Projecte de construcció de l’EDAR de Nuñomoral (Las Hurdes, Càceres)

El projecte de construcció de l’EDAR de Nuñomoral parteix de dos objectius clars. El primer objectiu és definir i valorar les obres d’infrastructura de sanejament i depuració, mitjançant un sistema compacte, de les aigües residuals urbanes de Nuñomoral, un dels sis municipis de la Mancomunitat que constitueix Las Hurdes. Degut a la gran similitud tant orogràfica com demogràfica dels sis municipis de Las Hurdes, aquest projecte també es marca l’objectiu de ser una guia a seguir per a la construcció de xarxa de depuradores que la zona necessita. La metodologia que s'ha aplicat en aquest projecte contempla un profund estudi de la literatura especialitzada en el tema, una recopilació de la informació de població, un inventari d’infraestructura de sanejament i abocaments, un reconeixement geològic, l’estudi del marc legal espanyol i extremeny referent a aigües residuals urbanes, i finalment l’anàlisi de les alternatives. Com a resultat d’aquest mètode previ, es projectarà una estació depuradora d’aigües residuals que es fonamenti en un procés biològic de fangs actius de doble etapa. Donat que al municipi d’estudi hi ha fortes oscil·lacions de cabal i càrrega en els períodes de baixa i alta ocupació poblacional, aquesta solució resulta idònia ja que permet, a l’etapa alta treballar amb la doble etapa, i a l’etapa baixa treballar amb la segona etapa del procés i així ajustar els consums i el funcionament a les necessitats reals. A més, la solució adoptada té un baix consum energètic, un baix cost de manteniment, un reduït volum de fangs produïts minimitza l’excavació necessària per a la seva implantació i el seu impacte ambiental. En general el disseny d’una depuradora d’aigües residuals per a un petit nucli urbà dóna bons resultats degut a què el residu d’origen domèstic està ben caracteritzat. L’únic gran problema que es planteja són les limitacions econòmiques i pressupostàries d’una petita comunitat que ha de complir amb les normatives d’abocament vigents

Description of surface transport in the region of the Belizean Barrier Reef based on observations and alternative high-resolution models

Author Posting. © The Author(s), 2015. This is the author's version of the work. It is posted here for personal use, not for redistribution. The definitive version was published in Ocean Modelling 106 (2016): 74–89, doi:10.1016/j.ocemod.2016.09.010.The gains from implementing high-resolution versus less costly low-resolution models to describe coastal circulation are not always clear, often lacking statistical evaluation. Here we construct a hierarchy of ocean-atmosphere models operating at multiple scales within a 1×1° domain of the Belizean Barrier Reef (BBR). The various components of the atmosphere-ocean models are evaluated with in situ observations of surface drifters, wind and sea surface temperature. First, we compare the dispersion and velocity of 55 surface drifters released in the field in summer 2013 to the dispersion and velocity of simulated drifters under alternative model configurations. Increasing the resolution of the ocean model (from 1/12° to 1/100°, from 1 day to 1 h) and atmosphere model forcing (from 1/2° to 1/100°, from 6 h to 1 h), and incorporating tidal forcing incrementally reduces discrepancy between simulated and observed velocities and dispersion. Next, in trying to understand why the high-resolution models improve prediction, we find that resolving both the diurnal sea-breeze and semi-diurnal tides is key to improving the Lagrangian statistics and transport predictions along the BBR. Notably, the model with the highest ocean-atmosphere resolution and with tidal forcing generates a higher number of looping trajectories and sub-mesoscale coherent structures that are otherwise unresolved. Finally, simulations conducted with this model from June to August of 2013 show an intensification of the velocity fields throughout the summer and reveal a mesoscale anticyclonic circulation around Glovers Reef, and sub-mesoscale cyclonic eddies formed in the vicinity of Columbus Island. This study provides a general framework to assess the best surface transport prediction from alternative ocean-atmosphere models using metrics derived from high frequency drifters’ data and meteorological stations.This research is supported by the National Science Foundation award NSF-OCE 1260424

