scholarly journals Infrasound and Gravity Waves Over the Andes Observed by a Pressure Sensor on Board a Stratospheric Balloon

2020 ◽  
Vol 125 (6) ◽  
Author(s):  
Guerman Poler ◽  
Raphaël F. Garcia ◽  
Daniel C. Bowman ◽  
Léo Martire
Keyword(s):  
Gravity Waves ◽  
Pressure Sensor ◽  
The Andes ◽  
Stratospheric Balloon

scholarly journals Observations of large stratospheric ozone variations over Mendoza, Argentina

2002 ◽  
Vol 2 (3) ◽  
pp. 507-523 ◽  
Author(s):  
C. Puliafito ◽  
S. Enrique Puliafito ◽  
G. K. Hartmann
Keyword(s):  
Water Vapor ◽  
Case Studies ◽  
Gravity Waves ◽  
Stratospheric Ozone ◽  
Andes Mountains ◽  
Wind Effect ◽  
Radiometric Measurements ◽  
The Andes ◽  
Andes Region ◽  
Ozone Variations

Abstract. Since November 1993 up to present from Benegas Station, Mendoza, Argentina (site of IEMA Institute) and from high locations in the Andes region, ground based radiometric measurements of stratospheric ozone and tropospheric water vapor have been achieved. Ozone measurements are performed by using a radiometer-spectrometer tuned at 142 GHz and tropospheric water vapor by means of a 92 GHz radiometer. In this paper two case studies of large stratospheric ozone variations due to dynamical processes will be presented. These processes are very likely associated to gravity waves, generated by airflow over the Andes Mountains, or due to Zonda wind effect.

scholarly journals First Direct Observational Evidence for Secondary Gravity Waves Generated by Mountain Waves Over the Andes

2020 ◽  
Vol 47 (17) ◽  
Author(s):  
Masaru Kogure ◽  
Jia Yue ◽  
Takuji Nakamura ◽  
Lars Hoffmann ◽  
Sharon L. Vadas ◽  
...  
Keyword(s):  
Gravity Waves ◽  
Observational Evidence ◽  
Mountain Waves ◽  
The Andes

scholarly journals Identification of the sources of inertia-gravity waves in the Andes Cordillera region

2008 ◽  
Vol 26 (9) ◽  
pp. 2551-2568 ◽  
Author(s):  
A. Spiga ◽  
H. Teitelbaum ◽  
V. Zeitlin
Keyword(s):  
Gravity Waves ◽  
Mesoscale Model ◽  
Jet Stream ◽  
Earth Atmosphere ◽  
Jet Streams ◽  
The Andes ◽  
Wave Parameters ◽  
The Earth ◽  
Andes Cordillera ◽  
Inertia Gravity Waves

Abstract. Four major sources of inertia-gravity waves are known in the Earth atmosphere: upper-tropospheric jet-streams, lower-tropospheric fronts, convection and topography. The Andes Cordillera region is an area where all of these major sources are potentially present. By combining ECMWF and NCEP-NCAR reanalysis, satellite and radiosoundings data and mesoscale WRF simulations in the Andes Cordillera region, we were able to identify the cases where, respectively, the jet-stream source, the convective source and the topography source are predominantly in action. We retrieve emitted wave parameters for each case, compare them, and analyse possible emission mechanisms. The WRF mesoscale model shows very good performance in reproducing the inertia-gravity waves identified in the data analysis, and assessing their likely sources.

scholarly journals Orographic and convective gravity waves above the Alps and Andes Mountains during GPS radio occultation events – a case study

2018 ◽  
Vol 11 (6) ◽  
pp. 3523-3539 ◽  
Author(s):  
Rodrigo Hierro ◽  
Andrea K. Steiner ◽  
Alejandro de la Torre ◽  
Peter Alexander ◽  
Pablo Llamedo ◽  
...  
Keyword(s):  
Case Studies ◽  
Gravity Waves ◽  
Radio Occultation ◽  
Convective Activity ◽  
Mountain Waves ◽  
Gps Radio Occultation ◽  
Convective Systems ◽  
The Andes ◽  
The Alps

