I. Introduction

The high-resolution transmission molecular absorption database (known under the acronym HITRAN) is a compilation of spectroscopic parameters from which a wide variety of computer simulation codes are able to calculate and predict the transmission and emission of radiation in the atmosphere. This database is a prominent and long running effort established by the Air Force at the Air Force Geophysics Laboratory (AFGL) in the late 1960s in response to the requirement of a detailed knowledge of infrared transmission properties of the atmosphere. With the advent of sensitive detectors, rapid computers, and higher resolution spectrometers, a large database representing the discrete molecular transitions that affect radiative propagation throughout the electromagnetic spectrum became a necessity. A wide range of applications for HITRAN has evolved including detection of trace and weakly absorbing features in the atmosphere, atmospheric modeling efforts, laser transmission studies, remote sensing, lidar, and a reference base for fundamental laboratory spectroscopic research. The HITRAN database has been periodically updated and enhanced since it first became generally available.[1]–[4] The most recent edition of the HITRAN database was made available in late 1986. This latest version now unites the data on twenty-eight molecular species with bands covering regions from the millimeter through visible portion of the spectrum. Originally the database contained for each molecular transition the following basic parameters: (1) resonant frequency; (2) line intensity; (3) air-broadened halfwidth; and (4) lower state energy (as well as unique quantum identifications). Additional parameters have recently been provided which permit new capabilities for remote sensing in the atmosphere and capabilities to deal with nonlocal thermodynamic equilibrium effects in the upper atmosphere. The overall structure of the database has been expanded to include files of cross-sectional data on heavy molecular species such as the chlorofluorocarbons (CFCs) and oxides of nitrogen which are not yet amenable to line-by-line representation. This has added to HITRAN the capability of qualitative detection of anthropogenic gases in the window regions of the infrared. Ongoing research efforts will gradually move some of these data to the main body of the database. The new file structure of HITRAN is shown in Fig. 1. New parameters have been added to the present edition of HIRTAN as well as fields included for anticipated parameters. Table I illustrates the actual image in the new database of an individual molecular transition. Formerly the database adhered to the card image concept, i.e., each transition was restricted to 80 characters; the new format has been expanded to 100 characters per transition. The new parameters are: the transition probability, the self-broadened halfwidth, and the exponent of temperature dependence of air-broadened halfwidth. Data fields have also been reserved for pressure shift of the transition, accuracy criteria for the three principal parameters, and references to the sources of the latter parameters. These fields have not at present been implemented (with some minor exceptions that will be discussed in Sec. II). We discuss below the definition of two of the newly presented parameters.

A parameter, R_if, which is both independent of temperature and isotopic abundance, has been added to the new edition of the database with the expectation that it will be quite useful for atmospheric calculations and applications utilizing Einstein coefficients. The transition probability, R_if, is related to the intensity of a transition, S_if, from state i to state f by

On the present compilation, R_if has been calculated as R_if/Q(T₀). Thus a user, at this time, must multiply the current R_if value given on the compilation by the appropriate value of Q (296 K) to take full advantage of this parameter. In future editions Eq. (1), as well as the corresponding relation for quadrupole transitions,

Provision for the self-broadened halfwidth, γ_s in cm⁻¹/atm at 296 K, has been made on the database. Presently, carbon dioxide and acetylene are the only two species where this parameter appears, although there is much available data for self-broadened halfwidths for other species; these will be introduced in subsequent editions of the database.

The exponent for temperature dependence of the air-broadened halfwidth has also been introduced in this edition. This parameter has begun to be measured accurately for various molecular species and has appeared in a previous edition of the GEISA (gestion et etude des informations spectroscopiques atmospheriques) databank.[5] The definition of the exponent, n, is given by

A great amount of effort was also made for this edition to create a more uniform treatment of the rotational quantum numbers (and other quantum identifiers unique to a transition). Presently this has been accomplished by formatting the transitions into one of six classes, shown in Table III. In addition, the vibrational quantum numbers (and electronic designation where necessary) which cover whole bands have now been designated by indices to provide a rapid means of access for applications such as nonlocal thermodynamic equilibrium calculations. The isotopic variants of a species have also been assigned sequential indices in the order of the telluric relative abundance (see Table IV). For example, in Table I, molecule 2, i.e., CO₂, appears three times and the isotope code is 1, 2, or 3 corresponding, respectively, to 626(¹²C¹⁶O₂), 636(¹³C¹⁶O₂), and 628(¹⁶O¹²C¹⁸O). This has made it necessary to include correspondence tables in associated files on the database. The values of the natural isotopic abundance, I_α in Eqs. (3) and (4), assumed for the current HITRAN database are given in Table IV. In this version of the database, provision has also been made for the error estimates of the frequency, intensity, and the air-broadened halfwidth (see Table I). This has only been implemented for some of the transitions as described in Sec. II.

The first file on the compilation is a fortran program called select that enables the user to interactively access the HITRAN database (the second file) to create files of portions of the atlas of interest based on selected criteria such as frequency range, molecule, isotope, vibrational bands, and intensity cutoff. The user can readily customize his output to correspond to specific program requirements or storage limitations.

Presently 348,043 transitions are given on the high resolution portion of HITRAN. A summary of the transitions now incorporated is given in Table V. The species are given in Table V in the order of their molecule index identification in the compilation. Figure 2 displays the spectral regions in which parameters can be found for each molecule in HITRAN.

In the following section modifications, updates, and additions to the database since the last edition[3],[4] are discussed. This is not meant to be a definitive discussion, and users are advised to consult the references for more detailed information. As a convenience to the user, some of the major updates planned will also be mentioned.

II. New or Modified Data

A. H₂O

The ground state pure rotation band of the monodeuterated isotope of water (HDO) has been updated. The data are from the Jet Propulsion Laboratory (JPL) Catalog[6] and were derived from a fit which included the microwave and submillimeter lines reported by Messer et al.[7] and an extensive set of ground state energy levels from the high resolution FTS measurements of Toth.[8] The estimated uncertainty of the line positions varies from line to line and ranges from 0.02 to 0.000001 cm⁻¹ for these lines. The uncertainty is given for each line in the parameter IER(1) on the HITRAN database (see Table I). The line intensities are accurate to 2–5%.

The bands of water in the 6.3- and 2.7-μm regions shown in Table V have been updated by incorporating data from Flaud et al.[9] These are the bands that were not previously[3] added to the database from [Ref. 9]. With the addition of the data in Table V, all the data of Flaud et al.[9] are present on the database producing a self-consistent set of water data. In general the accuracy of the line positions is better than ±0.005 cm⁻¹, and the line intensities are accurate to ≈20% (with the weaker lines being somewhat less accurate). The data show a deterioration of accuracy for high J lines.[10]

The ν₂ band of monodeuterated water has been replaced with the data of Toth.[8] The line positions are accurate to ±0.0004 cm⁻¹ for all unblended lines and slightly blended lines of medium to strong intensity. The line intensities were calculated by the F-factor formalism with corrections for centrifugal distortion and the Δ_κ effect. The line intensities are accurate to ∼5% for the stronger lines and for the weaker lines the uncertainty is ≈20%.

The air-broadened halfwidths of all water vapor lines on the database have been updated using the calculations of Gamache and Davies[11] for the principal isotopic species (H₂¹⁶O) and the optimum combination algorithm[12],[13] for all other species (HDO, H₂¹⁷O, H₂¹⁸O). All calculations were for N₂ broadening and have been scaled to air using the factor 0.9. Values for the principal isotope have an estimated uncertainty from 10 to 15%, with the less abundant species being slightly less accurate (20%).

B. CO₂

A complete update of the energy levels and intensities of the carbon dioxide parameters has been implemented for this edition of HITRAN. A summary of this effort is given by Rothman[14] which has been enhanced by the great amount of high resolution line positions of many bands observed in the period since the last edition of the database. More importantly, in this period Fourier transform spectrometers and diode laser systems have provided measurements of many band and line intensities of unprecedented photometric accuracy. The theoretical technique of Wattson and Rothman[15] has also been applied so that a higher-order self-consistent set of band intensities for the parallel bands of the main isotope have been furnished. The extensive new high resolution observations provide access to the majority of the vibrational energy levels for the two most abundant isotopic species below ∼7000 cm⁻¹. For the most abundant asymmetric species, ¹²C¹⁶O¹⁸O, this is also true up to ∼5000 cm⁻¹.

Of the 634 bands of carbon dioxide considered, 573 survived the intensity criterion to be included on the HITRAN database. Line positions that have been interpolated from the least-squares fit of observed transitions[14] are generally accurate to 0.0004 cm⁻¹. Some line positions have accuracies good to 0.0001 cm⁻¹; however, due to the calibration problem discovered between different spectroscopic facilities,[16] there remains a discrepancy of the former amount in many cases (see additional discussion of this problem below under the subsection for the methane molecule). This absolute calibration problem will be addressed in future work on the line positions. The intensities that have been updated are believed to be good to ∼10%. Much work is in progress at this time to improve the intensities of the bands on the database. Observations are being made on significant perpendicular bands previously only approximated, and important results are being obtained to provide higher-order reliable Herman-Wallis coefficients which will greatly improve the accuracy of the higher rotational lines than is now on the database.

New air-broadened halfwidths have been applied to all the carbon dioxide lines on the database. These have been taken from Arié et al.[17] A linear regression fit was applied to their data to extend the air-broadened values from |m| = 40 to 80; a constant value of 0.0606 cm⁻¹/atm was assumed beyond |m| = 80. (The running index m equals −J″ for the P branch, J″ for the Q branch, and J″ + 1 for the R branch.) The new values of halfwidth generally parallel the previous results, but show higher values at low J. These new parameters have been assumed for all bands and isotopes. Similarly, self-brpadened halfwidths have been taken from [Ref. 17] and have been adopted for all CO₂ bands.

