Biogeochemical modelling of upper ocean sulfur dynamics and its impact on cloud forming aerosols

Memoria de tesis doctoral presentada por Sergio M. Vallina Fernández para obtener el título de Doctor en Ciencias del Mar por la Universitat Politècnica de Catalunya (UPC), realizada bajo la dirección del Dr. Rafel Simó Martorell del Institut de Ciències del Mar (ICM-CSIC).-- 168 pages[EN] The CLAW hypothesis postulates that an increase in solar irradiance or in the heat flux to the ocean can trigger a biogeochemical response to counteract the associated increase in temperature and available sunlight. This natural (negative) feedback mechanism would be based on a multi-step response: first, an increase in seawater dimethylsulfide concentrations (DMSw ) and then its fluxes to the atmosphere (DMSflux ); second, an increase in the atmospheric cloud condensation nuclei (CCN) burden as a consequence of DMS oxidation to form biogenic CCN (CCNbio ); third, an increase in cloud albedo due to higher CCN numbers. Therefore, DMS is suggested to exert a cooling effect on the Earth radiative budget through its involvement in the formation and optical properties of tropospheric clouds over the ocean. Such a feedback has been regarded as a potential natural mechanism that might partly counteract anthropogenic GlobalWarming. This hypothesis, although suggestive, is highly speculative and some of itsmain postulates remain unproved. In this study we sought to contribute to the current knowledge of the oceanic biogenic sulfur cycle and its potential impact on climate by addressing some relevant open questions regarding the CLAW hypothesis. The climatic factor that drives oceanic DMS production, the impact of DMS oxidation on atmospheric CCN, and the potentiality of DMS to counteract Global Warming are investigated in detail based on modeling and data analyses. A new one-dimensional (1D) model of DMS dynamics (DMOS) is developed and coupled to a pre-existing ecological model that explicitly simulates the microbial-loop. The model is applied to the Sargasso Sea in order to explain what drives DMS seasonality. We have conducted a series of modeling experiments where some of the DMOS sulfur paths are turned ’off’ or ’on’, and the results on chlorophyll-a, dimethylsulfoniopropionate (DMSP; the DMS precursor) and DMS concentrations have been compared with the vertical profiles of these same variables measured during the years 1992 through 1993. Solar-induced DMS exudation by phytoplankton outstands as the process without which the model is unable to produce realistic DMS simulations and reproduce the DMS summer-paradox. The analysis of a global DMS database as well as local DMS time-series (Blanes Bay and Sargasso Sea) have revealed that it is the solar radiation dose in the upper mixed layer (or SRD) the climatic factor that seems to drive DMS dynamics. With a spatially resolved perspective, our analysis of globally derived SRD and DMS climatologies shows that the seasonal couplings between SRD and DMS are very tight and widespread over the Global Ocean, irrespective of latitude, temperature, and phytoplankton biomass. From these results, we have been able to obtain a global predictive diagnostic equation that relates DMS concentrations to the SRD. Statistical analyses of satellite and model-derived global data of several oceanic and atmospheric variables suggest that DMS oxidation can indeed be a major source of CCN over oceanic regions far from continental aerosol sources (eg. Southern Ocean, Subtropical South Pacific), especially in summer when the oxidation efficiency of DMS is the highest. Small sea-salt (SS) aerosols, although quantitatively important, do not seem to control CCN seasonality over the Southern Ocean, a region were SS production is amongst the highest of the world due to the