154 results on '"Intermediate complexity"'
Search Results
52. IMOGEN: an intermediate complexity model to evaluate terrestrial impacts of a changing climate
- Author
-
Lina M. Mercado, Peter Good, Rosie A. Fisher, Martin Best, Chris Huntingford, Ben B. B. Booth, Spencer Liddicoat, Graham P. Weedon, Mark R. Lomas, C. D. Jones, Nicola Gedney, Allan Spessa, A. C. Everitt, Jason Lowe, Stephen Sitch, and Przemyslaw Zelazowski
- Subjects
lcsh:Geology ,Biogeochemical cycle ,Intermediate complexity ,Greenhouse gas ,Climatology ,lcsh:QE1-996.5 ,Extrapolation ,Climate change ,Environmental science ,Climate model ,Vegetation ,Transient climate simulation ,Atmospheric sciences - Abstract
We present a computationally efficient modelling system, IMOGEN, designed to undertake global and regional assessment of climate change impacts on the physical and biogeochemical behaviour of the land surface. A pattern-scaling approach to climate change drives a gridded land surface and vegetation model MOSES/TRIFFID. The structure allows extrapolation of General Circulation Model (GCM) simulations to different future pathways of greenhouse gases, including rapid first-order assessments of how the land surface and associated biogeochemical cycles might change. Evaluation of how new terrestrial process understanding influences such predictions can also be made with relative ease.
- Published
- 2018
53. A Thermodynamic View of Bacterial Growth
- Author
-
Hans V. Westerhoff, M. M. Mulder, K. Van Dam, and J. Teixeira de Mattos
- Subjects
Abiotic component ,Intermediate complexity ,Growth kinetics ,Chemistry ,Kinetics ,Microbial metabolism ,Biomass ,Biochemical engineering ,Bacterial growth - Abstract
This chapter reviews the models of microbial growth that do not relate growth kinetics to cellular biochemistry, but are merely descriptive phenomenological. The new approaches to the modeling of microbial growth have appeared, which aimed specifically at closing the gap between biochemistry and microbial growth kinetics. The chapter discusses the position of these approaches relative to other models of microbial growth. A growing bacterium may be considered as an energy transducer that consumes substrates and produces biomass and other products. It is important to note that for the sake of description, all cells are together represented by one "super-cell". The contents of the vessel containing cells and medium are essentially divided into two compartments: the biotic and the abiotic compartments. The MNET model, with its intermediate complexity, is very well suited to analyze the efficiency of bacterial metabolism and, in particular, to pinpoint via relatively few experimental measurements where the quantitatively important "metabolic leaks" occur.
- Published
- 2018
- Full Text
- View/download PDF
54. Comparison of stochastic parameterizations in the framework of a coupled ocean-atmosphere model
- Author
-
Jonathan Demaeyer and Stéphane Vannitsem
- Subjects
Cultural Studies ,Singular perturbation ,010504 meteorology & atmospheric sciences ,Computer science ,Gaussian ,FOS: Physical sciences ,Atmospheric model ,01 natural sciences ,Homogenization (chemistry) ,Markov operator ,010305 fluids & plasmas ,Education ,symbols.namesake ,0103 physical sciences ,Statistical physics ,lcsh:Science ,Condensed Matter - Statistical Mechanics ,0105 earth and related environmental sciences ,Statistical Mechanics (cond-mat.stat-mech) ,lcsh:QC801-809 ,Nonlinear Sciences - Chaotic Dynamics ,lcsh:QC1-999 ,Physics - Atmospheric and Oceanic Physics ,Intermediate complexity ,lcsh:Geophysics. Cosmic physics ,Atmospheric and Oceanic Physics (physics.ao-ph) ,symbols ,Probability distribution ,lcsh:Q ,Chaotic Dynamics (nlin.CD) ,lcsh:Physics - Abstract
A new framework is proposed for the evaluation of stochastic subgrid-scale parameterizations in the context of MAOOAM, a coupled ocean-atmosphere model of intermediate complexity. Two physically-based parameterizations are investigated, the first one based on the singular perturbation of Markov operator, also known as homogenization. The second one is a recently proposed parameterization based on the Ruelle's response theory. The two parameterization are implemented in a rigorous way, assuming however that the unresolved scale relevant statistics are Gaussian. They are extensively tested for a low-order version known to exhibit low-frequency variability, and some preliminary results are obtained for an intermediate-order version. Several different configurations of the resolved-unresolved scale separations are then considered. Both parameterizations show remarkable performances in correcting the impact of model errors, being even able to change the modality of the probability distributions. Their respective limitations are also discussed., Comment: 44 pages, 12 figures, 4 tables
- Published
- 2018
- Full Text
- View/download PDF
55. The effect of overshooting 1.5 °C global warming on the mass loss of the Greenland ice sheet
- Author
-
Rückamp, Martin, Falk, Ulrike, Frieler, Katja, Lange, Stefan, and Humbert, Angelika
- Subjects
Surface mass balance ,Surface energy balance modeling ,Intermediate complexity ,Greenland Ice Sheet ,Surface elevations ,General circulation model ,Higher-order approximation ,Rate of mass loss - Abstract
Sea-level rise associated with changing climate is expected to pose a major challenge for societies. Based on the efforts of COP21 to limit global warming to 2.0 ∘C or even 1.5 ∘C by the end of the 21st century (Paris Agreement), we simulate the future contribution of the Greenland ice sheet (GrIS) to sea-level change under the low emission Representative Concentration Pathway (RCP) 2.6 scenario. The Ice Sheet System Model (ISSM) with higher-order approximation is used and initialized with a hybrid approach of spin-up and data assimilation. For three general circulation models (GCMs: HadGEM2-ES, IPSL-CM5A-LR, MIROC5) the projections are conducted up to 2300 with forcing fields for surface mass balance (SMB) and ice surface temperature (Ts) computed by the surface energy balance model of intermediate complexity (SEMIC). The projected sea-level rise ranges between 21–38 mm by 2100 and 36–85 mm by 2300. According to the three GCMs used, global warming will exceed 1.5 ∘C early in the 21st century. The RCP2.6 peak and decline scenario is therefore manually adjusted in another set of experiments to suppress the 1.5 ∘C overshooting effect. These scenarios show a sea-level contribution that is on average about 38 % and 31 % less by 2100 and 2300, respectively. For some experiments, the rate of mass loss in the 23rd century does not exclude a stable ice sheet in the future. This is due to a spatially integrated SMB that remains positive and reaches values similar to the present day in the latter half of the simulation period. Although the mean SMB is reduced in the warmer climate, a future steady-state ice sheet with lower surface elevation and hence volume might be possible. Our results indicate that uncertainties in the projections stem from the underlying GCM climate data used to calculate the surface mass balance. However, the RCP2.6 scenario will lead to significant changes in the GrIS, including elevation changes of up to 100 m. The sea-level contribution estimated in this study may serve as a lower bound for the RCP2.6 scenario, as the currently observed sea-level rise is not reached in any of the experiments; this is attributed to processes (e.g. ocean forcing) not yet represented by the model, but proven to play a major role in GrIS mass loss.
- Published
- 2018
- Full Text
- View/download PDF
56. Basic and Intermediate Complexity Nail Procedures
- Author
-
Ali Damavandy, Thuzar M. Shin, Jeremy R. Etzkorn, Nathaniel J. Jellinek, Joseph F. Sobanko, and Christopher J. Miller
- Subjects
medicine.medical_specialty ,Punch Biopsy ,integumentary system ,medicine.diagnostic_test ,business.industry ,General surgery ,Digital myxoid cyst ,Intermediate complexity ,medicine.anatomical_structure ,medicine ,Nail (anatomy) ,skin and connective tissue diseases ,business ,Shave biopsy - Abstract
Nail surgery allows practitioners to diagnose or treat the majority of nail conditions. Successful nail surgery requires knowledge of anatomy and pathology, which have been detailed in prior chapters. This chapter reviews reliable approaches to common office-based procedures, including plate, bed, and matrix surgery, with punch, shave, and fusiform techniques. With a strong foundation of nail anatomy and pathology, surgeons can use these basic and intermediate surgical techniques to diagnose or treat a wide array of nail conditions.
- Published
- 2018
- Full Text
- View/download PDF
57. LGM Permafrost Thickness and Extent in the Northern Hemisphere derived from the Earth System Model i LOVECLIM
- Author
-
Didier M. Roche, D.C. Kitover, Hans Renssen, Jef Vandenberghe, and R.T. van Balen
- Subjects
010504 meteorology & atmospheric sciences ,Lithology ,Northern Hemisphere ,Last Glacial Maximum ,010502 geochemistry & geophysics ,Permafrost ,Snow ,01 natural sciences ,Intermediate complexity ,13. Climate action ,Climatology ,Ground temperature ,Earth system model ,Geology ,0105 earth and related environmental sciences ,Earth-Surface Processes - Abstract
An estimate of permafrost extent and thickness in the northern hemisphere during the Last Glacial Maximum (LGM, ~ 21 ka) has been produced using the VU University Amsterdam Permafrost Snow (VAMPERS) model, forced by iLOVECLIM, an Earth System Model of Intermediate Complexity. We present model results that give both permafrost thickness and extent. In the northern hemisphere, permafrost is estimated to have extended southwards to approximately 50°N in Asia and have achieved 1500 m thickness in Russia. The simulated distribution is compared with a reconstruction of northern hemisphere permafrost extent (Vandenberghe et al., 2014). We contend that the areas which agree with Vandenberghe et al. (2014) are the approximate areas of continuous permafrost during the LGM. In Asia, the model results agree well until approximately 50°N, which is also the approximate 0°C mean annual ground temperature isotherm estimated by iLOVECLIM. South of this limit, therefore, were likely the areas of discontinuous, sporadic and isolated permafrost during the LGM. However, it becomes difficult to model these more sensitive areas of permafrost extent since formation is dependent on local factors that are too fine for our grid's spatial resolution. In Europe, the model results disagree with the reconstruction but this was to be expected since iLOVECLIM is known to carry a warm bias in this region. For permafrost thickness, we compare our estimates with previous research and find that we have reasonably close approximations but there is a wide range of uncertainty since the subsurface parameters of lithology and water content are generalised. Copyright © 2015 John Wiley & Sons, Ltd.
