Le rôle climatique des fronts océaniques de fine échelle en profondeur (prix Prud'homme 2020)

2021 ◽  
pp. 038
Author(s):  
Lia Siegelman
Keyword(s):  
Storage Capacity ◽  
Heat Storage ◽  
Spatial Scales ◽  
Surface Mixed Layer ◽  
Fine Scale ◽  
Pulmonary Alveoli ◽  
The Past ◽  
Oceanic Surface ◽  
Atmospheric Fronts ◽  
First Time

L'océan est le plus grand réservoir d'énergie de notre planète. La quantité de chaleur qu'il est capable de stocker est modulée par sa circulation complexe, opérant sur des échelles allant du centimètre à la dizaine de milliers de kilomètres. Les découvertes scientifiques des deux dernières décennies ont révélé l'existence de fronts de fine échelle (d'environ 1 à 50 km), analogues aux fronts atmosphériques, dans la couche de mélange océanique de surface. Ces fronts agissent comme des conduits entre l'océan et l'atmosphère, contrôlant les échanges de gaz et de chaleur. Combinant observation et modélisation, nous démontrons pour la première fois le rôle capital de ces fronts jusqu'à 1000 m de profondeur. Ils génèrent d'importants flux de chaleur dirigés de l'intérieur de l'océan vers la surface, pouvant modifier la capacité de stockage de chaleur de l'océan, avec des répercussions potentiellement majeures pour les systèmes biogéochimique et climatique. The ocean is the largest solar energy collector on Earth. The amount of heat it can store is modulated by its complex circulation, which spans a broad range of spatial scales, from centimeters to thousands of kilometers. Scientific discoveries of the past two decades revealed the existence of fine-scale fronts (≈ 10-20 km wide), analogous to atmospheric fronts, in the oceanic surface mixed layer. These fronts control the exchanges between the ocean and the atmosphere just as the capillary vessels of our pulmonary alveoli facilitate the exchange of gas when breathing. Combining observation and modeling, we demonstrate for the first time the crucial role played by these fronts in the ocean interior. These fine-scale fronts drive an anomalous upward heat transport from the ocean interior back to the surface. This can alter the ocean heat storage capacity, with potential major implications for the biogeochemical and climate systems.

Persistence in the fine-scale distribution and spatial aggregation of fishing

2018 ◽  
Vol 76 (4) ◽  
pp. 1072-1082 ◽  
Author(s):  
Niels T Hintzen ◽  
Geert Aarts ◽  
Adriaan D Rijnsdorp
Keyword(s):  
High Stability ◽  
Large Scale ◽  
Spatial Scales ◽  
Negative Relationship ◽  
Fishing Effort ◽  
Local Scale ◽  
Fine Scale ◽  
Effort Allocation ◽  
The Stability ◽  
First Time

Abstract High-resolution vessel monitoring (VMS) data have led to detailed estimates of the distribution of fishing in both time and space. While several studies have documented large-scale changes in fishing distribution, fine-scale patterns are still poorly documented, despite VMS data allowing for such analyses. We apply a methodology that can explain and predict effort allocation at fine spatial scales; a scale relevant to assess impact on the benthic ecosystem. This study uses VMS data to quantify the stability of fishing grounds (i.e. aggregated fishing effort) at a microscale (tens of meters). The model links effort registered at a large scale (ICES rectangle; 1° longitude × 0.5° latitude, ˜3600 km2) to fine spatial trawling intensities at a local scale (i.e. scale matching gear width, here 24 m). For the first time in the literature, the method estimates the part of an ICES rectangle that is unfavourable or inaccessible for fisheries, which is shown to be highly stable over time and suggests higher proportions of inaccessible grounds for either extremely muddy or courser substrates. The study furthermore shows high stability in aggregation of fishing, where aggregation shows a positive relationship with depth heterogeneity and a negative relationship with year-on-year variability in fishing intensity.