constant presence of strong winds. Rather, they appear to conform a fairly constant background of CCN. Differences in the seasonalities of wind speed and the small-mode fraction of aerosols support these conclusions. [...][ES] La hipótesis de CLAW establece que un incremento en la radiación solar o de los flujos de calor hacia el océano puede producir una respuesta biogeoquímica para contrarrestar el incremento de temperatura o radiación solar. Este mecanismo de retroalimentación se produciría en varios pasos: primero, habría un incremento de la concentración de dimetilsulfuro disuelto en la superficie del océano (DMSw ) y por tanto de su emisión a la atmósfera; segundo, como consecuencia de la oxidación del DMS en la atmósfera se produciría un incremento de la producción de núcleos de condensación de nubes (CCN) de origen biogénico (CCNbio ); tercero, gracias al incremento en CCN se aumentaría el albedo de las nubes. Por tanto, se ha sugerido que el DMS da lugar a un efecto refrigerante sobre los flujos radiativos de la Tierra a través de su efecto sobre la formación y las propiedades ópticas de las nubes de la troposfera oceánica. Dicho mecanismo de retroalimentación se ha propuesto que puede actuar como un proceso natural que podría contrarrestar en parte el Calentamiento Global de origen antropogénico. Esta hipótesis, aunque sugestiva, es muy especulativa y algunos de sus postulados principales continúan sin haber sido probados. En este estudio se pretende contribuir al conocimiento actual del ciclo del azufre biogénico marino y de su impacto potencial en el clima en base a abordar algunas preguntas que permanecen sin respuesta con respecto a la hipótesis de CLAW. El factor climático que gobierna la producción oceánica de DMS, el impacto de la oxidación atmosférica del DMS en los CCN, y el potencial de DMS para contrarrestar el Calentamiento Global son investigados en profundidad basándose en modelización y en el análisis de datos. Se ha desarrollado un modelo en una dimensión (1D) de la dinámica del DMS (bautizado ’DMOS’) y se acopló a un modelo de ecosistema pelágico pre-existente que simulaba explícitamente el bucle microbiano. El modelo se aplica al Mar de los Sargazos para intentar explicar qué proceso dirige la estacionalidad del DMS. Se realizaron una serie de experimentos (virtuales) con el modelo a partir de activar o desactivar algunos de los procesos presentes en DMOS. Las simulaciones obtenidas de clorofila-a, dimetilsulfoniopropionato (DMSP; el precursor del DMS), así como las concentraciones de DMS se comparan con perfiles verticales de las mismas variablesmedidos in-situ durante los años 1992 y 1993. La exudación de DMS por parte del fitoplancton como respuesta a altos niveles de radiación solar aparece como el proceso clave, sin el cual el modelo no es capaz de simular correctamente el DMS ni reproducir la ’DMS summer-paradox’. El análisis de una base de datos global de DMS así como de series temporales de DMS en lugares específicos (la Bahía de Blanes y el Mar de los Sargazos) reveló que la radiación solar recibida en la capa de mezcla oceánica (o SRD) es el factor climático que parece dirigir la dinámica del DMS. Desde un punto de vista global pero teniendo en cuenta la distribución espacial, el análisis de mapas globales mensuales climatológicos de SRD y DMS muestran que el acoplamiento estacional entre SRD y DMS es muy alto en la gran mayoría de la superficie oceánica, sin importar la latitud, temperatura o biomasa de fitoplancton. A partir de estos resultados se ha obtenido una ecuación predictiva diagnóstica que relaciona la concentración de DMS con la SRD. [...]This thesis has been funded by the Spanish “Ministry of Education and Science” (MEC) through a PhD studentship under the program “Formación de Personal Investigador” (FPI)Peer Reviewe