- Published
- 2015
- Full Text
- View/download PDF
58. Human population dynamics in Europe over the Last Glacial Maximum
- Author
-
Miska Luoto, Natalia Korhonen, Heikki Seppä, Miikka Tallavaara, Heikki Järvinen, Department of Philosophy, History and Art Studies, Department of Geosciences and Geography, Department of Physics, and INAR Physics
- Subjects
1171 Geosciences ,demography ,Time Factors ,niche modeling ,Climate ,Climate Change ,Population Dynamics ,Population ,Social Sciences ,Climate change ,INTERMEDIATE COMPLEXITY ,hunter-gatherers ,ICE-SHEET MODEL ,114 Physical sciences ,Human population dynamics ,ARCTIC-CIRCLE ,Paleolithic ,Prehistoric demography ,Humans ,Population growth ,TEMPORAL FREQUENCY-DISTRIBUTIONS ,Computer Simulation ,Ice Cover ,Glacial period ,education ,Ecosystem ,LATE MOUSTERIAN PERSISTENCE ,Population Density ,education.field_of_study ,Multidisciplinary ,Geography ,Population size ,Last Glacial Maximum ,SPECIES DISTRIBUTION MODELS ,Models, Theoretical ,15. Life on land ,Adaptation, Physiological ,Biological Evolution ,PART I ,Europe ,13. Climate action ,Climatology ,1181 Ecology, evolutionary biology ,GENOME SEQUENCES ,PREHISTORIC DEMOGRAPHY ,HUMAN-EVOLUTION ,Algorithms - Abstract
The severe cooling and the expansion of the ice sheets during the Last Glacial Maximum (LGM), 27,000-19,000 y ago (27-19 ky ago) had a major impact on plant and animal populations, including humans. Changes in human population size and range have affected our genetic evolution, and recent modeling efforts have reaffirmed the importance of population dynamics in cultural and linguistic evolution, as well. However, in the absence of historical records, estimating past population levels has remained difficult. Here we show that it is possible to model spatially explicit human population dynamics from the pre-LGM at 30 ky ago through the LGM to the Late Glacial in Europe by using climate envelope modeling tools and modern ethnographic datasets to construct a population calibration model. The simulated range and size of the human population correspond significantly with spatiotemporal patterns in the archaeological data, suggesting that climate was a major driver of population dynamics 30-13 ky ago. The simulated population size declined from about 330,000 people at 30 ky ago to a minimum of 130,000 people at 23 ky ago. The Late Glacial population growth was fastest during Greenland interstadial 1, and by 13 ky ago, therewere almost 410,000 people in Europe. Even during the coldest part of the LGM, the climatically suitable area for human habitation remained unfragmented and covered 36% of Europe.
- Published
- 2015
- Full Text
- View/download PDF
59. Impact of Sea Level Assimilation on ENSO Initialization and Prediction: The Role of the Sea Level Zonal Tilt and Zonal Mean
- Author
-
Sulian Thual, Nadia Ayoub, and Boris Dewitte
- Subjects
Atmospheric Science ,Intermediate complexity ,El Niño Southern Oscillation ,Data assimilation ,Simple Ocean Data Assimilation ,Climatology ,Initialization ,Ensemble Kalman filter ,Assimilation (biology) ,Atmospheric sciences ,Sea level - Abstract
At present, most models forecasting the El Niño–Southern Oscillation (ENSO) use data assimilation, which constrains models physics using available observations. In this article, an ENSO model of intermediate complexity is constrained by sea level observations: sea level from the Simple Ocean Data Assimilation (SODA) reanalysis is assimilated in the model forced by SODA winds, using an ensemble Kalman filter. In addition, retrospective ENSO forecasts over the period 1958–2007 are computed. The assimilation of sea level observations slightly improves the model’s predictive skill, which is due to the correction of the recharge–discharge process simulated by the model. To assess this, two indices relevant to the ENSO recharge–discharge theory are considered: the zonal tilt and zonal mean of sea level in the equatorial Pacific. The assimilation of those two observed indices alone leads to results that are qualitatively similar to the assimilation of full maps of sea level observations. This partly results from the fact that the leading statistical modes of the model errors on sea level have a zonal tilt and zonal mean structure. The data assimilation corrects in particular a too weak amplitude of the zonal mean sea level and its associated subsurface variability in the model. The authors suggest that insight on the role of the recharge–discharge process in other models could be gained by comparing the assimilation of full maps of sea level observations with the assimilation of the two indices of sea level.
- Published
- 2015
- Full Text
- View/download PDF
60. Experiencia de las pacientes frente a citología cérvico-vaginal reportada como ASCUS o LEI de bajo grado en dos instituciones de Bogotá (Colombia), 2014
- Author
-
Jairo Amaya-Guío, Yahira Rossini Guzmán-Sabogal, Solange Monsalve-Páez, Diana Valderrama-Vega, and Marcos Fidel Castillo-Zamora
- Subjects
Cervical cancer ,Gynecology ,medicine.medical_specialty ,Investigación cualitativa ,business.industry ,citología ,Obstetrics and Gynecology ,Cervicovaginal cytology ,Atypical Squamous Cells ,respuesta emocional ,medicine.disease ,lcsh:Gynecology and obstetrics ,Abnormal cytology ,Surgery ,Intermediate complexity ,Citología ,Cytology ,Respuesta emocional ,Medicine ,Anxiety ,medicine.symptom ,investigación cualitativa ,business ,Ascus ,lcsh:RG1-991 - Abstract
Objetivo: describir los conocimientos que tienen las pacientes acerca del uso de la citología, y las emociones y el comportamiento que genera en estas un resultado positivo en la citología vaginal con atipias escamosas de significado indeterminado (ASCUS) o lesión escamosa intraepitelial de bajo grado (LEI-BG).Materiales y métodos: investigación cualitativa fenomenológica, que busca establecer las experiencias vividas por mujeres entre 18 y 69 años que consultaron por primera vez, por el hallazgo en la citología cérvico-vaginal de ASCUS o LEI-BG, a la unidad de patología cervical de dos instituciones de nivel medio de complejidad en Bogotá (Colombia), una institución pública y otra un centro de atención ambulatorio privado. El tamaño de la muestra se determinó por saturación teórica y muestreo consecutivo. Se realizaron grupos focales y entrevistas, la información fue grabada y transcrita posteriormente, creando categorías para evaluar las experiencias: caracterización sociodemográfica, cognición, características afectivas y comportamiento. Se empleó el estilo de análisis mediante edición, presentado como material narrativo, a fin de ordenar la información recolectada para su síntesis e interpretación.Resultados: se incluyeron 27 mujeres. El resultado anormal de la citología cérvico-vaginal despierta sentimientos de culpa, angustia y preocupación pues lo relacionan con el cáncer de cuello uterino, dado que no es claro para ellas que este es un examen de tamización. La principal conducta posterior a recibir el resultado de la citología fue priorizar la cita médica. Hay alteraciones en las relaciones de pareja basadas en la percepción de infidelidad secundaria a la infección de VPH.Conclusiones: la toma de la citología cérvico-vaginal es considerada por las pacientes como importantísima y obligatoria en el marco de la necesidad de prevenir y tratar el cáncer de cuello uterino.
- Published
- 2015
61. Data-driven localization mappings in filtering the monsoon-Hadley multicloud convective flows
- Author
-
Michèle De La Chevrotière and John Harlim
- Subjects
Convection ,Atmospheric Science ,010504 meteorology & atmospheric sciences ,Computer science ,Kalman filter ,Monsoon ,Dynamical system ,01 natural sciences ,010305 fluids & plasmas ,Data-driven ,Intermediate complexity ,Physics - Atmospheric and Oceanic Physics ,Data assimilation ,0103 physical sciences ,Statistical physics ,Physics - Computational Physics ,0105 earth and related environmental sciences - Abstract
This paper demonstrates the efficacy of data-driven localization mappings for assimilating satellite-like observations in a dynamical system of intermediate complexity. In particular, a sparse network of synthetic brightness temperature measurements is simulated using an idealized radiative transfer model and assimilated to the monsoon-Hadley multicloud model, a nonlinear stochastic model containing several thousands of model coordinates. A serial ensemble Kalman filter is implemented in which the empirical correlation statistics are improved using localization maps obtained from a supervised learning algorithm. The impact of the localization mappings is assessed in perfect model observing system simulation experiments (OSSEs) as well as in the presence of model errors resulting from the misspecification of key convective closure parameters. In perfect model OSSEs, the localization mappings that use adjacent correlations to improve the correlation estimated from small ensemble sizes produce robust accurate analysis estimates. In the presence of model error, the filter skills of the localization maps trained on perfect and imperfect model data are comparable., Comment: monthly weather review (in press)
- Published
- 2017
62. An optimization strategy for identifying parameter sensitivity in atmospheric and oceanic models
- Author
-
Wang, Qiang, Tang, Youmin, Dijkstra, Henk A., Sub Physical Oceanography, Dep Natuurkunde, Marine and Atmospheric Research, Sub Physical Oceanography, Dep Natuurkunde, and Marine and Atmospheric Research
- Subjects
Friction coefficient ,Optimization ,Atmospheric Science ,010504 meteorology & atmospheric sciences ,Meteorology ,Sensitivity studies ,010505 oceanography ,01 natural sciences ,Pacific ocean ,Nonlinear programming ,Numerical analysis/modeling ,Intermediate complexity ,Path (graph theory) ,Meander ,Environmental science ,Applied mathematics ,14. Life underwater ,Sensitivity (control systems) ,Physics::Atmospheric and Oceanic Physics ,0105 earth and related environmental sciences - Abstract
A new optimization strategy is proposed to identify the sensitivities of simulations of atmospheric and oceanic models to uncertain parameters. The strategy is based on a nonlinear optimization method that is able to estimate the maximum values of specific parameter sensitivity measures; meanwhile, it takes into account interactions among uncertain parameters. It is tested using the Lorenz’63 model and an intermediate complexity 2.5-layer shallow-water model of the North Pacific Ocean. For the Lorenz’63 model, it is shown that the parameter sensitivities of the model results depend on the initial conditions. For the 2.5-layer shallow-water model used to simulate the Kuroshio large meander (KLM) south of Japan, the optimization strategy reveals that the prediction of the KLM path is insensitive to the uncertainties in the bottom friction coefficient, the interfacial friction coefficient, and the lateral friction coefficient. Rather, the KLM prediction is relatively sensitive to the uncertainties of the reduced gravity representing ocean stratification and the wind stress coefficient.
