PROPHET is a collaborative research program aimed at improving our understanding of gas phase and heterogenous oxidant chemistry, the exchange of gases and particulate matter between the biosphere and the atmosphere, and how forest-atmosphere interactions influence the composition of the atmosphere.

Initial PROPHET science goals focused on the role of reactive oxidized nitrogen in determining oxidant formation and distributions near the surface, how that nitrogen is processed in the atmosphere, and how emissions from the biosphere may influence tropospheric nitrogen chemistry.  We have been working to understand the role of biogenic hydrocarbon emissions on the distribution of nitrogen containing compounds since the inception of PROPHET.  Descriptions of these efforts can be found via the publications link. An overview paper can be viewed HERE.

As a result of our work to date, attention has turned to a focus on biosphere-atmosphere interactions. While it is well known that nitrogen is a critically important nutrient to plants, the relative role of atmospheric deposition as a source of this nitrogen, and the importance of the nature of atmospheric nitrogen is much less well defined. Specifically, we wish to understand:

  1. how the forest and its emissions influence the processing of atmospheric nitrogen (NOx)
  2. how this in turn influences rates and speciation of nitrogen deposition to the forest canopy and soil
  3. how the fate of that deposited nitrogen influences rates of photosynthesis and thus carbon uptake.

Organization and Infrastructure

A critical component of PROPHET is its laboratory location within the University of Michigan Biological Station (UMBS) near Pellston, Michigan just 15 miles south of the Macinac bridge on the shores of Douglas Lake. The PROPHET laboratory is located in a recently undisturbed and well-characterized mixed deciduous/coniferous forest 3 km southwest of the UMBS site. The Tower laboratory sits at the base of a 31 meter walk-up scaffolding tower, attached to which is a Pyrex sampling manifold that extends to 34 meters above the surface.

Associated with the PROPHET program and tower is the AmeriFlux tower, situated ~100 meters to the northeast.  At this tower, measurements of fluxes of heat, water vapor, CO2, and isoprene have been conducted since 1998.UMBS provides access to laboratory facilities, living and dining facilities, a lecture hall, library, and computer laboratories. UMBS research facilities include a soil biotron, a stream laboratory, chambers for studying  growth and trophic level effects, and sites instrumented for continuous measurements of UV-B and wet and dry deposition.  These facilities and the associated AmeriFlux research provide remarkable opportunities for effective collaboration between atmospheric and biological researchers, and facilitates the study of biosphere-atmosphere interactions that represents the current research focus of PROPHET. PROPHET has three Directors who are part of a larger Steering Committee. Additional input regarding the long term direction, funding mechanisms, etc., is obtained through interaction with the PROPHET Science Advisory Committee.

Click here to download a pdf file describing PROPHET