A Profiling System in Amazonia with Automatic Calibration based on the CIRAS-SC Analyzer
Amazonia constitutes a large global store of carbon. Forest conversion in Amazonia is a net source of carbon to the atmosphere, while recent measurements indicate that undisturbed forest systems may be a net carbon sink. The importance of sequestration of carbon in regrowing forest and abandoned lands is unclear. These issues represent uncertainties in the global carbon balance and may influence the carbon dioxide concentration of the atmosphere and thus interact with the climate system. How will changes in land use affect the net carbon balance between terrestrial ecosystems and atmosphere, and do undisturbed forest ecosystems function as net carbon sink? What are the sizes of the carbon pools in the vegetation and soils of intact, secondary and selectively-logged forests, savannas, and agricultural lands? What are the net rates of carbon exchange between the atmosphere, vegetation and soil, and how are the size of the pools and the rates of exchange altered by natural and human disturbances?
One of the systems used to collect data to achieve some answers is a profile system with automatic calibration using a CIRAS-SC analyzer, assembled by LIM (Meteorological Instrumentation Laboratory) from CPTEC-INPE based on Alterra/Wageningen system. In this system, there are six measurement levels selected through solenoid valves in a normal operation. The selected level is connected to a pump which flushes the tubing and to the CIRAS-SC through a 2 way valve. The CIRAS-SC pumps an air sample continuously with its internal pump at 100 ml/min letting the excess flow away to the atmosphere through the Nafion (Perma-Pure) humidifier to assure that the CIRAS-SC pump works properly and does not get damaged.