Journal of Quantitative Spectroscopy & Radiative Transfer最新文献

{"title":"Continuum absorption of millimeter waves by CH4-X (X=CH4, N2, CO2)","authors":"A.O. Koroleva ,&nbsp;T.A. Galanina ,&nbsp;I.S. Amerkhanov ,&nbsp;E.A. Serov ,&nbsp;A.Yu. Sekacheva ,&nbsp;M.A. Koshelev ,&nbsp;D.N. Chistikov ,&nbsp;A.A. Finenko ,&nbsp;M.Yu. Tretyakov","doi":"10.1016/j.jqsrt.2026.109841","DOIUrl":"10.1016/j.jqsrt.2026.109841","url":null,"abstract":"<div><div>The room-temperature continuum absorption of pure methane and of its mixture with nitrogen and carbon dioxide was measured in the millimeter wavelength range using resonator spectrometer. The line wings contribution to the continuum was estimated to be weak. The bimolecular nature of the observed continuum was confirmed by both the expected pressure dependences and the agreement with trajectory-based simulation.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"353 ","pages":"Article 109841"},"PeriodicalIF":1.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146048523","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}

{"title":"High accurate analysis of the excited (v4 = 1) and (v4 = 2) vibrational states of 12CH235Cl37Cl in the region up to 1.1 THz","authors":"O.N. Ulenikov,&nbsp;O.V. Gromova,&nbsp;E.S. Bekhtereva,&nbsp;Yu.V. Khudyakova,&nbsp;V.E. Nikolaeva","doi":"10.1016/j.jqsrt.2026.109832","DOIUrl":"10.1016/j.jqsrt.2026.109832","url":null,"abstract":"&lt;div&gt;&lt;div&gt;The high resolution submillimeter wave spectra of methylene chloride (earlier recorded in the I. Physikalisches Institut, Universität zu Köln (Germany) and Laboratoire PhLAM, Université de Lille (France) in the wide spectral region of 0.075–1.1 THz) were analyzed with the goal of high accurate description of the quadrupole-rotational structures of the &lt;sup&gt;12&lt;/sup&gt;CH&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;35&lt;/sup&gt;Cl&lt;sup&gt;37&lt;/sup&gt;Cl species in the (&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;v&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;4&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; = 1) and (&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;v&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;4&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; = 2) vibrational states. Assignment and analysis of transitions was made in the frame of the Watson’s Hamiltonian in &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;A&lt;/mi&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;reduction and &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;I&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;r&lt;/mi&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; representation with the use of the ASYMTOPTPU computer code and SPFIT/SPCAT package of Pickett. The 4983 unresolved lines (4088 transitions) in the excited (&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;v&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;4&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; = 1) vibrational state and 842 lines (1420 transitions) in the (&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;v&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;4&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; = 2)) vibrational state with the maximum values of quantum number &lt;span&gt;&lt;math&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;J&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mtext&gt;max&lt;/mtext&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt;&lt;/span&gt; = 95/79 and &lt;span&gt;&lt;math&gt;&lt;msubsup&gt;&lt;mrow&gt;&lt;mi&gt;K&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;a&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mtext&gt;max&lt;/mtext&gt;&lt;/mrow&gt;&lt;/msubsup&gt;&lt;/math&gt;&lt;/span&gt; = 19/19 for the (&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;v&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;4&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; = 1) and (&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;v&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;4&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; = 2) vibrational states were assigned in the experimental spectra. Weighted fit of the rotational and centrifugal distortion parameters, as well as, of the quadrupole splitting parameters was made. The obtained from the fit 19/16 rotational and centrifugal distortion parameters reproduces values of the 4983/842 experimental line positions (4088/1420 transitions) with the &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;d&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mtext&gt;rms&lt;/mtext&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; = 21/26 kHz for the states (&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;v&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;4&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; = 1) and (&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;v&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;4&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; = 2). Comparison with the rotational and centrifugal distortion parameters known in the literature is made and shown that the latter reproduce the same (assigned in the present study) set of the experimental line positions with the &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;d&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mtext&gt;rms&lt;/mtext&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; values which are considerably worse in comparison with the results of the present study. As to the quadrupole coupling &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;χ&lt;/mi&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;parameters, ","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"353 ","pages":"Article 109832"},"PeriodicalIF":1.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146048524","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}

