Is the data collection period of the large-scale biosphere-atmosphere experiment in amazonia representative of long-term climatology?

Abstract

The Large-Scale Biosphere-Atmosphere Experiment in Amazonia (LBA) sampled surface-atmosphere flux exchanges and related ecohydrometeorological processes at several flux tower sites in the Amazonian region between 1999 and 2006. This extensive database is now being analyzed to investigate, for example, the carbon balance of the Amazon basin and the effect of land use change in the basin on climate. It is therefore important to establish whether the period during which these data were collected is representative of the long-term climatology for the region. This study analyzed long-term climate station data for stations located nearby the LBA eddy flux tower sites. Measurements taken during the period of data collection were compared with the longterm station climatology using the Kolmogorov-Smirnov test and analysis of histogram from random samples from the long-term climatological, record. In terms of precipitation, the LBA data collection period is statistically consistent with the climatology for all LBA study sites. In terms of temperature, the same result is true for most flux station sites; the main exception being the Bananal Island site where the temperature during the LBA period is significantly warmer by about 10C. There were some short periods when temperature in the region of other LBA flux sites was also statistically different (higher) during the LBA data collection period and an average but not statistically significant tendency toward higher temperatures across the whole region during the LBA period relative to previous years. This is probably because there has been significant land cover change near some of the LBA study sites, but a contribution from climate warming cannot be ruled out. Copyright 2008 by the American Geophysical Union.