The 2020 edition of the GEISA spectroscopic database

High Resolution Infrared Spectroscopy in Support of Ozone Atmospheric Monitoring and Validation of the Potential Energy Function

“…The calculated lists include transition frequencies (ν ij ) and intensities ( S ij ), lower energy values ( E low ), and the quantum identification of upper and lower levels. Further, these lists, completed by the broadening (γ air , γ self ) and shifting (δ air ) parameters of spectral lines, are included in spectroscopic databases, such as the S&MPO [ 18 , 21 , 64 ], GEISA [ 223 ], and HITRAN [ 24 , 224 , 225 ] databases. Note that the calculated lists include a much larger number of bands than is shown in Table 6 .…”

“…One of the ways to obtain more accurate values of line positions in databases is to replace the calculated transition frequencies with observed values (or with the difference in empirical energy levels obtained from the observed line positions) when the differences will be greater than some chosen value (for example 0.001 cm −1 ). In a recent paper [ 21 ], this was done for the S&MPO database [ 64 ] and will be integrated in the two other databanks [ 24 , 223 ]. Note that these changes correspond to long and tedious work, since the same change must be applied to all transitions of the same upper energy level.…”

“…There is a significant decrease in the intensity of the bands above 5800 cm −1 , which once again demonstrates the advantage of recording these spectra by the LiPhy CRDS setup [33] and of using theoretical predictions for the analyses. As mentioned above, the results obtained in the studies presented here (νij, Σij, Elow, VR assignment), augmented with additional parameters (γair, γself, δair) and coefficients of their temperature dependence (at least in the range from −70 °C up to +50 °C), are incorporated into spectroscopic databases (for example, S&MPO [64], GEISA [223], and HI-TRAN [24]). The use of spectroscopic bases for various atmospheric tasks, such as the simulation of atmospheric absorption and transmission spectra, determination of the total molecular column and altitude profiles of molecular concentrations, radiative transfer in the atmosphere, radiation blocks of climate models, etc., places increasingly high demands on the accuracy of the parameters of these databases and their completeness.…”

Mid-infrared Supercontinuum-based Fourier Transform Spectroscopy for plasma analysis

“…Furthermore, the absorbance lines of ethylene (C 2 H 4 ) around 1880 cm − 1 are not included in the HITRAN database. Therefore, the GEISA database 40 was used to create a simulated reference spectrum for C 2 H 4 , indicating a concentration of 0.73 ± 0.03 % In summary, this experiment demonstrates the system's ability to accurately detect numerous molecular species created in electrical discharges of CO 2 /CH 4 , even for the ones with overlapping spectral features.…”

“…The absorbance spectrum is obtained by dividing the transmission spectrum of the sample to the background (the latter is taken after purging the MPC with pure N 2 gas) and taking the natural logarithm. The absorbance spectra of the different species are simulated, using parameters from the HITRAN2020 38 or GEISA 40 database and convoluted with a sinc instrument lineshape function, to t the natural boxcar apodization of the interferograms. GEISA was used to simulate the absorbance of ethylene (C 2 H 4 ) around 1900 cm − 1 , since this ethylene band is not completely included in HITRAN.…”