Mare Incognitum: A Glimpse into Future Plankton Diversity and Ecology Research

Chust, Guillem ... et al.-- 9 pages, 1 figure.-- Corrigendum: Mare Incognitum: A Glimpse into Future Plankton Diversity and Ecology Research, Frontiers in Marine Science 4: 122 (2017) https://doi.org/10.3389/fmars.2017.00122With global climate change altering marine ecosystems, research on plankton ecology is likely to navigate uncharted seas. Yet, a staggering wealth of new plankton observations, integrated with recent advances in marine ecosystem modeling, may shed light on marine ecosystem structure and functioning. A EuroMarine foresight workshop on the “Impact of climate change on the distribution of plankton functional and phylogenetic diversity” (PlankDiv) identified five grand challenges for future plankton diversity and macroecology research: (1) What can we learn about plankton communities from the new wealth of high-throughput “omics” data? (2) What is the link between plankton diversity and ecosystem function? (3) How can species distribution models be adapted to represent plankton biogeography? (4) How will plankton biogeography be altered due to anthropogenic climate change? and (5) Can a new unifying theory of macroecology be developed based on plankton ecology studies? In this review, we discuss potential future avenues to address these questions, and challenges that need to be tackled along the wayThis research was funded by the EuroMarine Network (http://www.euromarinenetwork.eu), through the organization of the PlankDiv EuroMarine Foresight workshop, held at the Observatoire Océanographique de Villefranche-sur-mer, Villefranche-sur-mer, France, in March 2016, and cofounded by the Basque Government (Department Deputy of Agriculture, Fishing and Food Policy). The PlankDiv workshop was also supported by the Laboratoire d'Océanographie de Villefranche-sur-mer (LOV, UPMC/CNRS), the PlankMed action of WP5 MERMEX/MISTRAL, and by the French national programme EC2CO-LEFE (FunOmics project).Peer Reviewe

Marine Primary Productivity Is Driven by a Selection Effect

10 páginas, 6 figuras, 1 tabla.-- Pedro Cermeño ... et al.-- This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these termsThe number of species of autotrophic communities can increase ecosystem productivity through species complementarity or through a selection effect which occurs when the biomass of the community approaches the monoculture biomass of the most productive species. Here we explore the effect of resource supply on marine primary productivity under the premise that the high local species richness of phytoplankton communities increases resource use through transient selection of productive species. Using concurrent measurements of phytoplankton community structure, nitrate fluxes into the euphotic zone, and productivity from a temperate coastal ecosystem, we find that observed productivities are best described by a population growth model in which the dominant species of the community approach their maximum growth rates. We interpret these results as evidence of species selection in communities containing a vast taxonomic repertory. The prevalence of selection effect was supported by open ocean data that show an increase in species dominance across a gradient of nutrient availability. These results highlight the way marine phytoplankton optimize resources and sustain world food stocks. We suggest that the maintenance of phytoplankton species richness is essential to sustain marine primary productivity since it guarantees the occurrence of highly productive speciesThis research was supported by grants CTM2011-25035, CTM2012-30680, and CGL2013-41256-P from the Spanish Government (SG). PC and SV are supported by Ramon y Cajal contracts from the SGPeer reviewe

Disentangling environmental effects in microbial association networks

Background Ecological interactions among microorganisms are fundamental for ecosystem function, yet they are mostly unknown or poorly understood. High-throughput-omics can indicate microbial interactions through associations across time and space, which can be represented as association networks. Associations could result from either ecological interactions between microorganisms, or from environmental selection, where the association is environmentally driven. Therefore, before downstream analysis and interpretation, we need to distinguish the nature of the association, particularly if it is due to environmental selection or not. Results We present EnDED (environmentally driven edge detection), an implementation of four approaches as well as their combination to predict which links between microorganisms in an association network are environmentally driven. The four approaches are sign pattern, overlap, interaction information, and data processing inequality. We tested EnDED on networks from simulated data of 50 microorganisms. The networks contained on average 50 nodes and 1087 edges, of which 60 were true interactions but 1026 false associations (i.e., environmentally driven or due to chance). Applying each method individually, we detected a moderate to high number of environmentally driven edges—87% sign pattern and overlap, 67% interaction information, and 44% data processing inequality. Combining these methods in an intersection approach resulted in retaining more interactions, both true and false (32% of environmentally driven associations). After validation with the simulated datasets, we applied EnDED on a marine microbial network inferred from 10 years of monthly observations of microbial-plankton abundance. The intersection combination predicted that 8.3% of the associations were environmentally driven, while individual methods predicted 24.8% (data processing inequality), 25.7% (interaction information), and up to 84.6% (sign pattern as well as overlap). The fraction of environmentally driven edges among negative microbial associations in the real network increased rapidly with the number of environmental factors. Conclusions To reach accurate hypotheses about ecological interactions, it is important to determine, quantify, and remove environmentally driven associations in marine microbial association networks. For that, EnDED offers up to four individual methods as well as their combination. However, especially for the intersection combination, we suggest using EnDED with other strategies to reduce the number of false associations and consequently the number of potential interaction hypotheses. Video abstrac