Sizable discrepancies have been observed for some time between observed and simulated spectra using the normal set of molecular parameters in the vicinity of strong Q branches.[18] This difference has been especially noted in the 15-μm region of CO₂. This phenomenon is attributed to line coupling (also called rotational collisional narrowing, line mixing, line interference, or Q-branch collapse) which manifests itself as a distortion of the line shape. For this edition, line coupling coefficients for three perpendicular bands, the fundamental at 667 cm⁻¹ and the two hot bands at 618 and 721 cm⁻¹, have been appended. These come from the room temperature studies of Hoke et al.[19] The corresponding modification to the line shape form factor, f(ν,ν_if), yields

The y_if values on the current edition apply only to a temperature of 296 K; atmospheric calculations through layers with different temperatures are certain to yield invalid results. A scheme for temperature scaling of the coupling coefficients will be included in a future edition of HITRAN.

C. O₃

The line parameters compilation for the ozone molecule has been expanded and improved considerably since the last edition. This includes updates of several bands as well as several new bands. The following discussion summarizes the new results in the current edition and also reports on several more recent studies which further improve the O₃ line parameters.

The ν₁ and ν₃¹⁶O₃ line parameters have been updated according to the recent analysis by Pickett et al.[21] of high resolution laboratory microwave and 10-μm infrared measurements (0.005-cm⁻¹ resolution). The analysis includes an expanded consideration of the Coriolis coupling coefficients for line positions and intensities. While the previous ν₃ total band intensity has been retained, the ν₁ total band intensity has been revised from 6.711 × 10⁻¹⁹ to 5.255 × 10⁻¹⁹ cm⁻¹/(molec · cm⁻²). The new line positions are accurate to 0.0006 cm⁻¹ and the intensities to 10%. This study[21] also provided the new pure rotation O₃ lines on the current edition which are based on a considerably improved dipole moment expansion.

It should be noted that in the 10-μm region, only the ν₁ and ν₃ lines of the principal isotope ¹⁶O₃ have been revised, while the isotopic and hot band lines have been retained from previous editions. These isotopic lines are based on crude approximations and, while satisfactory for low resolution spectra, cannot reproduce high resolution spectra. Fortunately, more recent studies by Flaud et al.[22] and Camy-Peyret et al.[23] provide line positions and intensities for the ν₁ and ν₃ bands of ¹⁶O¹⁸O¹⁶O and ¹⁶O¹⁶O¹⁸O, as well as a revised set for the principal isotope.[24] These studies are based on new high resolution (0.005-cm⁻¹) laboratory spectra of natural and oxygen-18 enriched ozone, and include high-order calculations for positions and intensities. These studies allowed the identification of individual isotopic O₃ lines in the atmospheric spectrum as reported by Rinsland et al.[25] Unfortunately, these parameters were not available in time for the present edition of the HITRAN database; they will be included in the next update and can be obtained from the authors if necessary before that release.

In the 2800-cm⁻¹ region, new line parameters for the important ν₁ + ν₂ + ν₃ combination band have been updated on the compilation. These are a slightly revised set of an earlier work, as described by Barbe et al.,[26] with line positions accurate to 0.004 cm⁻¹. The line intensities are based on a set of measured line intensities near 2776 cm⁻¹ by Meunier et al.,[27] with rigid rotor intensity calculations. The estimated accuracy is between 5% and 25%.

In the 3000-cm⁻¹ region, it should be noted that the line parameters originate from very early approximate calculations and do not agree with high resolution spectra. Further work on the analysis of the interacting states 2ν₁ + ν₃, ν₁ + 2ν₃, 3ν₃, and 3ν₁ is needed.

The hot band ν₁ + ν₂ + ν₃ − ν₂, which also contributes to the atmospheric spectrum in the 5-μm region in addition to the 2ν₃, ν₁ + ν₃, and 2ν₁ bands, has been added to the compilation, as described by Goldman and Barbe.[28] The hot band line parameters have been derived from 0.03-cm⁻¹ resolution laboratory spectra and provide line positions accurate to 0.004 cm⁻¹. The line intensities were derived as rigid rotor intensities, normalized to the ν₁ + ν₃ total band intensity multiplied by a ν₂ population factor. Some limitations, depending on the quantum numbers, should be noted.[26],[28] It is estimated that the individual line intensities are accurate to 10–30%.

The line parameters for the ν₂ and 2ν₂ – ν₂ bands have not been updated for this edition. However, these will soon be superseded by the newly derived line parameters by Pickett et al.[29] This study, based on high resolution laboratory spectra in the microwave and infrared, involves a detailed theoretical analysis which provides line positions accurate to 0.0006 cm⁻¹ and absolute intensities accurate to 5% in the range of the fitted data.

The 2ν₂ O₃ lines in the 1400-cm⁻¹ region are observable in atmospheric spectra, as reported by Goldman et al.,[30],[31] but parameters are not included in the current compilation. Based on the available spectroscopic constants of the (000) and (020) levels, line parameters have been generated and compared with atmospheric spectra.[31] It is found that while the calculated line positions are accurate to 0.004 cm⁻¹, there are considerable disagreements in the individual intensities. Thus a more refined intensity analysis is needed. In addition, new analyses of the ν₁ + ν₂ and ν₂ + ν₃ bands of ¹⁶O₃ have been completed,[32] and updated line parameters are expected to be available soon.

Air-broadened halfwidths were revised for all ozone transitions present on the database. The values up to J″ = 35 were from the calculations of Gamache and Rothman[33] scaled to air by the recommended factor, 0.95.[34] Average values were obtained for J″ > 35 by extrapolation of the calculated values. Transitions for the less abundant species were assumed to have the same halfwidths as the corresponding transitions for the principal isotopic species, ¹⁶O₃. The uncertainty is estimated at 7–10% ([Ref. 33]) for the principal isotopic species.

Recently Smith et al.[35] made measurements of halfwidths of ozone for N₂-, O₂-, and air-broadening. In a comparison, they noted that the calculated values[33] are low by a fairly constant 6% for ν₁ lines. For several ν₃ lines they found the calculations to be only ≈3% low. The better agreement for the ν₃ lines is attributed to the calculations for ν₃ explicitly including the vibrational dependence of the halfwidth (see [Ref. 34] for details).

D. N₂O

The line positions and intensities of nitrous oxide in the 894–2630-cm⁻¹ region are those of Toth[10],[36]–[39]; the remainder above that region (which date back to studies in the early 1970s) have not changed on the compilation. Below 894 cm⁻¹ the ν₂ region has been previously updated.[40] The majority of the new parameters were derived from laboratory measurements of which the uncertainties associated with positions are 0.0001 cm⁻¹ or better and the intensities are 2–5%.

Table V lists the N₂O band centers, isotopic species, upper and lower state vibrational states, frequency range of the band, number of lines, and sum of the line intensities. The updated bands (in terms of line positions and intensities) for this edition are indicated by a letter N after the sum of line intensities. The line positions and intensities for a number of transitions in the 10⁰1–10⁰0 band of the ¹⁴N₂¹⁶O species centered at 2195.9158 cm⁻¹ are perturbed and measured values of positions and intensities were inserted in place of the nonperturbed, computed values for those lines. The interacting states are 10⁰1,06⁰0, and 06²0, and only the transitions of the enhanced lines of the 06⁰0–10⁰0 and 06²0–10⁰0 bands were included in the listing. These interactions are very apparent in the ground state bands of these states located in the 3450-cm⁻¹ region. However, the positions and intensities of the perturbed transitions given in the present compilation do not consider these interactions and caution should be used for application of those lines. Further work[10] is in progress from which a listing of line positions and intensities covering the 2700–5300-cm⁻¹ region will be obtained and, where necessary, measured values will replace computed ones for the perturbed lines.

Updated halfwidths have been added to all the N₂O lines on the database. The values are from the work of Lacome et al.[41] which consist of experimental values for N₂- and O₂-broadening from |m| = 1 to 49 and theoretical values out to |m| = 61. The air-broadened values are given by the formula

Use of the theoretical values beyond |m| = 49 with the experimental values below 49 gives a discontinuity in the halfwidths as a function of |m|. The differences between the theoretical and experimental values were calculated and fitted to the formula dif = a + b|m|, giving a = −1.603, b = 0.2684 with the correlation coefficient of the fit being 0.9988. From this linear expression the halfwidths were smoothly continued to |m| = 61. Beyond |m| = 61 the default value of 0.0686 cm⁻¹/atm was used. The uncertainty in the measured halfwidths is estimated at 5–10% and between 10 and 20% for the scaled theoretical values.

E. CH₄

In the compilation, there are 32 individual bands of methane between 0 and 6107 cm⁻¹ with a total integrated absorption of 1.74 × 10⁻¹⁷ cm⁻¹/(molec·cm⁻²). Three isotopes are cataloged: ¹²CH₄, ¹³CH₄, and ¹²CH₃D. The bands fall in five spectral regions.

