Cloud Microphysics in Global Cloud Resolving Models

ABSTRACT

Global cloud resolving models (GCRMs) are a new type of general circulation model that explicitly calculates the growth of cloud systems with fine spatial resolutions and more than 10 GCRMs have been developed at present. This work reviews cloud microphysics schemes used in GCRMs with introductions to the recent progress and researches with GCRMs. Especially, research progress using a pioneer of GCRMs, Nonhydrostatic ICosahedral Atmospheric Model (NICAM), is focused. Since GCRMs deal with climatology and meteorology, it is a challenging issue to establish cloud microphysics schemes for GCRMs. A brief history of the development of cloud microphysics schemes and cloud-radiation coupling in NICAM is described. In addition, current progress in analytical techniques using satellite simulators is described. The combined use of multi-optical sensors enables us to constrain uncertain processes in cloud microphysics without artificial tuning. As a result, cloud microphysics schemes used in the NICAM naturally represent cloud systems, and hence, the radiative budget is well balanced with little optimization. Finally, a new satellite and a ground validation campaign are introduced for future work.

RÉSUMÉ

[Traduit par la rédaction] Les modèles globaux de résolution des nuages (Global cloud resolving models ou GCRM) sont un nouveau type de modèle de circulation générale qui calcule explicitement la croissance des systèmes nuageux avec de fines résolutions spatiales. Plus de dix GCRM ont été créés à ce jour. Le présent travail passe en revue les schémas de microphysique des nuages utilisés dans les GCRM avec des introductions aux progrès récents et aux recherches sur les GCRM. Les progrès de la recherche utilisant un pionnier des GCRM, le modèle atmosphérique non hydrostatique ICosahedral (NICAM), sont particulièrement ciblés. Puisque les GCRM traitent de la climatologie et de la météorologie, l’établissement de schémas de microphysique des nuages pour les GCRM est un défi. Un bref historique de l’élaboration des schémas de microphysique des nuages et du couplage nuage-radiation dans NICAM est décrit. En outre, les progrès actuels des techniques analytiques utilisant des simulateurs de satellites sont décrits. L’emploi combiné de capteurs multi-optiques nous permet de contraindre les processus incertains de la microphysique des nuages sans réglage artificiel. Par conséquent, les schémas de microphysique des nuages utilisés dans le NICAM représentent naturellement les systèmes nuageux, et donc, le bilan radiatif est bien équilibré avec peu d’optimisation. Enfin, un nouveau satellite et une campagne de validation au sol sont présentés pour les travaux futurs.

Keywords:

• global cloud resolving models
• cloud microphysics
• climate projection
• weather forecasting
• cloud radiative forcing
• model evaluation

Acknowledgments

The CloudSat and CERES satellite products were obtained from the NASA Langley Research Center Atmospheric Science Data Center. Authors were supported by the Integrated Research Program for Advancing Climate Models (TOUGOU) Grant (JPMXD0717935457) and “Program for Promoting Researches on the Supercomputer Fugaku” (Large Ensemble Atmospheric and Environmental Prediction for Disaster Prevention and Mitigation) (JPMXP1020351142, JPMXP1020200305), which are promoted by the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan. Authors were supported by the EarthCARE Program, Earth Observation Research Center of JAXA, and Program for Promoting Technological Development of Transportation (Ministry of Land, Infrastructure, Transport and Tourism of Japan), and Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research B (JP20H01967) for Ultra Site for Measuring Atmosphere of Tokyo Metropolitan Environment and Collaboration Studies with High-Resolution Atmospheric Models (ULTIMATE).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by JSPS: [Grant Number JP20H01967]; Japan Aerospace Exploration Agency: [Grant Number The EarthCARE Program]; Japanese Ministry of Education, Culture, Sports, Science and Technology: [Grant Number JPMXD0717935457, JPMXP1020351142, JPMXP1020200305]; Ministry of Land, Infrastructure, Transport and Tourism: [Grant Number Program for Promoting Technological Development of Transportation].