- Published
- 2017
63. Enzyme Kinetics Modeling as a Tool to Optimize Food Industry: A Pragmatic Approach Based on Amylolytic Enzymes
- Author
-
Charis M. Galanakis, Anna Patsioura, and Vassilis Gekas
- Subjects
Food industry ,Food Handling ,Stochastic modelling ,Computer science ,Industrial and Manufacturing Engineering ,Field (computer science) ,Environmental Biotechnology ,Αmylases ,Representation (mathematics) ,Monte Carlo ,Multienzyme kinetics ,Artificial neural network ,business.industry ,Empirical modelling ,General Medicine ,Models, Theoretical ,Michaelis–Menten ,Kinetics ,Intermediate complexity ,Νeural networks ,Amylases ,Engineering and Technology ,Εmpirical models ,Biochemical engineering ,business ,Algorithms ,Food Science - Abstract
Modeling is an important tool in the food industry since it is able to simplify explanation of phenomena and optimize processes that cover a broad field from manufacture to byproducts treatment. The goal of the current article is to explore the development of enzyme kinetic models and their evolution over the last decades. For this reason, corresponding simulations were classified in deterministic, empirical, and stochastic models, prior investigating limitations, corrections, and industrial applications in each case. The ultimate goal is to provide an answer to a major problem: how can we develop an intermediate complexity model that achieves satisfactorily representation of the main phenomena with a limited number of parameters?
- Published
- 2014
- Full Text
- View/download PDF
64. The Fine Structure of Shape Tuning in Area V4
- Author
-
Jude F. Mitchell, Tatyana O. Sharpee, John V. Reynolds, and Anirvan S. Nandy
- Subjects
Neuroscience(all) ,Curvature ,Article ,03 medical and health sciences ,0302 clinical medicine ,Form perception ,medicine ,Animals ,Invariant (mathematics) ,Visual Cortex ,030304 developmental biology ,Physics ,0303 health sciences ,Communication ,Quantitative Biology::Neurons and Cognition ,business.industry ,General Neuroscience ,Local variation ,Macaca mulatta ,Translation invariance ,Form Perception ,Intermediate complexity ,Visual cortex ,medicine.anatomical_structure ,Pattern Recognition, Visual ,Receptive field ,Biological system ,business ,Photic Stimulation ,030217 neurology & neurosurgery - Abstract
SummaryPrevious studies have shown that neurons in area V4 are involved in the processing of shapes of intermediate complexity and are sensitive to curvature. These studies also suggest that curvature-tuned neurons are position invariant. We sought to examine the mechanisms that endow V4 neurons with these properties. Consistent with previous studies, we found that response rank order to the most- and least-preferred stimuli was preserved throughout the receptive field. However, a fine-grained analysis of shape tuning revealed a surprising result: V4 neurons tuned to highly curved shapes exhibit very limited translation invariance. At a fine spatial scale, these neurons exhibit local variation in orientation. In contrast, neurons that prefer straight contours exhibit spatially invariant orientation-tuning and homogenous fine-scale orientation maps. Both of these patterns are consistent with a simple orientation-pooling model, with tuning for straight or curved shapes resulting, respectively, from pooling of homogenous or heterogeneous orientation signals inherited from early visual areas.
- Published
- 2013
- Full Text
- View/download PDF
65. The University of Victoria Cloud Feedback Emulator (UVic-CFE): cloud radiative feedbacks in an intermediate complexity model
- Author
-
Andreas Schmittner and D. J. Ullman
- Subjects
Intermediate complexity ,Meteorology ,business.industry ,Radiative transfer ,Environmental science ,Cloud computing ,Atmospheric sciences ,business ,Cloud feedback ,Physics::Atmospheric and Oceanic Physics ,Physics::Geophysics - Abstract
The dominant source of inter-model differences in comprehensive global climate models (GCMs) are cloud radiative effects on Earth's energy budget. Intermediate complexity models, while able to run more efficiently, often lack cloud feedbacks. Here, we describe and evaluate a method for applying GCM-derived shortwave and longwave cloud feedbacks from 4xCO2 and Last Glacial Maximum experiments to the University of Victoria Earth System Climate Model. The method generally captures the spread in top-of-the-atmosphere radiative feedbacks between the original GCMs, which impacts the magnitude and spatial distribution of surface temperature changes and climate sensitivity. These results suggest that the method is suitable to incorporate multi-model cloud feedback uncertainties in ensemble simulations with a single intermediate complexity model.
- Published
- 2016
- Full Text
- View/download PDF
66. Could artificial ocean alkalinization protect tropical coral ecosystems from ocean acidification?
- Author
-
Andreas Oschlies, Ellias Y. Feng, Wolfgang Koeve, and David P. Keller
- Subjects
0106 biological sciences ,South china ,010504 meteorology & atmospheric sciences ,Coral ,ocean acidification ,engineering.material ,01 natural sciences ,geoengineering ,Ecosystem ,Earth system model ,14. Life underwater ,0105 earth and related environmental sciences ,General Environmental Science ,Renewable Energy, Sustainability and the Environment ,010604 marine biology & hydrobiology ,Aragonite ,Public Health, Environmental and Occupational Health ,Ocean acidification ,Great barrier reef ,Intermediate complexity ,Oceanography ,13. Climate action ,engineering ,climate engineering ,Environmental science ,coral reef ,weathering enhancement ,ocean alkalinization - Abstract
Artificial ocean alkalinization (AOA) is investigated as a method to mitigate local ocean acidification and protect tropical coral ecosystems during a 21st century high CO2 emission scenario. Employing an Earth system model of intermediate complexity, our implementation of AOA in the Great Barrier Reef, Caribbean Sea and South China Sea regions, shows that alkalinization has the potential to counteract expected 21st century local acidification in regard to both oceanic surface aragonite saturation Omega and surface pCO(2). Beyond preventing local acidification, regional AOA, however, results in locally elevated aragonite oversaturation and pCO(2) decline. A notable consequence of stopping regional AOA is a rapid shift back to the acidified conditions of the target regions. We conclude that AOA may be a method that could help to keep regional coral ecosystems within saturation states and pCO(2) values close to present-day values even in a high-emission scenario and thereby might 'buy some time' against the ocean acidification threat, even though regional AOA does not significantly mitigate the warming threat.
- Published
- 2016
67. AMOC-emulator M-AMOC1.0 for uncertainty assessment of future projections
- Author
-
Andreas Schmittner, Pepijn Johannes Bakker, and Earth and Climate
- Subjects
Box model ,010504 meteorology & atmospheric sciences ,Global warming ,Greenland ice sheet ,Climate change ,010502 geochemistry & geophysics ,01 natural sciences ,Intermediate complexity ,General Circulation Model ,Climatology ,SDG 13 - Climate Action ,Environmental science ,Sensitivity (control systems) ,0105 earth and related environmental sciences - Abstract
State-of-the-science global climate models show that global warming is likely to weaken the Atlantic Meridional Overturning Circulation (AMOC). While such models are arguably the best tools to perform AMOC projections, they do not allow a comprehensive uncertainty assessment because of limited computational resources. Here we present an AMOC-emulator, a box model with a number of free parameters that can be tuned to mimic the sensitivity of the AMOC to climate change of a specific global climate model. The AMOC-emulator (M-AMOC1.0) is applied to simulations of global warming and melting of the Greenland Ice Sheet, performed with an intermediate complexity model. Predictive power of the AMOC-emulator is shown by comparison with a number of additional warming and Greenland Ice Sheet melt scenario that have not been used in the tuning of the AMOC-emulator, highlighting the potential of the AMOC-emulator to assess the uncertainty in AMOC projections.
