The Virtual Planetary Laboratory Molecular Spectra Search Engine is a search engine to query the molecular spectroscopic database HITRAN 2016 and display plots of line intensity versus wavelength (or wavenumber) within a user specified wavelength (or wavenumber) range. The HITRAN database contains high resolution spectroscopic data which has several orders of magnitude range in wavenumbers. Static plots of this data do not give enough fine resolution details. A major advantage of the VPL search engine is that by specifying wavelength (or wavenumber) ranges, it allows you to zoom in and zoom out to identify features of interest.
The y-axis is line intensity S ( in units of cm^(-1)/(molecule cm^(-2)) ).