Journal Article
Atmospheric Measurement Techniques, vol. 11, iss. 7, pp. 4291-4308, 2018
Authors
Nicola Bodini, Julie K. Lundquist, Rob K. Newsom
Abstract
Abstract. Despite turbulence being a fundamental transport process in the boundary
layer, the capability of current numerical models to represent it is
undermined by the limits of the adopted assumptions, notably that of local
equilibrium. Here we leverage the potential of extensive observations in
determining the variability in turbulence dissipation rate (ϵ).
These observations can provide insights towards the understanding of the
scales at which the major assumption of local equilibrium between generation
and dissipation of turbulence is invalid. Typically, observations of
ϵ require time- and labor-intensive measurements from sonic and/or
hot-wire anemometers. We explore the capability of wind Doppler lidars to
provide measurements of ϵ. We refine and extend an existing method
to accommodate different atmospheric stability conditions. To validate our
approach, we estimate ϵ from four wind Doppler lidars during the
3-month XPIA campaign at the Boulder Atmospheric Observatory (Colorado), and
we assess the uncertainty of the proposed method by data intercomparison
with sonic anemometer measurements of ϵ. Our analysis of this
extensive dataset provides understanding of the climatology of turbulence
dissipation over the course of the campaign. Further, the variability in
ϵ with atmospheric stability, height, and wind speed is also
assessed. Finally, we present how ϵ increases as nocturnal
turbulence is generated during low-level jet events.
