PhD position “Chasing convective storm evolution with swarms of space-borne Ka-band radars”

Politecnico di Torino, Turin, Italy
Closing date: 31 July 2022

There is a PhD position available in “Chasing convective storm evolution with swarms of space-borne Ka-band radars” at Politecnico di Torino, Turin (Italy)  in the IUSS PAVIA PhD program in Sustainable Development and Climate change (https://www.phd-sdc.it/researchtopic/#collapse1)

Deep convection has a profound influence on Earth’s climate system. Updraft plumes in deep convective clouds are in the tropics the principal pathway by which heat, moisture, mass and trace gases are transported into the upper atmosphere. Observations of the occurrence and magnitude of vertical transport in deep convection are simply not available over the tropical oceans and sparsely available over land. Monthly to seasonal prediction of weather is heavily influenced by the role of deep convection. Convection is therefore central to prediction of severe weather both at sub-seasonal and seasonal time scales. The sign and nature of changes to convective storms in a warming climate are also difficult to predict.

While moisture convergence is expected to increase at about 7% per degree of warming following the Clausius‐Clapeyron law, storms are likely to become deeper and narrower and to produce heavier precipitation at a rate which is still debated. It also remains unclear whether or not the increased transports will result in more moistening of the high troposphere and more cirrus clouds or will be compensated by heavier precipitation. Ground-breaking novel observations of convective clouds are expected from the NASA’s Earth Venture Program Investigation of Convective Updrafts (INCUS) mission (https://www.Nasa.Gov/press-release/nasa-selects-new-mission-to-study-storms-impacts-on-climate-models) with the launch (2027) in low Earth orbit of a constellation of satellites equipped with Ka-band (35 GHz) radars and microwave radiometers in close formation (Dt separation of the order of few minutes).

This observing system will allow to globally observe the explosive evolution of storms as never done before and should therefore provide new observables to test the realism of convection-permitting cloud resolving models. These models will represent the backbone of future operational weather forecast models, which are currently run at or near 5 km but will soon move to finer resolution capable of resolving convection.

Scope of the PhD is to perform ancillary studies in preparation of the mission with three main goals: 1) To simulate the radar and radiometer measurements by using fine temporal (sub-minute) and spatial (sub-km) resolution outputs from the WRF model. The study will capitalize on advanced radar and radiometer simulators (accounting for the viewing geometry, the radar sensitivity, the antenna pattern, the pulse compression schemes, etc) developed in the past ten years within the research team. 2) To investigate the sensitivity of the INCUS measurements to the different parametrizations and schemes of the WRF model). Stochastic schemes are capable to represent model uncertainty in ensemble simulations by applying a small perturbation at every time step to each member and very suitable for the convective clouds scale studies of this project 3) To refine algorithms for the derivation of convective-related quantities (updrafts, condensed mass vertical fluxes) based on the Dt measurements (collaboration with NASA INCUS PI, Prof. S. Van den Heever at Colorado State University).

Research team and environment
This project offers an excellent opportunity to develop and apply novel radar techniques to remote sensing of clouds and precipitation. The student will be trained in a wide range of topics including radar meteorology, cloud physics, radiative transfer and precipitation remote sensing. The PhD student will be supervised by Prof. A. Battaglia, expert in spaceborne radars and forward modelling of space-borne microwave sensors. The PhD student will be able to collaborate with the international INCUS team when refining the algorithms for the characterization of convection (specifically there will be weekly teleconferences with the INCUS PI and Prof. Kollias at Stony Brook, City College of New York). The student will benefit from the collaboration with the CIMA foundation group led by Dr. A. Parodi who will provide consolidated experience in the execution of cloud-resolving numerical experiments at kilometric scale by combining different microphysics and radiative schemes as well by using stochastic parameterization schemes.

Suggested skills
Applicants should have a science or engineering degree. Knowledge of meteorology would be beneficial. Programming skills in matlab/idl/Python/C/Java/C++ and knowledge of radar systems, signal processing and numerical modelling could also be beneficial. Team working attitude and excellent knowledge of spoken and written English are highly desirable.

To apply: https://www.phd-sdc.it/ and follow tab Apply.

For any query please contact:
Alessandro Battaglia
alessandro_battaglia@polito.it


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