Abstract. Gravity waves (GWs) and convective systems play a fundamental role in atmospheric circulation, weather, and climate. Two usual main sources of GWs are orographic effects triggering mountain waves and convective activity. In addition, GW generation by fronts and geostrophic adjustment must also be considered. The utility of Global Positioning System (GPS) radio occultation (RO) observations for the detection of convective systems is tested. A collocation database between RO events and convective systems over subtropical to midlatitude mountain regions close to the Alps and Andes is built. From the observation of large-amplitude GW structures in the absence of jets and fronts, subsets of RO profiles are sampled. A representative case study among those considered at each region is selected and analyzed. The case studies are investigated using mesoscale Weather Research and Forecasting (WRF) simulations, ERA-Interim reanalysis data, and measured RO temperature profiles. The absence of fronts or jets during both case studies reveals similar relevant GW features (main parameters, generation, and propagation). Orographic and convective activity generates the observed GWs. Mountain waves above the Alps reach higher altitudes than close to the Andes. In the Andes case, a critical layer prevents the propagation of GW packets up to stratospheric heights. The case studies are selected also because they illustrate how the observational window for GW observations through RO profiles admits a misleading interpretation of structures at different altitude ranges. From recent results, the distortion introduced in the measured atmospheric vertical wavelengths by one of the RO events is discussed as an illustration. In the analysis, both the elevation angle of the sounding path (line of tangent points) and the gravity wave aspect ratio estimated from the simulations and the line of sight are taken into account. In both case studies, a considerable distortion, over- and underestimation of the vertical wavelengths measured by RO, may be expected.

scholarly journals Probing the Analytical Cancellation Factor of Short Scale Gravity Waves Using Na Lidar and Nightglow Data from the Andes Lidar Observatory

Atmosphere ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1311
Author(s):  
Fabio Vargas ◽  
Javier Fuentes ◽  
Pedro Vega ◽  
Luis Navarro ◽  
Gary Swenson
Keyword(s):  
Ambient Temperature ◽  
Emission Line ◽  
Gravity Waves ◽  
Wave Amplitude ◽  
Lower Thermosphere ◽  
Lidar Data ◽  
The Andes ◽  
Propagating Waves ◽  
Mesosphere And Lower Thermosphere ◽  
Vertically Propagating

The cancellation factor (CF) is a model for the ratio between gravity wave perturbations in the nightglow intensity to those in the ambient temperature. The CF model allows us to estimate the momentum and energy flux of gravity waves seen in nightglow images, as well as the divergence of these fluxes due to waves propagating through the mesosphere and lower thermosphere region, where the nightglow and the Na layers are located. This study uses a set of wind/temperature Na lidar data and zenith nightglow image observations of the OH and O(1S) emissions to test and validate the CF model from the experimental perspective. The dataset analyzed was obtained during campaigns carried out at the Andes Lidar Observatory (ALO), Chile, in 2015, 2016, and 2017. The modeled CF was compared with observed CF values calculated using the ratio of wave amplitude in nightglow images to that seen in lidar temperatures for vertically propagating waves. We show that, in general, the modeled CF underestimates the observed CF results. However, the O(1S) emission line has better agreement with respect to the modeled value due to its supposedly simpler nightglow photochemistry. In contrast, the observed CF for the OH emission deviates by a factor of two from the modeled CF asymptotic value.

scholarly journals Gravity waves above the Andes detected from GPS radio occultation temperature profiles: Jet mechanism?

2006 ◽  
Vol 33 (24) ◽  
Author(s):  
A. de la Torre ◽  
P. Alexander ◽  
P. Llamedo ◽  
C. Menéndez ◽  
T. Schmidt ◽  
...  
Keyword(s):  
Gravity Waves ◽  
Radio Occultation ◽  
Temperature Profiles ◽  
Gps Radio Occultation ◽  
The Andes
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