RT Journal Article
T1 Interactions among drainage flows, gravity waves and turbulence: a BLLAST case study
A1 Román Cascón, Carlos
A1 Yagüe Anguis, Carlos
A1 Mahrt, Larry
A1 Sastre Marugán, Mariano
A1 Steeneveld, Gert Jan
A1 Pardyjak, E.
A1 Boer, A. van der
A1 Hartogensis, O.
AB The interactions among several stable-boundarylayer (SBL) processes occurring just after the evening transition of 2 July 2011 have been analysed using data from instruments deployed over the area of Lannemezan (France) during the Boundary Layer Late Afternoon and Sunset Turbulence (BLLAST) field campaign. The near-calm situation of the afternoon was followed by the formation of local shallow drainage flows (SDFs) of less than 10m depth at different locations. The SDF stage ended with the arrival of a stronger wind over a deeper layer more associated with the mountain-plain circulation, which caused mixing and destruction of the SDFs. Several gravity-wave-related oscillations were also observed on different time series. Wavelet analyses and wave parameters were calculated from high resolution and accurate surface pressure data of an array of microbarometers. These waves propagated relatively long distances within the SBL. The effects of these phenomena on turbulent parameters (friction velocity and kinematic heat flux) have been studied through multi-resolution flux decomposition methods performed on high frequency data from sonic anemometers deployed at different heights and locations. With this method, we were able to detect the different time-scales involved in each turbulent parameter and separate them from wave contributions, which becomes very important when choosing averaging-windows for surface flux computations using eddy covariance methods. The extensive instrumentation allowed us to highlight in detail the peculiarities of the surface turbulent parameters in the SBL, where several of the noted processes were interacting and producing important variations in turbulence with height and between sites along the sloping terrain.
PB Copernicus
SN 1680-7316
YR 2015
FD 2015-08-14
LK https://hdl.handle.net/20.500.14352/93520
UL https://hdl.handle.net/20.500.14352/93520
LA eng
NO Román-Cascón, C., Yagüe, C., Mahrt, L., Sastre, M., Steeneveld, G.-J., Pardyjak, E., van de Boer, A., and Hartogensis, O.: Interactions among drainage flows, gravity waves and turbulence: a BLLAST case study, Atmos. Chem. Phys., 15, 9031–9047, https://doi.org/10.5194/acp-15-9031-2015, 2015.
NO Gobierno de España
NO Institut National des Sciences de l'Univers, Centre national de la Recherche Scientifique (France)
NO Meteo-France
NO Observatoire Midi-Pyrenees (University of Toulouse)
NO European Facility for Airborne Research
NO European Cooperation in Science and Technology 
NO European Commission
NO Centre National de la Recherche Scientifique (Francia)
NO German Research Foundation
NO Netherlands Organization for Scientific Research 
DS Docta Complutense
RD 6 abr 2025