Microtopography Determines How CO2 and CH4 Exchanges Respond to Temperature and Precipitation in Polygonal Tundra

December 21st, 2017
The Science: 

Polygon microtopography affects CO2 and CH4 emissions, but landscape scaling of polygon types accurately represents landscape exchanges with the atmosphere. Much of the spatial and temporal variations in CO2 and CH4 fluxes were driven from topographic effects on water and snow movement

The Impact: 

We demonstrated excellent agreement between modeled and observed CH4 and CO2 fluxes (Figure) and the relevant biogeochemical, hydrological, and thermal controlling processes. Our results imply needed improvements to the DOE E3SM land model (ELMv1-ECA), which we are pursuing.

Summary: 

Using observations and three-dimensional modeling with ecosys, we quantified and scaled the effects of microtopography on biogeochemistry, hydrology, and plant processes and thereby CO2 and CH4 exchanges with the atmosphere.

Ecosys accurately represented eddy covariance measured surface (b) CO2 and (c) CH4 emissions when scaled from individual polygons to the landscape.

Contacts: 

William J. Riley

Lawrence Berkeley National Laboratory, wjriley@lbl.gov