In the dyad region (1000–1950 cm⁻¹), no changes have been made to the line positions of the two fundamentals of ¹²CH₄ and ¹³CH₄. However, the line intensities of ν₂ and ν₄ of ¹³CH₄ have been lowered by 3% and multiplied by an empirical Herman-Wallis factor previously applied to the bands of the main isotope.[3] The accuracies of the positions range from 0.0005 to 0.005 cm⁻¹ and intensities from 4% to 15%. The best accuracies are associated with the allowed lines of the ν₄ band of the main isotope. While several hot bands (such as ν₂ + ν₄ − ν₂ and 2ν₄ − ν₄) are needed to complete the compilation, only the prediction of the ν₃ − ν₄ hot band of ¹²CH₄ has been included.[42] However, the ν₃, ν₅, and ν₆ fundamentals of CH₃D ([Refs. 43]–[45]) from the GEISA compilation[5] have been added; intensities have been scaled by the isotopic abundance ratio of 6.0 × 10⁻⁴. Accuracies of the CH₃D positions are between 0.002 and 0.01 cm⁻¹. Because the CH₃D bands are perturbed, some predicted relative intensities may be in error by substantial amounts. The ν₂ fundamental of CH₃D at 2200 cm⁻¹ has not been added, but a nearby overtone band, 2ν₆ ([Ref. 46]), has been taken from the GEISA compilation.[5]

In the pentad region, the compilation has been extended to cover an additional 180 cm⁻¹, from 2255 to 3255 cm⁻¹, by combining the recent pentad prediction of the five bands (ν₃, ν₁, 2ν₄, 2ν₂, and ν₂ + ν₄) of the main isotope[47],[48] with old[49] and new[50] measurements. In this revision, all the positions of [Refs. 47] and [48] have been multiplied by 0.999999765 to conform with the P7 line calibration standard (2947.91206 cm⁻¹, [Ref. 51]). In addition, detailed comparisons with laboratory spectra from the Fourier transform spectrometer at the National Solar Observatory on Kitt Peak[50] have been used to guide the modification of some of the positions and intensities in the compilation. Calculated intensities of the pentad region have been used if they differ from the measured intensities by no more than 10%. New experimental line intensities[50] have been used in most of the 2250–2385-cm⁻¹ region and the 3200–3250-cm⁻¹ region. Finally, the CH₃D parameters appearing in this region on the 1982 compilation[3] have been replaced with the CH₃D list taken from the 1984 GEISA compilation.[5] The rotational quantum numbers follow two different conventions. The pentad calculation uses three quantum numbers, J, C, and N (see [Refs. 47] and [48]) while the older portions of the compilation use four quantum numbers, J, R, C, and N (see [Refs. 3] and [49]).

The parameters in the pentad region are, for the most part, still based on an experimental line list to which assignments of the three isotopes have been ascribed. The intensities[49] between 2385 and 3200 cm⁻¹ were generally measured at 0.02-cm⁻¹ resolution using a grating spectrometer, with gas samples whose temperatures differed by as much as 4° from scan to scan. However, the intensities were never normalized to 296 K because most lines were unassigned at the time of the original work.[3],[49] Later analysis indicated tentative assignments for many of the absorptions, but some lines may be wrongly assigned, or some isotopic lines (and bands) may be missing, or the observed absorption may actually arise from more transitions than are currently ascribed. Thus the sums of intensities given in Table V in many cases do not reflect the integrated band intensities. These parameters do reproduce laboratory spectra recorded at room temperature[50] and at 0.01-cm⁻¹ resolution, but extrapolation of weak lines to much different temperatures may produce large errors. While some of the line intensities are good to 2% or better (allowed P-branch lines of the ν₃ band of the main isotope), lines weaker than 10⁻²³ cm⁻¹/(molec·cm⁻²) are often good to only 15% and very weak lines may be in error by as much as 50%. Similarly, accuracies of positions range from 0.0006 to 0.005 cm⁻¹. Much work is needed to model the measurements and provide a complete and accurate prediction of the region.

The octad region from 3500 to 5000 cm⁻¹ is also based on measurements with tentative assignments given up to J = 12 of the main isotope.[50],[52],[53] However, only three bands (ν₂ + ν₄, ν₃ + ν₄, and ν₂ + ν₃) of a possible eight are indicated at present and, for the 4166–4666-cm⁻¹ region, no lines weaker than 2 × 10⁻²³ cm⁻¹(molec·cm⁻²) are given. For the 1986 edition, experimental positions and intensities[50],[53] in the region of 3ν₄ and 2ν₄ + ν₂ between 3750 and 4136 cm⁻¹ have been added without assignments. This change increases the total CH₄ absorption in this region of the compilation by ∼5%. Because of new calibration standards,[54] all positions appearing in the 1982 version[3] between 4136 and 4666 cm⁻¹ have been lowered by 0.0006 cm⁻¹.

The region between 5000 and 6500 cm⁻¹ contains up to 40 states, a dozen of which probably give rise to significant absorption in atmospheric spectra. At present, however, only an older prediction of one band, 2ν₃, is included and only to modest values of J. For the 1986 update, an error in band intensity (that has existed since the first edition[1]) has been corrected by multiplying intensities by 2.5 to conform to existing measurements.[55] The parameters of the ¹³CH₄ 2ν₃ band[56] have also been added using isotopically scaled intensities of the ¹²CH₄ prediction. The accuracies of the parameters are thought to be 0.005–0.020 cm⁻¹ for positions and 5–20% for intensities.

As in previous editions of the compilation, air-broadened halfwidths were determined from the calculated O₂- and N₂-broadened halfwidths of Tejwani and Fox[57] corrected to 296 K. In the future this parameter will be reevaluated in light of the measurements of Varanasi et al.[58],[59] and Devi et al.[60],[61]

F. O₂

The only update for oxygen on this edition has been the introduction of the zero frequency lines. These parameters have the frequency set to a synthetic frequency of g·J (where g is the degeneracy of the level) and come directly from [Ref. 6]. The transitions play an important role in the millimeter-wavelength soundings of the atmosphere. The halfwidths used for these lines are the same as previously employed for the 60-GHz transitions.

G. SO₂

The pure rotation lines of sulfur dioxide have been updated with the data of Poynter and Pickett.[6] The data are a refit of the pure rotational spectrum for all lines of J up to 74 and K up to 28. The Hamiltonian constants were obtained by fitting to the experimental measurements of Lovas[62] with additional selected lines taken from Carlotti et al.[63] The dipole moment was taken from the work of Patel et al.[64] The line intensities are accurate to a few percent and the line positions are accurate to ±0.001 cm⁻¹ or better. The error estimate is given in IER. As before, a constant value of 0.11 cm⁻¹/atm has been adopted for the air-broadened halfwidth.

H. NO₂

The positions and intensities of the nitrogen dioxide lines absorbing in the 6.2-, 3.4-, and 13.3-μm regions have been calculated using a theoretical model taking into account when necessary the Coriolis interaction affecting the rovibrational levels.

In the 6.2-μm region, the main absorbing band is ν₃ and the K_a = 4, 5, 6 subbands were correctly reproduced only because the strong Coriolis interaction between the rotational levels of (020) and (001) was taken into account.[65] The line intensities of the ν₃ band were calculated using a pure transition moment operator for this band; in fact the rotational corrections which appear in the transformed transition moment operator and which represent the effect of the vibration–rotation interactions on line intensities were not determined from the set of experimental intensities.[66] These corrections seem to be negligible for medium N and K_a values but they could have an influence for high N and K_a values. Together with the ν₃ band, the hot band ν₂ + ν₃ − ν₂ absorbing in the same spectral region was calculated. The accuracy of the line positions is believed to be on the average 0.003 cm⁻¹. The line intensities are known with a relative precision varying from 5% for low N and K_a values to 20% for high N and K_a values. The ν₃ band was not updated on the present compilation, but the improvements indicated in this paragraph can be obtained from the authors prior to the next edition of HITRAN.

In the 3.4-μm region, the NO₂ absorption is about 20 times weaker than the absorption in the 6.2-μm region, but the former region is of atmospheric interest because it corresponds to a relatively clear transmission window usable for atmospheric measurements from the ground. The main band of nitrogen dioxide absorbing around 3.4 μm is the ν₁ + ν₃ band and, as for the ν₃ band, the line positions of this combination band have been calculated taking into account the strong Coriolis interaction affecting the rotational levels of the (120) and (101) vibrational states.[67] Since a large set of precise individual line intensities was available for the ν₁ + ν₃ band,[68] it has been possible to determine through a least-squares fit the rotational expansion of the transformed transition moment operator of this combination band. Finally, this transition moment operator together with the rotational and spin-rotation constants has been used to generate the absorption lines of the ν₁ + ν₃ and ν₁ + 2ν₂ bands of NO₂. Moreover, the hot band ν₁ + ν₂ + ν₃ − ν₂ absorbing in the same spectral region has been computed.[67] The accuracy of line positions is believed to be on the average 0.0015 cm⁻¹, the relative accuracy of line intensities varying from 3 to 12%.

The main band absorbing in the 13.3-μm region is the ν₂ band. Diode laser spectra covering selected portions of this band were used to determine the rotational and spin-rotation constants.[69] Line intensities were also measured leading to the determination of the rotational expansion of the transformed transition moment operator of this band.[70] Finally, the spectrum of the ν₂ band of NO₂ was computed; the accuracy of line positions is believed to be 0.002 cm⁻¹ for low and medium K_a values, deteriorating for K_a > 8. The relative accuracy of the line intensities varies from 5 to 15%.

For all calculations which have been performed, the spin-rotation interaction has been treated using a perturbation method and it should be emphasized that for a few spin-rotation resonating levels the calculation is less precise, leading to positions whose accuracy is worse than the average values quoted here.

In this edition, parameters for the pure rotation band of nitrogen dioxide were added from [Ref. 6]. The spectrum was determined by a full diagonalization of the Hamiltonian. The data used in the fit were from Bowman and DeLucia.[71] The line intensities have an uncertainty of 2–3%. The accuracy of the line positions is J dependent and generally better than 0.00005 cm⁻¹ with a few of the lines having an uncertainty of 0.0003 cm⁻¹. The accuracy of the line positions is given for each line in IER. A constant air-broadened halfwidth of 0.062 cm⁻¹/atm has been assumed for the pure rotation band.

