@Article{Plana-FattoriDubuFomiCorr:2004:EsAtWa,
               author = "Plana-Fattori, Artemio and Dubuisson, Philippe and Fomin, Boris 
                         Alexeevitch and Correa, Marcelo de Paula",
          affiliation = "{CPTEC-INPE-Cachoeira Paulista-12630-000-SP-Brasil}",
                title = "Estimating the atmospheric water vapor content from multi-filter 
                         rotating shadow-band radiometry at Sao Paulo, Brazil",
              journal = "Atmospheric Research",
                 year = "2004",
               volume = "71",
               number = "3",
                pages = "171--192",
                month = "aug./set.",
             keywords = "solar transmission measurements, near-infrared, atmospheric water 
                         vapor content, aerosol optical depth, atmospheric turbidity, Sao 
                         Paulo, Brazil,molecular spectroscopic database, sun photometer, 
                         differential absorption, precipitable water, optical dept, trace 
                         gases, solar, aerosol, radiation, instrument.",
             abstract = "Selected measurements performed with Multi-Filter Rotating 
                         Shadow-band Radiometers under cloudless conditions at an urban 
                         tropical site, Sao Paulo, Brazil (23.65degreesS, 46.62degreesW, 
                         800 m above the mean sea level) are analyzed. Water vapor content 
                         (U) values are estimated from the analysis of measurements 
                         performed near 940 run with two bandwidths (10 and 3 5 nm). 
                         Narrow- and wide-band measurements performed near 940 nm are 
                         analyzed separately with the help of line-by-line radiative model 
                         computed transmittances, allowing independent (U) over cap (N) and 
                         (U) over cap (W) estimates. The ratio of these measurements is 
                         also analyzed, allowing a third water vapor content estimate (<(U) 
                         over cap>(NW)). Selected approaches for computing water vapor 
                         absorption are compared, including two line parameter databases 
                         and two line-by-line models. After pooling, all results obtained 
                         from measurements performed during 16 cloudless mornings and 
                         representing the water vapor absorption through HITRAN-2000 line 
                         parameters and CKD-2.4 continuum model, estimates (U) over cap 
                         (N), (U) over cap (W), and (U) over cap (NW) were on average 1.8, 
                         0.5, and 4.0 kg m(-2) lower than respective values provided by 
                         balloon-borne soundings, respectively; and (4, estimates were 3% 
                         to 14% smaller than respective (U) over cap (W) values. Assuming 
                         that the independent values provided by soundings are accurate, 
                         the ad hoc reduction of continuum absorption coefficients to 50% 
                         of values provided by CKD-2.4 model improved the reliability of 
                         narrow-band water vapor content estimates in this study. Lastly, 
                         the influence of aerosol extinction on water vapor content was 
                         minimized from the analysis of measurements performed near 870 and 
                         1035 nm. The corresponding turbidity exponent a assumed values 
                         between 0.7 and 1.1, which is somewhat weaker than those usually 
                         reported for urban conditions. (C) 2004 Elsevier B.V. All rights 
                         reserved.",
           copyholder = "SID/SCD",
                 issn = "0169-8095",
             language = "en",
           targetfile = "Plana-Fattori_Estimating_.pdf",
        urlaccessdate = "05 maio 2024"
}