Aircraft flux measurements during FIFE and BOREAS
Desjardins, R.L., MacPherson, I., Schuepp, P.H., Worth, D.E., Pattey, E. 2016. Aircraft flux measurements during FIFE and BOREAS. How FIFE and BOREAS changed the world Goddard Space Flight Center Greenbelt 2016/10/06 - 2016/10/07.
Résumé en langage clair
The First International Satellite Land Surface Climatology Project (ISLSCP) Field Experiment (FIFE) and Boreal Ecosystem Atmosphere Study (BOREAS) projects were large-scale interdisciplinary research studies that attempted to improve our understanding of the exchange of mass (e.g. carbon dioxide) and energy (e.g. temperature) between the land surface and the atmosphere. In this presentation, we demonstrate how aircraft-based measurements conducted during these projects have been valuable in improving flux measurements and will continue to be a valuable source of data for scientific research for years to come. In particular, this research has contributed to the development of the ‘source-area footprint’ concept, which tries to relate an area on the ground, with a measured flux. Further, long distance aircraft-based flux measurements have been important in determining the low-frequency or long-wavelength to the flux. Based on results obtained during FIFE and BOREAS, recommendations for future aircraft-based measurements are provided.
Aircraft flights conducted during FIFE and BOREAS contributed substantially to our understanding of flux measurements, and flux measuring systems. These flights allowed for the testing of strengths and weaknesses of different measurement approaches to be used with the eddy covariance method and were critical in the development of the footprint concept for relating fluxes of mass and energy to a source area. Long-transect flights conducted during FIFE and BOREAS have also proved to be useful in explaining the importance of mesoscale transfer on the lack of energy budget closure typically observed by eddy covariance. Further, these experiments have provided a database of integrated observations which are essential for understanding and modeling land-atmosphere interactions, as well as for the development of environmental response functions. This database will continue to sustain high-value research for many years to come. Based on results obtained during FIFE and BOREAS, it is recommended that for future aircraft-based studies as a part of large-scale projects, fewer tower/aircraft inter-comparisons be conducted, and instead that there be more of a focus on budget studies, and that that taking repeated measurements over long transects represents the best way to capture spatial and temporal variability, as well as to incorporate all frequency scales.