Modeling Dispersal of UV Filters in Estuaries

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Environmental Science & Technology, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see: http://dx.doi.org/10.1021/acs.est.8b03725Lagrangian ocean analysis, where virtual parcels of water are tracked through hydrodynamic fields, provides an increasingly popular framework to predict the dispersal of water parcels carrying particles and chemicals. We conduct the first direct test of Lagrangian predictions for emerging contaminants using (1) the latitude, longitude, depth, sampling date, and concentrations of UV filters in raft cultured mussel (Mytilus galloprovincialis) of the estuary Ria de Arousa, Spain (42.5°N, 8.9°W); (2) a hydrodynamic numerical model at 300 m spatial resolution; and (3) a Lagrangian dispersion scheme to trace polluted water parcels back to pollution sources. The expected dispersal distances (mean ± SD) are 2 ± 1 km and the expected dispersal times (mean ± SD) are 6 ± 2 h. Remarkably, the probability of dispersal of UV filters from potential sources to rafts decreases 5-fold over 5 km. In addition to predicting dispersal pathways and times, this study also provides a framework for quantitative investigations of concentrations of emerging contaminants and source apportionment using turbulent diffusion. In the coastline, the ranges of predicted concentrations of the UV-filters 4-methylbenzylidene-camphor, octocrylene, and benzophenone-4 are 3.2 × 10–4 to 0.023 ng/mL, 2.3 × 10–5 to 0.009 ng/mL, and 5.6 × 10–4 to 0.013 ng/mL, respectively. At the outfalls of urban wastewater treatment plants these respective ranges increase to 8.9 × 10–4 to 0.07 ng/mL, 6.2 × 10–5 to 0.027 ng/mL, and 1.6 × 10–3 to 0.040 ng/mL.This research is supported by the Spanish State Research Agency projects CTM2014-56628-C3-2-R, CTM2014-56628-C3-3-R, CTM2017-84763-C3-2-R, CTM2017-84763-C3-3-R, and CTM2017-90890-REDT (MINECO/AEI/FEDER, EU). This work used the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by the National Science Foundation grant number NSF-OCE170005S

Natural variability of surface oceanographic conditions in the offshore Gulf of Mexico

AbstractThis work characterizes patterns of temporal variability in surface waters of the central Gulf of Mexico. We examine remote-sensing based observations of sea surface temperature (SST), wind speed, sea surface height anomaly (SSHA), chlorophyll-a concentration (Chl-a) and Net Primary Production (NPP), along with model predictions of mixed layer depth (MLD), to determine seasonal changes and long-term trends in the central Gulf of Mexico between the early 1980s and 2012. Specifically, we examine variability in four quadrants of the Gulf of Mexico (water depth >1000m). All variables show strong seasonality. Chl-a and NPP show positive anomalies in response to short-term increases in wind speed and to cold temperature events. The depth of the mixed layer (MLD) directly and significantly affects primary productivity throughout the region. This relationship is sufficiently robust to enable real-time estimates of MLD based on satellite-based estimates of NPP. Over the past 15–20years, SST, wind speed, and SSHA show a statistically significant, gradual increase. However, Chl-a and NPP show no significant trends over this period. There has also been no trend in the MLD in the Gulf of Mexico interior. The positive long-term trend in wind speed and SST anomalies is consistent with the warming phase of the Atlantic Multidecadal Oscillation (AMO) that started in the mid-90s. This also coincides with a negative trend in the El Niño/Southern Oscillation Multivariate ENSO Index (MEI) related to an increase in the frequency of cooler ENSO events since 1999–2000. The results suggest that over decadal scales, increasing temperature, wind speed, and mesoscale ocean activity have offsetting effects on the MLD. The lack of a trend in MLD anomalies over the past 20years explains the lack of long-term changes in chlorophyll concentration and productivity over this period in the Gulf. Understanding the background of seasonal and long-term variability in these ocean characteristics is important to interpret changes in ocean health due to episodic natural and anthropogenic events and long term climate changes or development activities. With this analysis we provide a baseline against which such changes can be measured

Projecte de construcció de l’EDAR de Nuñomoral (Las Hurdes, Càceres)

El projecte de construcció de l’EDAR de Nuñomoral parteix de dos objectius clars.El primer objectiu és definir i valorar les obres d’infrastructura de sanejament i depuració, mitjançant un sistema compacte, de les aigües residuals urbanes de Nuñomoral, un dels sis municipis de la Mancomunitat que constitueix Las Hurdes.Degut a la gran similitud tant orogràfica com demogràfica dels sis municipis de Las Hurdes, aquest projecte també es marca l’objectiu de ser una guia a seguir per a la construcció dexarxa de depuradores que la zona necessita.La metodologia que s'ha aplicat en aquest projecte contempla un profund estudi de la literatura especialitzada en el tema, una recopilació de la informació de població, un inventari d’infraestructura de sanejament i abocaments, un reconeixement geològic, l’estudi del marc legal espanyol i extremeny referent a aigües residuals urbanes, i finalment l’anàlisi de les alternatives.Com a resultat d’aquest mètode previ, es projectarà una estació depuradora d’aigües residuals que es fonamenti en un procés biològic de fangs actius de doble etapa.Donat que al municipi d’estudi hi ha fortes oscil·lacions de cabal i càrrega en els períodes de baixa i alta ocupació poblacional, aquesta solució resulta idònia ja que permet, a l’etapa alta treballar amb la doble etapa, i a l’etapa baixa treballar amb la segona etapa del procés i així ajustar els consums i el funcionament a les necessitats reals. A més, la solució adoptada té un baix consum energètic, un baix cost de manteniment, un reduït volum de fangs produïtsminimitza l’excavació necessària per a la seva implantació i el seu impacte ambiental.En general el disseny d’una depuradora d’aigües residuals per a un petit nucli urbà dóna bons resultats degut a què el residu d’origen domèstic està ben caracteritzat. L’únic gran problema que es planteja són les limitacions econòmiques i pressupostàries d’una petita comunitat que ha de complir amb les normatives d’abocament vigents

Trajectories of fifty-five biodegradable drifters in the Belizean Barrier Reef.

