Anthropogenic perturbations to the atmospheric molybdenum cycle

Michelle Y. Wong*, Sagar D. Rathod, Roxanne Marino, Longlei Li, Robert W. Howarth, Andres Alastuey, Maria Grazia Alaimo, Francisco Barraza, Manuel Castro Carneiro, Shankararaman Chellam, Yu Cheng Chen, David D. Cohen, David Connelly, Gaetano Dongarra, Darió Gómez, Jenny Hand, R. M. Harrison, Philip K. Hopke, Christoph Hueglin, Yuan wen KuangFabrice Lambert, James Liang, Remi Losno, Willy Maenhaut, Chad Milando, Maria Inês Couto Monteiro, Yasser Morera-Gómez, Xavier Querol, Sergio Rodríguez, Patricia Smichowski, Daniela Varrica, Yi hua Xiao, Yangjunjie Xu, Natalie M. Mahowald

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

64 Downloads (Pure)

Abstract

Molybdenum (Mo) is a key cofactor in enzymes used for nitrogen (N) fixation and nitrate reduction, and the low availability of Mo can constrain N inputs, affecting ecosystem productivity. Natural atmospheric Mo aerosolization and deposition from sources such as desert dust, sea-salt spray, and volcanoes can affect ecosystem function across long timescales, but anthropogenic activities such as combustion, motor vehicles, and agricultural dust have accelerated the natural Mo cycle. Here we combined a synthesis of global atmospheric concentration observations and modeling to identify and estimate anthropogenic sources of atmospheric Mo. To project the impact of atmospheric Mo on terrestrial ecosystems, we synthesized soil Mo data and estimated the global distribution of soil Mo using two approaches to calculate turnover times. We estimated global emissions of atmospheric Mo in aerosols (<10 μm in diameter) to be 23 Gg Mo yr−1, with 40%–75% from anthropogenic sources. We approximated that for the top meter of soil, Mo turnover times range between 1,000 and 1,000,000 years. In some industrialized regions, anthropogenic inputs have enhanced Mo deposition 100-fold, lowering the soil Mo turnover time considerably. Our synthesis of global observational data, modeling, and a mass balance comparison with riverine Mo exports suggest that anthropogenic activity has greatly accelerated the Mo cycle, with potential to influence N-limited ecosystems.

Original languageEnglish
Article numbere2020GB006787
JournalGlobal Biogeochemical Cycles
Volume35
Issue number2
Early online date28 Jan 2021
DOIs
Publication statusPublished - Feb 2021

Bibliographical note

Funding Information:
We acknowledge the Atkinson Center for a Sustainable Future at Cornell University for funding for this project, and thank Adina Paytan for comments on an earlier version of this manuscript. Simulations were undertaken at the NCAR facility (National Center for Atmospheric Research, 2019). We acknowledge many observational networks and sites that were used in this study, including, but not limited to APAD and ASFID: Airborne Particulate Matter Databases Related to the Asia-Pacific Region (http://www.ansto.gov.au/aspdatabases), DEFRA (https://uk-air.defra.gov.uk), the European Monitoring and Evaluation Programme (https://www.emep.int/), the Ministerio del Medio Ambiente de Chile (https://mma.gob.cl), and the Research State Agency of Spain. Houston area measurements were made possible by funding from the Texas Air Research Center and the Texas Commission on Environmental Quality to S. Chellam. F. Lambert acknowledges support from projects ANID/Fondecyt 1191223, ANID/Fondap 15110009, and ANID/Millennium Science Initiative/Millennium Nucleus Paleoclimate NCN17_079. N. M. Mahowald acknowledges support from NSF CCF-1522054 and DE-SC0006791, and S. D. Rathod acknowledges support from DE-SS0016362.

Funding Information:
We acknowledge the Atkinson Center for a Sustainable Future at Cornell University for funding for this project, and thank Adina Paytan for comments on an earlier version of this manuscript. Simulations were undertaken at the NCAR facility (National Center for Atmospheric Research, 2019). We acknowledge many observational networks and sites that were used in this study, including, but not limited to APAD and ASFID: Airborne Particulate Matter Databases Related to the Asia‐Pacific Region ( http://www.ansto.gov.au/aspdatabases ), DEFRA ( https://uk-air.defra.gov.uk ), the European Monitoring and Evaluation Programme ( https://www.emep.int/ ), the Ministerio del Medio Ambiente de Chile ( https://mma.gob.cl ), and the Research State Agency of Spain. Houston area measurements were made possible by funding from the Texas Air Research Center and the Texas Commission on Environmental Quality to S. Chellam. F. Lambert acknowledges support from projects ANID/Fondecyt 1191223, ANID/Fondap 15110009, and ANID/Millennium Science Initiative/Millennium Nucleus Paleoclimate NCN17_079. N. M. Mahowald acknowledges support from NSF CCF‐1522054 and DE‐SC0006791, and S. D. Rathod acknowledges support from DE‐SS0016362.

Keywords

  • aerosol deposition
  • nitrogen fixation
  • nitrogenase
  • nutrient limitation
  • particulate matter

ASJC Scopus subject areas

  • Global and Planetary Change
  • Environmental Chemistry
  • Environmental Science(all)
  • Atmospheric Science

Fingerprint

Dive into the research topics of 'Anthropogenic perturbations to the atmospheric molybdenum cycle'. Together they form a unique fingerprint.

Cite this