Computations of room-temperature N-broadening coefficients are performed for 3546 lines in the infrared absorption band of ethylene to provide data required for atmospheric studies but missing in spectroscopic databases. The calculations are done in the framework of a semi-classical exact-trajectory approach developed previously (Buldyreva and Nguyen, 2008). The active molecule is rigorously treated

We propose a laser occultation method for simultaneous profiling atmospheric temperature and pressure. Measurements can be performed on the optical link between two low-orbit satellites, where frequency-stepwise laser pulses are transmitted from one to the other. These pulses, covering several oxygen absorption lines in the wavelength domain, measure the broadened atmospheric absorption optical depth

The weighted contribution of ground-reflected component of light emissions from artificial sources gradually increases as the transitioning from bad-shielded to modernized light sources with low or zero direct uplight takes place in cities or towns. In this work, we demonstrate that the modeling of reflected light on a large domain for Lambertian flat surfaces does not require information about the

Wavelength calibration in diffraction spectroscopy typically depends on identifying strong, well-known lines in the recorded spectra and fitting a calibration function to them. In this paper, we outline a novel method (order penalization) for improving spectroscopic calibrations by extending non-linear least squares fitting of the calibration curve. The method introduces an extra term into the minimized

A continuous-wave cavity ring-down spectrometer was employed to record the spectrum of the acetylene molecule spanning the 12350 - 12790 cm region. A total of 747 lines from the principal isotopologue and 68 lines from CCH were identified, with nearly all line intensities retrieved from the spectra. These lines belong to eighteen vibrational bands of CH and two vibrational bands of CCH, among which

This work is a supplement the article “Influence of arable land location incorporating its roughness on blue-sky albedo variation” [J Quant Spectrosc Radiat Transf. 296 (2023) 108,440]. It quantifies the influence of the location (expressed by latitude) of bare arable land on a global scale and its roughness on the optimal time () of land observation with acceptable errors to determine its mean diurnal

The NNand NArcontinuum absorption spectra are calculated using the classical trajectory-based simulation (CTS). The spectra obtained are validated by new measurements in the subTHz spectral range along with the previously reported data in the far infrared. A novelty of our approach consists in the use of the CTS method to simulate both the fundamental nitrogen absorption band and the rototranslational

In this work, we calculated Stark broadening widths of several doubly-ionized chlorine Cl III spectral lines using the modified semi-empirical approach. The theoretical values of Stark widths are calculated using term energies and oscillator strengths of Cl III from the AUTOSTRUCTURE atomic structure code. We compared the calculated Stark widths with available data from the literature. If we need to

Accurate estimation of solar power generation is crucial for the effective planning and operation of solar energy sector. Solar potential can be estimated at a location from long-term historical irradiance data processed from atmospheric reanalysis datasets. The current study employs a clear-sky radiative transfer model ( to simulate the net surface irradiance at four distinct locations in India, comparing

We investigated the molecular structure and spectroscopic properties of the charged system (FH) in interaction with a helium atom using an quantum chemistry approach in Jacobi coordinates. Our study focused on the ground state XΠ of (FH) with various theoretical methods including UCCSD, UCCSD(T) and UCCSD(T)-F12, alongside basis sets like aug-cc-pVnZ (n = T, Q, 5, and 6) and cc-pVQZ-F12. We evaluated

This study utilized the high-spectral resolution radiative transfer model (MODerate resolution atmospheric TRANsmission, MODTRAN6.0.2.5) to compute global clear-sky shortwave (SW) radiative flux and compared it with NASA’s Clouds and the Earth’s Radiant Energy System (CERES) Synoptic Radiative Fluxes and Clouds (SYN1deg) product. The comparison revealed that the global distributions of clear-sky downwelling

The discrete system Green’s function (DSGF) method is a fluctuational electrodynamics-based numerical framework for predicting near-field radiative heat transfer (NFRHT) between three-dimensional thermal sources of arbitrary number, shape, size, and material. In the DSGF method, thermal sources are discretized into cubic subvolumes along a cubic lattice, and the system Green’s functions between all

In this study the clear-sky total, direct, and diffuse shortwave (SW) fluxes at the surface, have been calculated by three radiation transfer models (RTMs) – MODTRAN6.0 (M6.0), Canadian Centre for Climate Modelling and Analysis (CCCma), and Langley-modified Fu-Liou (NASA CERES). These calculations have been evaluated by surface measurements collected from seven sites that represent different climatological

Collisional broadening and pressure shift parameters for the potassium resonance doublet, near 770 nm, are reported for collisions with molecular oxygen and carbon dioxide. Experiments were conducted in a reflected shock tube from 1200–2200 K and used potassium chloride (KCl) salt as the atomic potassium source. The measured absorption lineshapes were fit with Voigt profiles to infer the collisional

