January 14, 2025 (JST)

Japan Aerospace Exploration Agency
National Institute of Information and Communications Technology

 The Japan Aerospace Exploration Agency (JAXA, President: Hiroshi Yamakawa) and the National Institute of Information and Communications Technology (NICT, President: Hideyuki Tokuda) have successfully completed the commissioning and the initial calibration & validation　 for the Cloud Profiling Radar (CPR(*1)), which was jointly developed by JAXA and NICT, onboard Earth Cloud Aerosol and Radiation Explorer (EarthCARE) (Nickname: “Hakuryu”(*2)). The operations have moved to the mission operation phase. Also, the European Space Agency (ESA) announced the successful completion of the initial calibration validation verification of the Atmospheric Lidar (ATLID), the Multi-Spectral Imager (MSI), and the Broad-Band Radiometer (BBR).
 Accordingly, we are pleased to announce that Level 1 Product releases of all sensors onboard the EarthCARE satellite "Hakuryu" are set to commence.

 The EarthCARE satellite "Hakuryu" was launched on May 29, 2024 (Japan Standard Time) and the initial calibration & validation was carried out as follows:

 On January 14, 2025, we start releasing Level 1 Product, which contains engineering values converted from observation data of individual sensors, following the completion of the initial calibration & validation . (Appendix: Observation examples)

 Above data will be converted into Level 2 Product, which is the geophysical values (Cloud water content, Cloud ice content, Optical Thickness, etc.). In addition, data from multiple sensors of the EarthCARE satellite “Hakuryu” will be combined to provide accurate observation data that cannot be obtained from a single sensor alone. This data will be used to improve predictions of future climate change, contributing to studies on adaptation to climate change.
 Level 2 Product will be released gradually from the middle of March 2025. (*3)
 The data is available to anyone from the websites of JAXA and ESA:
• JAXA website (Japanese Version)
• JAXA website (English Version)
• ESA website (English Version) External Link

 The EarthCARE satellite "Hakuryu" will continue to acquire observation data throughout its operation. By analyzing acquired data, we will contribute to a better understanding of climate change and the improvement of its prediction accuracy. The data has been distributed only to special users, but with this release, the data will be available to all users, which is expected to increase the use of the data. We deeply appreciate the cooperation and support of stakeholders who assisted in the commissioning and initial calibration validation.

Appendix

 The CPR has continued observations since June 2024. This document presents examples of the CPR Level 1 Product from November 7, 2024. Figure 1 shows an orbit of one complete rotation of The EarthCARE satellite "Hakuryu". The EarthCARE satellite "Hakuryu" orbits the Earth approximately 16 times a day, with each orbit taking approximately 90 minutes. Figure 2 shows the vertical distribution of the radar reflectivity and Figure 3 shows the vertical distribution of Doppler velocity, along with the orbit in Figure 1. In Figures 2 and 3, each orbit is divided into eight scenes, each labeled with a letter from A to H.

 The CPR transmits radio waves from space to the Earth and receives the waves that bounce back after hitting cloud particles and raindrops in the sky. The radar reflectivity (Figure 2) represents the strength of these “bounced radio waves”. Higher values mean that there are more cloud droplets or raindrops in the sky. These figures show that various clouds around the globe are observed by the CPR.

 Doppler velocity (Figure 3) is the vertical motion of cloud particles or raindrops measured based on the Doppler effect. The Doppler effect is famously known as the change in pitch of the sound of an ambulance as it passes by. In the figure, the blue indicates the downward increase in Doppler velocity and corresponds to the fast-falling speed of the raindrops.

 The cloud and precipitation process, in which cloud droplets grow into rain, plays an important role in numerical models that predict heavy rainfall and future climates. It is expected that observations of different cloud regions by the CPR will help us understand the mechanism by which cloud droplets grow into rain and improve the cloud and precipitation processes in the numerical model, thereby improving the accuracy of predictions. In addition, the effect of clouds on the climate system is greatly influenced by factors such as cloud height, overlapping patterns, and cloud type. Therefore, using the four types of sensors of the EarthCARE satellite "Hakuryu" with different observation methods to measure vertical distributions of clouds, including their vertical motions on a global scale, will contribute to elucidating the mechanism by which clouds affect climate change.