I. NH₃

Two updates of ammonia parameters have been made for this edition. The ν₂ lines of the principal isotope have improved positions, taken from the work of Poynter and Margolis.[72] The ν₄ band has been replaced with the latest parameters from GEISA.[5] An effort was also made to standardize the vibrational notation for all ammonia transitions on this edition.

J. HNO₃

For this edition, the 11-μm bands have been significantly updated. Whereas on previous issues of the database this region was represented by a narrow spectral extent taken from diode laser measurements without lower state energy values, the new database has a broader coverage from 840 to 920 cm⁻¹. The calculations of the parameters are based on studies of laboratory data.[73] The bands now represented are the ν₅ and 2ν₉ bands, with approximated hot bands, ν₅ + ν₉ − ν₉ and 3ν₉ − ν₉. A few lines belonging to multiplets that cannot be resolved have been coalesced in the same manner as on previous editions, i.e., pairs with the same frequency and intensity have had their intensities added. The coalesced lines are indicated on the database by the omission of the K_a quantum number which allows an unambiguous regeneration of the multiplet if desired for theoretical purposes. Synthetic spectra using these new parameters have been calculated and show very good agreement with recent stratospheric balloon observations.[74] Discrepancies still exist in the region between the band centers of ν₅ and 2ν₉; these features will be improved in the future as the resonances of these two bands are adequately represented.

For this edition, the artificial set of lines representing the Q and R branches of the ν₃ band at 1326 cm⁻¹ has been removed from the main body of the database, and this band is now included in the cross-sectional file. It is expected that a discrete line parameter formulation for this region will be available for the next update.[75]

The ν₂ band has not been updated for this edition, but much improved parameters exist[76] and will be incorporated in the future. It should be noted that, although the relative intensities of the lines of this band are reasonable, the absolute intensities are too low by approximately a factor of 2.

K. OH

The microwave data for the hydroxyl radical for the ground ²π_3/2 and ²π_1/2 states have been updated. The data are from the JPL catalog[6] and were determined in the same manner as the previous data for this band[4] except that the calculations were extended up to 300 cm⁻¹. As in previous editions, a constant halfwidth of 0.083 cm⁻¹/atm was assumed for the lines. The reported intensities are accurate to a few percent. The accuracy of the line positions is generally better than 0.005 cm⁻¹ and shows a dependence on the rotational quantum number.

L. HF

The halfwidths of hydrogen fluoride were updated using the values of Thompson et al.[77] The measurements include values for the P3 through the R3 lines. The uncertainty of the measurements is estimated at 15%. Beyond the observations the previously assumed values were used. More recent measurements[78] of intensities and air- and self-broadened halfwidths will be incorporated in the next edition.

M. HCI

The air-broadened halfwidths for hydrogen chloride have been updated with the measurements of Ballard et al.[79] These measurements yield values for the P(1) through P(8) lines, and for the R(0) through R(7) lines and have an estimated uncertainty of 5–15%. The new halfwidths[78] have been applied to all bands and isotopes of HCI on the compilation; beyond the measurements the previous values have been retained. Similar to HF, the intensities and air- and self-broadened halfwidths will be updated[79],[80] in the next edition.

N. H₂CO

The pure rotation band of the principal isotopic species of formaldehyde has been updated with data from the JPL catalog.[6] The Hamiltonian formulation of Kirchhoff[81] was used to evaluate the rotational and centrifugal distortion constants. An expanded data set was used in the fit and is given in [Ref. 6]. The line positions are accurate to 0.003 cm⁻¹ for the high wavenumber lines and improves to 0.00002 cm⁻¹ or better for low (<1-cm⁻¹) wavenumber transitions (see IER). The dipole moment value was taken from Kondo and Oka[82] and the resulting line intensities are accurate to ≈2–5%. A constant air-broadened halfwidth of 0.107 cm⁻¹/atm was assigned to the data, unchanged from previous editions of the database.

O. HOCI

The pure rotational bands of the two isotopic species of hydrogen hypochlorite, HO³⁵C1 and HO³⁷C1, were added to the database. The data and calculational method are given in Singbeil et al.[83] The chlorine hyperfine structure has been omitted in the compilation since the splittings are generally smaller than the width of lower stratospheric lines. The calculations considered values of K up to 20. An arbitrary air-broadened halfwidth of 0.06 cm⁻¹/atm was assumed for the data. The line position accuracy is transition dependent and reported in IER. In general the uncertainty is better than 0.005 cm⁻¹. The line intensities are accurate to 5%.

P. HCN

The hydrogen cyanide air-broadened halfwidths were updated from the constant value used on previous editions of the database. The air-broadened values are based on the N₂-broadening measurements of Smith et al.[84] The measurements give values of the halfwidths as a function of |m| and range from |m| = 1 to 26. The relative uncertainty of the air-broadened halfwidths is estimated at 10–20% and the values are in good agreement with the results of Varghese and Hanson.[85] Beyond the range of measurements, a constant value of 0.099 cm⁻¹/atm was assumed.

Q. H₂O₂

The pure rotation band of hydrogen peroxide was added to this edition of the database. The spectral lines and method of calculation are from Helminger et al.[86] and additional lines and the dipole moment were measured by Cohen and Pickett.[87] Data are given for the τ = 1, 2, 3, and 4 torsional states. The line positions have a transition-dependent uncertainty with the worst case being ≈0.03 cm⁻¹ improving to 0.000001 cm⁻¹ for many of the lines. The error is given by the first number of the IER parameter. The line intensities are accurate to ≈2–5%. Updated line parameters for the ν₆ fundamental are now available[88] but not included in the compilation. A value of 0.10 cm⁻¹/atm was assumed for the air-broadened halfwidth, close to recent experimental measurements.[89]

R. C₂H₂

A total of eight bands of acetylene are represented on HITRAN as shown in Table V. The band center frequencies for the first four bands are from Varanasi et al.[90]; the band center frequencies for the remaining bands are from Rinsland et al.[91]

The sources for the line positions and intensities are as follows. In the 12–14-μm (ν₅ fundamental) region, the results are from Varanasi et al.[90] These parameters are the same as those in the 1984 GEISA compilation.[5] In the 3-μm (ν₃ fundamental) region, the parameters are from the work of Rinsland et al.[91] The ν₃ fundamental of H¹²C¹³CH has been added since the 1982 trace gas compilation.[4]

The air-broadened halfwidths are the experimental values measured by Devi et al.[92]P- and R-branch widths corresponding to the same value of |m| have been averaged, except for |m| = 1 (R0 and P1) where experimental results indicate significant differences between the widths. Beyond the range of measurements (|m| ≥ 32), the halfwidths have been arbitrarily extrapolated to an asymptotic value of 0.04 cm⁻¹/atm at 296 K.

The self-broadened halfwidths have been computed using a polynomial in |m| expansion derived from experimental data by Varanasi et al.[93] Above |m| = 25, a constant value of 0.11 cm⁻¹/atm at 296 K has been assumed. For Q-branch lines, both the air-broadened and self-broadened widths have been calculated using the expressions for the P- and R-branch transitions.

S. Temperature Dependence of Halfwidths

The temperature dependence of the halfwidth, n, is a new parameter in this edition of the database that has applications in infrared remote sensing and accurate transmission studies.

This parameter is now being measured for many of the gases in the atmosphere. The form of the temperature dependence can be understood in terms of a specific model. Here the halfwidth in cm⁻¹/atm is written as the product of density, velocity, and the optical cross section,

The temperature dependence of the density (n₀ · 273/T) and velocity (8kT/πμ)^1/2 are known. The optical cross section is assumed to vary in the form σ(T) = T^m · σ₀, where σ₀ is independent of temperature. Taking the ratio of the halfwidth at two temperatures gives

On the database the ratio of temperatures is inverted to remove the minus sign [Eq. (4)]. The temperature dependence is contained in the value of the exponent n. This model also gives the temperature dependence, m, of the optical cross section which can be useful to other studies. For molecules where there are no measured values of n available, the optical cross section is assumed temperature independent (m = 0) giving a temperature dependence of n = 1/2; this is sometimes called the classical value. The values of n used on the database are given in Table II and described below.

For water vapor, in the theoretical work of Davies and Oli,[12] three pure rotation lines and one ν₂ line were studied. The average exponent for N₂-broadening of the pure rotation lines was 0.64 and the ν₂ value was n = 0.45. These results have been discussed[13] and the value n = 0.64 was adopted for all water lines. In the future, the results of Gamache and Rothman,[94] theoretical calculations of n for some fifty water vapor transitions for both pure rotation and ν₂ bands, will be added to the H₂O lines on the database.

The temperature exponents used for carbon dioxide take into account the observed vibrational dependence of n. A value of n = 0.75 from the measurements of Planet et al.[95] is used for all bands except lines in the ν₃ band and the overtone band, ν₂ + ν₃ − ν₂. The data for these latter bands are from Devi et al.[96] and have the values n = 0.76 and n = 0.79, respectively.

The temperature exponent for all ozone transitions was taken from the calculations of Gamache.[97] These calculations considered 126 rotational–vibrational transitions and yield n as a function of J and K_a. The results compared well to the few experimental measurements available. From this work an average temperature exponent of n = 0.76 was adopted.

The values of the temperature exponents of the air-broadened halfwidth for N₂O are transition dependent and were taken from the work of Lacome et al.[41] Transitions that do not have a value reported in [Ref. 41] use an average value of n = 0.75 from Varanasi.[98]

For carbon monoxide the temperature exponent has been determined in several studies. Varanasi et al.[99] determined a value of n = 0.75. More recently Hiartmann et al.[100] experimentally determined a value of n = 0.69 ± 0.02 which agrees well with the calculations of Bonamy et al.[101] The value adopted for the CO lines on the database was n = 0.69.

