Spectral analysis of ship-based eddy covariance data

• Main Author: Rui, Zhang
• Other Authors: Thomas, Gabriel (Electrical and Computer Engineering) Papakyriakou, Tim (Environment and Geography), Cai, Jun (Electrical and Computer Engineering) Ehn, Jens (Environment and Geography)
• Format: Master Thesis
• Language: English
• Published: 2016
• Subjects: Eddy covariance; Spectral analysis; Motion correction; Flow distortion; Arctic; Breaker; Canadian Arctic Archipelago; Arctic Archipelago
• Online Access: http://hdl.handle.net/1993/31743

Because of complications associated with ship motion and airflow distortion, eddy covariance (EC) from ships has not seen widespread application. In 2011, high frequency (10 Hz) measurements of three-dimensional wind velocity, temperature, CO2 and humidity and slow response sensors recording air temperature, humidity, wind speed/direction, surface temperature were deployed on a tower installed on the foredeck of the research ice breaker CCGS Amundsen to characterize the surface fluxes within the Canadian Arctic Archipelago. The ensemble averaged co-spectra for wind, temperature and CO2 showed general agreements evaluated against theoretical curves (Kaimal et al. 1972). Port- and starboard-side co-spectra appear to follow the theoretical curves while an over-estimation was seen at high frequencies for winds coming over the bow. Fluxes were also compared against modern parameterizations for CO¬2, heat and momentum exchange for open water environments. The range of EC momentum and sensible fluxes looks reasonable while CO2 flux exhibits uncertainties. October 2016