Metal Abundances and Kinematics of the Ly-alpha absorbers

Both high resolution spectra of QSOs observed at the 8-10m telescopes and advanced methods of data analysis are crucial for accurate measurements of the chemical composition and physical parameters of the intervening clouds. An overview of our recent results obtained with the Monte Carlo inversion (MCI) procedure is presented. This includes: (1) variations of the shape of the local background ionizing continuum in the 1-5 Ryd range at redshift z ~ 2.8-3.0; (2) an inverse correlation between the measured metallicity, [C/H], and the absorber line-of-sight linear size, L; (3) a functional dependence between the line-of-sight velocity dispersion, sigma_v, and L.