Primary Biological Aerosol in the Atmosphere: Origins, Microphysical Processes, and Climatic Feedbacks

ended

Primary biological aerosols particles (PBAP) are emitted from the land and marine surfaces into the atmosphere, where they were found to be abundant. The PBAP are of high importance because of their potential involvement on ice-nucleation (IN) and precipitation formation processes, with potential implications on the climate. Older studies showed that the total concentration of PBAP is smaller than other types of ice-nucleation particles, e.g. dust, while recent studies showed that the reported concentrations of PBAP are highly underestimated, thus, their IN activity and climatic impacts have large uncertainty. According to the Fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC), the PBAP-cloud interactions, as a part of aerosol-cloud interactions, are still the least understood factor in our current understanding of climate change. In addition, combating climate change and its impacts is one of the Sustainable Development Goals of the United Nations. Therefore, it’s crucial to carry out further investigations on the emissions of PBAP and their consequent atmospheric microphysical processes and climatic impacts and feedbacks, which is the main objective of BIOAAT. The BIOAAT aims to: (i) deliver more realistic prediction of the emission flux and dispersion of PBAP; considering all ecosystems and meteorological conditions that lead to high variation in quantifying their concentrations, distributions, and emission fluxes, (ii) close the gap between observations and modelling studies on the impact of different types of PBAP on cloud ice and precipitation formation, and contribute to reducing the uncertainty of aerosol-cloud interactions, and (iii) ultimately delivers open-source models that describe the emission flux and ice nucleation rates of PBAP that can easily be implemented in different types of atmospheric models including climate models to better estimate past, present and future climate and environmental impacts of PBAP.