Centre National d'Etudes Spatiales
Job title:
201 Vertical air speed in thunderstorms as seen by C2OMODO
Company:
Centre National d’Etudes Spatiales
Job description
Updrafts in convective cores varies greatly depending on the growth phase and organization of thunderstorms, reaching vertical air speed up to 200 km/h locally. This makes the vertical air speed an essential climate variable, especially in the tropics where convection is the dominant term of vertical transport. However, the vertical air speed is still very poorly known because it is little or not measured. It is thus one of the most uncertain meteorological variables in kilometer-resolution models (Varble et al. 2014).The C2OMODO project (Convective Core Observations through MicrOwave Derivatives in the trOpics, ) is a concept of a tandem of microwave radiometers separated by several tens of seconds (Brogniez et al. 2022). Its main objective is to infer the vertical air speed in thunderstorms. Inferring this information would be very valuable as it would provide an observational constraint that is currently lacking. From synthetic C2OMODO observations at kilometer resolution, a preparatory study has shown that it would be possible to deduce the vertical air speed inside deep convective systems in growth phase (Auguste and Chaboureau 2022).The aim of the PhD project is to evaluate what C2OMODO data could contribute to our knowledge of the variability of vertical air speed as a function of the life cycle and organization of thunderstorm systems and the environmental conditions in which they develop (ocean or land, clean or polluted air, wind shear or not, etc.). It will be based on a dataset of large-eddy simulations (LESs) of several thunderstorms observed during past field campaigns (EXAEDRE, HAIC-Darwin, CADDIWA, etc.) in the tropics that is currently built for the C2OMODO project using the GPU version of Meso-NH (Escobar et al. 2024). The fine resolution offered by LESs is crucial to correctly reproduce updrafts and downdrafts as well as to capture the most energetic turbulent eddies.The first step will be to set up the experimental protocol for a simulated thunderstorm. This will include (i) evaluating the LES against radar observations, (ii) analyzing the updrafts in terms of size and intensity during their life cycle, (iii) emulating the C2OMODO images and derived geophysical products, and (iv) mapping their information in the vertical air speed to the updraft size and intensity. In a second step, this protocol will be repeated to other thunderstorms.This PhD project will contribute to the design of the C2OMODO microwave radiometer tandem, the geophysical products that will be derived from this observation system and the future field campaigns dedicated to the calibration and validation of C2OMODO. It is intended for a motivated student interested in the study of thunderstorms through numerical simulations and satellite observations.The supervision team has a strong expertise in fine-scale meteorological modeling and high performance computing. The thesis work will be based on the French community code Meso-NH (Lac et al. 2018, ) initially developed by the Laboratoire d’Aérologie (University of Toulouse, CNRS, UT3, IRD) and the Centre National de Recherches Météorologiques (Météo-France, CNRS, University of Toulouse). The code will be used at high resolution (100 m) on large grids in order to explicitly resolve both the entire storm and the updrafts, downdrafts and turbulent circulations within it. The ambition of the PhD project is thus to reach a computational realism at the cutting edge of numerical simulations in atmospheric modeling. A first handling of the Meso-NH model will be performed during the three-day training course at Météo-France in the fall of 2025.C2OMODO is the French instrumental contribution to the Atmosphere Observing System program (AOS, ). AOS, the next major NASA program involving CNES, CSA, DLR and JAXA, has the overall goal of better understanding the relationships between aerosols, clouds, convection and precipitation. Collaborations in the framework of the C2OMODO project and the international AOS program will be encouraged.Auguste and Chaboureau 2022, Deep convection as inferred from the C2OMODO concept of a tandem of microwave radiometers,Brogniez, et al. 2022, Time-delayed tandem microwave observations of tropical deep convection: Overview of the C2OMODO mission, ;Escobar et al. 2024, Porting the Meso-NH atmospheric model on different GPU architectures for the next generation of supercomputers (version MESONH-v55-OpenACC),Lac, Chaboureau, et al., 2018: Overview of the Meso-NH model version 5.4 and its applications, ;Varble et al. 2014, Evaluation of cloud-resolving and limited area model intercomparison simulations using TWP-ICE observations,For more Information about the topics and the co-financial partner (found by the lab !);contact Directeur de thèse –Then, prepare a resume, a recent transcript and a reference letter from your M2 supervisor/ engineering school director and you will be ready to apply online before March 14th, 2025 Midnight Paris time !
Expected salary
Location
Toulouse
Job date
Wed, 05 Feb 2025 07:25:41 GMT
To help us track our recruitment effort, please indicate in your email/cover letter where (vacanciesineu.com) you saw this job posting.