We study the resonant saturation of selective reflection at the interface between a transparent dielectric and high-density rubidium vapor on the D-line. Our estimates suggest that, within the selected atomic density range, the dipole–dipole self-broadening of the line can vary from 13.2 to 39.6 GHz. Two tunable lasers are used as sources of pump and probe beams with orthogonal linear polarizations

A comprehensive understanding of the nature of light-induced plasmonic nanobubbles (PNBs) generated around noble metal nanoparticles is essential for optimizing PNB-based applications, such as light-driven microfluidic control. To investigate the overall evolution pattern of plasmonic nanobubbles (PNBs) under continuous light illumination, a computational model based on the least-squares method is

We identify two metastable excited states in Sm highly charged ion as candidates for high accuracy optical clocks. Several atomic properties relevant to optical clock development are calculated using relativistic many-body methods. This includes energy levels, transition amplitudes, lifetimes, scalar polarizabilities, black body radiation shift, and the sensitivity to the fine structure constant variation

This paper report nitrogen- and oxygen-broadening coefficients, their speed-dependencies, and the collisional narrowing parameters of lines in the ν-band of methane. The parameters were determined from low (150 K) to high temperatures (600 K). The measurements were done with a high-resolution quantum cascade laser spectrometer coupled to specific absorption cells that allow to cool and heat the gas

Using a high-resolution mid-infrared dual-comb spectrometer operating in the 1300 cm spectral region, spectra of acetylene were recorded at room temperature. Spectroscopic parameters were measured in 3 vibrational bands of both and . Absolute line intensities () and self-broadening coefficients () were determined in the , and bands. For the main isotopologue, the collisional narrowing coefficients

We showcase a Raman scattering diagnostic for 2D imaging of the rotational and vibrational temperatures of H. Applications include environments with vibrational-rotational non-equilibrium such as H-containing supersonic jets and plasma reactors. We image segments of the laser scattering spectrum, containing one or more Raman features, using an ICCD camera that is equipped with one of several bandpass

The complexity of the rocket motor exhaust plume radiation phenomenon, along with the influence of numerous parameters and implicit propagation, makes the theoretical simulation calculations expensive. This hinders design optimization, parameter identification, and other studies. Hence, it is crucial to establish the direct correlation between thrust, velocity, altitude, detection angle, and plume

This paper presents comprehensive spectral measurements and a theoretical analysis of laser-produced germanium (Ge) plasma within the 7.5–17 nm wavelength range, with the measurements being performed using spatiotemporally-resolved emission spectroscopy. We obtained and analyzed the extreme ultraviolet (EUV) spectra and their variations meticulously at various positions adjacent to the target surface

This study presents a new experiment to measure the polarization-resolved two-dimensional light-scattering patterns, near and including the backscattering direction, of fixed particles representative of some atmospheric-aerosol types. The measurements are conducted across a broad spectrum, from 450 to 850 nm, and for different polarization states. A supercontinuum laser, achromatic optics, and polarizers

We introduce , the latest iteration of our high-resolution molecular spectroscopy database cluster. Comprising ten independent databases, each dedicated to a specific molecule (CH, CHCl, SF, CH, CF, GeH, RuO, SiF, UF, SiH), integrates updated and new databases since our previous publication. These databases include detailed lists of calculated spectral lines, eigenvectors, energy levels, and additional

In this study the prediction accuracy of latest versions of FSK and SLW models (Rank correlated) and WSGG model is assessed at the limit of smallest computation cost. The results of these predictions are compared with the Line-by-Line benchmark calculations. One-dimensional decoupled radiation calculation is performed on a variety of case studies in order to investigate the limit of computational cost

The largest share of greenhouse gas (GHG) emissions related to livestock originates from methane (CH) and nitrous oxide (NO) which have a far higher influence on global warming, it is therefore necessary to accurately monitor CH and NO emissions to provide theoretical and practical basis for further estimating and regulating GHG emissions from livestock and improving livestock production performance

We first present quantitative, broadband absorbance cross sections of the C=O stretch fundamental rovibrational band of methyl formate in the 1670–1850 cm range at temperatures of 300, 600, 800, and 1000 K and pressures of 1–2 atm. The title molecular spectra were additionally studied across the pressure range of 1 to 35 atm at room temperature. Elevated temperature measurements were taken in argon

Near-field radiative heat transfer (NFRHT) in point-dipole nanoparticle networks is complicated due to the multiple scattering of thermally excited electromagnetic wave (namely, many-body interaction, MBI). The MBI regime is analyzed using the many-body radiative heat transfer theory at the particle scale for networks of a few nanoparticles. Effect of MBI on radiative heat diffusion in networks of

We present recent advances in path-integral formulations designed for unbiased Monte Carlo sensitivity estimation (in the form of partial derivatives) within a coupled physics model. We establish the theoretical foundation and illustrate the approach by estimating instantaneous atmospheric radiative forcings. In climate studies, these quantities amount for the change in top-of-atmosphere (TOA) net

We solve the radiative transfer equation (RTE) in anisotropically scattering media as an infinite series. Each series term represents a distinct number of scattering events, with analytical solutions derived for zero and single scattering. Higher-order corrections are addressed through numerical calculations or approximations.

