02303naa a2200265 a 450000100080000000500110000800800410001910000160006024501220007626000090019852015620020765000130176965000130178265300280179570000160182370000210183970000140186070000130187470000140188770000140190170000150191570000200193070000160195077300710196620830842021-12-22       2017    bl uuuu     u00u1 u    #d1 aCHOR, T. L.  aFlux-variance and flux-gradient relationships in the roughnesssublayer over the Amazon forest.h[electronic resource]  c2017  aThe failure of the Monin?Obukhov Similarity Theory (MOST) in the roughness sublayer is a major prob-lem for the estimation of fluxes over tall forests, whenever indirect methods that rely on MOST, suchas flux-gradient or the variance method, are involved. While much research focuses on micrometeoro-logical measurements over temperate-climate forests, very few studies deal with such measurementsover tropical forests. In this paper, we show evidence that some similarity functions over the Amazonforest are somewhat different from temperate forests. Comparison of the nondimensional scalar gradi-ents canonical values for the inertial sublayer with our measurements in the roughness sublayer showedsmaller deviations than what is usually reported for temperate forests. Although the fluxes of watervapor and CO2derived from mean profiles show considerable scatter when compared with the eddycovariance measurements, using calibrated dimensionless gradients it is possible to estimate their meandaily cycle during the period of measurement (36 days in May and June, transition between rainy anddry season). Moreover, since mean ozone profiles were available, although without the correspondingeddy covariance measurements, mean daily ozone fluxes were calculated with the flux-gradient method,yielding a nighttime value of −0.05 and a daily peak of −0.45μgm−2s−1 (−1.04 and −9.37nmolm−2s−1, respectively). These values are comparable to previously measured fluxes in the literature for the Amazonforest.  aAmazonia  aFloresta  aSubcamada de rugosidade1 aDIAS, N. L.1 aARAUJO, A. C. de1 aWOLFF, S.1 aZAHN, E.1 aMANZI, A.1 aTREBS, I.1 aSÁ, M. O.1 aTEIXEIRA, P. R.1 aSÖRGEL, M.  tAgricultural and Forest Meteorologygv. 239, p. 213-222, May 2017.