{"title":"Beyond-Voigt collisional parameters of subTHz H2O lines for atmospheric applications","authors":"M.A. Koshelev,&nbsp;I.N. Vilkov,&nbsp;D.S. Makarov,&nbsp;G.Yu. Golubiatnikov,&nbsp;A.O. Koroleva,&nbsp;T.A. Galanina","doi":"10.1016/j.jqsrt.2026.109854","DOIUrl":"10.1016/j.jqsrt.2026.109854","url":null,"abstract":"<div><div>The profiles of nine key subTHz H<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>O lines were recorded at various pressures and room temperature using two fundamentally different spectroscopic techniques. The beyond-Voigt line shape taking into account the speed-dependence of the collision relaxation rate was employed to analyze the high quality experimental recordings. Collisional broadening, shifting and their quadratic speed-dependence were measured for major atmospheric perturbers H<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>O, N<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>, O<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>, and Ar. The found air-related line shape parameters can be used for updating atmospheric databases and propagation models.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"353 ","pages":"Article 109854"},"PeriodicalIF":1.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146071923","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}

{"title":"Generic polychromatic light scattering theories for particles of arbitrary shapes and morphologies illuminated by laser pulses","authors":"Gérard Gouesbet ,&nbsp;Leonardo A. Ambrosio ,&nbsp;Jhonas O. de Sarro","doi":"10.1016/j.jqsrt.2026.109834","DOIUrl":"10.1016/j.jqsrt.2026.109834","url":null,"abstract":"<div><div>We discuss a synthesis between (i) a generic formulation of generalized Lorenz–Mie theory (more generally of arbitrary light scattering theories) for an arbitrary scatterer illuminated by one laser pulse and (ii) a polychromatic generalized Lorenz–Mie theory in the strict sense, i.e. for a spherical homogeneous spherical particle, illuminated by several polychromatic non-continuous beams. The synthesis then takes the form of generic polychromatic light scattering theories for particles of arbitrary shapes and morphologies illuminated by several laser pulses, or train of pulses. Although the present work is discussed in an electromagnetic framework, it can be adapted to scalar, in particular acoustical, scattering.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"353 ","pages":"Article 109834"},"PeriodicalIF":1.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146033172","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}

{"title":"Measurement and assignment of E-symmetry states in the 6010-6110 cm−1 and 8940-9150 cm−1 ranges of methane using optical frequency comb double-resonance spectroscopy","authors":"Adrian Hjältén ,&nbsp;Vinicius Silva de Oliveira ,&nbsp;Michael Rey ,&nbsp;Isak Silander ,&nbsp;Kevin K. Lehmann ,&nbsp;Aleksandra Foltynowicz","doi":"10.1016/j.jqsrt.2026.109831","DOIUrl":"10.1016/j.jqsrt.2026.109831","url":null,"abstract":"<div><div>We use sub-Doppler optical-optical double-resonance (OODR) spectroscopy with a 3.3 µm single-frequency pump and a cavity-enhanced 1.65 µm comb probe to measure 33 ladder-type (3ν₃ ← ν₃) and 8 V-type (2ν₃) transitions in the 5880–6090 cm^-1 range of methane, reaching states with rovibrational E symmetry in the region of the <em>P</em>6 and <em>P</em>4 polyads, respectively. We assign the ladder-type transitions using new Hamiltonian predictions and the ExoMol line list, and the V-type transitions using the new Hamiltonian, ExoMol, HITRAN2020, and the WKLMC line lists. While 7 of the states in the 3ν₃ range have been previously observed either in earlier OODR work (without cavity enhancement) with 1.5 MHz accuracy or in FTIR measurements of cold bands with 150 MHz resolution, the states reported here have uncertainties down to 150 kHz (5 × 10^–6 cm^-1). The E-symmetry states exhibit first-order Stark splitting, which will be reported in our future work.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"353 ","pages":"Article 109831"},"PeriodicalIF":1.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145995113","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}

{"title":"Multiple scattering effects in noctilucent clouds: Numerical estimation and application to altitude and particle size measurements","authors":"Oleg S. Ugolnikov","doi":"10.1016/j.jqsrt.2026.109836","DOIUrl":"10.1016/j.jqsrt.2026.109836","url":null,"abstract":"<div><div>The simple 3-D radiative transfer model of the Earth’s atmosphere is developed for numerical comparison of direct solar radiation and limb scattering background at the definite middle or upper atmospheric layer during the deep twilight period. This model enables the quantification of the multiple scattering contribution in the field of high-altitude clouds, such as polar stratospheric and noctilucent clouds. This is the factor that can influence the results of altitude and microphysical particle study based on the approximation of single scattering. The possible errors caused by this effect are estimated together with the contribution of multiple scattering for different altitudes of the clouds, wavelengths, and solar zenith angles. The results are interpreted geometrically and optically, the color effects observed for noctilucent clouds are described.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"353 ","pages":"Article 109836"},"PeriodicalIF":1.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146000783","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}

