01/12/2017
Post-doc position in chemistry-aerosols mesoscale modeling

Université Paul Sabatier/CNRS, Toulouse, France

As part of the french ANR TTL-Xing project, a 12 months post-doc position is available to study the impact of monsoon convection on the composition of the UTLS and on the formation of the Asian Tropopause Aerosol Layer (ATAL).

The post-doc will perform high resolution simulations with the Meso-NH cloud resolving model in the Asian monsoon region to explicitly represent convective clouds and associated processes (scavenging of particles, aerosol-cloud interactions and in-cloud chemistry).

In a first step, simulations with passive tracers mimicking emissions from the different Asian regions will provide information about the transport processes (fast convective uplift versus slow diabatic heating) and about the origin of the pollutants. The simulated convective systems will be evaluated with satellite observations from meteorological geostationary platforms and from the GPM (Global Precipitation Measurement) system. This part of the project will benefit from StratoClim activities at LA which include Meso-NH cloud-resolved simulations and analyses.

The main task of the post-doc will consist in performing simulations with detailed aerosol chemistry and to quantify the aerosol budget of the ATAL. One part of the budget will consist in discriminating between the different types of aerosols (black carbon, primary and secondary organic aerosols, sulphates and nitrates) and the other one to determine their formation pathways (convective uplift of boundary layer particles, taking into account scavenging and chemical processing on the one hand, nucleation of small particles from convectively uplifted gases oxidized within the cloud on the other hand). Meso-NH will also be used to determine the impact of aerosols on the radiative budget of the Asian upper troposphere.

The high resolution Meso-NH simulations will be performed for case studies corresponding to observations from the StratoClim 2017 monsoon campaign. Airborne observations from StratoClim provide detailed and unprecedented information about the properties of the ATAL. The 2 mass spectrometers from the payload have documented the chemical speciation of the particles and size distributions from particle counters will help discriminate the formation pathways.

Workplace
Laboratoire d’Aérologie (Université Paul Sabatier/CNRS) in Toulouse, France. The applicant will interact with the other TTL-Xing partners (LMD, Paris, France and LPC2E, Orléans/France). In particular a strong interaction is expected with the LPC2E team who will perform climate-chemistry simulations of the Asian monsoon TTL and ATAL with the WACCM model.

Qualifications
A PhD in atmospheric chemistry or related fields (meteorology, climate). Experience in atmospheric modeling would be an important asset for the applicant.

Working conditions
The net monthly salary based on the French academic scale will depend upon experience, from 2000 € to 3100 €. Vacation benefits are 45 days in addition to public holidays. The position is full time for 12 months preferably starting in early 2018.

Contact
Brice Barret, Laboratoire d’Aérologie, Observatoire-Midi-Pyrénées, Toulouse, France, email: brice.barret@aero.obs-mip.fr