- Published
- 2016
- Full Text
- View/download PDF
68. Isotopic profiling of 13C-labeled biological samples by two-dimensional heteronuclear J-resolved nuclear magnetic resonance spectroscopy
- Author
-
Edern Cahoreau, Jane Hubert, Stéphane Massou, Frédéric Bringaud, Jean-Charles Portais, Lindsay Peyriga, Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Laboratoire d'Ingénierie des Systèmes Biologiques et des Procédés (LISBP), Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National de la Recherche Agronomique (INRA), Centre de résonance magnétique des systèmes biologiques (CRMSB), Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB), Résonance magnétique des systèmes biologiques (RMSB), Université Bordeaux Segalen - Bordeaux 2-Centre National de la Recherche Scientifique (CNRS), Université de Toulouse (UT), Institut National de la Recherche Agronomique (INRA)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), MetaToul FluxoMet (TBI-MetaToul), MetaboHUB-MetaToul, MetaboHUB-Génopole Toulouse Midi-Pyrénées [Auzeville] (GENOTOUL), Université de Toulouse (UT)-Université de Toulouse (UT)-Ecole Nationale Vétérinaire de Toulouse (ENVT), Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-MetaboHUB-Génopole Toulouse Midi-Pyrénées [Auzeville] (GENOTOUL), Université de Toulouse (UT)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Toulouse Biotechnology Institute (TBI), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), and Université de Bordeaux (UB)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
C-13 ,[SDV]Life Sciences [q-bio] ,Biophysics ,Analytical chemistry ,H-1 NMR ,010402 general chemistry ,Mass spectrometry ,01 natural sciences ,Biochemistry ,J-resolved spectroscopy ,GLUTAMATE ,03 medical and health sciences ,Nuclear magnetic resonance ,Metabolic flux analysis ,2D NMR ,METABOLIC FLUX ANALYSIS ,Spectroscopy ,Molecular Biology ,030304 developmental biology ,J resolved ,0303 health sciences ,Isotopic profiling ,STABILITY ,Chemistry ,MIXTURES ,MASS-SPECTROMETRY ,Cell Biology ,Nuclear magnetic resonance spectroscopy ,QUANTITATIVE-ANALYSIS ,0104 chemical sciences ,Intermediate complexity ,Heteronuclear molecule ,ESCHERICHIA-COLI ,NMR-SPECTROSCOPY ,C-13 enrichment ,Two-dimensional nuclear magnetic resonance spectroscopy ,Carbon labeling experiment ,LABELING EXPERIMENTS - Abstract
The use of two-dimensional heteronuclear J-resolved (2D H-JRES) nuclear magnetic resonance (NMR) spectroscopy for fast and reliable measurement of isotopic patterns from C-13-enriched compounds resulting from carbon labeling experiments was evaluated. Its use with biological samples of increasing complexity showed that 2D H-JRES spectroscopy is suitable for high-throughput isotopic profiling of any kind of labeled samples. Moreover, the method enabled accurate quantification of C-13 enrichments and, thus, can be used for metabolic flux analysis. The excellent trade-off between reduced experimental time and the number of measurable isotopic data makes 2D H-JRES NMR a promising approach for high-throughput flux analysis of samples of intermediate complexity. (C) 2012 Elsevier Inc. All rights reserved.
- Published
- 2012
- Full Text
- View/download PDF
69. Multispecies fisheries management and conservation: tactical applications using models of intermediate complexity
- Author
-
Vincent Lyne, Anthony D. M. Smith, Michael D. E. Haywood, Elisabetta B. Morello, James T. Thorson, Franz Smith, Elizabeth A. Fulton, Richard D. Pillans, Peter Bayliss, Olivier Thébaud, Trevor Hutton, Peter C. Rothlisberg, Éva E. Plagányi, Richard M. Hillary, and André E. Punt
- Subjects
Ecosystem health ,Computer science ,Process (engineering) ,business.industry ,Environmental resource management ,Stakeholder ,Context (language use) ,Management, Monitoring, Policy and Law ,Aquatic Science ,Oceanography ,Intermediate complexity ,13. Climate action ,Ecosystem model ,Ecosystem ,14. Life underwater ,Fisheries management ,business ,Ecology, Evolution, Behavior and Systematics - Abstract
Stakeholders increasingly expect ecosystem assessments as part of advice on fisheries management. Quantitative models to support fisheries decision-making may be either strategic (‘big picture’, direction-setting and contextual) or tactical (focused on management actions on short timescales), with some strategic models informing the development of tactical models. We describe and review ‘Models of Intermediate Complexity for Ecosystem assessments’ (MICE) that have a tactical focus, including use as ecosystem assessment tools. MICE are context- and question-driven and limit complexity by restricting the focus to those components of the ecosystem needed to address the main effects of the management question under consideration. Stakeholder participation and dialogue is an integral part of this process. MICE estimate parameters through fitting to data, use statistical diagnostic tools to evaluate model performance and account for a broad range of uncertainties. These models therefore address many of the impediments to greater use of ecosystem models in strategic and particularly tactical decision-making for marine resource management and conservation. MICE are capable of producing outputs that could be used for tactical decision-making, but our summary of existing models suggests this has not occurred in any meaningful way to date. We use a model of the pelagic ecosystem in the Coral Sea and a linked catchment and ocean model of the Gulf of Carpentaria, Australia, to illustrate how MICE can be constructed. We summarize the major advantages of the approach, indicate opportunities for the development of further applications and identify the major challenges to broad adoption of the approach.
- Published
- 2012
- Full Text
- View/download PDF
70. State-Dependence of the Climate Sensitivity in Earth System Models of Intermediate Complexity
- Author
-
Thomas F. Stocker and Patrik L. Pfister
- Subjects
geography ,geography.geographical_feature_category ,010504 meteorology & atmospheric sciences ,Extrapolation ,Magnitude (mathematics) ,Forcing (mathematics) ,010502 geochemistry & geophysics ,Atmospheric sciences ,01 natural sciences ,Earth system science ,Intermediate complexity ,Geophysics ,Climatology ,Sea ice ,General Earth and Planetary Sciences ,Climate sensitivity ,State dependence ,Environmental science ,0105 earth and related environmental sciences - Abstract
Growing evidence from general circulation models (GCMs) indicates that the equilibrium climate sensitivity (ECS) depends on the magnitude of forcing, which is commonly referred to as state-dependence. We present a comprehensive assessment of ECS state-dependence in Earth system models of intermediate complexity (EMICs) by analyzing millennial simulations with sustained 2×CO₂ and 4×CO₂ forcings. We compare different extrapolation methods and show that ECS is smaller in the higher-forcing scenario in 12 out of 15 EMICs, in contrast to the opposite behavior reported from GCMs. In one such EMIC, the Bern3D-LPX model, this state-dependence is mainly due to the weakening sea ice-albedo feedback in the Southern Ocean, which depends on model configuration. Due to ocean-mixing adjustments, state-dependence is only detected hundreds of years after the abrupt forcing, highlighting the need for long model integrations. Adjustments to feedback parametrizations of EMICs may be necessary if GCM intercomparisons confirm an opposite state-dependence.
- Published
- 2017
- Full Text
- View/download PDF
71. MIC and Trifecta in robot-assisted partial nephrectomy in highly complex tumors – similar results in comparison with tumors of low and intermediate complexity
- Author
-
Christian Wagner, Georg Schoen, G. Trabs, B. Ubrig, Alexander Roosen, Jorn H. Witt, Frank Schiefelbein, and Nina Harke
- Subjects
Intermediate complexity ,medicine.medical_specialty ,business.industry ,Urology ,medicine.medical_treatment ,medicine ,Robot ,business ,Nephrectomy - Published
- 2017
- Full Text
- View/download PDF
72. Modelagem do Impacto da Topografia Boreal no Clima Global (Modelling the Impact of Topography on Global Climate Boreal)
- Author
-
Bruno Lopes de Faria and Flávio Barbosa Justino
- Subjects
Hydrology ,lcsh:GE1-350 ,Atmospheric Science ,Global climate ,Geography, Planning and Development ,Climate change ,Intermediate complexity ,Geophysics ,Geography ,Boreal ,Air temperature ,Topografia, Mudanças Climáticas, Modelos Climáticos ,Climate model ,Computers in Earth Sciences ,lcsh:GB3-5030 ,Geomorphology ,lcsh:Physical geography ,lcsh:Environmental sciences ,Earth-Surface Processes ,General Environmental Science - Abstract
Foram realizadas simulacoes climaticas a partir de 2 experimentos de sensibilidade numerica conduzidos com um modelo acoplado de complexidade intermediaria, LOVECLIM , estendendo-se para um periodo de 300 anos. Sendo que, neste experimento foi realizada a reducao em 50% da topografia geral do hemisferio norte, um com modelo acoplado (oceano-atmosfera) e outro desacoplado (somente atmosfera). Nos resultados obtidos, foram observadas alteracoes no padrao de clima global e local, em especial a regiao da Asia, relacionadas com aumento de temperatura do ar a superficie e intensidade do vento. Maiores alteracoes foram observados em regioes continentais no hemisferio norte. Isto mostra o maior impacto local causado pela forcante topografica com o a reducao da pela metade da topografia boreal. Palavras-chave : Topografia, Mudancas Climaticas, Modelos Climaticos, Forcante Climatica Modelling the Impact of Topography on Global Climate Boreal ABSTRACT Simulations were conducted from two numerical sensitivity experiments conducted with a coupled model with intermediate complexity, LOVECLIM, extending for a period of 300 years. Since this experiment was carried out 50% reduction in the general topography of the northern hemisphere, with a coupled model (ocean-atmosphere) and the other uncoupled (atmosphere only). Their results have been observed changes in the pattern of global and local climate, particularly in Asia, linked to increase of air temperature and wind intensity. The biggest impacts were observed in continental regions in the north hemisphere. This shows the greater local impact caused by topographic forcing Keywords : Topography, Climate Change, Climate Models, Topographic Forcing
- Published
- 2011
73. Role of stochastic forcing in ENSO in observations and a coupled GCM
- Author
-
Javier Zavala-Garay, Harry H. Hendon, Chidong Zhang, and Atul Kapur
- Subjects
Atmospheric Science ,Intermediate complexity ,El Niño Southern Oscillation ,General Circulation Model ,Climatology ,Boreal spring ,Environmental science ,Multivariate ENSO index ,Stochastic forcing ,GCM transcription factors ,Madden–Julian oscillation ,Atmospheric sciences - Abstract
A procedure is presented to estimate the role of atmospheric stochastic forcing (SF) in El Nino–Southern Oscillation (ENSO) simulated by a coupled ocean–atmosphere general circulation model (CGCM), in direct comparison to observations represented by a global reanalysis product. SF is extracted from the CGCM and reanalysis as surface wind anomalies linearly independent of the sea-surface temperature anomalies. Madden–Julian Oscillation (MJO) is isolated from SF to quantify its role in ENSO. A coupled ocean–atmosphere model of intermediate complexity is forced with SF, as well as its MJO and non-MJO components, from the reanalysis and CGCM. The role of SF is estimated by comparing the original ENSO in observations and the CGCM with that reproduced by the intermediate model. ENSO statistics in both reanalysis and CGCM are better reproduced when the intermediate model is tuned to be weakly stable than unstable. The intermediate model driven by SF from the reanalysis reproduces most characteristics of observed ENSO, such as its spectrum, seasonal phase-locking, fast decorrelation of ENSO SST during boreal spring, and its lag-correlation with SF. In contrast, not all characteristics of ENSO in the CGCM are reproduced by the intermediate model when SF from the CGCM is used. The seasonal phase-locking of ENSO in the CGCM is not reproduced at all. ENSO, therefore, appears to be driven by SF to a lesser degree in the CGCM than in observations. Characteristics of observed ENSO reproduced by the intermediate model (driven by SF) can be largely attributed to the MJO; which, for instance, is responsible for the fast decorrelation of ENSO SST during boreal spring in both reanalysis and CGCM. The non-MJO component seems to be more responsible than the MJO for erroneous features of ENSO in the CGCM.
