Research Highlight:
ARL Participating in Ammonia Flux Experiment at Duke Forest

Air Resources Laboratory (ARL) scientists will contribute their expertise to the final phase of the U.S. Department of Agriculture (USDA) Ammonia Flux Experiment. The experiment will be held in the Blackwood Division of Duke Forest, NC from June 23 to July 3, 2008. ARL scientists from Headquarters, led by Winston Luke, and the Atmospheric Turbulence and Diffusion Division (ATDD), led by Tilden Meyers, will quantify ammonia fluxes in a forest ecosystem through various real-time and integrated measurement techniques. In addition, a NOAA EPP Undergraduate Scholar, Zakiya Hoyett, will use this experiment as her summer internship experience. ARL’s instrumentation will include gas and particle collection systems; fast-response gas collectors; and supplementary micrometeorological equipment. The ATDD also will take measurements to thoroughly characterize the site vegetation, including leaf area indices.

The USDA Ammonia Flux Experiment is a joint effort between North Carolina State University, U.S. EPA, and NOAA. The overall goal of the project is to measure the net flux and exchange processes of ammonia in forest and agricultural landscapes representative of the eastern U.S. Ammonia emissions from agriculture have increased dramatically in recent years. These emissions influence atmospheric chemistry and, through deposition, can alter soil and water chemistry. Previous phases of the experiment were conducted in 2006 and 2007 over soybean and maize crops, respectively.

This experiment will facilitate the determination of processes which govern the magnitude and temporal variability of ammonia flux. Increased ammonia flux may affect plant development and, in aquatic bodies, promote eutrophication. Data from the different measurement techniques will be compared to identify best practices for ammonia flux measurement.