Mixed Layer Instabilities and Restratification

2007 ◽  
Vol 37 (9) ◽  
pp. 2228-2250 ◽  
Author(s):  
Giulio Boccaletti ◽  
Raffaele Ferrari ◽  
Baylor Fox-Kemper
Keyword(s):  
Mixed Layer ◽  
Heat Budget ◽  
Spatial Scales ◽  
Forthcoming Paper ◽  
Growth Time ◽  
Surface Mixed Layer ◽  
Ocean Climate ◽  
Oceanic Surface ◽  
Ocean Models ◽  
Weak Surface

Abstract The restratification of the oceanic surface mixed layer that results from lateral gradients in the surface density field is studied. The lateral gradients are shown to be unstable to ageostrophic baroclinic instabilities and slump from the horizontal to the vertical. These instabilities, which are referred to as mixed layer instabilities (MLIs), differ from instabilities in the ocean interior because of the weak surface stratification. Spatial scales are O(1–10) km, and growth time scales are on the order of a day. Linear stability analysis and fully nonlinear simulations are used to study MLIs and their impact on mixed layer restratification. The main result is that MLIs are a leading-order process in the ML heat budget acting to constantly restratify the surface ocean. Climate and regional ocean models do not resolve the scales associated with MLIs and are likely to underestimate the rate of ML restratification and consequently suffer from a bias in sea surface temperatures and ML depths. In a forthcoming paper, the authors discuss a parameterization scheme to include the effect of MLIs in ocean models.

scholarly journals Repeated surveying over 6 years reveals that fine-scale habitat variables are key to tropical mountain ant assemblage composition and functional diversity

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mulalo M. Muluvhahothe ◽  
Grant S. Joseph ◽  
Colleen L. Seymour ◽  
Thinandavha C. Munyai ◽  
Stefan H. Foord
Keyword(s):  
Climate Change ◽  
Species Composition ◽  
High Altitude ◽  
Functional Diversity ◽  
Large Scale ◽  
Climate Models ◽  
Spatial Scales ◽  
Abiotic Factors ◽  
Composition Analysis ◽  
Fine Scale

AbstractHigh-altitude-adapted ectotherms can escape competition from dominant species by tolerating low temperatures at cooler elevations, but climate change is eroding such advantages. Studies evaluating broad-scale impacts of global change for high-altitude organisms often overlook the mitigating role of biotic factors. Yet, at fine spatial-scales, vegetation-associated microclimates provide refuges from climatic extremes. Using one of the largest standardised data sets collected to date, we tested how ant species composition and functional diversity (i.e., the range and value of species traits found within assemblages) respond to large-scale abiotic factors (altitude, aspect), and fine-scale factors (vegetation, soil structure) along an elevational gradient in tropical Africa. Altitude emerged as the principal factor explaining species composition. Analysis of nestedness and turnover components of beta diversity indicated that ant assemblages are specific to each elevation, so species are not filtered out but replaced with new species as elevation increases. Similarity of assemblages over time (assessed using beta decay) did not change significantly at low and mid elevations but declined at the highest elevations. Assemblages also differed between northern and southern mountain aspects, although at highest elevations, composition was restricted to a set of species found on both aspects. Functional diversity was not explained by large scale variables like elevation, but by factors associated with elevation that operate at fine scales (i.e., temperature and habitat structure). Our findings highlight the significance of fine-scale variables in predicting organisms’ responses to changing temperature, offering management possibilities that might dilute climate change impacts, and caution when predicting assemblage responses using climate models, alone.

