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Teyssèdre, G.; Tardieu, G.; Laurent, Christian

doi:10.1023/a:1014901809981

Cited by 27 publications

(10 citation statements)

References 21 publications

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“…Echelle) is an offline chemistry transport model used for research at Météo-France in a wide range of scientific studies on tropospheric and stratospheric chemistry at various spatial and temporal scales. It was used for example for studying the impact of climate on chemistry (Teyssèdre et al, 2007;Lacressonnière et al, 2012;Lamarque et al, 2013) or tropospheric-stratospheric exchanges using data assimilation (El Amraoui et al, 2010;Barré et al, 2013). MOCAGE is also used for daily operational air-quality forecasts in the framework of French platform Prev'Air (Rouil et al, 2009, http://www2.prevair.org/) and in the European CAMS project by being one of the models contributing to the regional ensemble forecasting system over Europe (Marécal et al, 2015, http://macc-raq-op.meteo.fr/index.…”

Section: Mocage (Modèle De Chimie Atmospherique à Grandementioning

confidence: 99%

Current state of the global operational aerosol multi‐model ensemble: An update from the International Cooperative for Aerosol Prediction (ICAP)

Xian¹,

Reid²,

Hyer³

et al. 2019

Quart J Royal Meteoro Soc

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Since the first International Cooperative for Aerosol Prediction (ICAP) multi‐model ensemble (MME) study, the number of ICAP global operational aerosol models has increased from five to nine. An update of the current ICAP status is provided, along with an evaluation of the performance of ICAP‐MME over 2012–2017, with a focus on June 2016–May 2017. Evaluated with ground‐based Aerosol Robotic Network (AERONET) aerosol optical depth (AOD) and data assimilation quality MODerate‐resolution Imaging Spectroradiometer (MODIS) retrieval products, the ICAP‐MME AOD consensus remains the overall top‐scoring and most consistent performer among all models in terms of root‐mean‐square error (RMSE), bias and correlation for total, fine‐ and coarse‐mode AODs as well as dust AOD; this is similar to the first ICAP‐MME study. Further, over the years, the performance of ICAP‐MME is relatively stable and reliable compared to more variability in the individual models. The extent to which the AOD forecast error of ICAP‐MME can be predicted is also examined. Leading predictors are found to be the consensus mean and spread. Regression models of absolute forecast errors were built for AOD forecasts of different lengths for potential applications. ICAP‐MME performance in terms of modal AOD RMSEs of the 21 regionally representative sites over 2012–2017 suggests a general tendency for model improvements in fine‐mode AOD, especially over Asia. No significant improvement in coarse‐mode AOD is found overall for this time period.

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Section: Mocage (Modèle De Chimie Atmospherique à Grandementioning

confidence: 99%

Current state of the global operational aerosol multi‐model ensemble: An update from the International Cooperative for Aerosol Prediction (ICAP)

Xian¹,

Reid²,

Hyer³

et al. 2019

Quart J Royal Meteoro Soc

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“…Two other approaches focusing on investigations of charge carrier migration and recombination should be mentioned here. One is based on measurements of the luminescence that appears upon ion recombination. − Another utilizes the detection of radiation-induced conductivity of polymers, ,,, in particular by using time-of-flight measurements, which allow determining the sign of charge carriers as well as their mobility. Typically, these approaches are used to provide data on the energy of charge carriers trapped in polymers, but it is difficult to use these data to identify the charge carriers that contribute to the detected signals.…”

Section: Introductionmentioning

confidence: 99%

Radiation-Induced Fluorescence from Doped Polyolefins on a Nanosecond Time Scale: Kinetics of the Processes Involving Geminate Radical Ions

2019

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The delayed radiation-induced fluorescence from polyethylene and its alkyl-and fluorine-substituted analogues doped with aromatic luminophores was studied in the time range of 1−1000 ns. Qualitative analysis of the effects of a magnetic field on the fluorescence decay indicated that, in all polyolefins studied, the main portion of the fluorescence observed arose from the recombination of geminate spincorrelated radical ion pairs (RIPs). In the case of polyethylene, this conclusion was supported by observing the effect of an external electric field on the fluorescence decay. It was shown by comparison with the computer simulation of intratrack recombination that the tunneling character of the RIP recombination, which had an asymptotic time dependence of the geminate recombination rate close to t −1 , was typical of most studied polyolefins at temperatures below 273 K in the time range studied. The increase to room temperature and above caused a gradual transition to a regime where the geminate recombination rate was mainly determined by the migration of RIP partners with time dependence close to t −3/2 . The low estimate of the electron transfer distance upon the ion recombination in this regime was about 2 nm. In polyethylenes, exposed to an irradiation of 0.3−0.4 MGy, the role of charge carrier diffusion became hardly noticeable because of the cross-linking of polyethylene chains and the increase in polymer matrix stiffness. Oxygen, dissolved in a polymer doped with aromatic molecules, caused quenching of the recombination luminescence due to electron transfer from the dopant radical anion to the oxygen molecules. At room temperature, typical distances for such electron transfer were estimated to be ∼1.5 nm.

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“…Past experimental and computational efforts have attempted to associate the physicochemical structures − and the electronic properties (e.g., trap depths and band gaps) of polymers, ,− most notably, for PE. − The empirical studies primarily involve the use of thermal-luminescences (TL), thermally stimulated current (TSC), thermally stimulated depolarization current, (TSDC) or space charge limited current (SCLC) , measurements to estimate the trap states induced by the chemical defects or the morphological disorders in the polymer. However, these measurements are, at best, only semiquantitative owing to the chemical and physical complexity of the polymers and the inherent limitations/assumptions of the instrumention techniques employed.…”

Section: Introductionmentioning

confidence: 99%

Electronic Structure of Polymer Dielectrics: The Role of Chemical and Morphological Complexity

et al. 2018

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The electronic structure of polymers contains signatures that correlate with their short-term and long-term integrity when subjected to large electric stresses. A detailed picture of the electronic structure of realistic models of polymers has been difficult to obtain, mainly due to the chemical and morphological complexity encountered in polymers. In this work, we have undertaken a comprehensive analysis of the electronic structure of six model polymers displaying chemical and morphological diversity, namely, polyethylene (PE), polypropylene (PP), polystyrene (PS), poly(methyl methacrylate) (PMMA), polyethylene terephthalate (PET), and polybutylene terephthalate (PBT), using first-principles density functional theory computations and classical molecular dynamics simulations. In particular, we have studied the role of monomer chemistry, tacticity, and large-scale morphological disorders in shaping the electronic structure of these polymers. We find that monomer chemistry and morphological disorder cooperate to create localized energy states and the formation of shallow/deep trap depths near the band edges, but tacticity has little effect on the band structure. Appropriate connections and comparisons between the computed results (e.g., band gap and trap depths) and the available experimental data have also been provided. Critical insights on physicochemical and electronic structure relationships are revealed, providing a pathway for understanding the factors that control electrical conduction and degradation of polymers (i.e., charge transport mechanisms, ionization processes, and carrier injections from electrodes).

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Cited by 27 publications

References 21 publications

Current state of the global operational aerosol multi‐model ensemble: An update from the International Cooperative for Aerosol Prediction (ICAP)

Current state of the global operational aerosol multi‐model ensemble: An update from the International Cooperative for Aerosol Prediction (ICAP)

Radiation-Induced Fluorescence from Doped Polyolefins on a Nanosecond Time Scale: Kinetics of the Processes Involving Geminate Radical Ions

Electronic Structure of Polymer Dielectrics: The Role of Chemical and Morphological Complexity

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