@Article{SimonLAGRMNAK:2005:LaDiRn,
               author = "Simon, E. and Lehmann, B. E. and Ammann, C. and Ganzeveld, L. and 
                         Rummel, U. and Meixner, F. X. and Nobre, Antonio Donato and 
                         Araujo, A. and Kesselmeier, J.",
          affiliation = "Max Planck Inst Chem, Biogeochem Dept, D-55020 Mainz, Germany and 
                         Univ Bern, Inst Phys, CH-3012 Bern, Switzerland and Swiss Fed Res 
                         Stn Agroecol \& Agr, Zurich, Switzerland and Max Planck Inst 
                         Chem, Atmospher Chem Dept, D-55128 Mainz, Germany and Meteorol 
                         Observ Lindenberg, Deutsch Wetterdienst, Lindenberg, Germany and 
                         Biogeochemistry Department, Max Planck Institute for Chemistry, 
                         P.O. Box 3060, D-55020 Mainz, Germany and Instituto Nacional de 
                         Pesquisas Espaciais, Divis{\~a}o de Processamento de Imagens 
                         (INPE, DSR) and Faculty of Earth Sciences, University Amsterdam, 
                         Netherlands and Biogeochemistry Department, Max Planck Institute 
                         for Chemistry, P.O. Box 3060, D-55020 Mainz, Germany",
                title = "Lagrangian dispersion of Rn-222, H2O and CO2 within Amazonian rain 
                         forest",
              journal = "Agricultural and Forest Meteorology",
                 year = "2005",
               volume = "132",
               number = "3 -4",
                pages = "286--304",
                month = "OCT",
             keywords = "canopy layer turbulence, first-order closure, Lagrangian 
                         simulation model, nocturnal processes, rain forest, radon / 
                         ATMOSPHERIC BOUNDARY-LAYERS, NET ECOSYSTEM EXCHANGE, MODEL-PLANT 
                         CANOPY, DOUGLAS-FIR FOREST, CARBON-DIOXIDE, TROPICAL FOREST, 
                         TURBULENCE STATISTICS, SOURCE DISTRIBUTIONS, VEGETATION CANOPIES, 
                         SCALAR DISPERSION.",
             abstract = "The present study focuses on the description of the vertical 
                         dispersion of trace gases within the Amazon rain forest. A 
                         Lagrangian approach is parameterised using in-canopy turbulence 
                         measurements made at a site in Rondonia (Reserva Jaru). In 
                         contrast to common scaling schemes that solely depend on friction 
                         parameters measured above the canopy, a combined scaling that also 
                         includes night-time free convective mixing in the lower part of 
                         dense vegetation canopies is proposed here. Rn-222 concentration 
                         profiles and soil flux measurements made at a second site near 
                         Manaus (Reserva Cuieiras) are used to evaluate the derived 
                         parameterisation and the uncertainties of the forward (prediction 
                         of concentration profiles) and inverse (prediction of vertical 
                         source/sink distributions) solution of the transfer equations. 
                         Averaged day- and night-time predictions of the forward solution 
                         agree with the observations within their uncertainty range. During 
                         night-time, a weak, but effective free convective mixing process 
                         in the lower canopy ensures a relatively high flushing rate with 
                         residence times of <1 h at half canopy height in contradiction to 
                         earlier estimates for Amazon rain forest. The inverse solution for 
                         Rn-222 source/sink distributions shows a high sensitivity to small 
                         measurement errors, especially for daytime conditions, when there 
                         is efficient turbulent mixing in the upper canopy and profile 
                         gradients are small. The inverse approach is also applied to CO2 
                         and H2O profiles. The predicted net fluxes show a reasonable 
                         agreement with Eddy Covariance (EC) measurements made above the 
                         forest canopy, although the scatter is large and the day-time 
                         solutions for CO2 are very sensitive to measurement errors. 
                         However, this is not the case for typical night-time conditions, 
                         where the CO2 profile gradients in the upper canopy are large. The 
                         inverse approach predicts a mean CO2 emission flux of 7.5 mu mol 
                         m(-2) s(-1) for the investigation period. This value is somewhat 
                         larger compared to estimates based on EC measurements, which are 
                         quite uncertain at night-time and thus reduces the upper bound of 
                         the estimated carbon sink strength for Amazonian rain forest. (c) 
                         2005 Elsevier B.V. All rights reserved.",
                 issn = "0168-1923",
             language = "en",
        urlaccessdate = "12 maio 2024"
}