Bremen-Cardiff Physics Seminar
Human driven changes in atomospheric deposition of nutrients to the ecosystems
Speaker: Prof. Dr. Maria Kanakidou (University of Crete)
Date: Thursday 17 June 2021
Time: 15:00 in UK
Venue: Zoom
Terrestrial and marine ecosystems are key to the formation of atmospheric oxygen with oceans being responsible for about half of the oxygen in the atmosphere. They are also a major source of food for humanity and without the ocean phytoplankton carbon dioxide in the atmosphere would have been about 200 ppm higher. The sink of carbon dioxide by carbon sequestration depends on the availability of nutrients to the ecosystem, since nutrients are essential for the ecosystem functioning. The relative abundance of them available to an ecosystem is also important because favoring the development of certain species against others can lead to biodiversity losses. Nutrients equilibria of both land and marine ecosystems have been disturbed during the Anthropocene period.
Material of natural and/or anthropogenic origin, particularly aerosols, deposited from the atmosphere to the Earth’s surface can act as a source of nutrients for the ecosystems, in particular into the open ocean, and affect nutrient’s equilibrium. Atmospheric acidity is a key driver of solubility changes of nutrients, making them readily available to the ecosystems, and is following the human-driven changes in the emissions of acidic and basic compounds into the atmosphere (mainly sulfur and nitrogen emissions).
We will discuss recent global chemistry-transport modeling studies that are based on laboratory and field experiments focusing on the biogeochemical cycles of nitrogen, iron and phosphorus, the role of atmospheric acidity and organics, how these cycles have been impacted by human activities and potential consequences for the ecosystems.