Aerosol-biogeochemistry interactions represent some of the poorest understood and yet most important feedbacks over the next 25 years. In this proposal we seek to link how human activities on land, including direct industrial emissions as well as fragmentation, land management and land cover change, impact the atmosphere and the biogeochemistry of the ocean and land. Our overall goal is to complement existing work at DOE labs to improve the capability and performance of the ACME model in short-term, high-resolution projections of climate.
Projections of ocean uptake of anthropogenic carbon are highly dependent on the details of the ocean physical and biogeochemistry parameterizations. Potentially equally important are the estimates of increases in iron and soluble nitrogen deposition in aerosols to the open ocean, but there are substantial uncertainties in these feedbacks. Simulation of wildfires in the ACME model is currently coupled to the land carbon model, but improvement is needed to more accurately simulate fire responses to climate variability as well as fire contributions to terrestrial climate feedbacks.
Our proposed work is separated into the following 5 tasks: i) improve representation of fire dynamics, ii) improve estimates of industrial emissions of iron and phosphorus, iii) improve representation of atmospheric iron, phosphorus and nitrogen transport, chemistry and deposition, iv) Improve representation of iron, phosphorus and nitrogen deposition impacts on ocean biogeochemistry, v) Couple emissions into atmosphere, to deposition onto land and ocean biogeochemistry. In all 5 tasks, careful validation that implementation has been done successfully through numerical experiments, as well as comparison to available observations will be conducted.
This proposal addresses four of the six priorities within the ACME call by improving the representation of fire, industrial combustion sources and desert dust and adding iron and soluble iron to the atmospheric chemistry (1); improving ocean biogeochemistry and the response of the oceans to anthropogenic atmospheric iron and nitrogen (3), improving the representation of land disturbance on fires and resulting feedbacks onto the land system (4); and coupling the land, atmosphere and ocean biogeochemical systems (6).