Modelling 540 million years of dust emission with GCM and dust model
Abstract
Dust plays a pivotal role in the climate system. It regulates the Earth's radiation budget directly and indirectly. Also, dust deposition brings nutrients into the ocean and can further affect the marine ecosystem. On the other hand, Variations in vegetation, moisture, precipitation and wind fields arising from climate change also affect the dust process. While there is relatively good knowledge of the modern global dust emission and its interactions with the ocean, it remains poorly understood on geological time scales.
In this study, we use the new ensemble of 109 simulations from the coupled general circulation model HadCM3L, which simulates the paleoclimate simulations through the Phanerozoic (since 540 Ma) and force a new offline dust model to simulate dust emissions in the deep time. We present a long-term variation record of dust emission that corresponds to the simulated experimental conditions settings. Our results show that dust emission was extremely high in the Triassic, 4 times or more than in the modern. The lowest dust emission is found in the early-Carboniferous. During the even earlier deep time, the dust emission is similar to that of the modern. Among the variables included in the dust model, The vegetation cover is the most important factor that influences dust emissions overall. To what extent the changes in the marine ecosystem during these periods are attributed to dust will be further investigated. This study will lead to new knowledge of dust record reconstructions and insights into the role of dust on ancient oceans on time scales of multi-million years.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2022
- Bibcode:
- 2022AGUFMEP42B..03X