A study of wave-modified turbulence in the stable boundary layer through wavelet analysis

Gravity waves and turbulence are often intermixed throughout the stable boundary layer and together they play an integral role in atmospheric dynamics. This paper reports on a climatological case study of wave-like disturbances and their impact on nocturnal boundary layer turbulence above a forest canopy. Atmospheric turbulence and flux measurements at three levels were made on a tall tower at the Savannah River AmeriFlux Site in Aiken, SC. Wave events were selected from April 2009 to February 2010 to identify the frequency of these waves as a function of season. Attention is also given to the behavior of these disturbances as a function of height on the tall flux tower. The use of different averaging times is also examined. The inflation percentage at the 34m measurement height was roughly 10%, 18% at the 68m height, while at 329m the value was as a much as 25%. As in the companion study of Durden (2013), our results further suggest that the presence of waves leads to substantial errors in the determination of important micrometeorological parameters such as friction velocity and atmospheric stability.