Several different temperature exponents are being used for methane, reflecting the dependence of n on the symmetry species of the transition. The values from Varanasi et al.[58] are n = 0.63 for the A-species, n = 0.75 for the E-species, and n = 1.0 for all F-species. For monodeuterated methane (CH₃D) a value of n = 0.75 from Varanasi et al.[59] has been adopted. The next edition of the database will incorporate the recent work of Devi et al.[102] in the evaluation of the exponent.

In future versions of the database, a value of 0.968 will be adopted for the temperature exponent of NO₂, based on N₂-broadened measurements of Devi et al.[103]

The temperature exponents for the halfwidths of hydrogen chloride were taken from the work of Ballard et al.[79] and vary from a maximum of 0.88 to a minimum of 0.20. For lines that do not have a measured temperature exponent the classical value was used, n = 0.5.

A value of n = 0.75 has been assumed for the temperature dependence of the halfwidths for all lines of acetylene based on the N₂-broadened measurements of Varanasi et al.,[93] which were obtained at 153 and 200 K.

All other molecules on the database presently use the classical value of n = 0.5. As data become available for the temperature exponent they will be reviewed for addition to the HITRAN database.

III. Cross Sections: Description and Application

There are several important atmospheric molecules with significant infrared features in specific spectral regions for which no line parameters are presently available. This category includes molecules such as the chlorofluorocarbons (CFCs), for which no line parameters are available in any spectral region, and also molecules such as HNO₃, for which good line parameters are available for only some of the important spectral regions.

For such cases the current edition of the HITRAN database provides a separate file of high resolution cross sections for a first approximation simulation of their spectra. These are approximate cross sections, derived by the Lambert-Beer law from 0.02-cm⁻¹ resolution room temperature laboratory absorption spectra acquired at the University of Denver,[104] as described by Massie et al.[105] In general, the accuracy of the data is of the order of 10–25%, but one should note that they are pressure independent and applicable for small absorptions only.

It is anticipated that some of these cross-sectional sets will be replaced by individual line parameters as they become available. However, for most heavy molecules with complex overlapping line structure (usually also with several hot bands), it will be unrealistic to expect line parameters for more than a few preselected narrow intervals. As an example, recent work[106] on the ν₆ region of CF₂Cl₂ shows that the 921–923-cm⁻¹ region can be modeled satisfactorily on a line-by-line basis, but this requires over 50,000 individual lines. Thus, for wider spectral intervals of such molecules, higher resolution (0.005 cm⁻¹) and temperature and pressure-dependent semiempirical cross sections will be required. Indeed, progress is being made toward these goals, as in the cases of the temperature-dependent cross sections of the major CF₂Cl₂ and CFCl₃ bands[107] and of the ClONO₂ bands.[108]

The cross sections σ_ν (cm⁻¹/molec·cm⁻²) can be incorporated directly into a line-by-line calculation as additive spectral values to the infinite resolution line absorption coefficients (with proper wavenumber interpolation), before the instrument function is applied. It is also possible to simulate the spectra by generating artificial line parameters such as has been done for the chlorine nitrate (ClONO₂) ν₄Q-branch.[109] In both approaches—until further information becomes available—the temperature dependence of the cross sections can be approximated by a rigid rotor, harmonic oscillator partition function with an effective rotation–vibration ground state energy.

It should be emphasized that, while the accuracy of the cross-sectional method is limited (especially for strong absorptions), omitting them in spectral regions where no line parameters are available leads to much larger errors in the interpretation of line-by-line simulations of atmospheric spectra.

Table VI summarizes the cross sections contained in file 4 on the HITRAN database. This file provides the molecule, the spectral interval, and the number of cross-sectional points in a header that appears at the beginning of data for each of the seventeen bands of the eleven heavy molecular species represented at this time. Each header contains additional information concerning the experimental conditions used at the University of Denver. The main body of the data after the header gives the cross sections at the discrete wavenumber steps determined by the spectral interval and the number of points.

IV. Concluding Remarks

This new edition of the HITRAN database represents the first major departure from the format originally established[1] by the Group on Atmospheric Transmission. This has been made necessary in part by the need and availability of molecular parameters for diverse applications. In addition, the previously separate compilations for the principal infrared telluric atmospheric absorbers and the species with lesser optical depth, are now united in one database. The overall goal in constructing the new HITRAN database has been for the database to be accessible and consistent; future editions may require additional parameters and information, but the user interface should provide a minimum of problems.

Updating is proceeding on several different aspects. As indicated in Sec. II, new data for several bands that are quite deficient on the database became available after this edition was finalized. These include new high resolution analyses[110] for water vapor in the visible region that would extend the database to ∼23,000 cm⁻¹. There is also the continuing effort to improve the band intensities of carbon dioxide following the methods previously mentioned.[14],[15] The latter effort is being enhanced by the attainment of better photometric accuracy for bands in the 4.3-, 14-, and 15-μm regions.[111],[112] The first high resolution analysis of ozone isotopic bands[22],[23] will make an immense improvement on the database. It is expected that with high temperature nitrous oxide measurements in progress[113] and methods similar to those in progress for CO₂, the parameters for N₂O will be substantially improved in the near future. As mentioned previously, the ν₂ band of nitric acid will be updated. The recent highly accurate measurements of HCl and HF intensities, broadening, and shifts by Pine et al.[78] and Chackerian et al.[80] will be incorporated. The quadrupole lines of nitrogen will also be updated.[114] It is anticipated that some of the species on the cross-sectional file, such as CF₂Cl₂, will become available for the main database. In addition, many of the new parameters compiled for the ATMOS experiment[115] will be evaluated and be placed on the next HITRAN database. The modifications outlined here represent a small fraction of the updates planned for a future edition.

A major thrust in future editions of the database will be to update halfwidths, both air- and self-broadened. The literature abounds with new data, especially for the latter parameter. Likewise, pressure shifts are now being observed and will be incorporated into the field that has been reserved for them. An effort will be made to acquire more line coupling parameters, such as for the oxygen 60-GHz lines. To include temperature dependency of the line coupling, a table with an interpolation scheme may be required. Similarly, we plan to provide the internal partition sum in tabular form for interpolating for different temperatures. Having the partition sum at 296 K will also facilitate the proper implementation of the transition probability parameter on the compilation. Hopefully, some implementation of the scheme for tagging references and criteria for the major parameters will be accomplished (this is a somewhat monumental and hazardous task).

The compilation can be obtained on a magnetic tape from the National Climatic Data Center, National Oceanic & Atmospheric Administration, Federal Building, Asheville, NC 28801.

This database is the result of cooperation and collaboration on an international scale; it would be difficult to acknowledge all those who have participated and contributed to this effort. We are deeply grateful to the spectroscopists and theoreticians who submitted their work, often prior to publication. In addition to contributions from other researchers from the authors' institutions, we would like to acknowledge the contributions from the following laboratories: Laboratoire d'Infrarouge, CNRS, France; the College of William & Mary; the Ohio State University; the Rutherford Appleton Laboratory, U.K.; Stewart Radiance Laboratory, Utah State University; the National Research Council of Canada; the National Bureau of Standards; the National Center for Atmospheric Research; and Visidyne, Inc. We would also like to express our deep appreciation to Kenneth F. Kozik of Digital Equipment Corp. for his assistance in software management for this project. This program has been supported by the Air Force Office of Scientific Research through AFGL Task 2310G1.

Figures and Tables

 

Fig. 1 File Structure of HITRAN.

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Fig. 2 Spectral regions covered for each molecule in HITRAN: (a) 0–10000 cm⁻¹; (b) 10,000–20,000 cm⁻¹.

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Table I. Example of Direct Image of Lines on 1986 HITRAN Database

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Table II. Range of Air-Broadened Halfwidths and Temperature Dependences

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Table III. Formats of the Six Classes of Local Quanta

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Table IV. Isotopic Variants in HITRAN

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Table V. Band Centers and Band Sums

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Table VI. Species Included in Cross-Sectional File

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References

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2. L. S. Rothman, “AFGL Atmospheric Absorption Line Parameters Compilation: 1980 Version,” Appl. Opt. 20, 791 (1981); [CrossRef]   [PubMed]  L. S. Rothman, et al., “AFGL Trace Gas Compilation: 1980 Version,” Appl. Opt. 20, 1323 (1981). [CrossRef]   [PubMed]  

3. L. S. Rothman, et al., “AFGL Atmospheric Absorption Line Parameters Compilation: 1982 Edition,” Appl. Opt. 22, 2247 (1983). [CrossRef]   [PubMed]  

4. L. S. Rothman, et al., “AFGL Trace Gas Compilation: 1982 Version,” Appl. Opt. 22, 1616 (1983). [CrossRef]   [PubMed]  

5. N. Husson, et al., “The GEISA Spectroscopic Line Parameters Data Bank in 1984,” Ann. Geophys. 4, 185 (1986).

6. R. L. Poynter and H. M. Pickett, “Submillimeter, Millimeter, and Microwave Spectral Line Catalog,” Appl. Opt. 24, 2235 (1985). [CrossRef]   [PubMed]  

7. J. K. Messer, F. C. DeLucia, and P. Helminger, “Submillimeter Spectroscopy of the Major Isotopes of Water,” J. Mol. Spectrosc. 105, 139 (1984). [CrossRef]  

8. R. A. Toth and R. L. Poynter, “Line Positions and Line Strengths of the (010–000) and (020–010) Bands of HD¹⁶O and the (010–000) Band of HD¹⁸O,” in preparation.