FC14-01 - Internal losses and the creation of “Nowhere land”: psychodynamic themes of adults with ADHD discovered during drama-therapy

2011 ◽  
Vol 26 (S2) ◽  
pp. 1893-1893
Author(s):  
I. Manor ◽  
G. Yazpan
Keyword(s):  
Drama Therapy ◽  
Transitional Space ◽  
Men And Women ◽  
The Past ◽  
Chronic Disorder ◽  
Pharmacological Aspect ◽  
Inner Self ◽  
Socioeconomic Strata ◽  
The Creation ◽  
First Time

ADHD is a well-known, chronic disorder that persists in adulthood. During the past 20 years its existence in adults is becoming clearer, yet its dynamic aspects are rarely discussed. The treatment of adults is vital, as much as that of children; however the literature discussing it, especially its non-pharmacological aspect, is scarce.We describe the results of our treatment with drama-therapy of two groups of adults with ADHD. These groups included 11 adults (from both groups), men and women, from most socioeconomic strata, aged ≥ 60 yrs., who were diagnosed as suffering from ADHD and were treated for it for the first time in their life. Drama-therapy was selected as we believed it to be a useful method with associative, distracted ADHD patients, since it enabled the use of transitional space through non-verbal images and acts.This presentation discusses the basic themes with which patients began therapy. Interestingly, all patients, however different, shared the same themes that were built on self doubt and the pre-presumption of disappointment. The impairment related to ADHD, that was felt, but not understood, led to a strong experience of heavy losses, which we tried to define separately: of a clear path, of control, of the inner perception of borders and of the loss of an integrative inner self. All these losses were accumulated in the transitional space in a place we named “Nowhere land”.We would like to present these themes of losses and of becoming lost and to discuss their meaning.

BRAZILIAN BISHOP OUTLINES "A PASTORAL STRATEGY IN TIMES OF REVOLUTION"

Exchange ◽  
1982 ◽  
Vol 11 (1) ◽  
pp. 48-57
Keyword(s):  
Northeast Brazil ◽  
Profound Change ◽  
Christian Communities ◽  
The Past ◽  
First Time

AbstractMons. Antonio Batista Fragoso has been bishop of Crateus in Northeast Brazil for the past ten years. Eighty percent of the 360,000 people in his diocese are impoverished peasants who engage in rudimentary farming. At least half of the peasants are landless. It is among these people that Bishop Fragoso has encouraged the formation of small grassroots Christian communities that are responsible for a profound change in the patterns of Christian living in his diocese. The following is LP's translation of excerpts from a talk that Bishop Fragoso gave to his fellow bishops and priests in Managua in October, 1980. This is the first time it has appeared in English. (Editor Latinamerica Press)

Hyperthermia and voluntary exhaustion: integrating models and future challenges

2007 ◽  
Vol 32 (4) ◽  
pp. 808-817 ◽  
Author(s):  
Stephen S. Cheung
Keyword(s):  
Heat Storage ◽  
Brain Temperature ◽  
Voluntary Exercise ◽  
Future Research ◽  
Laboratory Studies ◽  
Exertional Heat Illness ◽  
Non Invasive ◽  
The Past ◽  
Future Challenges ◽  
Effects Of Temperature

Over the past decade, research interest has risen on the direct effects of temperature on exercise capacity and tolerance, particular in the heat. Two major paradigms have been proposed for how hyperthermia may contribute to voluntary fatigue during exercise in the heat. One suggests that voluntary exhaustion occurs upon the approach or attainment of a critical internal temperature through impairment in a variety of physiological systems. An alternate perspective proposes that thermal inputs modulate the regulation of self-paced workload to minimize heat storage. This review seeks to summarize recent research leading to the development of these two models for hyperthermia and fatigue and explore possible bridges between them. Key areas for future research and development into voluntary exhaustion in the heat include (i) the development of valid and non-invasive means to measure brain temperature, (ii) understanding variability in perception and physiological responses to heat stress across individuals, (iii) extrapolating laboratory studies to field settings, (iv) understanding the failure in behavioural and physiological thermoregulation that leads to exertional heat illness, and (v) the integration of physiological and psychological parameters limiting voluntary exercise in the heat.

scholarly journals Imaging spectroscopy links aspen genotype with below-ground processes at landscape scales