- Published
- 2011
- Full Text
- View/download PDF
74. Ultra-high resolution pollen record from the northern Andes reveals rapid shifts in montane climates within the last two glacial cycles
- Author
-
W. Westerhoff, L. Contreras, J. van der Plicht, Henry Hooghiemstra, A. Betancourt, M. Vriend, Martin Ziegler, Juan Carlos Berrio, Sergio Gaviria, D. Ortega, O. Rangel, S. L. Weber, E. Tuenter, M. van der Linden, Catalina Giraldo, N. González, B. van Geel, T. van der Hammen, Jef Vandenberghe, J. H. F. Jansen, Gustavo Sarmiento, M.H.M. Groot, Martin Konert, R. G. Bogotá, Lucas Joost Lourens, Isotope Research, Paleoecology and Landscape Ecology (IBED, FNWI), Earth and Climate, and Climate Change and Landscape Dynamics
- Subjects
Marine isotope stage ,010506 paleontology ,Arboreal locomotion ,010504 meteorology & atmospheric sciences ,PAST 800,000 YEARS ,Aardwetenschappen ,Stratigraphy ,lcsh:Environmental protection ,TIME-SERIES ,INTERMEDIATE COMPLEXITY ,Forcing (mathematics) ,medicine.disease_cause ,GREENLAND ICE ,01 natural sciences ,Isotopes of oxygen ,000 YEARS ,lcsh:Environmental pollution ,Pollen ,GRIP ICE CORE ,medicine ,lcsh:TD169-171.8 ,Glacial period ,lcsh:Environmental sciences ,0105 earth and related environmental sciences ,lcsh:GE1-350 ,Global and Planetary Change ,OCEAN-ATMOSPHERE SYSTEM ,PAST 800 ,Elevation ,Paleontology ,Vegetation ,15. Life on land ,MILLENNIAL-SCALE ,TEMPERATURE-VARIATIONS ,13. Climate action ,Climatology ,EASTERN-CORDILLERA ,lcsh:TD172-193.5 ,TRANSIENT SIMULATION ,Geology - Abstract
Here we developed a composite pollen-based record of altitudinal vegetation changes from Lake Fúquene (5° N) in Colombia at 2540 m elevation. We quantitatively calibrated Arboreal Pollen percentages (AP%) into mean annual temperature (MAT) changes with an unprecedented ~60-year resolution over the past 284 000 years. An age model for the AP% record was constructed using frequency analysis in the depth domain and tuning of the distinct obliquity-related variations to the latest marine oxygen isotope stacked record. The reconstructed MAT record largely concurs with the ~100 and 41-kyr (obliquity) paced glacial cycles and is superimposed by extreme changes of up to 7 to 10° Celsius within a few hundred years at the major glacial terminations and during marine isotope stage 3, suggesting an unprecedented North Atlantic – equatorial link. Using intermediate complexity transient climate modelling experiments, we demonstrate that ice volume and greenhouse gasses are the major forcing agents causing the orbital-related MAT changes, while direct precession-induced insolation changes had no significant impact on the high mountain vegetation during the last two glacial cycles.
- Published
- 2011
- Full Text
- View/download PDF
75. TOEPLITZ SEQUENCES OF INTERMEDIATE COMPLEXITY
- Author
-
Hyoung-Keun Kim and Seung-Seol Park
- Subjects
Combinatorics ,Discrete mathematics ,Sequence ,Intermediate complexity ,General Mathematics ,Entropy (information theory) ,Toeplitz matrix ,Mathematics - Abstract
We present two constructions of Toeplitz sequences with an intermediate complexity function by using the generalized Oxtoby sequence. In the first one, we use the blocks from the infinite sequence, which has entropy dimension . The second construction provides the Toeplitz sequences which have various entropy dimensions.
- Published
- 2011
- Full Text
- View/download PDF
76. Learning: What and How? An Empirical Study of Adjustments in Workplace Organization Structure
- Author
-
Avner Ben-Ner and Stéphanie Lluis
- Subjects
Organizational Behavior and Human Resource Management ,Knowledge management ,business.industry ,Organizational systems ,Computer science ,Strategy and Management ,Complex system ,Management ,Intermediate complexity ,Empirical research ,Learning curve ,Management of Technology and Innovation ,Industrial relations ,Organizational learning ,Organizational structure ,business - Abstract
We seek to understand how firms learn about what adjustments they need to make in their organization structure at the workplace level. We define four organizational systems: traditional (the simplest system), high-performance (the most complex system), decision-making oriented, and financial-incentives oriented (intermediate complexity). We analyze (1) learning-by-doing on adoption of more or less complex systems, (2) the performance–experience learning curves associated with different systems, (3) the match between perceived organizational capabilities and the choice of systems, the influence of (4) other firms’ systems and performance on a firm’s adjustment decisions, and of (5) a firm’s location on its decisions.
- Published
- 2010
- Full Text
- View/download PDF
77. A study of the sensitivity of the surface temperature in Eurasia in winter to snow-cover anomalies: The role of the stratosphere
- Author
-
Yu. V. Martynova and V. N. Krupchatnikov
- Subjects
Atmospheric Science ,Anomaly (natural sciences) ,Climate system ,Forcing (mathematics) ,Oceanography ,Atmospheric sciences ,Physics::Geophysics ,Intermediate complexity ,Climatology ,Environmental science ,Climate simulation ,Stratosphere ,Physics::Atmospheric and Oceanic Physics ,Snow cover - Abstract
This study is devoted to the influence that anomalous snow cover in the Siberian autumn has on the surface temperature in the winter months using the intermediate complexity model of a climate system. The possible mechanisms of the effect that a thermal forcing anomaly on surfaces attributed to the troposphere-stratosphere interaction has on the temperature regime in winter are considered.
- Published
- 2010
- Full Text
- View/download PDF
78. Eventual saturation of the climate–carbon cycle feedback studied with a conceptual model
- Author
-
Igor I. Mokhov and Alexey V. Eliseev
- Subjects
Physics ,chemistry.chemical_compound ,Intermediate complexity ,chemistry ,Logarithm ,Control theory ,Ecological Modeling ,Carbon dioxide ,Thermodynamics ,Climate model ,Radiative forcing ,Saturation (chemistry) ,Carbon cycle - Abstract
A saturation of climate–carbon cycle feedback was found earlier in the simulations with the IAP RAS climate model of intermediate complexity. Here, this eventual saturation is interpreted by using a conceptual linearised coupled model. It is shown that this saturation is due to weak, logarithmic, dependence of the carbon dioxide radiative forcing on its atmospheric concentration. This eventual saturation leads to the non-monotonic behaviour of climate–carbon cycle parameter f in time. If the time scale of the atmospheric CO 2 build up is t p then, starting from an initial equilibrium, f approaches maximum in time ≃ t p . Afterwards, climate–carbon cycle parameter decreases and eventually tends to unity. The time scale of the latter decrease is t 1 = ( 1 − 5 ) t p . A dependence of t m and t 1 on governing parameters of the conceptual model is studied. It is argued that an eventual saturation of the climate–carbon cycle feedback is expected to occur also in the other integrations of sufficient length with coupled climate–carbon cycle models.
- Published
- 2008
- Full Text
- View/download PDF
79. A Simple Equation for Regional Climate Change and Associated Uncertainty
- Author
-
Filippo Giorgi
- Subjects
Atmospheric Science ,Intermediate complexity ,Global temperature ,Simple (abstract algebra) ,Simple equation ,Climatology ,Global warming ,Environmental science ,Climate change ,Probability density function ,Precipitation - Abstract
Simple equations are developed to express regional climate changes for the twenty-first century and associated uncertainty in terms of the global temperature change (GTC) without a dependence on the underlying emission pathways. The equations are applied to regional temperature and precipitation changes over different regions of the world, and relevant parameters are calculated using the latest multimodel ensemble of global climate change simulations. Examples are also shown of how to use the equations to develop probability density functions (PDFs) of regional climate change based on PDFs of GTC. The main advantage of these equations is that they can be used to estimate regional changes from GTC obtained either from simple and intermediate complexity models or from target CO2 stabilization concentrations.
- Published
- 2008
- Full Text
- View/download PDF
80. IMPACTO DA CONCENTRAÇÃO DO DIÓXIDO DE CARBONO ATMOSFÉRICO NO GELO MARINHO ANTÁRTICO
- Author
-
Flavio Justino, Carlos Ernesto Gonçalves Reynaud Schaefer, Felipe Hastenreiter, and Alice M. Grimm
- Subjects
geography ,Intermediate complexity ,Oceanography ,geography.geographical_feature_category ,Ecology ,Co2 concentration ,Sea ice ,Environmental science ,Polar ,Antarctic sea ice ,Southern Hemisphere ,Ice thickness - Abstract
IMPACT OF ATMOSPHERIC CO 2 CONCENTRATION ON ANTARCTIC SEA ICE. Five numerical experiments were conducted using a coupled model of intermediate complexity, lasting for 1500 modeled years, using different CO 2 concentrations (500, 600, 700 and 800 ppm). It was observed that increased atmospheric CO 2 concentration leads to a warming in the Southern Hemisphere polar region with serious implications on the sea ice cover. Numerical results revealed ice thickness reduction up to 1m in Weddell and Amuddsen Seas. In east Antarctic, from the Ross Sea to the Indian part of Antarctic Ocean, the absence of sea ice is the most prominent feature in the sensitivity experiments. The initial investigation indicates that the enhanced oceanic heat transport plays the main role in the modifications of the Southern Hemisphere sea ice under different CO 2 concentration as determined by the CO 2 simulations.
