MAESTRO

The ERC¹ funded MAESTRO project aims to answer this question by addressing the following goals:

• Unravel the physical processes that control the mesoscale organisation of shallow and deep convection over tropical ocean
• Understand how the organisation of convection impacts the Earth’s radiation budget through water vapor and clouds
• Assess the ability of the new emerging climate models to predict the interplay between the mesoscale organisation of convection and climate

As part of this project, an airborne field campaign will be organized to collect the observations needed to test mechanisms hypothesized to control the mesoscale organisation of shallow and deep convection, and to assess the quality of the new EarthCARE satellite observations. This campaign will be one component of the international initiative named ORCESTRA.

1. The MAESTRO project is funded by the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (ERC Advanced Grant agreement No 101098063)

The ORCESTRA/MAESTRO field campaign

The ORCESTRA/MAESTRO campaign will take place from Aug 10 to Sept 10 2024 over the Atlantic ocean near Cape Verde, with research aircraft operating out of Sal (16^o4’N, 22^o6’W).

The SAFIRE ATR-42 aircraft will fly in the lower troposphere with a rich ensemble of in-situ and remote sensing instruments to characterize the interplay between coherent structures in the subcloud-layer, cloud properties near the cloud base level, the geometry of convective clouds and the horizontal and vertical distribution of water vapor and temperature in-between clouds. These observations will be completed by measurements from the HALO aircraft flying a large circle in the upper troposphere and dropping sondes intensively to characterize the dynamical and thermodynamical properties of the environment at the mesoscale (e.g. divergence and vertical motion), geostationary satellite measurements from which we will infer informations about clouds and vertical motions in the clear-sky atmosphere, and EarthCARE measurements of radiative fluxes, precipitation, clouds and vertical motion within clouds.

MAESTRO/ORCESTRA will build on experimental advances from the EUREC⁴A field campaign, and will develop new experimental techniques to provide unprecedented observations of the convective atmosphere. In particular, the ATR-42 will probe the atmosphere in multiple directions with a W-band pulsed Doppler cloud radar (RASTA) pointing up and down, a Doppler High Spectral Resolution Lidar (LNG) pointing up or down, a Doppler cloud radar (BASTA) pointing horizontally and, for the first time, a Raman lidar pointing horizontally (AWALI). These measurements will be completed by an ensemble of probes and sensors to measure temperature, humidity and winds at a fast rate and to characterize aerosols and cloud microphysics of liquid and ice clouds.

Most ATR flights will consist in a series of straight legs flown at different altitudes (near the surface, in the subcloud-layer, at cloud base and in the mid-troposphere around 6 km). The ATR is expected to fly twice a day, three days a week. Each ATR flight is expected to last 3-4 hours, including one hour during which it will fly in coordination with HALO. Some flights will be devoted to the calibration and validation of the European Space Agency (ESA) EarthCARE satellite, which is expected to be launched in Spring 2024. These flights will take place as close as possible to the satelite orbit.