Physical Sciences and Mathematics Commons^™

Water Vapor Near-Uv Absorption: Laboratory Spectrum, Field Evidence, And Atmospheric Impacts, Linsen Pei, Qilong Min, Yuyi Du, Zhechen Wang, Bangsheng Yin, Kai Yang, Patrick Disterhoft, Thomas Pongetti, Lei Zhu

Environmental Health Sciences Faculty Scholarship

Absorption of solar radiation by water vapor in the near-UV region is a poorly-understood but important issue in atmospheric science. To better understand water vapor near-UV absorption, we constructed a cavity ring-down spectrometer with bandwidth of 5 cm^-1 (~0.05 nm) and obtained water vapor absorption cross-sections at 1 nm increments in the 290-350 nm region. Water vapor displays structured absorption over this range with maximum and minimum cross-sections of 8.4×10^-25 and 1.6×10^-25 cm²/molecule. Major water vapor absorption bands were observed at 293-295, 307-313, 319, 321-322, and 325 nm, with cross-section values higher than 4.0×10^{-25 …}