دورية أكاديمية

Developing a climatological simplification of aerosols to enter the cloud microphysics of a global climate model.

التفاصيل البيبلوغرافية
العنوان: Developing a climatological simplification of aerosols to enter the cloud microphysics of a global climate model.
المؤلفون: Proske, Ulrike, Ferrachat, Sylvaine, Lohmann, Ulrike
المصدر: EGUsphere; 11/30/2023, p1-38, 38p
مصطلحات موضوعية: CLIMATE change models, AEROSOLS, MICROPHYSICS, ATMOSPHERIC models, ICE clouds, ATMOSPHERIC nucleation
مستخلص: Aerosol particles influence cloud formation and properties. Hence climate models that aim for a physical representation of the climate system include aerosol modules. In order to represent more and more processes and aerosol species, their representation has grown increasingly detailed. However, depending on one's modeling purpose, the increased model complexity may not be beneficial, for example because it hinders understanding of model behaviour. Hence we develop a simplification in the form of a climatology of aerosol concentrations. In one approach, the climatology prescribes properties important for cloud droplet and ice crystal formation, the gateways for aerosols to enter the model cloud microphysics scheme. Another approach prescribes aerosol mass and number concentrations in general. Both climatologies are derived from full ECHAM-HAM simulations and can serve to replace the HAM aerosol module and thus drastically simplify the aerosol treatment. The first simplification reduces computational model time by roughly 65 %. However, the naive mean climatological treatment needs improvement to give results that are satisfyingly close to the full model. We find that mean CCN concentrations yield an underestimation of CDNC in the Southern Ocean, which we can reduce by allowing only CCN at cloud base (which have experienced hygroscopic growth in these conditions) to enter the climatology. This highlights the value of the simplification approach in pointing to unexpected model behaviour and providing a new perspective for its study and model development. [ABSTRACT FROM AUTHOR]
Copyright of EGUsphere is the property of Copernicus Gesellschaft mbH and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
قاعدة البيانات: Complementary Index
الوصف
DOI:10.5194/egusphere-2023-2783