## 2 Materials and Methods
### Database  
The database of meteorological, energy and CO\({}_{2}\) fluxes, as well as satellite data, covers the period from 1 January 2005 to 31 December 2008. The data analyzed in this study were collected from an automatic weather station (Table 1) belonging to the Large Scale Biosphere-Atmosphere Program (LBA), installed in a 52 m-high micrometeorological observation tower. Precipitation (PRP) was measured by a Campbell TB3/TB4 (CS700, Campbell Scientific, Leicester, UK) rain gauge. Air temperature (Tar) measurements were obtained using Campbell's HMP45 AC device (Campbell Scientific, Leicester, UK). The GPP was estimated from CO\({}_{2}\) flux data measured in situ, following the methodology of [PERSON] et al. (2007), with eddy covariance data measured from a Licor 7500 Open Path CO\({}_{2}\)/H\({}_{2}\)O Analyzer (LICOR, Lincoln, NE, USA), which works in conjunction with a Gill instruments 3D input unic sonic anemometer (Solent, Gill Instruments, Lymington, UK). All the inherent corrections of the eddy covariance method (such as coordinate rotation correction using the planar fit method, sonic virtual temperature correction, corrections for \begin{table}
\begin{tabular}{c c} \hline \hline
**Measurements/Sampling Rate/Averaging Period/Spatial Resolution** & **Data Source** \\ \hline Direction (\({}^{\circ}\)) and Wind Speed (m/s); Eddy Covariance: Turbulent & Three-dimensional sonic anemometer (Solent, Gill Instruments, \\ Fluxes of Latent Heat (W m\({}^{-2}\)), Sensible Heat (W m\({}^{-2}\)) and CO\({}_{2}\) & Lymington, UK); Li-750 infrared gas analyzer (LICOR, Lincoln, \\ (umol m\({}^{-2}\) s\({}^{-1}\))/5 Hz/30 min/55 m. & NE, USA) \\ \hline Incident and Reflected Photosynthetically Active Radiation & Skye quantum sensor (Skye Instruments, Powys, UK) \\ (umol m\({}^{-2}\) s\({}^{-1}\))/1 min/30 min/52 m. & \\ \hline Radiation Balance (W m\({}^{-2}\))/1 min/30 min/45.5 m. & 1 radiometer balance (CNR1, Kipp \& Zonen, Delft, The Netherlands) \\ \hline Temperature (\({}^{\circ}\)C) and Relative Humidity (\%)/1 min/30 min/53 m. & HMP45 AC (Campbell Scientific, Leicester, UK) \\ \hline Rainfall (mm)/1 min/30 min/53 m. & Bucket rainfall gauge (CS700, Campbell Scientific, Loughborough, UK) \\ \hline MODIS GPP (g C m\({}^{-2}\) day\({}^{-1}\))/8 days/500 m. (mean in 8 days) & MOD17A2H-MODIS/Terra Gross Primary Productivity \\ \hline NDVI and EVI/16 days/250 m. (mean in 16 days) & MOD13 QI-MODIS/Terra Vegetation Indices \\ \hline LAI/8 days/500 m. (mean in 8 days) & MCD15A2H-MODIS/Terra + Aqua \\ \hline \hline \end{tabular}
\end{table} 
Table 1: List of variables, measuring instruments and measuring units involved in the study (Source: LBA project and NASA). Figure 1: Location of the micrometeorological tower in the Caxiuaná-PA forest, with a view of the base of the installed tower and the temperature and humidity sensor at the top of the tower. density fluctuation (WPL-correction), and frequency response correction) for estimating energy and CO\({}_{2}\) fluxes, the complete instrumentation of the tower, and the gap filling method for missing data are described in previous publications [1; 49; 55; 57]. The information generated from the gas analyzer/sonic anemometer set was used to determine the flows and concentration of CO\({}_{2}\) at the ecosystem level, and this information was recorded on a data storage device (iPAQ). The evapotranspiration (\(ET\)) of the site was estimated using latent heat (Equation (1) [7]):  
\[ET=86\text{,}400\cdot\frac{LE}{L} \tag{1}\]  
where L (J kg\({}^{-1}\)) = 103 \(\times\) (2500 \(-\) 2.37 \(\times\) Ta), LE is the latent heat flux, and 86,400 is the daily integration factor. The flux density of an atmospheric variable is estimated on the concept that the turbulent flow of this magnitude is calculated by its covariance with the vertical component of the wind speed.