Recovery strategies for fluxes affected by the Gill-Solent WindMaster-Pro "w-boost" firmware bug
Abstract
In late 2015 and early 2016, work done by the AmeriFlux Tech Team helped to uncover a bug in the Gill WindMaster Pro sonic anemometers used by many researchers for eddy covariance flux measurements. Gill has addressed this issue and has since sent out a notice that the vertical wind speed component (a critical piece of all eddy covariance fluxes) was being erroneously computed and reported. The problem (known as the w-boost bug) resulted in positive (upward) wind speeds being under-reported by 16.6% and negative (downward) wind speeds being under-reported by 28.9%. This has the potential to cause similar underestimates in fluxes obtained from these instruments. While the manufacturer has offered a firmware upgrade to fix this bug, there exist many data sets that have already been affected by it. Researchers who use the affected units have contributed to numerous data archives (AmeriFlux, FluxNet, ICOS, etc.), and third-party scientists have, in turn used these data in many types of research projects. The volume of affected data over such a long period of time makes a complete reprocessing of the raw data sets impractical. To address this, the AmeriFlux Tech Team has endeavored to develop a method of correcting affected fluxes using only the downloadable data sets that are available from these archives. In a previous poster, we reported preliminary results from a pair of Arctic tundra flux towers, and showed that fluxes could be underestimated by 15% to 20%. In this poster, we present results that extend our study to include a forested site in Equatorial Africa. We also have evaluated methods to estimate flux errors without accessing the raw data sets.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2017
- Bibcode:
- 2017AGUFM.B21E1986B
- Keywords:
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- 0414 Biogeochemical cycles;
- processes;
- and modeling;
- BIOGEOSCIENCES;
- 0426 Biosphere/atmosphere interactions;
- BIOGEOSCIENCES;
- 0428 Carbon cycling;
- BIOGEOSCIENCES;
- 0452 Instruments and techniques;
- BIOGEOSCIENCES