title: Absorption by oxygen and water vapor in the real atmosphere.
abstract: Unexpected absorption in the real atmosphere in the window from 840 to 890 nm has been clearly observed through measurements of direct solar spectral irradiance under clear, cloud-free skies. This absorption is not predicted by the known theoretical models. The cause of this apparent absorption may be due to the presence of high thin nonvisible cirrus clouds. A quantitative evaluation of this absorption and an improvement of oxygen absorption coefficients has been carried out after a comparison of more than seventy experimental spectra. Moreover, it is necessary to take into account the different behavior of modeled and experimental data at low and high air masses.
authors.forename: V E
authors.initials: VE
authors.lastname: Cachorro
authors.forename: A M
authors.initials: AM
authors.lastname: de Frutos
authors.forename: J L
authors.initials: JL
authors.lastname: Casanova