Girişimciliğin ilk aşamasında finansman temin yolları ve finansman temininde karşılaşılan sorunlar: Gaziantep ilinde bir uygulama

Bugün işletmeler gelişen dünya pazarlarında rekabette bulunarak ekonomik ve finansal açıdan avantaj sağlamaktadırlar. İşletmeler, girişimcilerin temel özellikleri ile teknolojiyi kullanan ve geliştiren işletmeler olarak ülkelerin kalkınmasında önemli rol oynamaktadır. Teknolojik yeniliklerin yanında inovasyona da yatırım yaparak gelişimlerini tamamlarlar. Ancak her alanda olduğu gibi, girişimciler finansal açıdan da sorunlarla karşılaşmaktadırlar. Dolayısıyla işletme sayısının artarak ülkeye katkıda bulunabilmesi için finansman teminindeki sorunları farklı olan girişimcilerin desteklenmeleri ve yönlendirilmeleri gerekmektedir. Bu noktada, girişimcileri desteklemek amacıyla kamu kurum ve kuruluşları ve diğer kuruluşlar faaliyetlerini sürdürmektedir. Bu araştırmanın temel amacı, girişimciliğin ilk aşamasında finans temin yollarının belirlenerek finansman temin yönteminde karşılaşılan sorunları ortaya koymaktır. Bununla birlikte, bu çalışmada Türkiye’de girişimciliğin temel özellikleri, girişimcilik finansman türleri ve finansman temininde karşılaşılan sorunlara yönelik önerilerin sunulması amaçlanmaktadır. Araştırma kapsamında nitel ve nicel araştırma yöntemleri uygulanmıştır. Nicel araştırma kapsamında, 408 girişimciye anket uygulanmış, nitel araştırma kapsamında ise 180 girişimciyle yüz yüze görüşmeler yapılmıştır. Araştırma yöntemlerinden elde edilen veriler, çeşitli istatistiksel analizlere tabi tutulmuştur. Girişimciliğin ilk aşamasında, girişimcilerin finansman temininde karşılaştıkları sorunlar belirlenerek, bu sorunlara yönelik çözüm önerilerinde bulunulmuştur. Bu araştırmanın sonucunda, girişimciliğin ilk aşamasında, girişimcilerin finansman temin yöntemi konusunda yeterli derecede bilgi sahibi olmadıkları ve kendi kaynaklarını daha çok kullandıkları tespit edilmiştir

Modelling the effect of the tidal cycle on the high phytoplankton biomass area of Cape Trafalgar (SW Iberian Peninsula)

Physical-biological interactions in the ocean are known to be crucial for understanding ecosystem processes. This is particularly relevant in the highly dynamic coastal regions, where the biogeochemical processes associated with higher-frequency perturbations such as tidal waves play a key role in primary production. In this study, we examine the influence of the tide-topography interaction on the high productivity area of Cape Trafalgar (NW limit of the Strait of Gibraltar, Iberian Peninsula) using a high-resolution ocean circulation model coupled to an ecosystem model. The obtained results highlight the relevance of the tidal cycle explaining the high phytoplankton biomass that characterises this region through an active and periodic forcing, resulting in a pulsating upwelling system. Our model shows that the interaction of the westward zonal component of the tidal current (uvel) with the submarine ridge (i.e., Barbate High) that characterises this region, which is perpendicular to the coast, results in the pumping of deep, cold, salty, and nutrient-rich waters to the well-illuminated subsurface waters, fuelling phytoplankton growth. At the same time, the interaction of the westward tidal current with the ridge leads to the development of a cyclonic eddy, which enables the redistribution of the upwelled waters over and to the east of Barbate High. The fortnightly tidal period has been identified as the most influential because (an effective) tidal-pumping process only takes place when the westward uvel is ∼0.42 m s−1, a condition attained between ∼3 days before and after the moment of maximum tidal flow during spring tides. Simultaneously, the energy and the associated horizontal and vertical mixing of the cyclonic gyre also vary with the tidal cycle, being stronger during spring tides. Both tidally driven processes, i.e., the cyclical upslope advection of deep nutrient-rich water and the influence of the cyclonic gyre, are the main mechanisms that lead to the development of a persistent phytoplankton-rich tongue over Barbate High. Consequently, Cape Trafalgar acts as a source of nutrient- and phytoplankton-rich waters to the surrounding waters

