Ground-based remote sensing of Antarctic and Alpine solid precipitation

• Main Author: Durán Alárcon, Claudio
• Other Authors: Institut des Géosciences de l’Environnement (IGE), Institut de Recherche pour le Développement (IRD)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes 2016-2019 (UGA 2016-2019 ), Université Grenoble Alpes, Brice Boudevillain, Alexis Berne
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: HAL CCSD 2019
• Subjects: Snow; Radar remote sensing; Alps; Antarctica; Tropospheric Lidar; Modelling; Neige; Télédétection de radar; Alpes; Antarctique; Lidar troposphérique; Modélisation; [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology; Antarc*; Antarctic; Antarctique*; East Antarctica
• Online Access: https://theses.hal.science/tel-02452286; https://theses.hal.science/tel-02452286/document; https://theses.hal.science/tel-02452286/file/DURAN_ALARCON_2019_diffusion.pdf

Solid precipitation plays an important role in the Earth's climate system, as well as for the maintenance of ecosystems and the development of human society. The large uncertainty in precipitation estimates and the discrepancies within climate model projections make this component of the hydrological cycle important as a research topic. Remote sensing allows to monitor precipitation and clouds in regions where in-situ observations are scarce and scattered, but with limited temporal resolution and a blind zone close to the ground level for spaceborne sensors, and limited visibility in the lower atmosphere in complex terrain for ground-based radars. The objectives of this dissertation are the following: 1) to characterize cloud and precipitation in Antarctica, detecting the presence of supercooled liquid and ice particles near the ground level using a ground-based 532-nm depolarization lidar; 2) to characterize the vertical structure of the precipitation in two contrasted but important regions of the cryosphere, Antarctica and the Alps, in the low troposphere using ground-based radars.In this study, a cloud and precipitation hydrometeor detection method is proposed using lidar data, complemented with a K-band micro rain radar (MRR) to improve the detection of precipitation, both instruments deployed at the Dumont d'Urville (DDU) station in East Antarctica. A method based on lidar depolarization and attenuated backscattering coefficient and the use of k-means clustering is developed for the particle classification. The classification of cloud and precipitation particles provides the vertical distribution of supercooled liquid water, as well as planar oriented ice and randomly oriented ice particles. The comparison between ground-based and satellite-derived classifications shows consistent patterns for the vertical distribution of supercooled liquid water in clouds.The vertical structure of precipitation near the surface is analyzed using the Doppler moments derived from three MRR profiles at DDU, the Princess ...