Dr. David Nelson

Aerodyne Research, Inc.

Abstract :
We present recent results using Aerodyne laser trace gas monitors to address important measurement challenges in trace gas exchange between the atmosphere and the Earth’s surface. Aerodyne laser monitors are designed for fast time response (0.1 seconds when required) and for extremely high measurement precision for a wide variety of greenhouse gases and particle precursor gases. These capabilities enable sensitive and specific gas flux measurements using a variety of techniques: eddy covariance, surface chamber and gradient flux methods, for example. These flux measurements are critical for understanding biosphere- atmosphere interactions and for studying air pollution generated by human activities. We will present recent results involving a wide variety of molecules: N2O, CH4, CO, COS, NH3 , HCHO, HONO, NO, NO2 and the isotopes of carbon dioxide. We will also discuss a variety of measurement techniques including automated sampling systems that use one laser monitor to perform several tasks. For example, one trace gas monitor can perform tower profile measurements, surface chamber flux measurements and eddy flux measurements on an automated, but intelligent and flexible schedule.