using as a reference all known available in-situ observational data sources. The IBI model application is proven to adequately simulate the regional salinity, and the scenarios showcase the effects of varying imposed river outflows. Some model improvement is achieved using the new forcing (i.e., better capture of salinity variability and more realistic simulation of baroclinic frontal structures linked to coastal and river freshwater buoyancy plumes). Major impacts are identified in areas with bigger river discharges (i.e., the French shelf or the northwestern Iberian coast). Instead, the Portuguese shelf or the Gulf of Cadiz are less impacted by changes in the imposed river inflows, and other dynamical factors in these areas play a major role in the configuration of the regional salinityPart of this research work was conducted in the framework of the following 2 projects: The EU Interreg Atlantic Area MyCoast Project EAPA_285/2016 (F.C., A.M. and M.G.S.) and the CMEMS Service Evolution Project LAMBDA (F.C., F.S., E.O. and A.N.). It was also supported by activity from the CMEMS IBI-MFC (K.G., P.L. and A.A.B.)With the funding support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S), of the Spanish Research Agency (AEI)Peer reviewe