El poder dels productors primaris unicel·lulars

3 pages, 1 figure[EN] Marine phytoplankton, including cyanobacteria and microalgae, dominates primary production across two thirds of the earth’s surface, sustaining virtually all marine life and exerting a fundamental control over global climate through carbon sequestration into the deep ocean. These unicellular photoautotrophs are responsible for roughly 50% of global net primary production, which is equivalent to producing 50 gigatons of organic carbon (C) per year (about 140 million t per day). […][ES] El fitoplancton marino, que incluye tanto a las cianobacterias como a las microalgas, domina la producción primaria en dos tercios de la superficie de la Tierra, sustentando prácticamente toda la vida marina y ejerciendo un control fundamental sobre el clima global mediante el secuestro de carbono en las profundidades del océano. Estos productores primarios unicelulares son responsables de aproximadamente el 50% de la producción primaria neta mundial, lo que equivale a producir 50 gigatoneladas de carbono orgánico (C) al año (alrededor de 140 millones de toneladas al día). […][CAT] El fitoplàncton marí, que inclou tant als cianobacteris com a les microalgues, domina la producció primària en dos terços de la superfície de la Terra, sustentant pràcticament tota la vida marina i exercint un control fonamental sobre el clima global mitjançant el segrest de carboni en les profunditats de l’oceà. Aquests productors primaris unicel·lulars són responsables d’aproximadament el 50% de la producció primària neta mundial, la qual cosa equival a produir 50 gigatones de carboni orgànic (C) l’any (al voltant de 140 milions de tones al dia). […]The ideas embodied in this essay are part of the objectives of the PRODIGIO project “Developing early warning systems for improved microalgae PROduction and anaerobic DIGgestIOn”. The PRODIGIO project has received funding from the European Union’s Horizon 2020 Research and Innovation programme under grant agreement no. 101007006Peer reviewe

Nutrient supply does play a role on the structure of marine picophytoplankton communities

Conference communicationThe Margalef´s mandala (1978) is a simplified bottom-up control model that explains how mixing and nutrient concentration determine the composition of marine phytoplankton communities. Due to the difficulties of measuring turbulence in the field, previous attempts to verify this model have applied different proxies for nutrient supply, and very often used interchangeably the terms mixing and stratification. Moreover, because the mandala was conceived before the discovery of smaller phytoplankton groups (picoplankton <2 µm), it describes only the succession of vegetative phases of microplankton. In order to test the applicability of the classical mandala to picoplankton groups, we used a multidisciplinary approach including specifically designed field observations supported by remote sensing, database analyses, and modeling and laboratory chemostat experiments. Simultaneous estimates of nitrate diffusive fluxes, derived from microturbulence observations, and picoplankton abundance collected in more than 200 stations, spanning widely different hydrographic regimes, showed that the contribution of eukaryotes to picoautotrophic biomass increases with nutrient supply, whereas that of picocyanobacteria shows the opposite trend. These findings were supported by laboratory and modeling chemostat experiments that reproduced the competitive dynamics between picoeukaryote sand picocyanobacteria as a function of changing nutrient supply. Our results indicate that nutrient supply controls the distribution of picoplankton functional groups in the ocean, further supporting the model proposed by Margalef.Spanish Governmen

Tratamientos psicológicos empíricamente apoyados para adultos: Una revisión selectiva