- Published
- 2007
- Full Text
- View/download PDF
81. Acesso e uso de serviços de saúde em idosos residentes em áreas rurais, Brasil, 1998 e 2003
- Author
-
Claudia Travassos and Francisco Viacava
- Subjects
Gerontology ,Social characteristics ,Activities of daily living ,Acesso aos Serviços de Saúde ,business.industry ,Idoso ,Public Health, Environmental and Occupational Health ,MEDLINE ,Survey sampling ,Saúde da População Rural ,Limited access ,Health services ,Intermediate complexity ,Health problems ,Environmental health ,Medicine ,Pesquisa sobre Serviços de Saúde ,business - Abstract
Analisou-se o acesso aos serviços de saúde e sua utilização por idosos residentes em áreas rurais no Brasil em 2003, comparando os padrões observados com idosos residentes em área urbana e com o padrão existente em 1998, a partir dos dados dos suplementos sobre Acesso e Utilização de Serviços de Saúde da Pesquisa Nacional por Amostra de Domicílios. Observou-se que as barreiras de acesso eram maiores na área rural em comparação à urbana. A utilização de serviços de saúde era menor do que nos idosos urbanos, mesmo para aqueles que referiram problema de saúde. Não se observou diferença nas taxas de internação entre idosos rurais e urbanos. A análise do tipo de serviço utilizado mostrou que há acesso limitado a serviços de complexidade intermediária. Os resultados sugerem que os mais idosos apresentam barreiras de acesso ainda maiores. O diferencial de gênero na utilização favorável à mulher foi mais marcado nos idosos rurais. Barreiras financeiras também são mais marcadas. Houve indicativo de alguma melhora no desempenho dos serviços do Sistema Único de Saúde (SUS). Recomendou-se ampliação da oferta e adaptação dos serviços às especificidades territoriais, culturais e sociais dos idosos rurais.
- Published
- 2007
- Full Text
- View/download PDF
82. Session details: Complexity
- Author
-
Neil Immerman
- Subjects
Microbiology (medical) ,Intermediate complexity ,Theoretical computer science ,Libor ,Proof complexity ,Computer science ,Immunology ,Immunology and Allergy ,Algebraic number ,Column (database) ,Time complexity ,Session (web analytics) ,Range (computer programming) - Abstract
For years when I taught algorithms or complexity, I would tell my students that while there is an infinite range of intermediate complexity classes, problems occurring in practice tend to be complete for one of a handful of important complexity classes.I used to say that no one knows why this happens. Now however I can say that it happens for an algebraic reason which Libor Barto and his colleagues are close to figuring out. I am thrilled to have as our first Complexity Column in the SIGLOG Newsletter, the following survey on CSP.I am also happy to announce that upcoming complexity columns will include the following:---Anuj Dawar, "The Nature and Power of Fixed-Point Logic with Counting," [recent progress in the search for a logical language capturing order-independent Polynomial Time], Jan. 1, 2015.---Jakob Nordstrom, [using proof complexity to gain insights into the complexity of SAT].
- Published
- 2015
- Full Text
- View/download PDF
83. Diagnóstico da deficiência auditiva em Pernambuco: oferta de serviços de média complexidade - 2003 Hearing impairment diagnosis in Pernambuco: services of intermediate complexity - 2003
- Author
-
Gabriella Morais Duarte Miranda, Bianca Arruda Manchester de Queiroga, Fábio José Delgado Lessa, Mariana de Carvalho Leal, and Sílvio da Silva Caldas Neto
- Subjects
deficiência auditiva ,diagnosis ,lcsh:R ,intermediate complexity ,lcsh:Medicine ,média complexidade ,hearing impairment ,lcsh:Otorhinolaryngology ,lcsh:RF1-547 ,diagnóstico - Abstract
O acesso universal e igualitário às ações e serviços públicos garantido através da Constituição de 1988 tornou mais acessível o diagnóstico precoce da deficiência auditiva. Desta forma, por meio do Sistema Único de Saúde (SUS), prestadores públicos e privados de serviços proporcionam essa cobertura a toda população, nos diferentes níveis de complexidade. OBJETIVO: O trabalho tem como objetivo estudar a oferta de serviços de diagnóstico da Deficiência Auditiva na média complexidade em Pernambuco no 1º semestre de 2003. MATERIAL E MÉTODO: Através de um estudo de séries foram analisados 17669 procedimentos e 372 profissionais da área de diagnóstico da deficiência auditiva nos 185 municípios do estado de Pernambuco, dados retirados do Sistema de Informação Ambulatorial do Ministério da Saúde. RESULTADOS: Os resultados mostraram que os procedimentos estão sendo realizados em apenas cinco municípios, a maioria em unidades geridas pela esfera municipal. Também, identificou-se uma distribuição não-eqüitativa da oferta dos procedimentos de diagnóstico. CONCLUSÃO: Concluiu-se que muito ainda precisa ser feito para que o acesso e oferta do diagnóstico da deficiência auditiva ocorram de forma horizontal, respeitando as diferenças da comunidade através de um modelo universal, integrativo e eficiente como propõe o Sistema Único de Saúde.Universal and equal access to health care, granted to the population as of the brazilian constitution of 1988, made it easier the early diagnosis of hearing impairment. Thus, through the sistema único de saúde (sus), public and private health care providers granted this health coverage to the whole brazilian population, in the different levels of complexity. AIM: this paper aims at studying the supply of intermediate complexity hearing impairment diagnosis in pernambuco in the first semester of 2003. MATERIALS AND METHODS: a study of series analyzed 17669 procedures and 372 professionals in the field of hearing impairment in the 185 municipalities in the state of pernambuco - brazil - data taken from the outpatient information system of the ministry of health. RESULTS: the results showed that the procedures are being carried out in only five municipalities, most of them managed in municipal units. We also identified an unequal distribution of diagnostic procedures. CONCLUSION: we then concluded that much is still necessary to provide hearing impairment diagnostic in a horizontal fashion, considering the community differences through an universal, integrated and efficient model, as the one proposed by the sistema único de saúde.
- Published
- 2006
84. How good is your screening library?
- Author
-
John J. Irwin
- Subjects
High concentration ,Molecular complexity ,Library design ,Drug discovery ,Drug Evaluation, Preclinical ,Chemical biology ,Computational biology ,Biology ,Bioinformatics ,Biochemistry ,Analytical Chemistry ,Intermediate complexity ,Drug Design ,Combinatorial Chemistry Techniques - Abstract
Efficient library design is an ongoing challenge for investigators seeking novel ligands for proteins, whether for drug discovery or chemical biology. Strategies that add neglected chemistry or exclude unproductive compounds are two dominant recent themes, as is a growing awareness of molecular complexity and its implications. The choice of how complex molecules in screening libraries should be often amounts to how big they should be. Small, simple molecules have lower affinities and must be screened at high concentration, but they will also have higher hit rates. Larger compounds, on the other hand, will often more closely resemble final drugs, but because they are more highly functionalized and specific, they will have much lower hit rates. The best general-purpose screening libraries may well be those of intermediate complexity that are free of artifact-causing nuisance compounds.
- Published
- 2006
- Full Text
- View/download PDF
85. Westerly Wind Bursts: ENSO’s Tail Rather than the Dog?
- Author
-
Ian Eisenman, Eli Tziperman, and Lisan Yu
- Subjects
Atmospheric Science ,Intermediate complexity ,Sea surface temperature ,Amplitude ,El Niño Southern Oscillation ,Coupling strength ,Climatology ,Stochastic forcing ,Forcing (mathematics) ,Observation data ,Geology - Abstract
Westerly wind bursts (WWBs) in the equatorial Pacific occur during the development of most El Niño events and are believed to be a major factor in ENSO’s dynamics. Because of their short time scale, WWBs are normally considered part of a stochastic forcing of ENSO, completely external to the interannual ENSO variability. Recent observational studies, however, suggest that the occurrence and characteristics of WWBs may depend to some extent on the state of ENSO components, implying that WWBs, which force ENSO, are modulated by ENSO itself. Satellite and in situ observations are used here to show that WWBs are significantly more likely to occur when the warm pool is extended eastward. Based on these observations, WWBs are added to an intermediate complexity coupled ocean–atmosphere ENSO model. The representation of WWBs is idealized such that their occurrence is modulated by the warm pool extent. The resulting model run is compared with a run in which the WWBs are stochastically applied. The modulation of WWBs by ENSO results in an enhancement of the slow frequency component of the WWBs. This causes the amplitude of ENSO events forced by modulated WWBs to be twice as large as the amplitude of ENSO events forced by stochastic WWBs with the same amplitude and average frequency. Based on this result, it is suggested that the modulation of WWBs by the equatorial Pacific SST is a critical element of ENSO’s dynamics, and that WWBs should not be regarded as purely stochastic forcing. In the paradigm proposed here, WWBs are still an important aspect of ENSO’s dynamics, but they are treated as being partially stochastic and partially affected by the large-scale ENSO dynamics, rather than being completely external to ENSO. It is further shown that WWB modulation by the large-scale equatorial SST field is roughly equivalent to an increase in the ocean–atmosphere coupling strength, making the coupled equatorial Pacific effectively self-sustained.
