First comparison between EarthCARE’s CPR and airborne W-band cloud radar observations during ECALOT campaign

Improving future climate predictions requires enhancing the current meteorological numerical models for which a better understanding of the roles that clouds and aerosols (and their interactions) play in Earth’s weather and climate is crucial.  Along these lines, the European Space Agency (ESA) and the Japan Aerospace Exploration Agency (JAXA) successfully launched the Earth Cloud, Aerosol, and Radiation Explorer (EarthCARE) satellite in May 2024. This satellite mission aims to advance the studies of global aerosol and cloud properties via novel active and passive spaceborne observations.  EarthCARE carries four instruments: the ATmospheric LIDar (ATLID), the Cloud Profiling Radar (CPR), the Multi-Spectral Imager (MSI), and the Broadband Radiometer (BBR).  Of particular interest to this work are the CPR observations providing significant observations of clouds’ vertical structure, including the first ever in-cloud Doppler Velocity profiles from space.

As part of ESA’s global calibration/validation initiative, the EarthCARE Commissioning Calibration/Validation Campaign in Ottawa (ECALOT) took place in Canada from October 2024 to January 2025.  ECALOT collected essential airborne and surface observations to calibrate and validate key EarthCARE products. These include CPR and ATLID Level 1 and Level 2 products, composite and synergy products, as well as EarthCARE’s scene construction algorithm and radiation products.  ECALOT successfully observed fall and winter weather conditions with dedicated flights targeted to sample relevant weather underflying the EarthCARE path.  The National Research Council Canada’s (NRC) Convair-580 aircraft, equipped with W- and X- band radars (NAWX), 355nm Lidars, and a full array of state-of-the-art in-situ cloud microphysics and aerosol probes, provided critical independent observations to support EarthCARE validation efforts.  These observations were complemented by surface-based sites deployed by Environment and Climate Change Canada and McGill University near Ottawa airport and two Climate Sentinels network stations operated by McGill University and Université du Québec à Montréal in the Montreal region.

In this presentation, we will provide an initial evaluation of EarthCARE’s CPR performance during the ECALOT campaign.  A comprehensive analysis of the cloud vertical structure as seen by the CPR and NAWX observations and an intercomparison of vertical cross sections of reflectivity and Doppler velocity will be presented.  In addition, an assessment of the behavior of CPR under stratiform and convective conditions will be provided.