Database for water self-continuum measurements in the infrared atmospheric window and v2 region

Self-broadened H2O measurements and analysis were performed with to determine the H2O self-continuum. Zenodo serves as a repository for the continuum data and measurement database.

Measurements in the spectral range of 700 – 2000 cm⁻¹ were conducted using a Bruker 125HR Interferometer with an attached multi-reflection cell. The spectral resolution was 0.003 cm⁻¹. Measurements were corrected regarding the wavenumber axis (→ N2O reference lines [1]), detector non-linearity, thermal self-radiation, and the instrumental line profile function (→ LINEFIT [2]).

Continua were determined in the v2 in-band region (1350 – 1900 cm⁻¹) for five different temperatures between 279 K and 353 K, as well as in the atmospheric window (700 – 1350 cm⁻¹) for room temperature. The measurements used for this purpose had water vapor pressures between 3 and 20 mbar and absorption path lengths between 14 and 165 m. Local line contributions were also newly-determined, the corresponding line parameter database can be found in [3].

Provided files:

Readme:

Database for water self-continuum measurements in the infrared atmospheric window and v2 region – Readme.docx

H2O self-continuum data file:

database_self-continuum_H2O_700-2000_cm-1.xlsx

Measurement database:

H2O_measurements_700-2000cm-1.zip

References:

[1] Maki, A., & Wells, J. (1998). NIST Standard Reference Database 118: Wavenumber Calibration Tables from Heterodyne Frequency Measurements. NIST.

[2] Hase, F., Blumenstock, T., & Paton-Walsh, C. (1999). Analysis of the instrumental line shape of high-resolution Fourier transform IR spectrometers with gas cell measurements and new retrieval software. Applied Optics, 38(15), 3417-3422.

[3] Röske, C., Birk, M., & Wagner, G. (2024). Line parameter database H2O self-broadened 700-2000 cm-1 [Data set]. Zenodo. https://doi.org/10.5281/zenodo.13861692

[4] Mlawer, E. J., Payne, V. H., Moncet, J. L., Delamere, J. S., Alvarado, M. J., & Tobin, D. C. (2012). Development and recent evaluation of the MT_CKD model of continuum absorption. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 370(1968), 2520-2556.