Ismael Hernández-Carrasco

Mediterranean Institute for Advanced Studies -IMEDEA-

A 25-years surface velocity data-set for the Mediterranean Sea is presented in this paper. The velocity data is obtained using a modified Ekman model which allows us to obtain an analytical solution for the surface currents using satellite altimetry and available wind and waves data from synoptic observations. The new database consists of 6-hourly...

Fronts are ubiquitous discrete features of the global ocean often associated with enhanced vertical velocities, in turn boosting primary production. Fronts thus form dynamical and ephemeral ecosystems where numerous species meet across all trophic levels. Fronts are also targeted by fisheries. Capturing ocean fronts and studying their long-term var...

Coastal circulation influences the distribution of the European anchovy (Engraulis encrasicolus) at early life stages (ELS) in the Bay of Biscay (BoB). However, how this happens is not yet fully understood. In this work, further insight is provided by performing Lagrangian diagnostics based on observations of ELS anchovies' initial distributions an...

We present the Terms of Reference for a case study on a Mediterranean eco-region focusing on the environmental component of the Ecosystem Report Card. The objective of this case study is to describe and monitor the variability of environmental processes in the Mediterranean Sea that affect the ecology of large pelagic fishes, with a particular atte...

This article analyses the Balearic Islands wind-driven coastal upwelling in response to the intense and long-lasting Storm Blas, which affected the western Mediterranean Sea in November 2021. The storm was associated with a pronounced pressure low, generating heavy rains and intense winds and showing some characteristics of a tropical cyclone. The...

The Southwestern Atlantic Ocean (SWA), is considered one of the most productive areas of the world, with a high abundance of ecologically and economically important fish species. Yet, the biological responses of this complex region to climate variability are still uncertain. Here, using 24 years of satellite‐derived Chl‐a data, we classified the SW...

Diatoms are among the most efficient autotrophic organisms for oceanic primary production and carbon sequestration. Yet, the spatial distributions of these planktonic organisms remain puzzling and the underlying physical processes poorly known, especially in oligotrophic open waters. Here we investigate what dynamical conditions are conducive to ep...

We examine 20 years of monthly global ocean color data and modeling outputs of nutrients using self-organizing map (SOM) analysis to identify characteristic spatial and temporal patterns of high-nutrient low-chlorophyll (HNLC) regions and their association with different climate modes. The global nitrate-to-chlorophyll ratio threshold of NO3 : Chl...

In the Panama Bight, two different seasonal surface circulation patterns coincide with a strong mean sea level variation, as observed from 27 years of absolute dynamic topography (ADT) and the use of self-organizing maps. From January to April, a cyclonic gyre with a strong southwestward Panama Jet Surface Current (PJSC) dominates the basin circula...

We study the impact of the Ekman currents and Stokes drift on the surface horizontal transport and mixing properties of the Mediterranean Sea. Finite Size Lyapunov Exponents (FSLE) at the ocean surface are computed over the whole basin using 25 years of satellite altimetry derived geostrophic currents, 10‐m wind velocity and wave fields. We find th...

The Southwestern Atlantic Ocean (SAO), is considered as one of the most productive areas of the world, with high abundance of ecologically and economical important fish species. Yet, the biological responses of this complex region to climate variability are still uncertain. Here, using 24 years of satellite derived Chl-a datasets, we classified the...

Diatoms are among the most efficient marine organisms for primary production and carbon sequestration, absorbing at least 10 billion tonnes of carbon dioxide every year. Yet, the spatial distributions of these planktonic organisms remain puzzling and the underlying physical processes poorly known. Here we investigate what dynamical conditions are c...

Attribution of sea-level change to its different drivers is typically done using a sea-level budget approach. While the global mean sea-level budget is considered closed, closing the budget on a finer spatial scale is more complicated due to, for instance, limitations in our observational system and the spatial processes contributing to regional se...

