Pub Date : 2024-12-25DOI: 10.1016/j.jqsrt.2024.109335
Tianrui Bai, Lynette Edline Momo Jeulefack, Songfeng Li, Jie Cheng, Shuidong Dai, Linhua Liu, Fei Li
Photodissociation of AlO may be important for the aluminium chemistry in various astrophysical regions. The photodissociation cross sections and rates of AlO were investigated over the temperature range from 0 to 15000 K in this work. Firstly, the state-resolved cross sections at the wavelength of 50 − 5000 nm for transitions from the ground and first excited states were calculated using ab initio potential energy curves and transition dipole moments. The temperature-dependent cross sections were then obtained by assuming a Boltzmann distribution to describe the population of the initial state. Several common radiation fields (interstellar, solar and blackbody radiation field) were selected as the radiation fields, and then the photodissociation rates in different radiation fields were obtained. The photodissociation rates in all studied radiation fields exhibit a positive correlation with increasing temperature. This finding indicates that the total photodissociation rates are sensitive to the temperature. In addition, the photodissociation rates in the solar radiation field are higher than those in the interstellar radiation fields, indicating that photodissociation rate is associated with the type of radiation field in which the molecule is exposed. The calculated photodissociation cross sections and rates of AlO are useful to investigate the chemical evolution of the aluminum element in the interstellar environment.
{"title":"Absorption spectroscopy of AlO including photodissociation","authors":"Tianrui Bai, Lynette Edline Momo Jeulefack, Songfeng Li, Jie Cheng, Shuidong Dai, Linhua Liu, Fei Li","doi":"10.1016/j.jqsrt.2024.109335","DOIUrl":"https://doi.org/10.1016/j.jqsrt.2024.109335","url":null,"abstract":"Photodissociation of AlO may be important for the aluminium chemistry in various astrophysical regions. The photodissociation cross sections and rates of AlO were investigated over the temperature range from 0 to 15000 K in this work. Firstly, the state-resolved cross sections at the wavelength of 50 − 5000 nm for transitions from the ground and first excited states were calculated using <ce:italic>ab initio</ce:italic> potential energy curves and transition dipole moments. The temperature-dependent cross sections were then obtained by assuming a Boltzmann distribution to describe the population of the initial state. Several common radiation fields (interstellar, solar and blackbody radiation field) were selected as the radiation fields, and then the photodissociation rates in different radiation fields were obtained. The photodissociation rates in all studied radiation fields exhibit a positive correlation with increasing temperature. This finding indicates that the total photodissociation rates are sensitive to the temperature. In addition, the photodissociation rates in the solar radiation field are higher than those in the interstellar radiation fields, indicating that photodissociation rate is associated with the type of radiation field in which the molecule is exposed. The calculated photodissociation cross sections and rates of AlO are useful to investigate the chemical evolution of the aluminum element in the interstellar environment.","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"34 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142929291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-24DOI: 10.1016/j.jqsrt.2024.109322
Louis Rihouey, Philippe Ben-Abdallah, Riccardo Messina
We introduce a theoretical framework to describe the heat flux radiated in the near-field regime by a set of magneto-optical thermal nanoemitters close to a substrate in the presence of an external magnetic field. Then, we investigate the particular case of a single emitter and we demonstrate that the external field can induce both an amplification of the heat exchanged between emittter and substrate and a focusing of the Poynting field at the substrate interface at deep sub-wavelength scale. These effects open up promising perspectives for the development of heat-assisted magnetic-recording technology.
