Mineral dust is an important component of the Earth’s climate system. Dust-climate feedbacks result from direct radiative effects of dust and from indirect effects including cloud formation and (micro-)nutrient supply to remote marine and terrestrial ecosystems. In particular, the increase in airborne iron (Fe) supply promotes primary and export production in surface waters of the Fe-deficient Southern Ocean. As this mechanism can lead to a significant drawdown of atmospheric CO2, the Southern Hemisphere dust cycle has attracted increasing attention over the last decades.
This talk will provide an overview of the role of dust in the climate system with a focus on the Southern Hemisphere and how recent findings from South Pacific marine sediments challenge the existing picture of dust (-Fe) transport across the Southern Ocean.
Fig. Global distribution of aerosols including mineral dust (red), sea salt (blue), organic/black carbon (green), and sulfates (white). Dust is transported from the main Southern Hemisphere source regions across the Southern Ocean by the westerly winds (modified after: William Putman, NASA/Goddard Space Flight Center).