The project will combine observations, models and theory in four work packages
moving up in scale from small-scale processes (1) to the large-scale circulation (4):
1. Small-scale processes:
Ground-based and (existing) airborne measurements will expose relationships between the
structure of winds, shallow convection and cloudiness. Furthermore, Large-Eddy Simulation
(LES) of tropical and mid-latitude cases will systematically explore the role of different wind profiles (shear) and convective
organization on convective momentum transport.
2. New data & techniques:
A flight campaign with DLR's Falcon aircraft carrying the ADM Aeolus demonstrator
(A2D) lidar and the 2 μm Doppler wind lidar (DWL) will validate space-borne Aeolus
measurements of winds at low levels (< 5 km) for different convective states of the atmosphere.
Momentum fluxes at 100 Hz are measured using in-situ sensors
of wind, which inform relationships between wind and momentum transport.
Constraints and boundaries on the influence of convective momentum transport on the
momentum budget are evaluated using high resolution simulations in idealized settings (LES)
and high resolution simulations in realistic settings (hind-casts over the tropical Atlantic
and LES run in forecast modes). Existing treatments of momentum
transport by cumulus parameterizations are re-examined.
4. Large-scale circulation:
In collaboration with climate modeling institutes and NWP centers general circulation models
are used to study the influence of
different representations of convective momentum transport on wind patterns and the large-scale
circulation As an outlook, this can be explored in more complex
settings in CMIP models. Satellite remote sensing (including Aeolus) will be used to look for
traces of interactions between shallow cumuli and large-scale winds in phases of strong and weak