Marine aerosol feedback on biogeochemical cycles and the climate in the Anthropocene: lessons learned from the Pacific Ocean

Abstract

Human activities have profoundly altered the air quality and the climate on a global scale in the Anthropocene. It is our task to quantitatively evaluate the impact of human activities on marine ecosystems and the climate through various feedbacks in biogeochemical cycles. Atmospheric aerosols over the Pacific Ocean are largely influenced by anthropogenic (e.g., metal production, fossil fuel combustion, and agriculture), marine and terrestrial biogenic, pyrogenic (open biomass burning), and lithogenic (mineral dust) sources. To what extent do oceanic (sea salt) and marine biogenic emissions of aerosols and their precursor gases change the marine cloud properties under the influence of anthropogenic and biogeochemical activities and thereby affect the climate? At the same time, to what extent does atmospheric deposition of nutrients change marine biogeochemistry under the influence of anthropogenic and terrestrial biogeochemical activities and thereby affect marine ecosystems? We summarize the progress in research on organic aerosols, nitrogen, and iron in the atmosphere over the Pacific Ocean. Future perspectives include interdisciplinary research of field observational, laboratory experimental, and numerical modeling studies.