Airborne Laboratory for Atmospheric Research
We have developed the capability to routinely measure the fluxes of greenhouse gases using our light aircraft with particular focus on CO2 and H2O over forested environments using cavity ring-down spectroscopy (CRDS) and standard eddy covariance technique. Fossil fuel emissions of CO2 and CH4 from Indianapolis are also quantified using a combination of flask measurements, CRDS, and a mass balance approach. In flight calibrations for CO2 and CH4 are conducted using our computer-controlled calibration system and three reference cylinders from NOAA.
Real-time (50Hz) vertical wind data is measured using the BAT probe developed by Crawford et al., Bound. Lay. Meteor, 1992. The vertical wind data is complemented by aircraft altitude measurements using an inertial navigation system and Global Positioning System. A set of wind tunnel and in-flight experiments were used to calibrate and characterize the vertical wind system to minimize systematic errors caused by airflow measurements that depart from a commonly used theoretical potential flow model. The results of these vertical wind studies are published in Garman et al., J. Atmos. Ocean. Tech., 2006.
Highlights of our research conducted on ALAR are as follows:
- Quantification of fossil fuel emissions from Indianapolis, Mays et al., 2009, Env. Sci. Tech.
- Measurement of particle number concentration over the Great Lakes, Slade et al., 2010, GRL.
- Quantification of regional surface fluxes of CO2, Martins et al., 2009, Agr. Forest Meteorol.
- Study of aircraft lift-induced upwash to provide a correction to vertical winds for flux calculations, Garman et al. 2008, Bound. Lay. Meteorol.