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Abstract The role of manganese (Mn) in ecosystem carbon (C) biogeochemical cycling is gaining increasing attention. While soil Mn is mainly derived from bedrock, atmospheric deposition could be a major source of Mn to surface soils, with implications for soil C cycling. However, quantification of the atmospheric Mn cycle, which comprises emissions from natural (desert dust, sea salts, volcanoes, primary biogenic particles, and wildfires) and anthropogenic sources (e.g., industrialization and land‐use change due to agriculture), transport, and deposition, remains uncertain. Here, we use compiled emission data sets for each identified source to model and quantify the atmospheric Mn cycle by combining an atmospheric model and in situ atmospheric concentration measurements. We estimated global emissions of atmospheric Mn in aerosols (<10 μm in aerodynamic diameter) to be 1,400 Gg Mn year−1. Approximately 31% of the emissions come from anthropogenic sources. Deposition of the anthropogenic Mn shortened Mn “pseudo” turnover times in 1‐m‐thick surface soils (ranging from 1,000 to over 10,000,000 years) by 1–2 orders of magnitude in industrialized regions. Such anthropogenic Mn inputs boosted the Mn‐to‐N ratio of the atmospheric deposition in non‐desert dominated regions (between 5 × 10−5and 0.02) across industrialized areas, but that was still lower than soil Mn‐to‐N ratio by 1–3 orders of magnitude. Correlation analysis revealed a negative relationship between Mn deposition and topsoil C density across temperate and (sub)tropical forests, consisting with atmospheric Mn deposition enhancing carbon respiration as seen in in situ biogeochemical studies.
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1750 to 2010 Refractory Black Carbon Deposition from a Global Ice-Core Array, Arctic, Antarctic, and alpine regions
Refractory black carbon (rBC) aerosols in air and precipitation result from incomplete combustion. Prior to 18th century industrialization, the primary emission sources were wildfires and agricultural fires. After industrialization, fossil fuel burning has become an important emission source as well. Because these aerosols are import contributors to Earth’s radiative forcing both in the air and when deposited to bright surfaces such as fresh snow, quantifying past rBC emissions is critical to accurate Earth System Modeling. This data set contains 1750 to 2010 annual rBC depositional fluxes measured in a global array of 31, mostly polar ice cores. They were used (Zhang et al., Nature Communications, 2024) to reconstruct atmospheric rBC emissions using the atmospheric chemical transport GEOS-Chem. Details on the rBC measurement methods and chronology development are provided in the associated references for the individual ice core records.
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- Award ID(s):
- 2102917
- PAR ID:
- 10530634
- Publisher / Repository:
- Arctic Data Center
- Date Published:
- Format(s):
- Medium: X Other: text/xml
- Sponsoring Org:
- National Science Foundation
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