[1] Water vapor is an important greenhouse gas in the Earth's atmosphere. Absorption of solar radiation by water vapor in the near-UV region may partially account for up to 30% discrepancy between the modeled and the observed solar energy absorbed by the atmosphere. But the magnitude of water vapor absorption in the near-UV region at wavelengths shorter than 384 nm is not known. We have determined absorption cross sections of water vapor at 5 nm intervals in the 290-350 nm region, by using cavity ring-down spectroscopy. Water vapor cross-section values range from 2.94 × 10 À24 to 2.13 × 10 À25 cm 2 /molecule in the wavelength region studied. The effect of the water vapor absorption in the 290-350 nm region on the modeled radiation flux at the ground level has been evaluated using radiative transfer model. Citation: Du, J., L. Huang, Q. Min, and L. Zhu (2013), The influence of water vapor absorption in the 290-350 nm region on solar radiance: Laboratory studies and model simulation, Geophys. Res. Lett., 40,[4788][4789][4790][4791][4792]