Simulated historical (1995-2014) and future (2081-2100) pollen emission using PECM2.0

Atmospheric aerosols are emitted from both natural and anthropogenic sources, and they play an important role in climate, impacting solar radiation and cloud formation. Compared to other types of aerosol particles, primary biological aerosol particles (PBAP, e.g., fungal spores, bacteria, pollen, virus, etc.) are relatively understudied. However, they are linked to adverse health effects and have the potential to influence ice nucleation at higher temperatures. Anemophilous (or wind-driven) pollen is one of the important PBAP, impacts cloud properties under some conditions, and triggers allergic diseases such as allergic rhinitis (also known as hay fever) and asthma. Because pollen emission is closely associated with environmental drivers, the climatic change could influence pollen emission and consequently the incidence of allergic disease. Using CMIP6 model data, our research projects continental-scale changes in pollen emissions at the end of the century, considering the effects of temperature, precipitation, CO2, and future vegetation distribution change. While prior studies have evaluated single types of pollen, we use a mechanistic model to comprehensively simulate total pollen across the United States from all sources. Similar to previous single-source pollen studies, our simulations suggest that pollen season duration will lengthen, and pollen emission will increase in the future, but in addition, we identify new synergies between different pollen types that can influence the maximum daily pollen. Our work highlights that the changes of overlap between pollen seasons of different vegetation taxa can magnify or mitigate the impacts of climate change, which addresses the importance to study all pollen emissions comprehensively. Given pollen is one of the most common triggers of seasonal allergies, our findings also provide information to evaluate global health conditions in the future. In this study, all of the pollen emission data are written in NetCDF files. Atmospheric aerosols are emitted from both natural and anthropogenic sources, and they play an important role in climate, impacting solar radiation and cloud formation. Compared to other types of aerosol particles, primary biological aerosol particles (PBAP, e.g., fungal spores, bacteria, pollen, virus, etc.) are relatively understudied. However, they are linked to adverse health effects and have the potential to influence ice nucleation at higher temperatures. Anemophilous (or wind-driven) pol