{"title":"Deep sub-wavelength scale focusing of heat flux radiated by magneto-optical nanoemitters in the presence of an external magnetic-field","authors":"Louis Rihouey, Philippe Ben-Abdallah, Riccardo Messina","doi":"10.1016/j.jqsrt.2024.109322","DOIUrl":"https://doi.org/10.1016/j.jqsrt.2024.109322","url":null,"abstract":"We introduce a theoretical framework to describe the heat flux radiated in the near-field regime by a set of magneto-optical thermal nanoemitters close to a substrate in the presence of an external magnetic field. Then, we investigate the particular case of a single emitter and we demonstrate that the external field can induce both an amplification of the heat exchanged between emittter and substrate and a focusing of the Poynting field at the substrate interface at deep sub-wavelength scale. These effects open up promising perspectives for the development of heat-assisted magnetic-recording technology.","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"27 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142929293","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-24DOI: 10.1016/j.jqsrt.2024.109324
Robert J. Hargreaves, Iouli E. Gordon, Xinchuan Huang, Geoffrey C. Toon, Laurence S. Rothman
An updated carbon dioxide line list for the HITEMP spectroscopic database is presented. This line list covers the 0–17697 cm−1 (>565 nm) spectral range and is built upon the AI-3000K semi-empirical line list for 12C16O2, 13C16O2, 16O12C18O, and 16O12C17O (Huang et al., 2023), combined with HITRAN2020 data, additional isotopologues, and further improvements described in this work. In order to make the line list practical for applications, over 36 billion individual transitions of the original AI-3000K line list have been separated into “strong” and “weak”. “Strong” transitions were adapted directly, while the weak transitions were then combined into so-called “effective” lines. The latter can accurately account for the intensity contribution of underlying weak AI-3000K transitions while reducing the database by over two orders of magnitude (to ∼326 million). In addition, pressure broadening parameters have been revised for this work to improve applicability at high temperatures. The line list has been added to HITEMP and is suitable for modeling the spectrum of carbon dioxide at temperatures up to 3000 K.
提出了HITEMP光谱数据库中最新的二氧化碳谱线表。该谱线列表涵盖0-17697 cm−1 （>565 nm）光谱范围，基于AI-3000K 12C16O2、13C16O2、16O12C18O和16O12C17O的半经验谱线列表（Huang et al., 2023），结合HITRAN2020数据、额外的同位素以及本工作中描述的进一步改进。为了使线路列表在实际应用中更加实用，原始AI-3000K线路列表中超过360亿个单独的过渡被分为“强”和“弱”。“强”的过渡被直接改编，而弱的过渡则被组合成所谓的“有效”的线条。后者可以准确地解释潜在的弱AI-3000K转换的强度贡献，同时将数据库减少两个数量级以上（至~ 3.26亿）。此外，还对压力展宽参数进行了修订，以提高在高温下的适用性。该线列表已添加到HITEMP，适用于模拟温度高达3000k的二氧化碳光谱。
{"title":"Updating the carbon dioxide line list in HITEMP","authors":"Robert J. Hargreaves, Iouli E. Gordon, Xinchuan Huang, Geoffrey C. Toon, Laurence S. Rothman","doi":"10.1016/j.jqsrt.2024.109324","DOIUrl":"https://doi.org/10.1016/j.jqsrt.2024.109324","url":null,"abstract":"An updated carbon dioxide line list for the HITEMP spectroscopic database is presented. This line list covers the 0–17<ce:hsp sp=\"0.16667\"></ce:hsp>697 cm<ce:sup loc=\"post\">−1</ce:sup> (<mml:math altimg=\"si1.svg\" display=\"inline\"><mml:mo>></mml:mo></mml:math>565 nm) spectral range and is built upon the AI-3000K semi-empirical line list for <ce:sup loc=\"post\">12</ce:sup>C<ce:sup loc=\"post\">16</ce:sup>O<ce:inf loc=\"post\">2</ce:inf>, <ce:sup loc=\"post\">13</ce:sup>C<ce:sup loc=\"post\">16</ce:sup>O<ce:inf loc=\"post\">2</ce:inf>, <ce:sup loc=\"post\">16</ce:sup>O<ce:sup loc=\"post\">12</ce:sup>C<ce:sup loc=\"post\">18</ce:sup>O, and <ce:sup loc=\"post\">16</ce:sup>O<ce:sup loc=\"post\">12</ce:sup>C<ce:sup loc=\"post\">17</ce:sup>O (Huang et al., 2023), combined with HITRAN2020 data, additional isotopologues, and further improvements described in this work. In order to make the line list practical for applications, over 36 billion individual transitions of the original AI-3000K line list have been separated into “strong” and “weak”. “Strong” transitions were adapted directly, while the weak transitions were then combined into so-called “effective” lines. The latter can accurately account for the intensity contribution of underlying weak AI-3000K transitions while reducing the database by over two orders of magnitude (to <mml:math altimg=\"si2.svg\" display=\"inline\"><mml:mo>∼</mml:mo></mml:math>326 million). In addition, pressure broadening parameters have been revised for this work to improve applicability at high temperatures. The line list has been added to HITEMP and is suitable for modeling the spectrum of carbon dioxide at temperatures up to 3000 K.","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"23 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142929292","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-22DOI: 10.1016/j.jqsrt.2024.109327