In the Panama Bight, a reverse seasonal surface circulation coincides with a strong mean sea level variation, as observed from 27 years of Absolute Dynamic Topography (ADT) and the use of Self-Organizing Maps. From January to April, a cyclonic gyre dominates the basin circulation, forced by the Panama surface wind jet that also produce upwelling, r...

In this work, the backward wave breaking process by the presence of flow separation vortices under a solitary wave is studied. Based on a set of non-dimensional variables defined from the Buckingham theorem, a set of numerical experiments are performed in order to analyze the effect of varying the submerged obstacle geometry on the surrounding flow...

This article analyzes the Balearic Islands wind-driven coastal upwelling in response to the intense and long-lasting storm Blas which affected the Western Mediterranean Sea in November 2021. The storm was associated with a pronounced pressure low, generating heavy rains and intense winds and showing some characteristics of a tropical cyclone. The B...

Attribution of sea-level change to its different drivers is typically done using a sea-level budget (SLB) approach. While the global mean SLB is considered closed, closing the SLB on a finer spatial scale is more complicated due to, for instance, limitations in our observational system and the spatial processes contributing to regional sea-level ch...

We examine 20-years of monthly global ocean color data and modelling outputs of nutrients using self-organizing map analysis (SOM) to identify characteristic spatial and temporal patterns of High Nutrient Low Chlorophyll (HNLC) regions and their association with different climate modes. Analyzing the properties of the probability distribution funct...

The spatial distribution, the monthly and seasonal variability of mesoscale eddy-observations derived from the AVISO eddy atlas are assessed in the Caribbean Sea for the period between 1993 and 2019 (both included). The average lifetime for the whole set of eddies is 61.8±37.1days, mean amplitude of 7.4 ± 4.2 cm for ciclonic and 6.7 ± 3.7 cm for an...

Mean wave energy flux (hereinafter WEF) is assessed in the Caribbean Sea from a 60-year (1958–2017) wave hindcast. We use a novel approach, based on neural networks, to identify coherent regions of WEF and their association with different climate patterns. This method allows for a better evaluation of the underlying dynamics behind seasonal and int...

Due to the semi-enclosed nature of the Mediterranean Sea, natural disasters and anthropogenic activities impose stronger pressures on its coastal ecosystems than in any other sea of the world. With the aim of responding adequately to science priorities and societal challenges, littoral waters must be effectively monitored with high-frequency radar...

The Mediterranean Sea is a prominent climate-change hot spot, with many socioeconomically vital coastal areas being the most vulnerable targets for maritime safety, diverse met-ocean hazards and marine pollution. Providing an unprecedented spatial and temporal resolution at wide coastal areas, high-frequency radars (HFRs) have been steadily gaining...

The Mediterranean Sea is a prominent climatechange hot spot, with many socioeconomically vital coastal areas being the most vulnerable targets for maritime safety, diverse met-ocean hazards and marine pollution. Providing an unprecedented spatial and temporal resolution at wide coastal areas, high-frequency radars (HFRs) have been steadily gaining...

Due to the semi-enclosed nature of the Mediterranean Sea, natural disasters and anthropogenic activities impose stronger pressures on its coastal ecosystems than in any other sea of the world. With the aim of responding adequately to science priorities and societal challenges, littoral waters must be effectively monitored with high-frequency radar...

Understanding how the surface dynamics of the ocean influence the spawning and larval ecology of many large pelagic species, in particular tuna species, is a major challenge. For temperate tunas, the selection of geographically restricted spawning grounds is influenced by environmental conditions, but the influence of surface mixing properties on t...

The spatial distribution, the monthly and seasonal variability of mesoscale eddy-observations derived from the AVISO eddy atlas are assessed in the Caribbean Sea for the period between 1993 and 2019 (both included). The average lifetime for the whole set of eddies is 61.8±37.1days, mean amplitude of 7.4 ± 4.2 cm for ciclonic and 6.7 ± 3.7 cm for an...

