RING 2

A central barrier preventing the scientific community from understanding the carbon balance of the continent is methodological; it is technically difficult to bridge the gap in spatial scales that exists between the detailed understanding of ecological processes that can be gathered via intensive local field study, and the overarching but mechanistically poor understanding of the global carbon cycle that is gained by analyzing the atmospheric CO2 budget. The NACP’s Midcontinental Intensive (MCI) study seeks to bridge this gap by conducting a rigorous methodological test of our ability to measure the terrestrial carbon balance of the upper Midwest. A critical need in bridging this gap is increased data density.

Our work adds a regional network of five communications-tower based atmospheric CO2 observations from April 2007 through October 2008 to the planned long-term atmospheric CO2 observing network (tall towers, aircraft profiles, and well-calibrated CO2 measurements on AmeriFlux towers) in the midcontinent intensive region. A primary goal of the project is to increase the regional atmospheric CO2 data density so that 1) atmospheric inversions can derive well-constrained regional ecosystem carbon flux estimates and 2) the trade off between data density and accuracy of the flux estimates can be determined quantitatively using field observations, thus providing guidance to future observational network designs.

This work builds upon the success of the first ring of towers, deployed as part of the ChEAS in northern Wisconsin. We present results from this first ring, in addition to observation and analysis plans for the second ring.