Masaki Satoh

This study proposes the EarthCARE-ORCESTRA Model Intercomparison Project (ECOMIP), a framework for evaluating various range of atmospheric models, including global or regional km-scale models using observations from the EarthCARE satellite and the ORCESTRA (Organized Convection and EarthCARE Studies over the Tropical Atlantic) field campaign. The goal of ECOMIP is not to rank model performance but to provide a clear path to improve models by considering how new satellite observations, combined with in situ measurements and satellite simulators, can constrain cloud microphysics, precipitation, and convective dynamics. This paper presents the protocol for Phase 1 of the ECOMIP framework, consisting of 2-day simulations designed for comparison with EarthCARE and ORCESTRA observations. As a first examination of the model intercomparison, NICAM, ICON, and IFS simulations are evaluated with EarthCARE observations during the satellite overpass over the ORCESTRA domain on 3 September 2024. Along the EarthCARE track, the occurrence of a mesoscale convective system and Southern Hemisphere cirrus clouds is captured in both simulations. The three models exhibit different convective organization characteristics. NICAM and IFS tend to produce larger and more coherent convective systems, whereas ICON shows more scattered convective cores. Although conclusions from a single EarthCARE frame cannot be generalized, these results provide an example of model-dependent characteristics and demonstrate the potential of the proposed protocol for improving our understanding through the analysis of a larger number of EarthCARE cases and datasets in future studies. We also present the comprehensive framework of ECOMIP after Phase 1, including statistical free-run simulations and observationally constrained parameter-sensitivity experiments.

The Earth Cloud, Aerosol and Radiation Explorer (EarthCARE) provides the first spaceborne Doppler radar measurements. We construct a tropical cyclone (TC) dataset by collocating 16 months of EarthCARE observations with the International Best Track Archive for Climate Stewardship, comprising 96 intercepts of 27 TCs. The inner-core region exhibits enhanced reflectivity, stronger and more variable upward air motion, and a broader Doppler velocity distribution. Two independent inner-core intercepts show consistent Doppler and air velocity structures. In the rainband region, the Doppler velocity distribution shifts toward more negative values, accompanied by more negative particle terminal velocities and a bright band near the melting level. Particle classifications show small ice dominates the upper troposphere, whereas snow extends toward more negative Doppler velocities between 5 and 12 km. These results show that radial variations in Doppler velocity reflect differences in both air motion and particle sedimentation. We conduct a preliminary single-case comparison for Hurricane Humberto using the Nonhydrostatic Icosahedral Atmospheric Model with two common microphysical configurations. Both configurations underestimate TC intensity and produce narrower distributions than observed. Compared with the Kodama et al. (2021) configuration, the Takasuka et al. (2024) configuration more closely reproduces upper-level structure, with more gradual reflectivity and Doppler velocity changes and a broader cloud ice distribution. Because the comparison is limited to one case, it demonstrates sensitivity to the microphysical configurations rather than a general evaluation of model performance. Overall, EarthCARE provides complementary constraints on vertical air motion, condensate properties, and particle sedimentation for evaluating TC microphysics.

This study proposes the EarthCARE-ORCESTRA Model Intercomparison Project (ECOMIP), a framework for evaluating various range of atmospheric models, including global or regional km-scale models using observations from the EarthCARE satellite and the ORCESTRA (Organized Convection and EarthCARE Studies over the Tropical Atlantic) field campaign. The goal of ECOMIP is not to rank model performance but to provide a clear path to improve models by considering how new satellite observations, combined with in situ measurements and satellite simulators, can constrain cloud microphysics, precipitation, and convective dynamics. This paper presents the protocol for Phase 1 of the ECOMIP framework, consisting of 2-day simulations designed for comparison with EarthCARE and ORCESTRA observations. As a first examination of the model intercomparison, NICAM, ICON, and IFS simulations are evaluated with EarthCARE observations during the satellite overpass over the ORCESTRA domain on 3 September 2024. Along the EarthCARE track, the occurrence of a mesoscale convective system and Southern Hemisphere cirrus clouds is captured in both simulations. The three models exhibit different convective organization characteristics. NICAM and IFS tend to produce larger and more coherent convective systems, whereas ICON shows more scattered convective cores. Although conclusions from a single EarthCARE frame cannot be generalized, these results provide an example of model-dependent characteristics and demonstrate the potential of the proposed protocol for improving our understanding through the analysis of a larger number of EarthCARE cases and datasets in future studies. We also present the comprehensive framework of ECOMIP after Phase 1, including statistical free-run simulations and observationally constrained parameter-sensitivity experiments.