Tatiana Zhuravleva
The results of statistical modeling of the angular characteristics of reflected solar radiation in the atmosphere containing a layer of ice crystal clouds with anisotropy caused by the orientation of particles in space are presented. Numerical experiments are carried out using (1) original algorithm of the Monte Carlo method for calculating characteristics of unpolarized solar radiation taking into account the multiple scattering, reflection from the underlying surface, and attenuation by aerosol particles and due to molecular scattering and (2) optical model of anisotropic medium, composed of horizontally oriented hexagonal plates or Parry columns (visible range), developed previously in Institute of Atmospheric Optics, Siberian Branch, Russian Academy of Sciences, Tomsk, Russia. We discuss the patterns of formation of reflected solar radiation without taking into account the aerosol-molecular component of the atmosphere and surface reflection; these simulation results make it possible to identify the specific features of radiative transfer, caused exclusively by the effects of anisotropy of ice-crystal clouds. The factors that determine the influence of the surface reflection and aerosol attenuation on halo phenomena are described. It is shown that, as the surface albedo increases, the near-isotropic radiation field is formed outside the main halo lines and the intensity of different halo lines decreases down to the level when these lines or their components become almost invisible against the background of the contribution formed by surface-reflected radiation. Our radiation code is to be used for a research into the optical phenomena, observed from the Earth's surface and space, and, in particular, for an additional study of scattering by oriented ice crystals near the specular reflection direction (solar glint).
{"title":"Statistical simulation of the angular distribution of reflected solar radiation in optically anisotropic ice-crystal clouds: Horizontally oriented particles","authors":"Tatiana Zhuravleva","doi":"10.1016/j.jqsrt.2024.109327","DOIUrl":"https://doi.org/10.1016/j.jqsrt.2024.109327","url":null,"abstract":"The results of statistical modeling of the angular characteristics of reflected solar radiation in the atmosphere containing a layer of ice crystal clouds with anisotropy caused by the orientation of particles in space are presented. Numerical experiments are carried out using (1) original algorithm of the Monte Carlo method for calculating characteristics of unpolarized solar radiation taking into account the multiple scattering, reflection from the underlying surface, and attenuation by aerosol particles and due to molecular scattering and (2) optical model of anisotropic medium, composed of horizontally oriented hexagonal plates or Parry columns (visible range), developed previously in Institute of Atmospheric Optics, Siberian Branch, Russian Academy of Sciences, Tomsk, Russia. We discuss the patterns of formation of reflected solar radiation without taking into account the aerosol-molecular component of the atmosphere and surface reflection; these simulation results make it possible to identify the specific features of radiative transfer, caused exclusively by the effects of anisotropy of ice-crystal clouds. The factors that determine the influence of the surface reflection and aerosol attenuation on halo phenomena are described. It is shown that, as the surface albedo increases, the near-isotropic radiation field is formed outside the main halo lines and the intensity of different halo lines decreases down to the level when these lines or their components become almost invisible against the background of the contribution formed by surface-reflected radiation. Our radiation code is to be used for a research into the optical phenomena, observed from the Earth's surface and space, and, in particular, for an additional study of scattering by oriented ice crystals near the specular reflection direction (solar glint).","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"14 