Dataset: Drifter dataTrajectories of fifty-five biodegradable drifters in the Belizean Barrier Reef. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/729896NSF Division of Ocean Sciences (NSF OCE) OCE-126042

Vertical Structure of the Water Column at the Virgin Islands Shelf Break and Trough

The steep US Virgin Islands Shelf Break (VISB) and the Virgin Islands Trough (VIT) at the Northeastern Caribbean Sea comprise a dynamic region of the Atlantic Ocean. In situ oceanographic data collected in the region during April 2017 were used to examine the spatial variability in temperature, density, salinity, and relative Chlorophyll-a. Analysis of data from the upper 300 m of the water column, that include deep and shallow water stations in the shelf break region, shows strong stratification of the water column. Stations shallower than 800 m along the shelf break are more variable in temperature, density, and salinity than those that are deeper than 800 m along the trough. For shallow stations, the mixed layer depth deepens along-shelf from West to East while at the deep stations the opposite occurs. Salinity maxima exhibit more variability in depth and range of values in the shallow stations compared to deep stations. Six different types of water masses that contribute to the strong stratification in the region were identified in our study: Caribbean Surface Water, Subtropical Underwater, Sargasso Sea Water, Tropical Atlantic Central Water, Antarctic Intermediate Water, and North Atlantic Deep Water. The upper level Caribbean Surface Water, Subtropical Underwater, and Sargasso Sea Water are present in shallow stations, indicating potential meridional intrusions from the VIT to the VISB which may not be resolved by current ocean circulation models and are not captured in satellite data. The analysis presented here indicates that competing physical processes may be controlling the vertical structure of the water column in the region and merit further examination

Eddies in the Hawaiian archipelago region: formation, characterization, and potential implications on larval retention of reef fish

Author Posting. © American Geophysical Union, 2020. 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: Oceans 125(5), (2020): e2019JC015348, doi:10.1029/2019JC015348.Here we present an assessment of eddy activity in a 3,500 × 2,000 km region of the North Pacific. Eddies were identified and tracked within a numerical simulation that used the Massachusetts Institute of Technology general circulation model and an eddy characterization algorithm. Spatially, eddy births were more frequent: (1) nearshore (cyclones) and offshore (anticyclones) on the windward side of the main Hawai‘ian Islands; (2) in patches of cyclones and anticyclones that resembled the dipole structure of wind stress curl along the islands’ leeward side; and (3) in zonal patches of eddies of both polarities west and north of the islands. Temporally, high eddy activities occurred in spring. There was a meridional distribution of eddy lifespans, which increased northward. Cyclones were more abundant, longer‐lived, smaller, and more nonlinear. Reef fish spawning locations in Hawai‘i coincide with the regions of high eddy activity, with nonlinear eddies responsible for high larval retention.This work was supported by the National Ocean and Atmospheric Administration (NOAA) Fisheries And The Environment (FATE) Award WE133F17SE1020. This work used the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by the National Science Foundation Grant NSF‐OCE170005.2020-10-2

Modeling dispersal of UV-filters in estuaries

Lagrangian ocean analysis, where virtual parcels of water are tracked through hydrodynamic fields, provides an increasingly popular framework to predict the dispersal of water parcels carrying particles and chemicals. We conduct the first direct test of Lagrangian predictions for emerging contaminants using (1) the latitude, longitude, depth, sampling date, and concentrations of UV filters in raft cultured mussel (Mytilus galloprovincialis) of the estuary Ria de Arousa, Spain (42.5°N, 8.9°W); (2) a hydrodynamic numerical model at 300 m spatial resolution; and (3) a Lagrangian dispersion scheme to trace polluted water parcels back to pollution sources. The expected dispersal distances (mean ± SD) are 2 ± 1 km and the expected dispersal times (mean ± SD) are 6 ± 2 h. Remarkably, the probability of dispersal of UV filters from potential sources to rafts decreases 5-fold over 5 km. In addition to predicting dispersal pathways and times, this study also provides a framework for quantitative investigations of concentrations of emerging contaminants and source apportionment using turbulent diffusion. In the coastline, the ranges of predicted concentrations of the UV-filters 4-methylbenzylidene-camphor, octocrylene, and benzophenone-4 are 3.2 × 10-4 to 0.023 ng/mL, 2.3 × 10-5 to 0.009 ng/mL, and 5.6 × 10-4 to 0.013 ng/mL, respectively. At the outfalls of urban wastewater treatment plants these respective ranges increase to 8.9 × 10-4 to 0.07 ng/mL, 6.2 × 10-5 to 0.027 ng/mL, and 1.6 × 10-3 to 0.040 ng/mL