- Published
- 2005
- Full Text
- View/download PDF
86. Abstracts of the 14th Annual Meeting of the Israel Society for Neuroscience
- Author
-
Shimon Ullman, Boris Epshtein, Assaf Harel, and Shlomo Bentin
- Subjects
Intermediate complexity ,business.industry ,Computer science ,General Neuroscience ,Computer vision ,Artificial intelligence ,Object (computer science) ,business - Published
- 2005
- Full Text
- View/download PDF
87. Visual features of intermediate complexity and their use in classification
- Author
-
Erez Sali, Shimon Ullman, and Michel Vidal-Naquet
- Subjects
Communication ,genetic structures ,Computer science ,business.industry ,General Neuroscience ,Visual task ,Pattern recognition ,Maximization ,Visual processing ,Intermediate complexity ,Pattern Recognition, Visual ,Face ,Human visual system model ,Image Processing, Computer-Assisted ,Humans ,Computer Simulation ,Artificial intelligence ,business ,Neuroscience - Abstract
The human visual system analyzes shapes and objects in a series of stages in which stimulus features of increasing complexity are extracted and analyzed. The first stages use simple local features, and the image is subsequently represented in terms of larger and more complex features. These include features of intermediate complexity and partial object views. The nature and use of these higher-order representations remains an open question in the study of visual processing by the primate cortex. Here we show that intermediate complexity (IC) features are optimal for the basic visual task of classification. Moderately complex features are more informative for classification than very simple or very complex ones, and so they emerge naturally by the simple coding principle of information maximization with respect to a class of images. Our findings suggest a specific role for IC features in visual processing and a principle for their extraction.
- Published
- 2002
- Full Text
- View/download PDF
88. A new earth’s climate system model of intermediate complexity, PlaSim-ICMMG-1.0: description and performance
- Author
-
I. Borovko, Gennady Platov, E. N. Golubeva, V. N. Krupchatnikov, and Yu Martynova
- Subjects
geography.geographical_feature_category ,010504 meteorology & atmospheric sciences ,Atmospheric circulation ,Climate system ,010502 geochemistry & geophysics ,Atmospheric sciences ,01 natural sciences ,Intermediate complexity ,Geography ,Climatology ,Sea ice ,Cover (algebra) ,Earth (chemistry) ,0105 earth and related environmental sciences - Published
- 2017
- Full Text
- View/download PDF
89. Modeling in Earth system science up to and beyond IPCC AR5
- Author
-
Hideki Okajima, Masahiro Sugiyama, Michio Kawamiya, Michio Watanabe, Shingo Watanabe, Akinori Ito, Tomohiro Hajima, Etsushi Kato, and Kaoru Tachiiri
- Subjects
business.industry ,Earth science ,Environmental resource management ,Climate change ,Global change ,Ocean acidification ,Earth system science ,Intermediate complexity ,Planetary science ,General Earth and Planetary Sciences ,Marine ecosystem ,Geoengineering ,business ,Geology - Abstract
Changes in the natural environment that are the result of human activities are becoming evident. Since these changes are interrelated and can not be investigated without interdisciplinary collaboration between scientific fields, Earth system science (ESS) is required to provide a framework for recognizing anew the Earth system as one composed of its interacting subsystems. The concept of ESS has been partially realized by Earth system models (ESMs). In this paper, we focus on modeling in ESS, review related findings mainly from the latest assessment report of the Intergovernmental Panel on Climate Change, and introduce tasks under discussion for the next phases of the following areas of science: the global nitrogen cycle, ocean acidification, land-use and land-cover change, ESMs of intermediate complexity, climate geoengineering, ocean CO2 uptake, and deposition of bioavailable iron in marine ecosystems. Since responding to global change is a pressing mission in Earth science, modeling will continue to contribute to the cooperative growth of diversifying disciplines and expanding ESS, because modeling connects traditional disciplines through explicit interaction between them.
- Published
- 2014
- Full Text
- View/download PDF
90. The Physics and Chemistry of Small Translucent Molecular Clouds. XII. More Complex Species Explainable by Gas‐Phase Processes
- Author
-
B. E. Turner, R. Terzieva, and Eric Herbst
- Subjects
Extinction ,Chemistry ,Range (biology) ,Molecular cloud ,Astronomy and Astrophysics ,Astrophysics ,Gas phase ,Metal ,Intermediate complexity ,Space and Planetary Science ,Chemical physics ,visual_art ,Thermal ,Small range ,visual_art.visual_art_medium - Abstract
We have observed 10 molecular species of "intermediate" complexity (four to seven atoms) in three translucent clouds and in TMC-1 and L183. Of these species HNCO, HOCO+, H2CCO, CCH, and CH3CCH are detected in all five objects, while HCOOH, CH3CHO, CH3CN, CH2NH, and VyCN are detected in fewer objects. These species are chosen because they are expected to mark the transition between simpler species that are formed in the gas phase and complex hydrogenated species [NH2CHO, EtOH, EtCN, (CH3)2O, and CH3OCHO] that are believed to form by grain chemistry. The C/O ratio and the metal abundances are determining factors in the abundances of most of the species. The gas-phase chemistry of HNCO is set out for the first time. HNCO, H2CCO, CCH, and CH3CCH are successfully modeled for a wide range of C/O, metals, and cloud conditions. HOCO+, HCOOH, CH3CN, and VyCN are well modeled under fewer conditions, while CH3CHO and CH2NH are fitted in only a small range of conditions. For most species, the models tend to underestimate the observed abundances. By introducing or modifying a number of gas-phase reactions in the New Standard Model we are able to explain the abundances of most species for specific sets of physical conditions (density, temperature, extinction), abundances (metals, C/O), and time epoch. The parameter sets for the different species are largely non overlapping. However, we have been able to find a single, unique set of parameters including a specific epoch for each of TMC-1, L183, and the translucent clouds that explains eight of the 10 species. The exceptions are CH2NH, which requires higher C/O than other species, and CH3CHO, which is possibly modeled in dark clouds but not in translucent objects. For the eight well-fitted species, C/O=0.4 is favored, and the time epoch is 5(5)±4(5) yr for each type of object. In this exercise we cannot distinguish between high and low metals. Previously studied species (HCN, C3H2, CCS, and HC3N) fit the same set of conditions. It is possible that all 10 species may be explained by gas-phase chemistry, perhaps when suitable neutral-neutral reactions are found for species such as CH3CHO and CH2NH. Until then, grain processes cannot be ruled out for these and other species such as HOCO+ (formed from desorbed CO2) or VyCN (highly saturated). Ortho/para and E/A ratios are found to lie within the thermal limits for all cases except O/P (H2CCO), whose value of 5.9 in TMC-1 exceeds the limit of 3.0, which confirms an earlier result by Ohishi. This result cannot be explained by grain interactions. Nevertheless, in the species of intermediate complexity, we may be encountering the boundary between gas and grain chemistry for partly hydrogen-saturated species. The transition to grain chemistry seems clearly to occur at the next level of complexity, which includes NH2CHO, EtOH, EtCN, (CH3)2O, and CH3OCHO, species we have failed to detect after exhaustive searches in translucent and dark clouds.
- Published
- 1999
- Full Text
- View/download PDF
91. Design of a simulated moving bed in the presence of mass-transfer resistances
- Author
-
Diana C. S. Azevedo and Alírio E. Rodrigues
- Subjects
Environmental Engineering ,Computer simulation ,General Chemical Engineering ,Binary number ,Separator (oil production) ,Bilinear interpolation ,Limiting ,Mechanics ,Intermediate complexity ,chemistry.chemical_compound ,chemistry ,Mass transfer ,Simulated moving bed ,Simulation ,Biotechnology ,Mathematics - Abstract
Two different strategies presented determine the sets of operating conditions that yield desired product purities for an SMB separator. The search was performed numerically by solving the analogous true-moving-bed model equations. A linear equilibrium binary mixture and mass-transfer effects were taken into account by using a bilinear driving force approximation to describe intraparticle diffusion. The strategies are equivalent and produce the same results. Comparison with the linear equilibrium model strategy indicates that there are new limiting values for the flow-rate constraints in the presence of mass-transfer effects. The constraints on sections I, II and III were more restrictive than those derived from equilibrium models, whereas the constraint on section IV was less affected. Qualitative observations drawn from a model of intermediate complexity were also presented to confirm our results.
- Published
- 1999
- Full Text
- View/download PDF
92. An intermediate complexity dynamic model for predicting accumulation of atmospherically-deposited metals (Ni, Cu, Zn, Cd, Pb) in catchment soils: 1400 to present
- Author
-
Edward Tipping, Laura Shotbolt, Alan J. Lawlor, and Stephen Lofts
- Subjects
Health, Toxicology and Mutagenesis ,Drainage basin ,Environmental pollution ,Toxicology ,Ecology and Environment ,Atmosphere ,Metal ,Soil ,Metals, Heavy ,Soil Pollutants ,geography ,geography.geographical_feature_category ,Chemistry ,General Medicine ,Pollution ,Intermediate complexity ,Deposition (aerosol physics) ,Agriculture and Soil Science ,Models, Chemical ,Environmental chemistry ,visual_art ,Soil water ,visual_art.visual_art_medium ,Environmental Pollution ,Environmental Monitoring - Abstract
The Intermediate Dynamic Model for Metals (IDMM) is a model for prediction of the pools of metals (Ni, Cu, Zn, Cd, Pb) in topsoils of catchments resulting from deposition of metals from the atmosphere. We used the model to simulate soil metal pools from 1400 onwards in ten UK catchments comprising semi-natural habitats, and compared the results with present day observations of soil metal pools. Generally the model performed well in simulating present day pools, and further improvements were made to simulations of Ni, Cu, Zn and Cd by adjusting the strength of metal adsorption to the soils. Some discrepancies between observation and prediction for Pb appeared to be due either to underestimation of cumulative deposition, or to overestimation of the metal pool under ‘pristine’, pre-industrial conditions. The IDMM provides a potential basis for large scale assessment of metal dynamics in topsoils.
- Published
- 2013
93. Hospital Parroquial de San Bernardo, Chile: 115 años sirviendo a la comunidad
- Author
-
Ricardo Espinoza G
- Subjects
Gerontology ,Education, Medical ,business.industry ,education ,Medical school ,Community health services ,Hospitals, Community ,General Medicine ,Hospitals community ,Medical care ,Intermediate complexity ,Spiritual support ,Nursing ,Medicine ,business - Abstract
The Parochial Hospital of San Bernardo is an intermediate complexity hospital that functions in its original 115- year- old building. It is one of the oldest hospitals in the country. Driven by the local Catholic Church and despite multiple difficulties, the hospital has uninterruptedly served a progressively growing community, with medical care and spiritual support. In the last two decades, it also has incorporated teaching activities with Universidad de los Andes Medical School.