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142889186","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Black carbon (BC) is a type of light absorbing substances in atmosphere, which has a significant impact on regional and global radiation balance. When evaluating the climatic effects of BC, the complex morphology of BC poses a challenge for large-scale climate models to proceed with the calculations. In this study, we developed a deep convolutional neural network (CNN) that combines residual links with one-dimensional multi-scale dilated convolutions. Using the multiple sphere T-matrix (MSTM), the extinction efficiency (Qext), absorption efficiency (Qabs), scattering efficiency (Qsca), and asymmetry factor (g) for coated BC were evaluated under different fractal dimensions, monomer radii, refractive indices, and incident wavelengths, by considering the volume fraction of thinly coated BC and thickly coated BC in the range from 20 % to 60 % and 2 % to 10 %, respectively. The optical properties of small particles were then treated as the training set to train the CNN, and the trained CNN was used to output the optical properties of large particles. By comparing the Qext, Qabs, Qsca, and g predicted by the CNN with those obtained from the MSTM, we found that the CNN has superior predictive capabilities for the optical properties of coated BC, and the newly established CNN exhibited broad applicability in predicting the optical properties of coated BC. Although relative deviations are observed in predicting the optical properties of small particles using the CNN, the errors for large particle predictions are essentially <1 %, with the mean absolute errors and root mean square errors being lower than 0.029 and 0.043, respectively. This study demonstrates that the CNN has great potential for further development. Future research should focus on how to use less data to predict more accurate results for the range of computational parameters for BC.
{"title":"Using convolutional neural networks to predict the optical properties of coated black carbon","authors":"Zhenhai Qin, Jinhong Wu, Haihui Wang, Yongming Zhang, Qixing Zhang","doi":"10.1016/j.jqsrt.2024.109326","DOIUrl":"https://doi.org/10.1016/j.jqsrt.2024.109326","url":null,"abstract":"Black carbon (BC) is a type of light absorbing substances in atmosphere, which has a significant impact on regional and global radiation balance. When evaluating the climatic effects of BC, the complex morphology of BC poses a challenge for large-scale climate models to proceed with the calculations. In this study, we developed a deep convolutional neural network (CNN) that combines residual links with one-dimensional multi-scale dilated convolutions. Using the multiple sphere T-matrix (MSTM), the extinction efficiency (<ce:italic>Q<ce:inf loc=\"post\">ext</ce:inf></ce:italic>), absorption efficiency (<ce:italic>Q<ce:inf loc=\"post\">abs</ce:inf></ce:italic>), scattering efficiency (<ce:italic>Q<ce:inf loc=\"post\">sca</ce:inf></ce:italic>), and asymmetry factor (<ce:italic>g</ce:italic>) for coated BC were evaluated under different fractal dimensions, monomer radii, refractive indices, and incident wavelengths, by considering the volume fraction of thinly coated BC and thickly coated BC in the range from 20 % to 60 % and 2 % to 10 %, respectively. The optical properties of small particles were then treated as the training set to train the CNN, and the trained CNN was used to output the optical properties of large particles. By comparing the <ce:italic>Q<ce:inf loc=\"post\">ext</ce:inf>, Q<ce:inf loc=\"post\">abs</ce:inf>, Q<ce:inf loc=\"post\">sca</ce:inf></ce:italic>, and <ce:italic>g</ce:italic> predicted by the CNN with those obtained from the MSTM, we found that the CNN has superior predictive capabilities for the optical properties of coated BC, and the newly established CNN exhibited broad applicability in predicting the optical properties of coated BC. Although relative deviations are observed in predicting the optical properties of small particles using the CNN, the errors for large particle predictions are essentially <1 %, with the mean absolute errors and root mean square errors being lower than 0.029 and 0.043, respectively. This study demonstrates that the CNN has great potential for further development. Future research should focus on how to use less data to predict more accurate results for the range of computational parameters for BC.","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"65 