This study proposes the EarthCARE-ORCESTRA Model Intercomparison Project (ECOMIP), a framework for evaluating various range of atmospheric models, including global or regional km-scale models using observations from the EarthCARE satellite and the ORCESTRA (Organized Convection and EarthCARE Studies over the Tropical Atlantic) field campaign. The goal of ECOMIP is not to rank model performance but to provide a clear path to improve models by considering how new satellite observations, combined with in situ measurements and satellite simulators, can constrain cloud microphysics, precipitation, and convective dynamics. This paper presents the protocol for Phase 1 of the ECOMIP framework, consisting of 2-day simulations designed for comparison with EarthCARE and ORCESTRA observations. As a first examination of the model intercomparison, NICAM, ICON, and IFS simulations are evaluated with EarthCARE observations during the satellite overpass over the ORCESTRA domain on 3 September 2024. Along the EarthCARE track, the occurrence of a mesoscale convective system and Southern Hemisphere cirrus clouds is captured in both simulations. The three models exhibit different convective organization characteristics. NICAM and IFS tend to produce larger and more coherent convective systems, whereas ICON shows more scattered convective cores. Although conclusions from a single EarthCARE frame cannot be generalized, these results provide an example of model-dependent characteristics and demonstrate the potential of the proposed protocol for improving our understanding through the analysis of a larger number of EarthCARE cases and datasets in future studies. We also present the comprehensive framework of ECOMIP after Phase 1, including statistical free-run simulations and observationally constrained parameter-sensitivity experiments.

We conducted a 220‐m mesh simulation over the global domain with realistic topography. This can be called a first “global large‐eddy simulation” (GLES) for deep convection. The resolution dependence across km‐ to sub‐km scales and sensitivity to turbulence schemes are investigated. The results showed that the too‐intense localized precipitation frequently produced in km‐scale models, known as “popcorn‐like” precipitation, weakens as resolution increases. Although zonal mean precipitation differs substantially across turbulence schemes at km‐scale resolution, it decreases as resolution increases, indicating convergence across the schemes. Low cloud fraction decreases with increasing resolution, whereas the resolution dependence of high cloud fraction depends on the turbulence scheme: it increases for the Smagorinsky‐type scheme and decreases for the Mellor‐Yamada‐type schemes. The response of low cloud distribution differs between the turbulence schemes. The present results indicate that GLES is promising for simulating precipitation intensity, while cloud simulation remains uncertain.

The precipitation of tropical cyclones crossing the Philippines between 2001 and 2022 is analysed over the 9 h periods before the cyclone makes landfall and after it then re-enters the ocean (‘seafall’). Precipitation is favoured over the land side for landfalling storms. However, the precipitation from a seafalling storm is more spread out and asymmetric on the ocean side. When adjusted for intensity, seafall storms have a larger total precipitation rate than landfall storms by 25 % . The precipitation pattern in the landfalling storms appears to be the result of both orography and land–sea frictional and thermal contrasts. Seafalling storm precipitation anomalies are likely caused by a local boost in surface heat and moisture supply from the ocean.

This study proposes the EarthCARE-ORCESTRA Model Intercomparison Project (ECOMIP), a framework for evaluating various range of atmospheric models, including global or regional km-scale models using observations from the EarthCARE satellite and the ORCESTRA (Organized Convection and EarthCARE Studies over the Tropical Atlantic) field campaign. The goal of ECOMIP is not to rank model performance but to provide a clear path to improve models by considering how new satellite observations, combined with in situ measurements and satellite simulators, can constrain cloud microphysics, precipitation, and convective dynamics. This paper presents the protocol for Phase 1 of the ECOMIP framework, consisting of 2-day simulations designed for comparison with EarthCARE and ORCESTRA observations. As a first examination of the model intercomparison, NICAM, ICON, and IFS simulations are evaluated with EarthCARE observations during the satellite overpass over the ORCESTRA domain on 3 September 2024. Along the EarthCARE track, the occurrence of a mesoscale convective system and Southern Hemisphere cirrus clouds is captured in both simulations. The three models exhibit different convective organization characteristics. NICAM and IFS tend to produce larger and more coherent convective systems, whereas ICON shows more scattered convective cores. Although conclusions from a single EarthCARE frame cannot be generalized, these results provide an example of model-dependent characteristics and demonstrate the potential of the proposed protocol for improving our understanding through the analysis of a larger number of EarthCARE cases and datasets in future studies. We also present the comprehensive framework of ECOMIP after Phase 1, including statistical free-run simulations and observationally constrained parameter-sensitivity experiments.