2014 ◽  
Vol 369 (1643) ◽  
pp. 20130194 ◽  
Author(s):  
Michael D. Madritch ◽  
Clayton C. Kingdon ◽  
Aditya Singh ◽  
Karen E. Mock ◽  
Richard L. Lindroth ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Populus Tremuloides ◽  
Spatial Scales ◽  
Imaging Spectroscopy ◽  
Spectral Signature ◽  
Spectral Variation ◽  
Fine Scale ◽  
Below Ground ◽  
Landscape Scales ◽  
Spectrometer Data

Fine-scale biodiversity is increasingly recognized as important to ecosystem-level processes. Remote sensing technologies have great potential to estimate both biodiversity and ecosystem function over large spatial scales. Here, we demonstrate the capacity of imaging spectroscopy to discriminate among genotypes of Populus tremuloides (trembling aspen), one of the most genetically diverse and widespread forest species in North America. We combine imaging spectroscopy (AVIRIS) data with genetic, phytochemical, microbial and biogeochemical data to determine how intraspecific plant genetic variation influences below-ground processes at landscape scales. We demonstrate that both canopy chemistry and below-ground processes vary over large spatial scales (continental) according to aspen genotype. Imaging spectrometer data distinguish aspen genotypes through variation in canopy spectral signature. In addition, foliar spectral variation correlates well with variation in canopy chemistry, especially condensed tannins. Variation in aspen canopy chemistry, in turn, is correlated with variation in below-ground processes. Variation in spectra also correlates well with variation in soil traits. These findings indicate that forest tree species can create spatial mosaics of ecosystem functioning across large spatial scales and that these patterns can be quantified via remote sensing techniques. Moreover, they demonstrate the utility of using optical properties as proxies for fine-scale measurements of biodiversity over large spatial scales.

Efficient synthesis of regular spherical GO/SiO2@Solar Salt microcapsules to enhance heat-storage capacity and cycle stability

2021 ◽  
Vol 245 ◽  
pp. 114637
Author(s):  
Wei Ji ◽  
Xiaomin Cheng ◽  
Haixue Chen ◽  
Linfeng Li ◽  
Yuanyuan Li ◽  
...  
Keyword(s):  
Storage Capacity ◽  
Heat Storage ◽  
Cycle Stability ◽  
Efficient Synthesis ◽  
Solar Salt

scholarly journals Novel AI driven approach to classify infant motor functions

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Simon Reich ◽  
Dajie Zhang ◽  
Tomas Kulvicius ◽  
Sven Bölte ◽  
Karin Nielsen-Saines ◽  
...  
Keyword(s):  
Learning Algorithm ◽  
Movement Pattern ◽  
Video Stream ◽  
Typically Developing ◽  
The Past ◽  
Movement Assessment ◽  
Computer Based ◽  
Ablation Study ◽  
First Time ◽  
Efficient Screening

AbstractThe past decade has evinced a boom of computer-based approaches to aid movement assessment in early infancy. Increasing interests have been dedicated to develop AI driven approaches to complement the classic Prechtl general movements assessment (GMA). This study proposes a novel machine learning algorithm to detect an age-specific movement pattern, the fidgety movements (FMs), in a prospectively collected sample of typically developing infants. Participants were recorded using a passive, single camera RGB video stream. The dataset of 2800 five-second snippets was annotated by two well-trained and experienced GMA assessors, with excellent inter- and intra-rater reliabilities. Using OpenPose, the infant full pose was recovered from the video stream in the form of a 25-points skeleton. This skeleton was used as input vector for a shallow multilayer neural network (SMNN). An ablation study was performed to justify the network’s architecture and hyperparameters. We show for the first time that the SMNN is sufficient to discriminate fidgety from non-fidgety movements in a sample of age-specific typical movements with a classification accuracy of 88%. The computer-based solutions will complement original GMA to consistently perform accurate and efficient screening and diagnosis that may become universally accessible in daily clinical practice in the future.

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