‘Estimating ecosystem respiration from flux tower and chamber data: insights from Cumberland Plain'
Dr Peter Isaac
Prof. Elise Pendall
Recent work using TERN data to explore the temperature response of ecosystem Gross Primary Productivity (GPP) showed that there was a high level of noise in GPP at some TERN OzFlux monitoring sites, most notably at the TERN Cumberland Plain Woodland SuperSite. Additionally, two methods of estimating Ecosystem Respiration (ER) gave opposite temperature responses. A further puzzle, possibly related, was the poor performance of friction velocity (u*) threshold detection techniques at this site. Examination of spectra, cospectra and the quality control of the flux data led to a significant reduction in the noise of the CO₂ flux data and a consequent improvement in the processed results.
This talk uses the experiences at the Cumberland Plain Woodland SuperSite to explore methods of improving the quality of TERN OzFlux data and indicators of data quality. It also provides insight into the uncertainty inherent in data partitioning techniques. Reducing this uncertainty has contributed to a better understanding of the sensitivity of Australian ecosystems to climate warming.