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142889188","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The optical properties of oceanic foam are crucial for satellite remote sensing inversion and target identification, with the volume scattering properties of foam layers significantly influencing the directionality of light scattering, making them a focal point in sea surface scattering research. To achieve efficient computation and analysis of the volume scattering properties of foam layers, this paper establishes a large-scale foam aggregate light scattering model based on geometric optics theory. An efficient algorithm for the foam volume scattering phase function was developed using GPU acceleration, and its convergence and acceleration performance were analyzed and evaluated. Furthermore, the influences of various factors, including different fractal models, particle numbers, random orientations of fractal structures, and asymmetric geometries, on the average volume scattering properties of the foam multi-spherical aggregates were analyzed. The results indicate that the influences of the fractal structures, particle numbers, and orientations of fractal structures on the average scattering properties is minimal, with correlation coefficients exceeding 0.99. This study provides an efficient algorithm for obtaining the average volume scattering phase function of foam, offering strong support for further research on sea surface scattering characteristics involving foam layers.
{"title":"An effective computational method and analysis of scattering characteristics for sea surface foam layer","authors":"Yue Zhang, Xiaoxiao Yu, Peng Gao, Chunlin Huang, Qixiang Chen, Yuan Yuan, Shikui Dong, Kaifeng Lin","doi":"10.1016/j.jqsrt.2024.109332","DOIUrl":"https://doi.org/10.1016/j.jqsrt.2024.109332","url":null,"abstract":"The optical properties of oceanic foam are crucial for satellite remote sensing inversion and target identification, with the volume scattering properties of foam layers significantly influencing the directionality of light scattering, making them a focal point in sea surface scattering research. To achieve efficient computation and analysis of the volume scattering properties of foam layers, this paper establishes a large-scale foam aggregate light scattering model based on geometric optics theory. An efficient algorithm for the foam volume scattering phase function was developed using GPU acceleration, and its convergence and acceleration performance were analyzed and evaluated. Furthermore, the influences of various factors, including different fractal models, particle numbers, random orientations of fractal structures, and asymmetric geometries, on the average volume scattering properties of the foam multi-spherical aggregates were analyzed. The results indicate that the influences of the fractal structures, particle numbers, and orientations of fractal structures on the average scattering properties is minimal, with correlation coefficients exceeding 0.99. This study provides an efficient algorithm for obtaining the average volume scattering phase function of foam, offering strong support for further research on sea surface scattering characteristics involving foam layers.","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"1 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142889190","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-21DOI: 10.1016/j.jqsrt.2024.109328
J.X. Wang, Z.G. Xu, F.Q. Zhang
Graphene grating structures have potential in enhancing near-field radiative heat transfer because of their anisotropic properties and single-layer graphene grating structures have shown excellent capability for thermal modulation in magnetic fields. In this study, a theoretical model for the near-field radiative heat transfer under the influence of a magnetic field in twisted bilayer graphene grating structures is proposed, in which there exists a rotation angle between bilayer graphene gratings. The emitter and absorber are mirror images of each other. The combined effect of the magnetic field and graphene chemical potentials on modulating near-field radiative heat transfer is investigated. The effect of the graphene grating filling factor on the surface state and the near-field radiative heat transfer is discussed. By manipulating the rotation angle of the graphene gratings, the magnetic field enhances thermal modulation. The hyperbolic and elliptic surface plasmon polaritons of the graphene gratings undergo topological transitions as the rotation angle increases.