The Earth Cloud, Aerosol and Radiation Explorer (EarthCARE) satellite mission provides the first spaceborne Doppler radar measurements, enabling new insights into the vertical structure of clouds and precipitation. In this study, we construct a dataset of EarthCARE overpasses of tropical cyclones (TCs) by collocating satellite observations with the International Best Track Archive for Climate Stewardship (IBTrACS). Based on 14 months of observations, we examine the radial structure of radar reflectivity, Doppler velocity, retrieved air motion, and cloud particle types. The results show a transition from convective-like structures in the eyewall to stratiform-like characteristics in the rainband region. The eyewall exhibits stronger updrafts, enhanced reflectivity, and broader Doppler velocity distributions. In contrast, the rainband region shows that weaker vertical motions and Doppler signals are more strongly influenced by hydrometeor fall speeds. We further evaluate TC simulations using the Nonhydrostatic ICosahedral Atmospheric Model (NICAM) with two different cloud microphysical configurations of hydrometeor fall speeds. Both experiments reproduce the overall TC structure but exhibit more confined distributions of radar reflectivity, Doppler velocity, and air velocity compared to the observations. Differences between the two simulations highlight the sensitivity of vertical structure to hydrometeor fall speeds. These results indicate that EarthCARE Doppler observations provide valuable constraints on the coupling between dynamics and cloud microphysics in TCs.

The Earth Cloud, Aerosol and Radiation Explorer (EarthCARE) satellite mission provides the first spaceborne Doppler radar measurements, enabling new insights into the vertical structure of clouds and precipitation. In this study, we construct a dataset of EarthCARE overpasses of tropical cyclones (TCs) by collocating satellite observations with the International Best Track Archive for Climate Stewardship (IBTrACS). Based on 14 months of observations, we examine the radial structure of radar reflectivity, Doppler velocity, retrieved air motion, and cloud particle types. The results show a transition from convective-like structures in the eyewall to stratiform-like characteristics in the rainband region. The eyewall exhibits stronger updrafts, enhanced reflectivity, and broader Doppler velocity distributions. In contrast, the rainband region shows that weaker vertical motions and Doppler signals are more strongly influenced by hydrometeor fall speeds. We further evaluate TC simulations using the Nonhydrostatic ICosahedral Atmospheric Model (NICAM) with two different cloud microphysical configurations of hydrometeor fall speeds. Both experiments reproduce the overall TC structure but exhibit more confined distributions of radar reflectivity, Doppler velocity, and air velocity compared to the observations. Differences between the two simulations highlight the sensitivity of vertical structure to hydrometeor fall speeds. These results indicate that EarthCARE Doppler observations provide valuable constraints on the coupling between dynamics and cloud microphysics in TCs.

The Earth Cloud, Aerosol and Radiation Explorer (EarthCARE) satellite mission provides the first spaceborne Doppler radar measurements, enabling new insights into the vertical structure of clouds and precipitation. In this study, we construct a dataset of EarthCARE overpasses of tropical cyclones (TCs) by collocating satellite observations with the International Best Track Archive for Climate Stewardship (IBTrACS). Based on 14 months of observations, we examine the radial structure of radar reflectivity, Doppler velocity, retrieved air motion, and cloud particle types. The results show a transition from convective-like structures in the eyewall to stratiform-like characteristics in the rainband region. The eyewall exhibits stronger updrafts, enhanced reflectivity, and broader Doppler velocity distributions. In contrast, the rainband region shows that weaker vertical motions and Doppler signals are more strongly influenced by hydrometeor fall speeds. We further evaluate TC simulations using the Nonhydrostatic ICosahedral Atmospheric Model (NICAM) with two different cloud microphysical configurations of hydrometeor fall speeds. Both experiments reproduce the overall TC structure but exhibit more confined distributions of radar reflectivity, Doppler velocity, and air velocity compared to the observations. Differences between the two simulations highlight the sensitivity of vertical structure to hydrometeor fall speeds. These results indicate that EarthCARE Doppler observations provide valuable constraints on the coupling between dynamics and cloud microphysics in TCs.