oCean Atmosphere Interactions in the Antarctic regions and Convergence latitude

Polar Boundary Layers (BL) are poorly understood but key elements of the Earth’s climate
system through which energy, mass and momentum are redistributed between the different
spheres. The changing polar BL structure and its role in the Earth’s climate system are central,
but to-date severely understudied. Focusing on the sea, a high latitudes of Southern Hemisphere,
the poor knowledge/observation of long-lived and shallow Marine Polar BLs (MPBL) and
ocean-atmosphere interactions pose a very strong limitation to the understanding of climate
changes. Actual estimations of the phenomenology are obtained mainly using a modelling
approach.
We propose to fill the experimental gap and provide very relevant and necessary information on
MPBL in Antarctic and on selected key processes, making use of the Laura Bassi, with an
approach that combines in-situ observations and 3-D modelling. The overarching goal is to
improve representation of MPBL dynamics and turbulence features in numerical weather
prediction (NWP) models at different scales, leading to a better knowledge of radiative and cloud
formation processes, with a particular attention on the role of aerosols. Observation activities
will focus on i) determination of radiation surface components/budget as well as exchange fluxes
at the sea-ice-atmosphere interfaces, and ii) characterization of primary and secondary aerosols,
and their climate-relevant properties. The acquired data will support modelling activities of
MPBL in three different sub-regions (open sea, mixed sea ice, full sea ice). Considering the
limitation of commercial atmospheric instrumentation for operations on a mobile platform, a
significant part of the project will be devoted to develop new technical solutions.