Comparison of Gradient Flux and Eddy Covariance Approaches
2018 Ocean Sciences Meeting, Portland, Oregon, February 11-16, 2018
he gradient flux (GF) approach quantifies surface fluxes by measuring the mean chemical and velocity gradient in the turbulent boundary layer, and was recently applied to study benthic aquatic fluxes. This approach offers several advantages over the traditional eddy covariance (EC) technique such as less stringent sensing requirements and reduced data processing. However, this approach still needs to be rigorously assessed for its accuracy and its limitations. Here, we compare the protic flux (H+) that was simultaneously measured using the GF and EC approach. Results from two sites will be presented: one from a seagrass meadow in Bermuda, and another from a coral reef terrace in Palmyra Atoll. Each deployment was 3 days long. A modified Honeywell Ion Sensitive Field Effect Transistor (ISFET) with a response time of ~200 ms was used for the EC system. Good agreement between the two approaches was observed, demonstrating that consistent flux measurements can be obtained using either technique. Finally, the pros and cons for each approach will be compared, and future directions will be discussed.
Takeshita, Yuichiro; McGillis, Wade R.; Andersson, Andreas J.; Briggs, Ellen; Cyronak, Tyler; Martz, Todd R.; Price, Nichole; and Smith, Jennifer, "Comparison of Gradient Flux and Eddy Covariance Approaches" (2018). Marine & Environmental Sciences Faculty Proceedings, Presentations, Speeches, Lectures. 568.