9:15 AM - 9:30 AM
[AAS07-02] Case studies using EarthCARE/CPR Level 1 products
Keywords:Earth Observation Satellite, Doppler radar, cloud observation
The EarthCARE Cloud Profiling Radar (CPR) is a quite unique sensor with highly sensitive cloud observation and the Doppler velocity observation to the nadir direction. It is expected that CPR can detect very weak echoes that cannot be observed by previous spaceborne radars and dynamical characteristics in the clouds for various locations. Level 1 data of CPR show that CPR is detecting various kind of phenomena. In this report, we will introduce some of the unique cases observed by CPR.
The first case is the periodical upward/downward Doppler velocity field observed over Greenland, Alaska, Antarctica etc. In these cases, wave structure is inferred to be generated under stable atmospheric condition and triggered by orography. The most typical case was observed over Greenland on October 31 (orbit #02424) that shows the depth of 6 km and maximum Doppler velocity of 3-4 m/s with the wavelength of about 11 km. All the radar echo, Mie backscattering from ATLID and cloud image from MSI show clear wave structure. From the MSI observation, flight track of the EarthCARE has an angle of about 45 degrees to the cloud direction, indicating the wavelength of the wave is about 6-7 km. For other cases, clear deep wave structure hasn’t been observed. This Doppler velocity observation may be helpful to evaluate numerical model simulation.
The second case is very weak and shallow echo over India and Sahara Desert. Over India, two types of weak shallow echoes were observed; one is echo appeared about 2 km height with constant altitude that has already reported by JAXA as possible artificial echo, the other appears below 2 km and it may not be an artificial echo. Comparison with Mie backscattering from ATLID indicates that the backscattering region appeared almost the same height, but altitude was not constant. Clear relationship low level echo and Mie backscatter cannot be seen at this time. The source of the scatterer of CPR observation is suspected as bugs. The case over Sahara Desert shows weak echo appeared below 2 km. It seems like artificial echo, but it extended near the surface. Mie backscattering from ATLID show very weak echo below 2.5 km. It is inferred as dust from desert. Further investigation is needed to understand these phenomena.
The third case is the winter shallow convective cloud observed over Japan sea associated with cold outbreak from Siberia observed on December 26 and 27, 2024. CPR clearly detected the development of the cloud from upstream to the downstream. The echo height was about 2 km in the area close to the continent, but it developed to about 4 to 5 km in the area close to Japan, and the radar reflectivity factor (Z) also increased greatly. The Doppler velocity characteristics in the area close to the continent showed an updraft (up to around 3 m/s) extending from the surface to the cloud top, and a downdraft around it. In the area around Japan, the distribution of the updraft is not uniform from the lower to upper layers. However, it is necessary to take into account that the falling speed of precipitation particles (such as snow and hail) is increasing due to the increase in Z.
The first case is the periodical upward/downward Doppler velocity field observed over Greenland, Alaska, Antarctica etc. In these cases, wave structure is inferred to be generated under stable atmospheric condition and triggered by orography. The most typical case was observed over Greenland on October 31 (orbit #02424) that shows the depth of 6 km and maximum Doppler velocity of 3-4 m/s with the wavelength of about 11 km. All the radar echo, Mie backscattering from ATLID and cloud image from MSI show clear wave structure. From the MSI observation, flight track of the EarthCARE has an angle of about 45 degrees to the cloud direction, indicating the wavelength of the wave is about 6-7 km. For other cases, clear deep wave structure hasn’t been observed. This Doppler velocity observation may be helpful to evaluate numerical model simulation.
The second case is very weak and shallow echo over India and Sahara Desert. Over India, two types of weak shallow echoes were observed; one is echo appeared about 2 km height with constant altitude that has already reported by JAXA as possible artificial echo, the other appears below 2 km and it may not be an artificial echo. Comparison with Mie backscattering from ATLID indicates that the backscattering region appeared almost the same height, but altitude was not constant. Clear relationship low level echo and Mie backscatter cannot be seen at this time. The source of the scatterer of CPR observation is suspected as bugs. The case over Sahara Desert shows weak echo appeared below 2 km. It seems like artificial echo, but it extended near the surface. Mie backscattering from ATLID show very weak echo below 2.5 km. It is inferred as dust from desert. Further investigation is needed to understand these phenomena.
The third case is the winter shallow convective cloud observed over Japan sea associated with cold outbreak from Siberia observed on December 26 and 27, 2024. CPR clearly detected the development of the cloud from upstream to the downstream. The echo height was about 2 km in the area close to the continent, but it developed to about 4 to 5 km in the area close to Japan, and the radar reflectivity factor (Z) also increased greatly. The Doppler velocity characteristics in the area close to the continent showed an updraft (up to around 3 m/s) extending from the surface to the cloud top, and a downdraft around it. In the area around Japan, the distribution of the updraft is not uniform from the lower to upper layers. However, it is necessary to take into account that the falling speed of precipitation particles (such as snow and hail) is increasing due to the increase in Z.