David
Roy
Fitzjarrald, Jungle Research Group, ASRC, UAlbany, SUNY, fitz@asrc.cestm.albany.edu
(Presenting)
Ricardo
Kendi
Sakai, Jungle Research Group, ASRC, UAlbany, SUNY, sakai@asrc.cestm.albany.edu
Osvaldo
Luiz Leal de
Moraes, Dept. de Física, Universidade Federal de Santa Maria, RS, moraes@mail1.ufsm.br
Matthew
J.
Czikowsky, Jungle Research Group, ASRC, UAlbany, SUNY, matt@asrc.cestm.albany.edu
Acevedo
Otavio
C., Dept. de Física, Universidade Federal de Santa Maria, RS, otavio@smail.ufsm.br
Raimundo
Cosme de
Oliveira Jr., Embrapa Amazônia Oriental,, cosme@cpatu.embrapa.br
Characteristics of the LBA Santarém study area might introduce a bias in the ecosystem productivity estimates. In the Santarém study areas, the tall flux towers, for example, are located in a thin area of forest sandwiched between cleared lands and near to large rivers that are known to influence cloudiness and alter winds in their proximity. The mesoclimate of the region must be understood before results regarding net forest carbon uptake can be generalized.
To understand radiation, rainfall and temperature anomalies led to the development of a network of eight surface weather stations. Each station was upgraded by CD-03 to include a GPS receiver that keeps track of time, a barometer, and soil temperature and moisture sensors. Meteorological measurements made at the three flux towers complete the network.
Results for the first six years of data will be discussed. We find that that temperature and precipitation are higher and wind speed is lower during the LBA-ECO years compared to the recent past. The daily averaged wind speed at Santarém correlates well with the observed Belém-Santarém surface pressure difference. From composite data we deduce the river breeze pressure gradient forcing, identify double diurnal peaks in precipitation and specific humidity, and discuss recent interannual variability. The precipitation peak in the early morning hours is consistent with previous studies of propagating squall line circulations from the Atlantic coast. Nocturnal flows following local topographic gradients are seen, including the terral along the Tapajós River identified by Bates in 1864.