Wave energy flux (WEF) is assessed in the Caribbean Sea from a 60-year (1958--2017) wave hindcast. We use a novel approach, based on neural networks, to identify coherent regions of similar WEF and their association with different climate patterns. This method allows for a better evaluation of the underlying dynamics behind seasonal and inter-annua...

The Mediterranean Sea is a prominent climate change hot spot, being their socio-economically vital coastal areas the most vulnerable targets for maritime safety, diverse met-ocean hazards and marine pollution. Providing an unprecedented spatial and temporal resolution at wide coastal areas, High-frequency radars (HFRs) have been steadily gaining re...

Due to the semi-enclosed nature of the Mediterranean Sea, natural disasters and anthropogenic activities impose stronger pressures on its coastal ecosystems than in any other sea of the world. With the aim of responding adequately to science priorities and societal challenges, littoral waters must be effectively monitored with High-Frequency radar...

[This corrects the article DOI: 10.1016/j.dib.2021.107153.].

Effects of wind and waves on the surface dynamics of the Mediterranean Sea are assessed using a modified Ekman model including a Stokes‐Coriolis force in the momentum equation. Using 25 years of observations, we documented intermittent but recurrent episodes during which Ekman and Stokes currents substantially modulate the total mesoscale dynamics...

The use of high-frequency radar (HFR) data is increasing worldwide for different applications in the field of operational oceanography and data assimilation, as it provides real-time coastal surface currents at high temporal and spatial resolution. In this work, a Lagrangian-based, empirical, real-time, short-term prediction (L-STP) system is prese...

This article presents a 60 years wave hindcast from 1958 to 2017, covering the Colombian Caribbean basin. Each output consists on 6-hour field of significant wave height Hs , mean wave period T m −01, T mm −10 and mean direction θm with a resolution of 11.8 km 11.4 km. The simulation was performed using SWAN model forced with JRA-55 wind fields. Mo...

We analyzed the influence of the stratification process in the vertical distribution of larval fish in a microtidal coastal Mediterranean zone. By applying a Self Organizing Maps (SOM) technique, we could analyze a complex dataset accounting for non-linear processes. The analysis integrated multivariate data on larval fish and environmental paramet...

Connectivity is a fundamental structural feature of a network that determines the outcome of any dynamics that happens on top of it. However, an analytical approach to obtain connection probabilities between nodes associated with to paths of different lengths is still missing. Here, we derive exact expressions for random-walk connectivity probabili...

Connectivity is a fundamental structural feature of a network that determines the outcome of any dynamics that happens on top of it. However, an analytical approach to obtain connection probabilities between nodes associated to paths of different lengths is still missing. Here, we derive exact expressions for random-walk connectivity probabilities...

Search and rescue (SAR) modeling applications, mostly based on Lagrangian tracking particle algorithms, rely on the accuracy of met-ocean forecast models. Skill assessment methods are therefore required to evaluate the performance of ocean models in predicting particle trajectories. The Skill Score (SS), based on the Normalized Cumulative Lagrangia...

The variability of La Guajira upwelling system, in the south-central Caribbean Sea, is strongly influenced by the intensity and location of the atmospheric Caribbean Low-Level Jet (CLLJ), a near-surface branch of the easterlies, as well as by the regional ocean circulation. During favorable conditions (i.e., strong easterlies blowing almost paralle...

Effects of wind and waves on the surface dynamics of the Mediterranean Sea are assessed using a modified Ekman model including a Stokes-Coriolis force in the momentum equation. Using 25 years of observations, we documented intermittent but recurrent episodes during which Ekman and Stokes currents substantially modulate the total mesoscale dynamics...

Influence of frontal dynamics on phytoplankton distribution and composition was studied combining in-situ observations and Lagrangian computations from altimetry satellite derived currents. Four transects during the SHEBEX cruise (May 2015) over the Western Mediterranean were examined identifying a region with high spatial variability in the dynami...