{"title":"Near field radiative heat transfer in twisted bilayer graphene grating structures based on magnetic modulation","authors":"J.X. Wang, Z.G. Xu, F.Q. Zhang","doi":"10.1016/j.jqsrt.2024.109328","DOIUrl":"https://doi.org/10.1016/j.jqsrt.2024.109328","url":null,"abstract":"Graphene grating structures have potential in enhancing near-field radiative heat transfer because of their anisotropic properties and single-layer graphene grating structures have shown excellent capability for thermal modulation in magnetic fields. In this study, a theoretical model for the near-field radiative heat transfer under the influence of a magnetic field in twisted bilayer graphene grating structures is proposed, in which there exists a rotation angle between bilayer graphene gratings. The emitter and absorber are mirror images of each other. The combined effect of the magnetic field and graphene chemical potentials on modulating near-field radiative heat transfer is investigated. The effect of the graphene grating filling factor on the surface state and the near-field radiative heat transfer is discussed. By manipulating the rotation angle of the graphene gratings, the magnetic field enhances thermal modulation. The hyperbolic and elliptic surface plasmon polaritons of the graphene gratings undergo topological transitions as the rotation angle increases.","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"50 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142889191","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-21DOI: 10.1016/j.jqsrt.2024.109331
Claudia D. Morello, Robert A. West, Matthew J. Berg
Enceladus, the sixth largest moon of Saturn, is known to be a geologically active icy body. Observations by NASA's Cassini spacecraft show that Enceladus has cryovolcanoes on its south pole as well as a global subsurface ocean hidden beneath its frozen crust. Photographs from NASA's Cassini Spacecraft during flybys of Enceladus document Enceladus's surface and the cryovolcano plumes. It is known that larger particles ejected from the cryovolcanoes deposit on the surface, while smaller particles escape into Saturn's E-ring. Cassini observations of the sunlight scattered by the plume particles on the surface may provide information about the plume composition and potentially the dynamics of the ocean below. This work presents Enceladus’ disk-averaged degree of linear polarization (DoLP), which has yet to be analyzed, and compares it to spherical, spheroidal, cylindrical, and hexagonal ice particles simulated by light scattering codes ADDA and T-Matrix using a multiple-scattering approximation. The Pearson correlation coefficient is used to quantify the fit of each morphology to the surface polarization data in the GRN (569 nm) and MT2 (727 nm) wavelength filters. The polarization of Enceladus’ surface implies the particles are likely non-spherical, and possibly occur in a narrow size distribution near a mean of two microns in radius.
{"title":"Polarization Analysis of Enceladus’ Surface","authors":"Claudia D. Morello, Robert A. West, Matthew J. Berg","doi":"10.1016/j.jqsrt.2024.109331","DOIUrl":"https://doi.org/10.1016/j.jqsrt.2024.109331","url":null,"abstract":"Enceladus, the sixth largest moon of Saturn, is known to be a geologically active icy body. Observations by NASA's Cassini spacecraft show that Enceladus has cryovolcanoes on its south pole as well as a global subsurface ocean hidden beneath its frozen crust. Photographs from NASA's Cassini Spacecraft during flybys of Enceladus document Enceladus's surface and the cryovolcano plumes. It is known that larger particles ejected from the cryovolcanoes deposit on the surface, while smaller particles escape into Saturn's E-ring. Cassini observations of the sunlight scattered by the plume particles on the surface may provide information about the plume composition and potentially the dynamics of the ocean below. This work presents Enceladus’ disk-averaged degree of linear polarization (DoLP), which has yet to be analyzed, and compares it to spherical, spheroidal, cylindrical, and hexagonal ice particles simulated by light scattering codes ADDA and T-Matrix using a multiple-scattering approximation. The Pearson correlation coefficient is used to quantify the fit of each morphology to the surface polarization data in the GRN (569 nm) and MT2 (727 nm) wavelength filters. The polarization of Enceladus’ surface implies the particles are likely non-spherical, and possibly occur in a narrow size distribution near a mean of two microns in radius.","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"74 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142929295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-19DOI: 10.1016/j.jqsrt.2024.109310
