Campaign Dates: 07/01/2016 – 08/01/2016

Atmospheric models lack the ability to reproduce observations seen over forested environments, preventing us from predicting the impact biogenic emissions have on the atmosphere. It is only through improving our understanding of this important chemistry that we will be able to better foresee how these emissions will change in the future as a result of forest succession and climate change.

PROPHET is a multi-year investigation that has studied the relationships of atmospheric nitrogen, ozone and forest-atmosphere interactions. This year’s study hopes to bring scientific collaborators with a range of instruments and expertise to better understand the sources, sinks and cycling of important radicals (HOx) and oxidation products in order to help better constrain current models.

In particular, the Wennberg group built a high resolution gas chromatotograph coupled with a time-of-flight chemical ionization mass spectrometer (GC-HR-ToF) through the support of NSF’s Major Research Instrumentation program. Sitting at approximately 30 m atop the PROPHET tower, we obtained data that will allow us to determine the flux rate of important oxygenated volatile compounds between the atmosphere and forest canopy. Additionally, in situ isomer distributions of isoprene oxidation products were observed for the first time in the field, allowing us to test our current understanding of isoprene photooxidation and providing new insight into the fate and importance of these particular biogenic compounds.