The CLImate relevant processing of Mineral Dust by volatile Organic compounds (CLIMDO) project

As emphasized by the Intergovernmental Panel for Climate Change (IPCC), aerosols contribute the largest uncertainty to global radiative forcing budget estimates. The uncertainty stems largely from the lack of information related to global aerosol distributions, composition, and aging effects in the atmosphere, all of which affect aerosol radiative properties.

Of the two major categories of aerosols, natural and anthropogenic, natural aerosols remain the largest source of the uncertainty. This limits our capacity to measure and attribute total climate forcings. Without a firm understanding of total climate forcing, our ability to predict its evolution over time diminishes and limits the development of adaptation strategies for future climate change.

Aerosolized mineral dust is the largest single component of the global aerosol mass budget, making up nearly half of annual particle emissions to the atmosphere. Mineral dust aerosols influence the global climate through both direct interactions with radiation (scattering and absorption in the visible and IR regions) as well as indirect interactions with radiation (by serving as cloud condensation nuclei (CCN) or ice nuclei (IN)). One potentially important aspect of dust aerosols is that they are able to uptake and heterogeneously react with gases. Henceforth, mineral dust may also play a significant but mostly unknown role in secondary organic aerosol (SOA) formation in the atmosphere.

While the combination of the complex reaction pathways and processing mechanisms inherent to the dust/organic system is hampering our understanding of dust and organic aerosols on global climate, and despite a great number of progresses on climate-relevant properties of mineral dust and SOA in these past ten years, studies of the heterogeneous chemistry occurring between dust and organic species are sparse.

The CLImate relevant processing of Mineral Dust by volatile Organic compounds (CLIMDO) project tackles this under-explored science question by proposing the first comprehensive process-driven project addressing the reactivity of complex and realistic mineral dust/organic systems to better understand how dust and VOCs influence the global climate system.

CLIMDO will investigate the heterogeneous interaction of mineral dust with two of the most common organic SOA precursors: glyoxal and methylglyoxal from ubiquitous anthropogenic and biogenic sources, thought combination of innovative laboratory experiments in a well-controlled and characterized environment (the atmospheric simulation chamber CESAM) and advanced flow reactors and optical cells), the development of novel modelling schemes of both the reaction mechanisms and the resulting optical properties of mineral dust, and new simulations of the global direct radiative effect and SOA distribution using the LMDzOR-INCA.

This presentation describes the strategy and workplan of the CLIMDO project, including dissemination of results and open data, to inform the science community and foster and cluster new collaborations.