9. J.-M. Flaud, C. Camy-Peyret, and R. A. Toth, Selected Constants: Water Vapour Line Parameters from Microwave to Medium Infrared (Pergamon, Oxford, 1981).

10. R. A. Toth, Jet Propulsion Laboratory; unpublished data.

11. R. R. Gamache and R. W. Davies, “Theoretical Calculations of N₂-Broadened Halfwidths of H₂O Using Quantum Fourier Transform Theory,” Appl. Opt. 22, 4013 (1983). [CrossRef]   [PubMed]  

12. R. W. Davies and B. A. Oli, “Theoretical Calculations of H₂O Linewidths and Pressure Shifts: Comparison of the Anderson Theory with Quantum Many-Body Theory for N₂ and Air-Broadened Lines,” J. Quant. Spectrosc. Radiat. Transfer 20, 95 (1978). [CrossRef]  

13. R. W. Davies, GTE Laboratories; private communication (1980).

14. L. S. Rothman, “Infrared Energy Levels and Intensities of Carbon Dioxide. Part 3,” Appl. Opt. 25, 1795 (1986). [CrossRef]   [PubMed]  

15. R. B. Wattson and L. S. Rothman, “Determination of Vibrational Energy Levels and Parallel Band Intensities of ¹²C¹⁶O₂ by Direct Numerical Diagonalization,” J. Mol. Spectrosc. 119, 83 (1986). [CrossRef]  

16. L. R. Brown and R. A. Toth, “Comparison of the Frequencies of NH₃, CO₂, H₂O, N₂O, CO, and CH₄ as Infrared Calibration Standards,” J. Opt. Soc. Am. B 2, 842 (1985). [CrossRef]  

17. E. Arié, N. Lacome, P. Arcas, and A. Levy, “Oxygen- and Air-Broadened Linewidths of CO₂,” Appl. Opt. 25, 2584 (1986). [CrossRef]   [PubMed]  

18. L. L. Strow and B. M. Gentry, “Rotational Collisional Narrowing in an Infrared CO₂Q Branch Studied with a Tunable Diode Laser,” J. Chem. Phys. 84, 1149 (1986); [CrossRef]  J. Johns, National Research Council of Canada; private communication.

19. M. L. Hoke, S. A. Clough, W. Lafferty, and B. W. Olson, “Line Coupling in Carbon Dioxide,” presented at the Forty-First Symposium on Molecular Spectroscopy (16–20 June 1986), paper TB9 (replacement).

20. E. W. Smith, “Absorption and Dispersion in the O₂ Microwave Spectrum at Atmospheric Pressures,” J. Chem. Phys. 74, 6658 (1981). [CrossRef]  

21. H. M. Pickett, E. A. Cohen, and J. S. Margolis, “The Infrared and Microwave Spectra of Ozone for the (0,0,0), (1,0,0) and (0,0,1) States,” J. Mol. Spectrosc. 110, 186 (1985). [CrossRef]  

22. J.-M. Flaud, C. Camy-Peyret, V. M. Devi, C. P. Rinsland, and M. A. H. Smith, “The ν₁ and ν₃ Bands of ¹⁶O¹⁸O¹⁶O: Line Positions and Intensities,” J. Mol. Spectrosc. 118, 334 (1986). [CrossRef]  

23. C. Camy-Peyret, J.-M. Flaud, A. Perrin, V. M. Devi, C. P. Rinsland, and M. A. H. Smith, “The Hybrid-Type Bands ν₁ and ν₃ of ¹⁶O¹⁶O¹⁸O: Line Positions and Intensities,” J. Mol. Spectrosc. 118, 345 (1986). [CrossRef]  

24. J.-M. Flaud, C. Camy-Peyret, V. M. Devi, C. P. Rinsland, and M. A. H. Smith, “The ν₁ and ν₃ Bands of ¹⁶O₃: Line Positions and Intensities,” J. Mol. Spectrosc. (1987), in press.

25. C. P. Rinsland, V. M. Devi, J.-M. Flaud, C. Camy-Peyret, M. A. H. Smith, and G. M. Stokes, “Identification of ¹⁸O-Isotopic Lines of Ozone in Infrared Ground-Based Solar Absorption Spectra,” J. Geophys. Res. 90, 10719 (1985). [CrossRef]  

26. A. Barbe, C. Secroun, A. Goldman, and J. R. Gillis, “Analysis of the ν₁ + ν₂ + ν₃ Band of O₃,” J. Mol. Spectrosc. 100, 377 (1983). [CrossRef]  

27. C. Meunier, P. Marche, and A. Barbe, “Intensities and Air Broadening Coefficients of O₃ in the 5- and 3-μm Regions,” J. Mol. Spectrosc. 95, 271 (1982). [CrossRef]  

28. A. Goldman and A. Barbe, “Line Parameters for the ν₁ + ν₂ + ν₃ Bands of O₃,” DU-Reims Collaborative Studies on Atmospheric Spectroscopy, Final Report (Oct. 1985).

29. H. M. Pickett, et al., “The Vibrational and Rotational Spectra of Ozone for the (0,1,0) and (0,2,0) States,” J. Mol. Spectrosc. in press.

30. A. Goldman, J. R. Gillis, and A. Barbe, “Calculated Line Parameters for the 2ν₂¹⁶O₃ Band,” Technical Report, Physics Department, U. Denver (1983).

31. A. Goldman, R. D. Blatherwick, F. J. Murcray, J. W. VanAllen, F. H. Murcray, and D. G. Murcray, “New Atlas of Stratospheric IR Absorption Spectra, Volume I: Line Positions and Identifications. Volume II: The Spectra,” U. Denver (Sept. 1986).

32. V. M. Devi, J.-M. Flaud, C. Camy-Peyret, C. P. Rinsland, and M. A. H. Smith, “Line Positions and Intensities for the ν₁ + ν₂ and ν₂ + ν₃ Bands of ¹⁶O₃,” J. Mol. Spectrosc. (1987), in press.

33. R. R. Gamache and L. S. Rothman, “Theoretical N₂-broadened Halfwidths of ¹⁶O₃,” Appl. Opt. 24, 1651 (1985). [CrossRef]   [PubMed]  

34. R. R. Gamache and R. W. Davies, “Theoretical N₂-, O₂-, and Air-Broadened Halfwidths of ¹⁶O₃ Calculated by Quantum Fourier Transform Theory with Realistic Collision Dynamics,” J. Mol. Spectrosc. 109, 283 (1985). [CrossRef]  

35. M. A. H. Smith, K. B. Thakur, C. P. Rinsland, V. M. Devi, and D. C. Benner, “Diode Laser Measurements in the ν₁ Band of ¹⁶O₃,” presented at the Forty-First Symposium on Molecular Spectroscopy, paper RF6, (16–20 June 1986);M. A. H. Smith, C. P. Rinsland, V. M. Devi, D. C. Benner, and K. B. Thakur, “Measurements of Air-Broadened and Nitrogen-Broadened Halfwidths and Shifts of Ozone Lines near 9 μm,” J. Opt. Soc. Am. B (1987), submitted.

36. R. A. Toth, “Line Strengths of N₂O in the 1120–1440-cm⁻¹ Region,” Appl. Opt. 23, 1825 (1984). [CrossRef]   [PubMed]  

37. R. A. Toth, “Frequencies of N₂O in the 1100- to 1440-cm⁻¹ Region,” J. Opt. Soc. Am. B 3, 1263 (1986). [CrossRef]  

38. R. A. Toth, “N₂O Vibration–Rotation Parameters Derived from Measurements in the 900–1090- and 1580–2380-cm⁻¹ Regions,” J. Opt. Soc. Am. B 4, 357 (1987). [CrossRef]  

39. R. A. Toth, “Line Strengths (1100–2370 cm⁻¹) Self-Broadened Linewidths and Frequency Shifts (1800–2630 cm⁻¹) of N₂O and Isotopic Variants,” in preparation.

40. W. B. Olson, A. G. Maki, and W. J. Lafferty, “Tables of N₂O Absorption Lines for the Calibration of Tunable Infrared Lasers from 522 cm⁻¹ to 657 cm⁻¹ and from 1115 cm⁻¹ to 1340 cm⁻¹,” J. Chem. Phys. Ref. Data 10, 1065 (1981). [CrossRef]  

41. N. Lacome, A. Levy, and G. Guelachvili, “Fourier Transform Measurement of Self-, N₂-, and O₂-Broadening of N₂O Lines: Temperature Dependence of Linewidths,” Appl. Opt. 23, 425 (1984). [CrossRef]   [PubMed]  

42. J. C. Hilico, M. Loete, and L. R. Brown, “Line Strengths of the ν₃–ν₄ Band of Methane,” J. Mol. Spectrosc. 111, 119 (1985). [CrossRef]  

43. G. Tarrago, K. N. Rao, and L. W. Pinkley, “Analysis of the ν₃ Band of ¹²CH₃D at 7.6 μm,” J. Mol. Spectrosc. 79, 31 (1980). [CrossRef]  

44. G. Tarrago, Laboratoire d'Infrarouge, France; unpublished data (1980).

45. L. W. Pinkley, K. N. Rao, G. Tarrago, G. Poussigue, and M. Dang-Nhu, “Analysis of the ν₆ Band of ¹²CH₃D at 8.6 μm,” J. Mol. Spectrosc. 68, 195 (1977). [CrossRef]  

46. G. Poussigue, G. Tarrago, P. Cardinet, and A. Valentin, “Absorption of Monodeuteromethane ¹²CH₃D at 4.5 μm. Analysis of the Overtone Band 2ν₆,” J. Mol. Spectrosc. 82, 35 (1980). [CrossRef]  