Nigar Asadova, Karim Achouri, Kristian Arjas, Baptiste Auguié, Roland Aydin, Alexandre Baron, Dominik Beutel, Bernd Bodermann, Kaoutar Boussaoud, Sven Burger, Minseok Choi, Krzysztof M. Czajkowski, Andrey B. Evlyukhin, Atefeh Fazel-Najafabadi, Ivan Fernandez-Corbaton, Puneet Garg, David Globosits, Ulrich Hohenester, Hongyoon Kim, Seokwoo Kim, Philippe Lalanne, Eric C. Le Ru, Jörg Meyer, Jungho Mun, Lorenzo Pattelli, Lukas Pflug, Carsten Rockstuhl, Junsuk Rho, Stefan Rotter, Brian Stout, Päivi Törmä, Jorge Olmos Trigo, Frank Tristram, Nikolaos L. Tsitsas, Renaud Vallée, Kevin Vynck, Thomas Weiss, Peter Wiecha, Thomas Wriedt, Vassilios Yannopapas, Maxim A. Yurkin, Grigorios P. Zouros
The transition matrix, frequently abbreviated as T-matrix, contains the complete information in a linear approximation of how a spatially localized object scatters an incident field. The T-matrix is used to study the scattering response of an isolated object and describes the optical response of complex photonic materials made from ensembles of individual objects. T-matrices of certain common structures, potentially, have been repeatedly calculated all over the world again and again. This is not necessary and constitutes a major challenge for various reasons. First, the resources spent on their computation represent an unsustainable financial and ecological burden. Second, with the onset of machine learning, data is the gold of our era, and it should be freely available to everybody to address novel scientific challenges. Finally, the possibility of reproducing simulations could tremendously improve if the considered T-matrices could be shared. To address these challenges, we found it important to agree on a common data format for T-matrices and to enable their collection from different sources and distribution. This document aims to develop the specifications for storing T-matrices and associated metadata. The specifications should allow maximum freedom to accommodate as many use cases as possible without introducing any ambiguity in the stored data. The common format will assist in setting up a public database of T-matrices.
{"title":"T-matrix representation of optical scattering response: Suggestion for a data format","authors":"Nigar Asadova, Karim Achouri, Kristian Arjas, Baptiste Auguié, Roland Aydin, Alexandre Baron, Dominik Beutel, Bernd Bodermann, Kaoutar Boussaoud, Sven Burger, Minseok Choi, Krzysztof M. Czajkowski, Andrey B. Evlyukhin, Atefeh Fazel-Najafabadi, Ivan Fernandez-Corbaton, Puneet Garg, David Globosits, Ulrich Hohenester, Hongyoon Kim, Seokwoo Kim, Philippe Lalanne, Eric C. Le Ru, Jörg Meyer, Jungho Mun, Lorenzo Pattelli, Lukas Pflug, Carsten Rockstuhl, Junsuk Rho, Stefan Rotter, Brian Stout, Päivi Törmä, Jorge Olmos Trigo, Frank Tristram, Nikolaos L. Tsitsas, Renaud Vallée, Kevin Vynck, Thomas Weiss, Peter Wiecha, Thomas Wriedt, Vassilios Yannopapas, Maxim A. Yurkin, Grigorios P. Zouros","doi":"10.1016/j.jqsrt.2024.109310","DOIUrl":"https://doi.org/10.1016/j.jqsrt.2024.109310","url":null,"abstract":"The transition matrix, frequently abbreviated as T-matrix, contains the complete information in a linear approximation of how a spatially localized object scatters an incident field. The T-matrix is used to study the scattering response of an isolated object and describes the optical response of complex photonic materials made from ensembles of individual objects. T-matrices of certain common structures, potentially, have been repeatedly calculated all over the world again and again. This is not necessary and constitutes a major challenge for various reasons. First, the resources spent on their computation represent an unsustainable financial and ecological burden. Second, with the onset of machine learning, data is the gold of our era, and it should be freely available to everybody to address novel scientific