{"title":"In-plane spectral, directional radiative properties of flat and corrugated polished copper surfaces between 550 and 1100 nm","authors":"Ehsan Mofidipour,&nbsp;Matthew R. Jones,&nbsp;Brian D. Iverson","doi":"10.1016/j.jqsrt.2026.109855","DOIUrl":"10.1016/j.jqsrt.2026.109855","url":null,"abstract":"<div><div>Control of radiative surface properties is critical in the design and optimization of thermal systems. Intrinsic radiative surface properties are generally static, but apparent radiative surface properties may be controlled by modifying the geometry of a surface. Therefore, geometric modifications enable the adaptation of thermal management systems to transient environmental conditions through dynamic control of radiative surface properties. In this study, the radiative properties of a flat, polished copper surface and the apparent radiative properties of a corrugated, polished copper surface are measured for various angles of incidence of the spectral intensity, over a limited range within the visible and near-infrared spectra (550–1100 nm). A measurement framework that relates measurements of the in-plane spectral, directional-directional reflectivity to the in-plane spectral, bidirectional reflectance distribution function (BRDF) is presented. Since the BRDF is the fundamental radiative surface property, it may be used to obtain the spectral, directional emissivity for surfaces. Results indicate that the spectral, directional-hemispherical reflectivity of the corrugated surface is significantly less than that of the flat surface. The spectral, directional emissivity of the corrugated copper surface is greater than approximately 0.93 at all wavelengths. In contrast, the spectral, directional emissivity of the flat copper surface varies between 0.6–0.73 in the visible spectral range studied and this value decreases in the near-infrared region across all directions (∼0.18–0.23). The orientation of the grooves with respect to the incident intensity affects the spectral, directional emissivity. The spectral, directional emissivity of the corrugated surface decreases by 24% (from 0.95 to 0.71), 16% (from 0.93 to 0.77), and 13% (from 0.96 to 0.83) when it was rotated 60° at 600, 800, and 1000 nm, respectively. These observations suggest that emission by the corrugated surface may be guided in a preferred direction.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"353 ","pages":"Article 109855"},"PeriodicalIF":1.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146071594","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}

{"title":"Theoretical study of energy levels and radiative transitions of K-shell excited states in the Be-like Sc17+ ion","authors":"Yan Sun ,&nbsp;Feng Hu ,&nbsp;Qing Chen ,&nbsp;CuiCui Sang ,&nbsp;Dongdong Liu ,&nbsp;Xi Liu ,&nbsp;Chong Han ,&nbsp;Zhe Shi","doi":"10.1016/j.jqsrt.2026.109856","DOIUrl":"10.1016/j.jqsrt.2026.109856","url":null,"abstract":"<div><div>Energy levels, lifetimes, line strengths, oscillator strengths, and transition probabilities for the <span><math><mrow><mn>1</mn><mi>s</mi><mn>2</mn><msup><mrow><mi>s</mi></mrow><mrow><mn>2</mn></mrow></msup><mi>n</mi><mi>l</mi></mrow></math></span>, <span><math><mrow><mn>1</mn><mi>s</mi><mn>2</mn><mi>s</mi><mn>2</mn><mi>p</mi><mi>n</mi><mi>l</mi></mrow></math></span>, and <span><math><mrow><mn>1</mn><mi>s</mi><mn>2</mn><msup><mrow><mi>p</mi></mrow><mrow><mn>2</mn></mrow></msup><mi>n</mi><mi>l</mi></mrow></math></span> (<span><math><mrow><mi>n</mi><mo>≤</mo><mn>3</mn></mrow></math></span>, <span><math><mrow><mi>l</mi><mo>=</mo><mi>s</mi><mo>,</mo><mi>p</mi><mo>,</mo><mi>d</mi></mrow></math></span>) configurations of the Be-like Sc<span><math><msup><mrow></mrow><mrow><mn>17</mn><mo>+</mo></mrow></msup></math></span> ion were calculated using the multiconfiguration Dirac-Hartree–Fock (MCDHF) method, with the contributions of the Breit interaction and quantum electrodynamics (QED) corrections included. Atomic parameters for 250 K-shell excited fine-structure levels and 2441 corresponding electric dipole (E1) transitions are presented. The computed K<span><math><mi>α</mi></math></span> X-ray wavelengths are in good agreement with previous experimental and theoretical results, with most differences below 0.095%. The uncertainty of the calculated transition data was carefully estimated based on relative deviations from transition probabilities from different gauges. Furthermore, the accuracy of each E1 transition was individually assessed. These high-precision results are crucial for identifying and analysing X-ray spectral lines in astrophysical sources and in high-temperature laboratory plasmas, thereby enabling more accurate plasma diagnostics and modelling.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"354 ","pages":"Article 109856"},"PeriodicalIF":1.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146134654","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}