47. G. Poussigue, E. Pascaud, J. P. Champion, and G. Pierre, “Rotational Analysis of Vibrational Polyads in Tetrahedral Molecules. Stimultaneous Analysis of the Pentad Energy Levels of ¹²CH₄,” J. Mol. Spectrosc. 93, 351 (1982). [CrossRef]  

48. G. Pierre, J. P. Champion, G. Guelachvili, E. Pascaud, and G. Poussigue, “Rotational Analysis of Vibrational Polyads in Tetrahedral Molecules: Line Parameters of the Infrared Spectrum of ¹²CH₄ in the Range 2250–3260 cm⁻¹: Theory Versus Experiment,” J. Mol. Spectrosc. 102, 344 (1983). [CrossRef]  

49. R. A. Toth, L. R. Brown, R. H. Hunt, and L. S. Rothman, “Line Parameters of Methane from 2385 to 3200 cm⁻¹,” Appl. Opt. 20, 932 (1981). [CrossRef]   [PubMed]  

50. L. R. Brown, Jet Propulsion Laboratory; unpublished data.

51. D. J. E. Knight, G. J. Edwards, P. R. Pearce, and N. R. Cross, “Measurement of the Frequency of the 3.39-μm Methane-Stabilized Laser to ±3 Parts in 10¹¹,” IEEE Trans. Instrum. Meas. IM-29, 257 (1980). [CrossRef]  

52. L. R. Brown and L. S. Rothman, “Methane Line Parameters for the 2.3-μm Region,” Appl. Opt. 21, 2425 (1982). [CrossRef]   [PubMed]  

53. L. R. Brown, “Laboratory Spectroscopy to Support Remote Sensing of Planetary Atmospheres: Experimental Line Parameters of Methane at 2.55 μm,” in Abstracts, Ninth Colloquium on High Resolution Molecular Spectroscopy, Riccione, Italy (Sept. 1985).

54. C. R. Pollock, F. R. Petersen, D. A. Jennings, J. S. Wells, and A. G. Maki, “Absolute Frequency Measurements of the 2–0 Band of CO at 2.3 μm; Calibration Standard Frequencies from High Resolution Color Center Laser Spectroscopy,” J. Mol. Spectrosc. 99, 357 (1983). [CrossRef]  

55. J. S. Margolis, “Line Strength Measurements of the 2ν₃ Band of Methane,” J. Quant. Spectrosc. Radiat. Transfer 13, 1097 (1973). [CrossRef]  

56. K. Fox, G. W. Halsey, and D. E. Jennings, “High Resolution Spectrum and Analysis of 2ν₃ of ¹³CH₄ at 1.67 μm,” J. Mol. Spectrosc. 83, 213 (1980). [CrossRef]  

57. G. D. T. Tejwani and K. Fox, “Calculated Linewidths for CH₄ Broadened by N₂ and O₂,” J. Chem. Phys. 60, 2021 (1974); [CrossRef]  G. D. T. Tejwani and K. Fox, “Calculated Self- and Foreign-Gas Broadened Linewidths for CH₃D,” J. Chem. Phys. 61, 759 (1974). [CrossRef]  

58. P. Varanasi, L. P. Giver, and F. P. J. Valero, “Thermal Infrared Lines of Methane Broadened by Nitrogen at Low Temperatures,” J. Quant. Spectrosc. Radiat. Transfer 30, 481 (1983). [CrossRef]  

59. P. Varanasi, L. P. Giver, and F. P. J. Valero, “A Laboratory Study of the 8.65 μm Fundamental of ¹²CH₃D at Temperatures Relevant to Titan's Atmosphere,” J. Quant. Spectrosc. Radiat. Transfer 30, 517 (1983). [CrossRef]  

60. V. M. Devi, C. P. Rinsland, M. A. H. Smith, and D. C. Benner, “Measurements of ¹²CH₄ν₄ Band Halfwidths Using a Tunable Diode Laser System and a Fourier Transform Spectrometer,” Appl. Opt. 24, 2788 (1985). [CrossRef]  

61. V. M. Devi, C. P. Rinsland, M. A. H. Smith, and D. C. Benner, “Tunable Diode Laser Measurements of Widths of Air- and Nitrogen-Broadened Lines in the ν₄ Band of ¹³CH₄,” Appl. Opt. 24, 3321 (1985). [CrossRef]  

62. F. J. Lovas, “Microwave Spectral Tables II. Triatomic Molecules,” J. Phys. Chem. Ref. Data 7, 1445 (1978). [CrossRef]  

63. M. Carlotti, G. DiLonardo, L. Fusina, B. Carli, and F. Mencaraglia, “The Submillimeter-Wave Spectrum and Spectroscopic Constants of SO₂ in the Ground State,” J. Mol. Spectrosc. 106, 235 (1984). [CrossRef]  

64. D. Patel, D. Margolese, and T. R. Dyke, “Electric Dipole Moment of SO₂ in Ground and Excited States,” J. Chem. Phys. 70, 2740 (1979). [CrossRef]  

65. C. Camy-Peyret, J.-M. Flaud, A. Perrin, and K. N. Rao, “Improved Line Parameters for the ν₃ and ν₂ + ν₃ − ν₂ Bands of ¹⁴N¹⁶O₂,” J. Mol. Spectrosc. 95, 72 (1982). [CrossRef]  

66. V. M. Devi, et al., “Tunable Diode Laser Spectroscopy of NO₂ at 6.2 μm,” J. Mol. Spectrosc. 93, 179 (1982). [CrossRef]  

67. A. Perrin, J.-M. Flaud, and C. Camy-Peyret, “Calculated Line Positions and Intensities for the ν₁ + ν₃ and ν₁ + ν₂ + ν₃ − ν₂ Bands of ¹⁴N¹⁶O₂,” Infrared Phys. 22, 343 (1982). [CrossRef]  

68. R. A. Toth and R. H. Hunt, “Line Strengths, Spin-Splittings, and Forbidden Transitions in the (101) Band of ¹⁴N¹⁶O₂,” J. Mol. Spectrosc. 79, 182 (1980). [CrossRef]  

69. J.-M. Flaud, C. Camy-Peyret, V. Malathy Devi, P. P. Das, and K. Narahari Rao, “Rao Diode Laser Spectra of the ν₂ Band of ¹⁴N¹⁶O₂: The (010) State of NO₂,” J. Mol. Spectrosc. 84, 234 (1980). [CrossRef]  

70. V. M. Devi, P. P. Das, A. Bano, K. N. Rao, J.-M. Flaud, C. Camy-Peyret, and J.-P. Chevillard, “Diode Laser Measurements of Intensities, N₂-Broadening, and Self-Broadening Coefficients of Lines of the ν₂ Band of ¹⁴N¹⁶O₂,” J. Mol. Spectrosc. 88, 251 (1981). [CrossRef]  

71. W. C. Bowman and F. C. DeLucia, “The Millimeter and Submillimeter Spectrum of NO₂: A Study of Electronic Effects in a Nonsinglet Light Asymmetric Rotor,” J. Chem. Phys. 77, 92 (1982). [CrossRef]  

72. R. L. Poynter and J. S. Margolis, “The ν₂ Spectrum of NH₃,” Mol. Phys. 51, 393 (1984). [CrossRef]  

73. A. G. Maki, W. B. Olson, A. Fayt, J. S. Wells, and A. Goldman, “High Resolution Measurements and Analysis of the ν₂, ν₃, ν₄, ν₅, and 2ν₉ Bands of Nitric Acid,” presented at Forty-First Symposium on Molecular Spectroscopy, Ohio State U. (1986), paper TE8.

74. A. Goldman, J. R. Gillis, C. P. Rinsland, F. J. Murcray, and D. G. Murcray, “Stratospheric HNO₃ Quantification from Line-by-Line Nonlinear Least-Squares Analysis of High-Resolution Balloon-Borne Solar Absorption Spectra in the 870-cm⁻¹ Region,” Appl. Opt. 23, 3252 (1984); [CrossRef]   [PubMed]  D. G. Murcray, F. J. Murcray, F. H. Murcray, and G. Vanasse, “Measurements of Atmospheric Emission at High Spectral Resolution,” J. Meteorol. Soc. Jpn. 63, 320 (1985).

75. A. Goldman, U. Denver unpublished data.

76. A. Maki, “High Resolution Measurements of the ν₂ Band of HNO₃ and the ν₃ Band of Trans-HONO,” J. Mol. Spectrosc.00, 000 (198X), in press.

