Portal de Periódicos da CAPES

Photosynthetic Control of Atmospheric Carbonyl Sulfide During the Growing Season

2008; American Association for the Advancement of Science; Volume: 322; Issue: 5904 Linguagem: Inglês

10.1126/science.1164015

1095-9203

J. Elliott Campbell, Gregory R. Carmichael, Tianfeng Chai, M. Mena‐Carrasco, Youhua Tang, D. R. Blake, N. J. Blake, S. A. Vay, G. J. Collatz, Ian Baker, Joseph A. Berry, S. A. Montzka, Colm Sweeney, J. L. Schnoor, Charles O. Stanier,

Plant responses to elevated CO2

Climate models incorporate photosynthesis-climate feedbacks, yet we lack robust tools for large-scale assessments of these processes. Recent work suggests that carbonyl sulfide (COS), a trace gas consumed by plants, could provide a valuable constraint on photosynthesis. Here we analyze airborne observations of COS and carbon dioxide concentrations during the growing season over North America with a three-dimensional atmospheric transport model. We successfully modeled the persistent vertical drawdown of atmospheric COS using the quantitative relation between COS and photosynthesis that has been measured in plant chamber experiments. Furthermore, this drawdown is driven by plant uptake rather than other continental and oceanic fluxes in the model. These results provide quantitative evidence that COS gradients in the continental growing season may have broad use as a measurement-based photosynthesis tracer.