This work reports on the first measurements of the lowest-lying singlet states as studied by photon spectroscopy for -fluorotoluene, 4-CHF. Here we present the high-resolution vacuum ultraviolet photoabsorption spectrum in the 4.3–10.8 eV energy-range, with assignments supported by calculations (vertical excitation energies and oscillator strengths) at two different levels of theory, equation-of-motion

Spectrophotometers or optical benches using integrating spheres to measure normal-hemispherical transmittance are widespread laboratory equipments. Although it is known that they cannot be used for ”highly turbid” samples, because multiple scattering may lead transmitted radiation to miss the entrance of the integrating sphere, very little is generally known about their exact validity range. Here we

Methane (CH) is the second-largest greenhouse gas contributing to global warming, surpassed only by CO, has a large difference in its vertical concentration distribution, and closely affects the global environment and climate change. The variations in the vertical concentrations of CH need to be monitored. Ground-based infrared hyperspectrometers can measure the fine variations of the CH concentrations

We present broadband dual frequency comb laser absorption measurements of 2 % HO (natural isotopic abundance of 99.7 % HO) in air from 6600 to 7650 cm (1307–1515 nm) with a spectral point spacing of 0.0068 cm. Twenty-nine datasets were collected at temperatures between 300 and 1300 K (±0.82 % average uncertainty) and pressures ranging from 20 to 600 Torr (±0.25 %) with an average residual absorbance

The radiation characteristics of microalgae are of great significance for the design of photobioreactors and ocean optical remote sensing. The complex structure of microalgae makes it difficult to theoretically calculate its radiation characteristics. Herein, the spherical microalgae cells are modeled, considering the shape of cells similar to the spherical cell microstructure, and a heterogeneous

The energy levels and transitions of highly charged Sn ions are key data for analyzing emission spectra, radiative opacity, and conversion efficiency of laser-produced Sn plasmas. Temporally–resolved spectra in the 6–45-nm range were acquired via high-precision, spatio–temporally resolved techniques. In addition, the Cowan code, based on Hartree–Fock multi-configurational interactions, was used to

The Monte Carlo method, renowned for its ability to handle the spectral and geometric complexities of 3D radiative transfer, is extensively utilized across various fields, including concentrated solar power design, atmospheric science, and computer graphics. The success of this method also extends to the estimation of sensitivity—the derivative of an observable with respect to a given system parameter

The Tx/Rx common aperture system not only needs to suppress out-of-field stray light, but also needs to suppress the influence of optical surface backscatter on detectivity. Backscatter generated by optical surfaces is often the dominant source of stray radiation that causes T/R isolation problems, and the black surfaces chosen for baffles also play a significant role in stray light suppression. Four

Most radiative transfer models developed for the analysis of urban configurations consider a transparent urban atmosphere and gray sky conditions. The aim of the present work is to investigate these assumptions, focusing on the longwave domain. For this purpose, reference Line-by-Line Monte-Carlo calculations are first performed. A more efficient radiative transfer model based on the Finite Volume

Gypsum, a typical hydrous calcium sulfate, has been found in some carbonaceous chondrites with aqueous alterations and has also been identified on Mars using visible and near-infrared (VNIR) reflectance spectra measured by orbiting and in-situ sensors. Therefore, gypsum may exist on more extraterrestrial bodies that have undergone hydration processes. Due to the dependence of spectral features on illumination

Measurements of spectral zenith radiance in the 320–950 nm wavelength range have been carried out since 2021 at the Thule High Arctic Atmospheric Observatory (THAAO, , 76.5° N, 68.8° W, 225 m a.s.l) located in Pituffik, northern Greenland. This study evaluates whether such observations could provide, in principle, scientifically meaningful cloud optical depth (τ) estimates, what would be the limitations

We perform simulations of coherent backscattering enhancement, explicitly accounting for the finiteness of spatial coherence of radiation. Three plausible models are considered, which produce the broadening of the coherent backscattering angular profile with the loss of spatial coherence. These models show fair agreement with data obtained earlier for biological media. Additionally, the exact solution

