Interest of lidar measurements for the study of aerosols and polar stratospheric clouds and their climatic disturbances

• Main Author: Tencé, Florent
• Other Authors: STRATO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Saclay, Alain Sarkissian, Julien Jumelet
• Format: Doctoral or Postdoctoral Thesis
• Language: French
• Published: HAL CCSD 2023
• Subjects: Aerosols; Stratosphere; Lidar; Volcanism; Biomass wildfires; Aérosols; Stratosphère; Volcanisme; Feux de biomasse; [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; Antarc*; Antarctic
• Online Access: https://theses.hal.science/tel-04071938; https://theses.hal.science/tel-04071938/document; https://theses.hal.science/tel-04071938/file/114094_TENCE_2023_archivage.pdf

As the understanding of the interactions between stratospheric ozone chemistry and climate change progresses, the consequences of both temperature change and perturbations in stratospheric aerosol loading are becoming a topic of major scientific interest.It is well established that volcanism is the main source of stratospheric aerosols and that major volcanic episodes are associated with negative ozone anomalies. However, the high latitude effect of an overload of sulphate aerosols, precursors of polar stratospheric clouds (PSC), remains poorly understood.In addition, stratospheric injections of carbonaceous aerosols have been observed during major fires in recent years. In Canada in 2017 and Australia in 2020, aerosol masses comparable to those emitted by moderate volcanism were reported. This is of great scientific interest, as carbon does not naturally occur in the stratosphere and the effects of its significant intake are yet to be studied. Also, climate change is expected to favour the occurrence of major fires, adding the question of long-term trends in aerosol loading to the need to finely characterise the effect of such a disturbance.PSCs, formed on aerosols, are the precursors of seasonal ozone destruction and are at the heart of these issues. Lidar is a suitable instrument for studying these condensed phases. Using the lidar at the French Antarctic station Dumont d'Urville (DDU) and relevant space instruments, this thesis investigates trends and processes related to PSCs and stratospheric aerosol perturbations.Measurements acquired at DDU use different classifications of PSCs to illustrate fine processes that are only accessible through the geometry of a ground-based instrument. The parameterisation of the PSCs is based on a concise and representative classification, and the coastal location of the station is an advantage due to the high variability of the particle observations it allows. A trend in the number of PSC days per year at DDU from 2007 to 2020 is established by combining lidar and ...