77. R. E. Thompson, J. H. Park, M. A. H. Smith, G. A. Harvey, and J. M. Russell III, “Nitrogen-Broadened Halfwidths of HF Lines in the 1–0 Band,” J. Mol. Spectrosc. 106, 251 (1984). [CrossRef]  

78. A. S. Pine, A. Fried, and J. W. Elkins, “Spectral Intensities in the Fundamental Bands of HF and HC1,” J. Mol. Spectrosc. 109, 30 (1985); [CrossRef]  A. S. Pine and J. P. Looney, “N₂ and Air Broadening in the Fundamental Bands of HF and HC1,” J. Mol. Spectrosc. 122, 41 (1987); [CrossRef]  A. S. Pine and A. Fried, “Self-Broadening in the Fundamental Bands of HF and HC1,” J. Mol. Spectrosc. 114, 148 (1985). [CrossRef]  

79. J. Ballard, W. B. Johnston, P. H. Moffat, and D. T. Llewellyn-Jones, “Experimental Determination of the Temperature Dependence of Nitrogen Broadened Line Widths in the 1–0 Band of HC1,” J. Quant. Spectrosc. Radiat. Transfer 33, 365 (1985). [CrossRef]  

80. C. Chackerian Jr., D. Goorvitch, and L. P. Giver, “HC1 Vibrational Fundamental Band: Line Intensities and Temperature Dependence of Self-Broadening Coefficients,” J. Mol. Spectrosc. 113, 373 (1985). [CrossRef]  

81. W. H. Kirchhoff, “On the Calculation and Interpretation of Centrifugal Distortion Constants: A Statistical Basis for Model Testing: The Calculation of the Force Field,” J. Mol. Spectrosc. 41, 333 (1972). [CrossRef]  

82. K. Kondo and T. Oka, “Stark-Zeeman Effects on Asymmetric Top Molecules. Formaldehyde H₂CO,” J. Phys. Soc. Jpn. 15, 307 (1960). [CrossRef]  

83. H. E. G. Singbeil, et al., “The Microwave and Millimeter Wave Spectra of Hypochlorous Acid,” J. Mol. Spectrosc. 103, 466 (1984). [CrossRef]  

84. M. A. H. Smith, G. A. Harvey, G. L. Pellett, A. Goldman, and D. J. Richardson, “Measurements of the HCN ν₃ Band Broadened by N₂,” J. Mol. Spectrosc. 105, 105 (1984). [CrossRef]  

85. P. L. Varghese and R. K. Hanson, “Tunable Diode Laser Measurements of Spectral Parameters of HCN at Room Temperature,” J. Quant. Spectrosc. Radiat. Transfer 31, 545 (1984). [CrossRef]  

86. P. Helminger, W. C. Bowman, and F. C. DeLucia, “A Study of the Rotational-Torsional Spectrum of Hydrogen Peroxide between 80 and 700 GHz,” J. Mol. Spectrosc. 85, 120 (1981). [CrossRef]  

87. E. A. Cohen and H. Pickett, “The Dipole Moment of Hydrogen Peroxide,” J. Mol. Spectrosc. 87, 582 (1981). [CrossRef]  

88. J. J. Hillman, D. E. Jennings, W. B. Olson, and A. Goldman, “High-Resolution Infrared Spectrum of Hydrogen Peroxide: The ν₆ Fundamental Band,” J. Mol. Spectrosc. 117, 46 (1986). [CrossRef]  

89. V. M. Devi, C. P. Rinsland, M. A. H. Smith, D. C. Benner, and B. Fridovich, “Tunable Diode Laser Measurements of Air-Broadened Linewidths in the ν₆ Band of H₂O₂,” Appl. Opt. 25, 1844 (1986). [CrossRef]   [PubMed]  

90. P. Varanasi, L. P. Giver, and F. P. J. Valero, “Infrared Absorption by Acetylene in the 12–14 μm Region at Low Temperatures,” J. Quant. Spectrosc. Radiat. Transfer 30, 497 (1983). [CrossRef]  

91. C. P. Rinsland, A. Baldacci, and K. N. Rao, “Acetylene Bands Observed in Carbon Stars: A Laboratory Study and an Illustrative Example of Its Application to IRC+10216,” Astrophys. J. Suppl. 49, 487 (1982). [CrossRef]  

92. V. M. Devi, D. C. Benner, C. P. Rinsland, M. A. H. Smith, and B. D. Sidney, “Tunable Diode Laser Measurements of N₂- and Air-Broadened Halfwidths: Lines in the (ν₄ + ν₅)⁰ Band of ¹²C₂H₂ Near 7.4 μm,” J. Mol. Spectrosc. 114, 49 (1985). [CrossRef]  

93. P. Varanasi, L. P. Giver, and F. P. J. Valero, “Measurements of Nitrogen-Broadened Line Widths of Acetylene at Low Temperatures,” J. Quant. Spectrosc. Radiat. Transfer 30, 505 (1983). [CrossRef]  

94. R. R. Gamache and L. S. Rothman, “Temperature Dependence of N₂-Broadened Halfwidths of Water Vapor: the Pure Rotation and ν₂ Bands,” J. Mol. Spectrosc. (1987), submitted.

95. W. G. Planet, G. L. Tettemer, and J. S. Knoll, “Temperature Dependence of Intensities and Widths of N₂-Broadened Lines in the 15 μm CO₂ Band from Tunable Laser Measurements,” J. Quant. Spectrosc. Radiat. Transfer 20, 547 (1978); [CrossRef]  W. G. Planet and G. L. Tettemer, “Temperature Dependent Intensities and Widths of N₂-Broadened CO₂ Lines at 15 μm Band from Tunable Laser Measurements,” J. Quant. Spectrosc. Radiat. Transfer 22, 345 (1979); [CrossRef]  G. L. Tettemer and W. G. Planet, “Intensities and Pressure-Broadened Widths of CO₂ R-Branch Lines at 15 μm from Tunable Laser Measurements,” J. Quant. Spectrosc. Radiat. Transfer 24, 343 (1980). [CrossRef]  

96. V. M. Devi, B. Fridovich, G. D. Jones, and D. G. S. Snyder, “Diode Laser Measurements of Strengths, Half-Widths, and Temperature Dependence of Half-Widths for CO₂ Spectral Lines Near 4.2 μm,” J. Mol. Spectrosc. 105, 61 (1984). [CrossRef]  

97. R. R. Gamache, “Temperature Dependence of N₂-Broadened Halfwidths of Ozone,” J. Mol. Spectrosc. 114, 31 (1985). [CrossRef]  

98. P. Varanasi, SUNY-Stony Brook; private communication.

99. P. Varanasi, “Measurement of Line Widths of CO of Planetary Interest at Low Temperatures,” J. Quant. Spectrosc. Radiat. Transfer 15, 191 (1975); [CrossRef]  P. Varanasi and S. Sarangi, “Measurements of Intensities and Nitrogen-Broadened Linewidths in the CO Fundamental at Low Temperatures,” J. Quant. Spectrosc. Radiat. Transfer 15, 473 (1975). [CrossRef]  

100. J. M. Hartmann, M. Y. Perrin, J. Taine, and L. Rosenmann, “Diode Laser Measurements and Calculations of CO 1–0 P(4) Line-Broadening in the 294–765K Temperature Range,” J. Mol. Spectrosc., submitted.

101. J. Bonamy, D. Robert, and C. Boulet, “Simplified Models for the Temperature Dependence of Linewidths at Elevated Temperatures and Applications to CO Broadened by Ar and N₂,” J. Quant. Spectrosc. Radiat. Transfer 31, 23 (1984). [CrossRef]  

102. V. M. Devi, B. Fridovich, G. D. Jones, and D. G. S. Snyder, “Strengths and Lorentz Broadening Coefficients for Spectral Lines in the ν₃ and ν₂ + ν₄ Bands of ¹²CH₄ and ¹³CH₄,” J. Mol. Spectrosc. 97, 333 (1983). [CrossRef]  

103. V. M. Devi, B. Fridovich, G. D. Jones, D. G. S. Snyder, and A. C. Neuendorffer, “Temperature Dependence of the Widths of N₂-Broadened Lines of the ν₃ Band of ¹⁴N¹⁶O₂,” Appl. Opt. 21, 1537 (1982). [CrossRef]   [PubMed]  

104. D. G. Murcray, F. J. Murcray, A. Goldman, F. S. Bonomo, and R. D. Blatherwick, “High Resolution Infrared Laboratory Spectra,” U. Denver, Physics Department (Apr. 1984).

105. S. T. Massie, A. Goldman, D. G. Murcray, and J. C. Gille, “Approximate Absorption Cross Sections of F12, F11, ClONO₂, N₂O₅, HNO₃, CCl₄, CF₄, F21, F113, F114, and HNO₄,” Appl. Opt. 24, 3426 (1985). [CrossRef]   [PubMed]  

106. A. Goldman and C. Deroche, “Line Parameters for F12 in the 920 cm⁻¹ Region,” U. Denver, Physics Department (July 1986).

107. J. W. Elkihs, R. L. Sams, and J. Wen, “Measurements of the Temperature Dependence on the Infrared Band Strengths and Shapes for Halocarbons F-11 and F-12,” Natl. Bur. Stand. U.S. Report 553-K-86 (1986).

108. V. G. Kunde, et al., “Atmospheric Infrared Emission of ClONO₂ Observed by a Balloon-Borne Fourier Spectrometer,” AGU Fall Meeting (1986).

109. C. P. Rinsland, et al., “Tentative Identification of the 780-cm⁻¹ν₄ Band Q Branch of Chlorine Nitrate in High-Resolution Solar Absorption Spectra of the Stratosphere,” J. Geophys. Res. 90, 7931 (1985). [CrossRef]  

110. J.-Y. Mandin, J.-P. Chevillard, C. Camy-Peyret, J.-M. Flaud, and J. W. Brault, “The High-Resolution Spectrum of Water Vapor between 13200 and 16500 cm⁻¹,” J. Mol. Spectrosc. 116, 167 (1986); [CrossRef]  C. Camy-Peyret, et al., “The High Resolution Spectrum of Water Vapor Between 16500 and 25250 cm⁻¹,” J. Mol. Spectrosc. 113, 208 (1985). [CrossRef]  

111. J. Johns, National Research Council of Canada; private communication.

112. V. Dana, U. Pierre et Marie Curie, France; private communication.

113. M. P. Esplin, Stewart Radiance Laboratory; private communication.

114. D. Reuter, D. E. Jennings, and J. W. Brault, “The v = 1 ← 0 Quadrupole Spectrum of N₂,” J. Mol. Spectrosc. 115, 294 (1986). [CrossRef]  

115. L. R. Brown, C. B. Farmer, C. P. Rinsland, and R. A. Toth, “Molecular Line Parameters for the Atmospheric Trace Molecule Spectroscopy (ATMOS) Experiment,” submitted to Appl. Opt., 1987. [PubMed]