[02389] Exploring the excess of cloud condensation nuclei and rain suppression using a minimal 3D Boussinesq model with bulk cloud microphysics
Session Time & Room : 3C (Aug.23, 13:20-15:00) @D408
Type : Contributed Talk
Abstract : For many decades the hypothesis that an increase in air pollution could affect the rain formation processes has been discussed with theoretical, experimental, and numerical arguments. Several studies have shown that higher pollutant concentrations can inhibit, decrease or increase precipitation. Differences between results arise partly from the complexity of the problem, which requires the consideration of processes at multiple scales. This study aims to provide a very simple numerical model that satisfactorily represents the atmospheric dynamics and cloud microphysics to explore the effect of pollution on rain formation. We adapted and extended a previously existing three-dimensional minimal model consisting of five equations describing the atmospheric dynamics and implemented a simple bulk parametrization that represents the role of cloud condensation nuclei (CCN) 's role in cloud formation processes. To explore the effect of different CCN concentrations and distributions, we used two CCN profiles, one with a single accumulation layer and one with two layers, modifying their concentrations. Our results showed that polluted scenarios resulted in rain inhibition when a single CCN layer was initially present and rain increment when two layers were present. In low-polluted environments, both CCN initial profiles generated similar precipitation and showed similar dynamic patterns. In this talk, we will highlight the importance of the vertical distribution of CCN, not only concentration, on the formation of rain, its inhibition, or suppression. This is joint work with Olmo Guerrero Medina.
