How well can we quantify dust deposition to the ocean?

R F Anderson; H Cheng; R L Edwards; M Q Fleisher; C T Hayes; K-F Huang; D Kadko; P J Lam; W M Landing; Y Lao; Y Lu; C I Measures; S B Moran; P L Morton; D C Ohnemus; L F Robinson; R U Shelley

doi:10.1098/rsta.2015.0285

How well can we quantify dust deposition to the ocean?

Philos Trans A Math Phys Eng Sci. 2016 Nov 28;374(2081):20150285. doi: 10.1098/rsta.2015.0285.

Authors

R F Anderson^{1

2}, H Cheng^{3

4}, R L Edwards³, M Q Fleisher⁵, C T Hayes⁶, K-F Huang⁷, D Kadko⁸, P J Lam⁹, W M Landing¹⁰, Y Lao¹¹, Y Lu¹², C I Measures¹³, S B Moran¹⁴, P L Morton¹⁰, D C Ohnemus¹⁵, L F Robinson¹⁶, R U Shelley¹⁷

Affiliations

¹ Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY 10964, USA boba@ldeo.columbia.edu.
² Department of Earth and Environmental Sciences, Columbia University, New York, NY 10027, USA.
³ Department of Earth Sciences, University of Minnesota, Minneapolis, MN 55455, USA.
⁴ Institute of Global Environmental Change, Xi'an Jiaotong University, Xi'an, People's Republic of China.
⁵ Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY 10964, USA.
⁶ Department of Marine Science, University of Southern Mississippi, Stennis Space Center, MS 39529, USA.
⁷ Institute of Earth Sciences, Academia Sinica, Taipei, Taiwan, Republic of China.
⁸ Applied Research Center, Florida International University, Miami, FL 33174, USA.
⁹ Department of Ocean Sciences, University of California Santa Cruz, Santa Cruz, CA 95064, USA.
¹⁰ Department of Earth, Ocean and Atmospheric Science, Florida State University, Tallahassee, FL 32306, USA.
¹¹ Department of Laboratory Services, Massachusetts Water Resources Authority, 190 Tafts Avenue, Winthrop, MA 02152, USA.
¹² Earth Observatory of Singapore, 50 Nanyang Avenue, Singapore 639798, Republic of Singapore.
¹³ Department of Oceanography, University of Hawaii, Honolulu, HI 96822, USA.
¹⁴ College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Fairbanks, AK 99775, USA.
¹⁵ Bigelow Laboratory for Ocean Sciences, East Boothbay, ME 04544, USA.
¹⁶ School of Earth Sciences, University of Bristol, Queens Road, Bristol BS8 1RJ, UK.
¹⁷ LEMAR/UMR CNRS 6539/IUEM, Technopôle Brest-Iroise, Place Nicolas Copernic, Plouzané 29280, France.

Abstract

Deposition of continental mineral aerosols (dust) in the Eastern Tropical North Atlantic Ocean, between the coast of Africa and the Mid-Atlantic Ridge, was estimated using several strategies based on the measurement of aerosols, trace metals dissolved in seawater, particulate material filtered from the water column, particles collected by sediment traps and sediments. Most of the data used in this synthesis involve samples collected during US GEOTRACES expeditions in 2010 and 2011, although some results from the literature are also used. Dust deposition generated by a global model serves as a reference against which the results from each observational strategy are compared. Observation-based dust fluxes disagree with one another by as much as two orders of magnitude, although most of the methods produce results that are consistent with the reference model to within a factor of 5. The large range of estimates indicates that further work is needed to reduce uncertainties associated with each method before it can be applied routinely to map dust deposition to the ocean. Calculated dust deposition using observational strategies thought to have the smallest uncertainties is lower than the reference model by a factor of 2-5, suggesting that the model may overestimate dust deposition in our study area.This article is part of the themed issue 'Biological and climatic impacts of ocean trace element chemistry'.

Keywords: GEOTRACES; aerosols; dust; northeast tropical Atlantic.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.