{"title":"Estimation of Cloud Condensation Nuclei (CCN) using a neural network retrieval algorithm—A synthetic study for SPEXone on the NASA PACE mission","authors":"Neranga K. Hannadige ,&nbsp;Guangliang Fu ,&nbsp;Bastiaan van Diedenhoven ,&nbsp;Hailing Jia ,&nbsp;Zihao Yuan ,&nbsp;Otto Hasekamp","doi":"10.1016/j.jqsrt.2026.109853","DOIUrl":"10.1016/j.jqsrt.2026.109853","url":null,"abstract":"&lt;div&gt;&lt;div&gt;Proper proxies for CCN are vital to provide accurate observation-based estimates of Aerosol-Cloud Interactions (ACI), which are commonly used to constrain climate models. An effective proxy for CCN is the column number of aerosol particles that surpass a predetermined threshold radius (&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mtext&gt;CCN&lt;/mtext&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; [m&lt;span&gt;&lt;math&gt;&lt;msup&gt;&lt;mrow&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt;&lt;/span&gt;]). This CCN proxy has been estimated from PARASOL using level 2 aerosol microphysical and/or optical property retrievals. With the advanced multi-angle polarimeters (MAPs) such as the Spectro-Polarimeter for Planetary EXploration one (SPEXone) onboard the Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) satellite, further improvements in &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mtext&gt;CCN&lt;/mtext&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; retrievals are expected. This paper presents a deep neural network (NN) MAP algorithm as an extension for the Remote sensing of Trace gas and Aerosol Products (RemoTAP)-NN algorithm to directly retrieve &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mtext&gt;CCN&lt;/mtext&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; and &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mtext&gt;CCN&lt;/mtext&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; within the 0–2 km atmosphere (a representation for the boundary layer (BL)), &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mtext&gt;CCN&lt;/mtext&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mtext&gt;BL&lt;/mtext&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; [m&lt;span&gt;&lt;math&gt;&lt;msup&gt;&lt;mrow&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt;&lt;/span&gt;] from SPEXone measurements. The algorithm consists of two distinct NN models to perform the retrieval and to estimate the goodness-of-fit of the retrieval. The NN models are trained on synthetic SPEXone measurements based on 3 aerosol modes: fine mode, insoluble coarse/dust mode, and soluble coarse mode. The algorithm’s potential has been validated independently against synthetic SPEXone measurements simulated based on the 7 aerosol modes from the ECHAM-HAM global aerosol-climate model. The relative RMSE of &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mtext&gt;CCN&lt;/mtext&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; retrieved from the NN algorithm is 0.20 over the ocean and 0.29 over land. For &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mtext&gt;CCN&lt;/mtext&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mtext&gt;BL&lt;/mtext&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;, the relative RMSE increases to 0.46 over the ocean and 1.04 over land. For the same validation data, the relative RMSE of &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mtext&gt;CCN&lt;/mtext&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; estimated from the RemoTAP physics-based/classical algorithm is 0.34 over the ocean and 0.54 over land. For &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mtext&gt;CCN&lt;/mtext&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mtext&gt;BL&lt;/mtext&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;, the relative RMSE is 0.93 over the ocean and 1.18 over land. Our ","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"354 ","pages":"Article 109853"},"PeriodicalIF":1.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146134658","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}

{"title":"Re-evaluation and clarification of discrepancies in hyperfine structure constants of Nb II based on experimental and semi-empirical data","authors":"L. Windholz ,&nbsp;S. Kröger ,&nbsp;J. Ruczkowski ,&nbsp;M. Elantkowska","doi":"10.1016/j.jqsrt.2026.109852","DOIUrl":"10.1016/j.jqsrt.2026.109852","url":null,"abstract":"<div><div>Recently, revised energy values of the Nb II levels have been published, based on precise determinations of the center of gravity (cg) wavenumbers of 1121 spectral lines [ADNDT 159 (2024) 101664]. For finding the cg wave numbers for lines with widely spread hyperfine (hf) structure patterns it is necessary to know the hf constants of the involved energy levels, which are also revised or new determined in this paper. Based on these results, new semi-empirical studies of the fine- and hf-structure of Nb II were published [JQSRT 344 (2025) 109512 and 346 (2025) 109583]. In the ADNDT-paper, experimental <em>A</em>-values of 349 levels are given. For the majority of the levels the semi-empirically determined <em>A</em>-values agree well with the experimental ones, but for 28 levels a conspicuous deviation can be noticed. In the present work we tried to clarify these discrepancies. For 14 of these 28 levels revised <em>A</em>-values are given. For the remaining 14 levels the previously published experimental values were retained.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"353 ","pages":"Article 109852"},"PeriodicalIF":1.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146048522","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}