Antecedentes: los tratamientos psicológicos han mostrado su eficacia, efectividad y eficiencia para el abordaje de los trastornos mentales; no obstante, considerando el conocimiento científico generado en los últimos años, no se dispone de trabajos de actualización en español sobre cuáles son los tratamientos psicológicos con respaldo empírico. El objetivo fue realizar una revisión selectiva de los principales tratamientos psicológicos empíricamente apoyados para el abordaje de trastornos mentales en personas adultas. Método: se recogen niveles de evidencia y grados de recomendación en función de los criterios propuestos por el Sistema Nacional de Salud de España (en las Guías de Práctica Clínica) para diferentes trastornos psicológicos. Resultados: los resultados sugieren que los tratamientos psicológicos disponen de apoyo empírico para el abordaje de un amplio elenco de trastornos psicológicos. El grado de apoyo empírico oscila de bajo a alto en función del trastorno psicológico analizado. La revisión sugiere que ciertos campos de intervención necesitan una mayor investigación. Conclusiones: a partir de esta revisión selectiva, los profesionales de la psicología podrán disponer de información rigurosa y actualizada que les permita tomar decisiones informadas a la hora de implementar aquellos procedimientos psicoterapéuticos empíricamente fundamentados en función de las características de las personas que demandan ayuda. Background: Psychological treatments have shown their efficacy, effectiveness, and efficiency in dealing with mental disorders. However, considering the scientific knowledge generated in recent years, in the Spanish context, there are no updating studies about empirically supported psychological treatments. The main goal was to carry out a selective review of the main empirically supported psychological treatments for mental disorders in adults. Method: Levels of evidence and degrees of recommendation were collected based on the criteria proposed by the Spanish National Health System (Clinical Practice Guidelines) for different psychological disorders. Results: The results indicate that psychological treatments have empirical support for the approach to a wide range of psychological disorders. These levels of empirical evidence gathered range from low to high depending on the psychological disorder analysed. The review indicates the existence of certain fields of intervention that need further investigation. Conclusions: Based on this selective review, psychology professionals will be able to have rigorous, up-to-date information that allows them to make informed decisions when implementing empirically based psychotherapeutic procedures based on the characteristics of the people who require help

What controls CCN seasonality in the Southern Ocean? A statistical analysis based on satellite-derived chlorophyll and CCN and model-estimated OH radical and rainfall

13 pages, 4 figuresA 3-year time series set (from January 2002 to December 2004) of monthly means of satellite-derived chlorophyll (CHL) and cloud condensation nuclei (CCN), as well as model outputs of hydroxyl radical (OH), rainfall amount (RAIN), and wind speed (WIND) for the Southern Ocean (SO, 40°S–60°S) is analyzed in order to explain CCN seasonality. Chlorophyll is used as a proxy for oceanic dimethylsulfide (DMS) emissions since both climatological aqueous DMS and atmospheric methanesulfonate (MSA) concentrations are tightly coupled with chlorophyll seasonality over the Southern Ocean. OH is included as the main atmospheric oxidant of DMS to produce CCN, and rainfall amount as the main loss factor for CCN through aerosol scavenging. Wind speed is used as a proxy for sea salt (SS) particles production. The CCN concentration seasonality is characterized by a clear pattern of higher values during austral summer and lower values during austral winter. Linear and multiple regression analyses reveal high significant correlations between CCN and the product of chlorophyll and OH (in phase) and rainfall amount (in antiphase). Also, CCN concentrations are anticorrelated with wind speed, which shows very little variability and a slight wintertime increase, in agreement with the sea salt seasonality reported in the literature. Finally, the fraction of the total aerosol optical depth contributed by small particles (ETA) exhibits a seasonality with a 3.5-fold increase from austral winter to austral summer. The biogenic contribution to CCN is estimated to vary between 35% (winter) and 80% (summer). Sea salt particles, although contributing an important fraction of the CCN burden, do not play a role in controlling CCN seasonality over the SO. These findings support the central role of biogenic DMS emissions in controlling not only the number but also the variability of CCN over the remote oceanThis work is part of the AMIGOS project, funded by the Spanish Ministerio de Ciencia y TecnologíaPeer reviewe