A view factor is a fundamental parameter for evaluating radiative heat transfer between two surfaces. View factors for various geometries have been investigated in the past studies. However, the view factors of a spheroid and an ellipse are known only for limited configurations. In this study, the analytical view factor expressions of an ellipse and a spheroid from a plate element are derived. The

This work aims at expanding the applicability of photon density wave spectroscopy (PDWS) to in-situ characterization of dispersed aggregates of spherical primary particles. For this purpose, an approximate optical model within the Rayleigh-Debye-Gans-theory was developed that links the experimentally determined reduced scattering coefficients with the fractal dimension and the radius of gyration of

To extend the research on the atomic structure of tungsten ions with an open 4-shell, we conducted an investigation into the M1 transitions originating from the ground configuration of W using the SHHtscEBIT in the 420–600 nm range. Three different calculational methods, including the relativistic configuration interactions (RCI) and the relativistic many-body perturbation theory (RMBPT) implemented

We have recently devoted two reports to the very weak absorption spectrum of water vapor in the 12,969 – 13,417 cm region by high sensitivity cavity ring down spectroscopy (CRDS) [Vasilchenko et al. J. Quant. Spectrosc. Radiat. Transfer 275 (2021) 107,847; doi.org/10.1016/j.jqsrt.2021.107847; Vasilchenko et al. Molecular Physics e2051762; doi.org/10.1080/00,268,976.2022.2051762]. This spectral interval

Quantum assignments are reported for 1382 transitions towards 33 vibrational sub-levels belonging to three weak Triacontad bands 6ν, ν+5ν, ν+4ν of CH 1.28µm. Empirical values of the origins of the corresponded sub-bands were determined for the first time from high resolution spectra analysis. The positions of all assigned lines were fitted to a model adopting an effective Hamiltonian whose initial

The Atmospheric Chemistry Experiment (ACE) is a satellite mission that has been in orbit since 2003. The primary instrument on ACE is a Fourier transform spectrometer (FTS) that records infrared atmospheric transmittance spectra in the limb geometry using the Sun as a light source. Version 5 of ACE-FTS data processing contains improved volume mixing ratio (VMR) profiles for 46 molecules and 24 isotopologues

This work presents a hybrid approach to solve the unsteady one-dimensional coupled heat conduction-radiation problem in a non-gray semitransparent planar medium. The diffusely absorbing/emitting medium scatters radiation anisotropically and is bounded by two gray or non-gray parallel planar surfaces that are diffuse in emission and diffuse or specular in reflection. A combination of the Discrete Ordinate

There are large temporal variations in the optical properties and types of aerosols. These are due to the effects of environmental and meteorological conditions, industrial and agricultural influences, and other human influences and natural factors in each ecological functional area. Aerosol optical depth AOD and Ångström exponent AE parameters were extracted from the Moderate Resolution Imaging Spectroradiometer

This article presents two very different models for the resolution of conduction-radiation coupling within grey Beerian and non-Beerian semi-transparent slabs enclosed between two black surfaces imposing their intensities and temperatures. The first model is deterministic, based on finite differences and discrete ordinates. The second one is fully stochastic, using Monte Carlo ray tracing for the modeling

Missing Stark widths for 30 spectral lines of zinc ion (Zn IV) have been calculated using our quantum mechanical method. Recently, 21 Zn IV lines among the considered lines have been newly detected in the UV spectrum of the hot white dwarf G191B2B (DA type). This recent discovery encourages us to calculate their Stark widths to fill the lack of the data base STARK-B and for use in investigations of

We present the results of multiconfiguration semi-empirical calculations of the fine structure () and the hyperfine structure () for the odd-parity level system of Co I, using all available experimental data. Our analysis incorporates all electromagnetic interactions within the atom, including effective electrostatic interactions and electrostatically correlated spin–orbit interactions, as well as

The spectra from singly ionized argon Ar II has significant diagnostic capability in the characterization and modelling of both magnetically-confined fusion and astrophysical plasmas. The literature has several pre-existing data sets for Ar but this paper presents the results from 3 new atomic structure and electron-impact scattering models in order to better constrain the differences in atomic data

In this paper, we present an ab initio theoretical calculation of the atomic parameters, including energy levels, wavelengths, lifetimes, and transition parameters, associated with the 12 and 12 ( 2–4, −1) configurations of Be-like sequence: Os LXXIII, Ir LXXIV, Pt LXXV, and Au LXXVI. Our analysis is based on the relativistic wavefunctions derived from the multi-configuration Dirac–Fock (MCDF) method

Ten high resolution Fourier transform spectra of the pentad region near of methane diluted in carbon dioxide at total pressures up to 800 hPa have been recorded at K. Including a high resolution spectrum of pure methane at low pressure, these spectra have been analyzed using multi-spectrum fitting techniques. The methane lines were modeled using hard-collision speed-dependent line profiles and line