- Published
- 2013
94. Decadal and Seasonal Dependence of ENSO Prediction Skill
- Author
-
Michael K. Davey, Magdalena Balmaseda, and David L. T. Anderson
- Subjects
Atmosphere ,Atmospheric Science ,Sea surface temperature ,Intermediate complexity ,El Niño Southern Oscillation ,Climatology ,Environmental science ,Forecast skill ,Climate model ,Decadal change ,Phase locking - Abstract
When forecasting sea surface temperature (SST) in the Equatorial Pacific on a timescale of several seasons, most prediction schemes have a spring barrier; that is, they have skill scores that are substantially lower when predicting northern spring and summer conditions compared to autumn and winter. This feature is investigated by examining predictions during the 1970s and the 1980s, using a dynamic ocean model of intermediate complexity coupled to a statistical atmosphere. Results show that predictions initialized during the 1970s exhibit the typical prominent skill decay in spring, whereas the seasonal dependence in those predictions initialized during the 1980s is rather small. Similar changes in seasonal dependence are also found in predictions based on simple persistence of observed SST anomalies. This decadal change in the spring barrier is related to decadal variations found in the seasonal phase locking of the SST anomalies, which is largely determined by the timing of El Nino events. The...
- Published
- 1995
- Full Text
- View/download PDF
95. Corrigendum to 'Dynamics of the Atlantic meridional overturning circulation and Southern Ocean in an ocean model of intermediate complexity' [Prog. Oceanogr. 143 (2016) 46–81]
- Author
-
Fabian Schloesser, Theodore W. Burkhardt, Julian P. McCreary, Ryo Furue, and Masami Nonaka
- Subjects
Intermediate complexity ,Oceanography ,Climatology ,Geology ,Aquatic Science - Published
- 2016
- Full Text
- View/download PDF
96. Population viability of the Snake River chinook salmon (Oncorhynchus tshawytscha)
- Author
-
John M. Emlen
- Subjects
education.field_of_study ,Chinook wind ,biology ,Population ,Endangered species ,Aquatic Science ,biology.organism_classification ,Persistence (computer science) ,Fishery ,Intermediate complexity ,Oncorhynchus ,Resource management ,education ,Ecology, Evolution, Behavior and Systematics ,Salmonidae - Abstract
In the presence of historical data, population viability models of intermediate complexity can be parameterized and utilized to project the consequences of various management actions for endangered species. A general stochastic population dynamics model with density feedback, age structure, and autocorrelated environmental fluctuations was constructed and parameterized for best fit over 36 years of spring chinook salmon (Oncorhynchus tshawytscha) redd count data in five Idaho index streams. Simulations indicate that persistence of the Snake River spring chinook salmon population depends primarily on density-independent mortality. Improvement of rearing habitat, predator control, reduced fishing pressure, and improved dam passage all would alleviate density-independent mortality. The current value of the Ricker α should provide for a continuation of the status quo. A recovery of the population to 1957–1961 levels within 100 years would require an approximately 75% increase in survival and (or) fecundity. Manipulations of the Ricker β are likely to have little or no effect on persistence versus extinction, but considerable influence on population size.
- Published
- 1995
- Full Text
- View/download PDF
97. Dynamische Simulation von Wärmeübertragern
- Author
-
Tilman Walter Botsch and Karl Stephan
- Subjects
Chemical process ,Engineering ,business.industry ,General Chemical Engineering ,Mechanical engineering ,General Chemistry ,Heat transfer coefficient ,Mechanics ,Industrial and Manufacturing Engineering ,Intermediate complexity ,NTU method ,Heat exchanger ,Transient (oscillation) ,Single phase ,business ,Condenser (heat transfer) - Abstract
Four models for heat exchangers under transient conditions are presented. Three of them describe a single phase heat exchanger, and the forth one is used for the simulation of a condenser. All models are of intermediate complexity and valid for simulation of both single heat exchangers and chemical processes. They use distributed variables and incorporate the calculation of local heat transfer coefficients so that temperature profiles over the apparatus can be determined in addition to the transient behaviour of the outlet variables
- Published
- 1995
- Full Text
- View/download PDF
98. The medieval climate anomaly in Europe: Comparison of the summer and annual mean signals in two reconstructions and in simulations with data assimilation
- Author
-
Hugues Goosse, Y. Sallaz-Damaz, Svetlana Dubinkina, Michael E. Mann, Joel Guiot, Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Collège de France (CdF)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Institut National de la Recherche Agronomique (INRA), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Collège de France (CdF (institution))-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA), and Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
seasonal climate signal ,LAST MILLENNIUM ,010504 meteorology & atmospheric sciences ,Atmospheric circulation ,atmospheric circulation ,[SDE.MCG]Environmental Sciences/Global Changes ,INTERMEDIATE COMPLEXITY ,010502 geochemistry & geophysics ,Oceanography ,01 natural sciences ,SURFACE-TEMPERATURE ,Mediterranean sea ,Paleoclimatology ,Physical ,LATE HOLOCENE ,data assimilation ,0105 earth and related environmental sciences ,Global and Planetary Change ,LAND-COVER CHANGE ,Multidisciplinary ,Geography ,Anomaly (natural sciences) ,FENNOSCANDIAN SUMMERS ,Westerlies ,NORTH-ATLANTIC OSCILLATION ,Geology ,Europe ,TEMPERATURE-VARIATIONS ,CIRCULATION VARIABILITY ,Physical Geography ,13. Climate action ,North Atlantic oscillation ,[SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology ,Climatology ,Common spatial pattern ,Climate model ,0921-8181 ,CARBON-CYCLE ,Geosciences - Abstract
The spatial pattern and potential dynamical origin of the Medieval Climate Anomaly (MCA, around 1000 AD) in Europe are assessed with two recent reconstructions and simulations constrained to follow those reconstructions by means of paleoclimate data assimilation. The simulations employ a climate model of intermediate complexity (LOVECLIM). The data assimilation technique is based on a particle filter using an ensemble of 96 simulations. The peak winter (and annual mean) warming during the MCA, in our analyses, is found to be strongest at high latitudes, associated with strengthened mid-latitude westerlies. Summer warmth, by contrast, is found to be greatest in southern Europe and the Mediterranean Sea, associated with reduced westerlies and strengthened southerly winds off North Africa. The results of our analysis thus underscore the complexity of the spatial and seasonal structure of the MCA in Europe. (C) 2011 Elsevier B.V. All rights reserved.
- Published
- 2012
- Full Text
- View/download PDF
99. Modeling the Interglacials of the Last 1 Million Years
- Author
-
André Berger and Qiuzhen Yin
- Subjects
Intermediate complexity ,Seasonal distribution ,Geography ,Greenhouse gas ,Climatology ,Astronomical forcing ,Air temperature ,Interglacial ,Northern Hemisphere ,Precession ,Atmospheric sciences - Abstract
The climate response associated with the interglacial peaks of the last 1 million years is investigated with an Earth model of intermediate complexity, LOVECLIM, to the variations of the astronomically induced insolation and of the greenhouse gas concentrations. The dates selected are those where the Northern Hemisphere summer occurs at perihelion. The simulated global annual mean air temperature shows that, on average, the interglacials after the Mid-Brunhes Event are warmer than those before, as expected from the larger average CO2 concentration. However, the seasonal response came more as a surprise with the warming being mainly during the winter season in response to the astronomical forcing. The latitudinal and seasonal distribution of insolation is indeed characterized by less energy available, in average, over the Earth during Northern Hemisphere summer but more during Northern Hemisphere winter for the interglacials after Mid-Brunhes Event than before. The relationship to the long-term variations of precession and obliquity is discussed.
- Published
- 2012
- Full Text
- View/download PDF
100. ENSO Forcing of Climate Variability over the North Atlantic/European Region in a Warmer Climate Conditions
- Author
-
Ivana Herceg Bulić
- Subjects
Intermediate complexity ,El Niño Southern Oscillation ,Climatology ,General Circulation Model ,Co2 concentration ,Environmental science ,Forcing (mathematics) ,Climate state ,Climate variability ,ENSO tropical-extratropical teleconnections ,warmer climate ,North Atlantic/European region ,European region ,Atmospheric sciences ,Composite analysis - Abstract
Changes in winter climate variability in the North Atlantic European (NAE) region associated with El Niño–Southern Oscillation (ENSO) forcing in a warmer climate are investigated. The study is based on two 20-member ensembles of numerical integrations by utilizing an atmospheric general circulation model (AGCM) of intermediate complexity. Current climate experiment is based on simulations forced with observed sea-surface temperatures (SST) for the period 1855-2002. Warmer climate corresponds to the doubled CO2 concentration with SST forcing represented by the same SST anomalies as in the current climate experiment superimposed on the climatological SST that was obtained from a complex atmosphere–ocean general circulation model forced with the doubled CO2. A composite analysis of atmospheric response is based on categorization into warm and cold composites according to the strength of SST anomalies in the Niño3.4 region. In the current climate, ENSO impact on the winter interannual variability in the NAE region is rather weak, but is still discernible and statistically significant. Over the south-western part of Europe warm (cold) ENSO events are mainly associated with warmer (colder) and dryer (wetter) conditions than usual. According to the results of numerical simulations in the climate with doubled CO2 concentrations, substantial modifications of ENSO influence on the NAE region are found. The spatial pattern of the ENSO impact on the NAE precipitation projects onto the distribution of differences between the warmer climate and the current climate precipitation climatology fields. Therefore, a considerable ENSO impact on temperature and precipitation may be expected in warmer climate conditions implying a possibility of greater importance of tropical-extratropical teleconnections for future climate variability in the NAE region. Since temperature and precipitation are the variables of great interest of policy makers for adaptation and mitigation purposes, their proper representation is essential for climate projections.
- Published
- 2011
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.