The spatial and temporal dynamics of ocean biomes are affected by the dynamics of Earth’s climate system and understanding their response to ongoing change is of primary importance. We use 20-years of monthly global ocean color data and modelling outputs of nutrients to identify characteristic spatial and temporal patterns of High Nutrient Low Chlo...

The use of High Frequency Radar (HFR) data is increasing worldwide for operational oceanography and data assimilation, as it provides real-time coastal surface currents at high temporal and spatial resolution. In this work, a Lagrangian based empirical real-time, Short-Term Prediction (L-STP) system is presented in order to provide short term forec...

This work analyzes the coastal impacts of the combined effect of extreme waves and sea level extremes, including surges and projected mean sea level rise in Bocagrande, Cartagena (Colombia). Extreme waves are assessed from a wave reanalysis that are propagated from deep waters to the beach considering the hydrodynamic processes and taking into acco...

Presentation of IBISAR downstream data service focused on the methodology, the creation of added value HFR data and skill assessment results

IBISAR downstream data service presentation, its three main elements, the skill assessment methodology, the first results obtained in the Ibiza Channel

We study the influence of global climates modes of variability (ENSO and AO) in wave variability in the Pacific Ocean and more specifically over the Colombian Pacific. 34 years of wave reanalysis (1979-2012) from CAWCR, are first validated with in situ buoys as well as from the marine Atlas of Chile. The analysis is made for the annual and monthly...

This research quantitatively indicates the influence of the El Niño Southern Oscillation (ENSO), as well as other oscillations of interannual and decadal scale (Antarctic Oscillation and Pacific Decadal Oscillation) in the wave conditions of the Pacific Ocean and its incidence in the Colombian Pacific. This research constitutes as a tool for the op...

High-frequency radar, HFR, is a cost-effective monitoring technique that allows us to obtain high-resolution continuous surface currents, providing new insights for understanding small-scale transport processes in the coastal ocean. In the last years, the use of Lagrangian metrics to study mixing and transport properties has been growing in importa...

Brief overview of IBISAR downstream data service, key numbers, its main elements and description of the skill assessment methodology. Benefits for targeted users and the impact on CMEMS

A new methodology has been developed in order to improve the description of the spatial and temporal variability of not well-resolved oceanic variables from other well-observed high-resolution oceanic variables. The method is based on the cross-scale inference of information, incorporating the common features of different multifractal high-resoluti...

Coastal ocean ecosystems are major contributors to the global biogeochemical cycles and biological productivity. Physical factors induced by the turbulent flow play a crucial role in regulating marine ecosystems. However, while large-scale open-ocean dynamics is well described by geostrophy, the role of multiscale transport processes in coastal reg...

A combined space- and -time domain Self-Organizing Maps analysis of Altimetry derived finite-size Lyapunov exponents is used to extract characteristic spatial patterns of mesoscale features and to classify the western Mediterranean in regions of different variability of mixing activity. In particular, a recurrent and intense front is unveiled betwe...

A combined space and time domain Self-Organizing Maps analysis of Altimetry-derived finite-size Lyapunov exponents is used to extract characteristic spatial patterns of mesoscale features and to classify the western Mediterranean in regions of different variability of mixing activity. In particular, a recurrent and intense front is unveiled between...

The Mediterranean Sea exhibits a strong basin and regional scale phytoplankton variability correlated to its semi-enclosed nature, complex orography and the variety of physical and chemical processes that regulate its productivity. Herein, using 17 years of ocean-color composites, we investigate differences in the regional pat- terns of interannual...

In coastal basins HF radar, HFR, is a cost-effective monitoring technique that allows to obtain high-resolution continuous surface currents, providing new insights for understanding small-scale coastal ocean transport and dispersion processes. In the last years the use of Lagrangian diagnosis to study mixing and transport properties is growing in i...