challenges. Finally, the possibility of reproducing simulations could tremendously improve if the considered T-matrices could be shared. To address these challenges, we found it important to agree on a common data format for T-matrices and to enable their collection from different sources and distribution. This document aims to develop the specifications for storing T-matrices and associated metadata. The specifications should allow maximum freedom to accommodate as many use cases as possible without introducing any ambiguity in the stored data. The common format will assist in setting up a public database of T-matrices.","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"114 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142889197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Structure-engineering has proven successful in enhancing the thermochromic properties of VO2-based film for smart thermal management under dynamic thermal loads. However, traditional multilayer structures based on interlayer interference and grating structures based on resonance effect exhibit certain wavelength selectivity, thereby hindering broadband absorption. This limitation constrains the improvement of high temperature integrated emissivity (εH), posing great challenges for achieving greater average emissivity tunability (Δε=εH-εL). In this work, we propose a VO2-based 3D pyramid structured film by combining the multilayer structure with the grating structure, achieving an unprecedented high emissivity tunability Δε reaching 0.68. Based on the Magneto-polaron (MP) resonance effect, high absorption over a wide spectral range at high temperature is achieved, with εH of 0.954. Through optimizing the VO2 thickness δ to 30 nm and tilt angle β to 80° respectively, we achieve optimal thermochromic performance of the film. Compared with conventional multilayer and grating regimes, the pyramid textured structure proposed in this work demonstrates a larger design space, which can be a reference for the design and optimization of spacecraft thermal control skin.
{"title":"Pyramid-structured VO2-based thin films with large emissivity tunability for thermochromic radiators","authors":"Yifan Sun, Guoliang Chen, Qingze Chen, Haoyang Fu, Benzhi Min, Zhengwei Tao, Tongtong Yue, Junming Zhao, Jun Qiu","doi":"10.1016/j.jqsrt.2024.109325","DOIUrl":"https://doi.org/10.1016/j.jqsrt.2024.109325","url":null,"abstract":"Structure-engineering has proven successful in enhancing the thermochromic properties of VO<ce:inf loc=\"post\">2</ce:inf>-based film for smart thermal management under dynamic thermal loads. However, traditional multilayer structures based on interlayer interference and grating structures based on resonance effect exhibit certain wavelength selectivity, thereby hindering broadband absorption. This limitation constrains the improvement of high temperature integrated emissivity (<ce:italic>ε</ce:italic><ce:inf loc=\"post\">H</ce:inf>), posing great challenges for achieving greater average emissivity tunability (Δ<ce:italic>ε</ce:italic>=<ce:italic>ε</ce:italic><ce:inf loc=\"post\">H</ce:inf>-<ce:italic>ε</ce:italic><ce:inf loc=\"post\">L</ce:inf>). In this work, we propose a VO<ce:inf loc=\"post\">2</ce:inf>-based 3D pyramid structured film by combining the multilayer structure with the grating structure, achieving an unprecedented high emissivity tunability Δ<ce:italic>ε</ce:italic> reaching 0.68. Based on the Magneto-polaron (MP) resonance effect, high absorption over a wide spectral range at high temperature is achieved, with <ce:italic>ε</ce:italic><ce:inf loc=\"post\">H</ce:inf> of 0.954. Through optimizing the VO<ce:inf loc=\"post\">2</ce:inf> thickness <ce:italic>δ</ce:italic> to 30 nm and tilt angle <ce:italic>β</ce:italic> to 80° respectively, we achieve optimal thermochromic performance of the film. Compared with conventional multilayer and grating regimes, the pyramid textured structure proposed in this work demonstrates a larger design space, which can be a reference for the design and optimization of spacecraft thermal control skin.","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"319 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142889198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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