Corrections and Additions for the HITRAN Water Vapor Spectroscopic Database

 

Research Staff: Lawrence P. Giver, Charles Chackerian, Jr., and David W. Schwenke

The HITRAN database has been used extensively in the calculation of atmospheric absorption of solar radiation. We have recently published extensive corrections for HITRAN water vapor line intensities in the 450 to 1250 nm spectral region. These corrections have been incorporated into the HITRAN database, and have been important in the re-analysis of some satellite measurements of stratospheric water vapor abundances. Additional improvements are now being made to the water vapor line list, in the expectation that they will also be incorporated into the HITRAN database. There are four different types of improvements being made to the water vapor line list in the 450 to 1250 nm spectral region:

1) There are nearly 2000 lines on HITRAN that do not have rotational assignments, and thus their temperature dependence cannot be calculated. Many of these have now been assigned, based on the earlier calculated line list of Partridge and Schwenke (http://george.arc.nasa.gov/~dschwenke).

2) We have measured positions for the observable H218O, H217O, and HD16O isotopic lines. Our measured positions were made on Ames laboratory spectra taken with a BOMEM Fourier Transform Spectrometer and a White absorption cell using 1107 meters absorption path, and 4 and 12 torr water vapor pressure. These lines in HITRAN currently have approximate positions from older computations.

3) Over 500 additional lines have been observed in the Ames laboratory spectra, and assigned, which can be included in the database.

4) The lower state energy values, E", are erroneous on the HITRAN database for lines of the 121-010 vibrational transition. The correct values for these lines must be entered on the HITRAN database.

Collaborators: Prasad Varanasi, State University of New York at Stony Brook; Richard S. Freedman, Space Physics Research Institute

 

Point of Contact: Lawrence P. Giver, 650/604-5231, lgiver@mail.arc.nasa.gov