DOI: 10.5281/zenodo.17910007
title: MIRA cloud radar data from the PERCUSION field campaign (Level 2)

description: In May 2024, the ESA/JAXA EarthCARE mission was launched, marking the first time a high-spectral-resolution lidar and a Doppler cloud radar have been integrated on a single satellite platform, along with a multispectral imager and a broadband radiometer. This sensor configuration enables comprehensive observations of aerosol, cloud, and precipitation processes. To support scientific exploitation of the mission, robust validation of the measurements and associated data products of EarthCARE is essential.

For this purpose, an EarthCARE-analogous payload was implemented on the German research aircraft HALO (High Altitude and Long Range). The system was deployed during the PERCUSION campaign (Persistent EarthCARE Underflight Studies of the ITCZ and Organized Convection), conducted as part of the larger ORCESTRA initiative (Organized Convection and EarthCARE Studies over the Tropical Atlantic). ORCESTRA coordinates multiple measurement activities aiming to improve understanding of mesoscale convective organization in the tropics and to validate remote-sensing products of EarthCARE.

ORCESTRA combined several sub-campaigns carried out from the Cape Verde Islands and Barbados in August and September 2024. These activities investigated how organized deep convection interacts with tropical waves and air–sea coupling, and how this interplay affects the radiative budget of Earth atmosphere.

A key ORCESTRA component was the German-led PERCUSION campaign, which featured airborne measurements from HALO with coincident satellite observations of EarthCARE. PERCUSION was designed to examine factors that influence the organization of deep maritime convection and to assess how convective organization modifies the surrounding large-scale environment. Each HALO research flight included an underpass of EarthCARE to provide high-quality datasets for validation.

HALO operations were conducted during the commissioning phase of EarthCARE in August 2024 from Sal, Cape Verde, and in September 2024 from Barbados. Additional flights from Oberpfaffenhofen, Germany, in November 2024 sampled atmospheric conditions not encountered earlier. Across the full campaign, 33 underpasses of EarthCARE were completed under diverse aerosol and cloud regimes. Several flights were coordinated with complementary in-situ or remote-sensing platforms, including the French ATR-42 aircraft, the German research vessel METEOR, and ground-based radar and lidar systems in Mindelo (Cape Verde), Barbados, and the ACTRIS stations at Antikythera, Leipzig, Lindenberg, and Munich. Moreover, four coordinated underflights beneath NASA’s PACE mission were performed.

This sub-dataset provides the downward looking profiles from the MIRA cloud radar, which is part of the HALO Microwave Package. The radar reflectivity was calibrated using laboratory measurements and the backscatter of the sea surface. The doppler velocity was corrected for platform-motion and contributions of the horizontal wind component contained in the original line-of-sight measurements. The data is provided on the same grid like the lidar measurements from WALES (10.5281/zenodo.15527242, 10.5281/zenodo.17153148, 10.5281/zenodo.17153625). This repository of consolidated MIRA measurements collected during PERCUSION is intended for long-term preservation and for use in future validation and process-studies related to aerosol–cloud–precipitation interactions and the remote-sensing capabilities of EarthCARE.

Data Products




radar_constant_correction_factor
Radar constant correction factor (near field correction, noisecom calibration, original variable 'SNRCorFaCo'


radar_signal_to_noise
Radar signal to noise ratio as determined with the Hildebrand and Sekhorn method


radar_instrument_mask
0=valid radar measurements / -1=below WGS84 geoid/ -2=ground clutter / -3=above platform / -4=radar non operational / -5=radar sensitivity suboptimal / -6=radar calibration / -7=platform in curve (roll lt 5) / -8=radar data not available / -9=below topography / -10=above LDR thresold (-10 dB)


radar_reflectivity
The factor is calculated from the measured radar return power assuming the target is composed of liquid water droplets (K^2=0.93) scattering in the Rayleigh regime


radar_linear_depolarization_ratio
Ratio between the radar reflectivities measured in the cross- and co-channel


radar_cross_correlation
Correlation between the IQ signals measured in the cross- and co-channel


radar_differential_phase
Differential phase of the backscattered signal measured between co- and cross-channel


radar_gaseous_attenuation
Path integrated attenuation (2-way, linear) due to water vapour and oxygen


radar_doppler_velocity
Line of sight doppler velocity (towards the instrument is positive)


radar_doppler_velocity_width
Line of sight doppler velocity width (broadened by platform motion)


radar_doppler_velocity_skewness
Line of sight doppler velocity skewness (influenced by platform motion)


radar_doppler_velocity_peaks
Number of line of sight doppler velocity peaks


radar_doppler_velocity_corrected_no_wind
Vertical doppler velocity (upward is positive, motion corrected)


radar_doppler_velocity_corrected
Vertical doppler velocity (upward is positive, motion corrected, horizontal wind corrected)


model_wind_u
Wind vector component which is positive when directed eastward (negative westward)


model_wind_v
Wind vector component which is positive when directed northward (negative southward)


model_wind_w
Wind vector component which is positive when directed upward (negative downward)


model_air_pressure
Air pressure (IFS OP 1h an/fcst)


model_air_temperature
Air temperature (IFS OP 1h an/fcst)




 

Remarks



All data is re-gridded to a constant altitude scale above sea level. The actual flight altitude is given as a separate variable.