Offre de Post-Doc au LHEEA : "Modelling of aerosol dynamics in the coastal atmospheric boundary-layer"

Work description :

Sea spray droplets (aerosols) are formed by the interaction between air and water. With 70% of our planet covered by water, sea spray represents a major component of the natural aerosol loading of the atmosphere. By scattering and absorption of solar light the aerosols affect the Earth radiation budget, and thereby have a significant effect on climate. Unfortunately, quantification of this effect has proven elusive, as noted multiple times by the IPCC Panel. Significant uncertainties exist in numerical models as to the prediction of the concentration and distribution of atmospheric aerosols, and significant biases for climate predictions have been noted. There is thus an urgent need to improve our understanding of the generation of sea spray particles and the subsequent transport in the atmosphere. Specifically for the transport of sea spray in the coastal zone, local atmospheric inhomogeneities induced by the wave field, sea-land transition or orography lead to spatio-temporal fluctuations in the concentrations. Numerical modelling of these inhomogeneities requires a highly resolved description of the flow field, which can be provided by Large-Eddy-Simulations that resolve the flow field down to spatial scales of 10s of meters.

As part of the project “Atmospheric Modelling for Radiation Transmission in Coastal Atmosphere”, one of the objectives is the fine characterization of the dynamics of the lower atmosphere in coastal areas and the dispersion processes of marine aerosols. In close collaboration with the other researchers involved in the project, in charge of performing regional scale modelling or having collected wind and aerosol concentration data during the dedicated field campaign carried out on the French Atlantic coast (Le Croisic, France), the postdoctoral work will consist in implementing and assessing tools for a better understanding of the aerosol dynamics.

The main tasks the candidate will be entrusted with are :

• To develop in the ARPS (Advanced Regional Prediction System) model the modules for the simulation of marine aerosol dynamics (source functions, transport-diffusion equations);
• To carry out numerical simulations of the atmospheric boundary layer at high resolution and of the dynamics of marine aerosols under certain conditions of the experimental campaign;
• To analyse the numerical simulation data with reference to the on-site measurement data (wind measurements by LiDAR scanning over the sea, concentration measurements) and to the meteorological data available around the site;
• To propose coastal-specific adaptations of classical semi-empirical models for estimating marine aerosol concentrations.

The candidate will contribute to the writing of the project report and to the diffusion of the results in peer-reviewed journals.

Technical skills & knowledge :

• Required qualifications are related to:
• PhD in Atmospheric Sciences or Fluid Dynamics
• Numerical modelling of turbulent flows
• Atmospheric boundary-layer physics
• Data processing
• Programming experience in Fortran (skills in other languages appreciated)

Personal quality:

• Teamwork skills  
• Organizational ability
• Ability to communicate work (developments and results)
• Ability to analyse and synthesize
• Autonomy and initiative

About the position :

• The postdoctoral position is for 12 month
• Full time
• Starting date : 1st July 2021
• Salary  from : 29,5K€

Application :  

Interested candidates should submit a cover letter and curriculum vitae to : candidatures7c523e75-0f22-460d-b007-e746ab58cf84@ec-nantes.fr