Tiny aerosol particles may be able to intensify tropical convective clouds, and a new study suggests the atmosphere can sometimes create the conditions needed for that process, according to ScienceDaily.
The research, published in Advances in Atmospheric Sciences, analyzed aircraft observations from NASA’s Cloud, Aerosol and Monsoon Processes Philippines Experiment in 2019. Researchers from China, the United States and Israel estimated quasi-steady-state supersaturation inside the clouds using updraft speeds and cloud droplet size data.
The study found that supersaturation increased higher in the clouds and reached about 10% near minus 5 degrees Celsius. The companion study, using data from a separate aircraft campaign over coastal Texas and Louisiana, found rare supersaturation of about 11% in deep convective updrafts.
According to the researchers, the results do not prove aerosols strengthened the clouds, but they do show that the conditions needed for condensational aerosol convective invigoration can occur in real tropical convective clouds. Daniel Rosenfeld said the mechanism is most likely to appear in deep, clean clouds over the ocean rather than in polluted or shallow clouds.
The team plans more aircraft studies to compare clean and polluted tropical clouds and better understand how aerosol effects may influence deep convection, rainfall, lightning and climate.
