Póster elaborado para la European Geosciences Union General Assembly celebrada los días 22-27 de abril de 2012 en Viena. ; The research was partially supported by European Union 7th Framework Programme (FP7/2007-2013) under grant agreement no. 212095 (CityZen) in the frame of the BOLCHEM model development activity. This research has also been partly funded by the Spanish Ministry of Education and Science (project CGL2009-12797- C03-03). The GR35/10 program (supported by Banco Santander and UCM) has also partially financed this work through the Research Group "Micrometeorology and Climate Variability" (nº 910437).
Near-monochromatic gravity waves (GWs) associated with a mesoscale convective system (MCS) were detected during the Boundary Layer Late Afternoon and Sunset Turbulence (BLLAST) field campaign in Lannemezan (France) on 21 June 2011. These GWs are analyzed using available instrumental data (e.g. an array of microbarometers, a microwave system Humidity And Temperature PROfiler (HATPRO) and an ultra-high-frequency (UHF) wind profiler). Pressure oscillations of up to 0.5 hPa were recorded after a pronounced pressure drop of 1.4 hPa, identified as the MCS weak low. Wavelet analysis and evaluated wave parameters confirm the occurrence of such GWs (period ∼9 min, horizontal wavelength ∼7 km), which propagated from southwest to northeast, i.e. in the same direction of propagation as the MCS. Observational evidence suggests the downdraughts associated with the rear-inflow jet at the weak low zone of the MCS as the most likely generator mechanism of the GWs. However, the complex orography and proximity of the Pyrenees to the field campaign could also play an important role. Wave propagation was possible through the ducting mechanism, favoured by the existence of a critical level in a wind-sheared environment around 2000 m above ground level. Wave-like motions related to the passage of the GWs were also observed in other atmospheric parameters close to the surface and within the lower troposphere. The effects of GWs on the surface fluxes have also been analyzed through Multi-Resolution Flux Decomposition (MRFD) methods. ; This research has been funded by the Spanish Government (projects CGL2009-12797- C03-03, CGL2011-13477-E and CGL2012-37416-C04-02). The tower equipment and UHF radar have been supported by CNRS, University of Toulouse and European POCTEFA FluxPyr program and FEDER program (Contract 34172 – IRENEA – ESPOIR). The edge-site measurements were financed by the DFG (Deutsche Forschungsgemeinschaft) project GR2687/3-1 and SCHU2350/2-1.
Póster presentado en: EGU General Assembly celebrada del 23 al 28 de abril de 2017 en Viena, Austria. ; This research has been partially funded by the Spanish Government (MINECO projects CGL2015-65627-C3-3-R and CGL2012-37416-C04-02) and by the GR3/14 program (supported by UCM and Banco Santander) through the Research Group "Micrometeorology and Climate Variability" (No.910437).
