Author
Sophie Bonnet
Other affiliations: Université du Québec à Montréal, University of Grenoble, Institut de recherche pour le développement ...read more
Bio: Sophie Bonnet is an academic researcher from Aix-Marseille University. The author has contributed to research in topics: Trichodesmium & Diazotroph. The author has an hindex of 35, co-authored 116 publications receiving 4687 citations. Previous affiliations of Sophie Bonnet include Université du Québec à Montréal & University of Grenoble.
Topics: Trichodesmium, Diazotroph, Phytoplankton, Mesocosm, South Pacific Gyre
Papers published on a yearly basis
Papers
More filters
••
TL;DR: The results imply that humans could be substantially impacting iron and bioavailable iron deposition to ocean regions, but there are large uncertainties in the authors' understanding.
562 citations
••
University of Perpignan1, Pierre-and-Marie-Curie University2, Centre national de la recherche scientifique3, IFREMER4, University of Toulouse5, Université Paul Cézanne Aix-Marseille III6, University of Montpellier7, Stazione Zoologica Anton Dohrn8, Spanish National Research Council9, Institut de radioprotection et de sûreté nucléaire10, University of Nice Sophia Antipolis11, University College West12, École Normale Supérieure13, University of Georgia14, Plymouth Marine Laboratory15, university of lille16
TL;DR: In this article, a review of current functioning and responses of Mediterranean marine biogeochemical cycles and ecosystems with respect to key natural and anthropogenic drivers and to consider the ecosystems' responses to likely changes in physical, chemical and socio-economical forcings induced by global change and by growing anthropogenic pressure at the regional scale.
391 citations
••
University of Bremen1, University of Liverpool2, Université du Québec3, GNS Science4, Alexandria University5, United States Geological Survey6, University of Bordeaux7, Assiut University8, Autonomous University of Barcelona9, Utrecht University10, Nagasaki University11, Geological Survey of Canada12, Wellington Management Company13, University of Victoria14, Jinan University15, Université du Québec à Rimouski16, Aarhus University17, Ghent University18, Commonwealth Scientific and Industrial Research Organisation19
TL;DR: This Atlas summarises the modern global distribution of 71 organic-walled dinoflagellate cyst species and examines the relationship between seasonal and annual variations of these parameters and the relative abundance of the species.
370 citations
••
Woods Hole Oceanographic Institution1, University of Las Palmas de Gran Canaria2, Bar-Ilan University3, Aix-Marseille University4, Linnaeus University5, University of Hawaii6, University of Southern California7, San Francisco State University8, National Sun Yat-sen University9, Montana State University10, National Autonomous University of Mexico11, University of Vigo12, Max Planck Society13, University of Tokyo14, University of Valencia15, University of Southern Mississippi16, University of Georgia17, Leibniz Association18, Oregon State University19, University of Massachusetts Dartmouth20, University of California, Santa Cruz21, National Oceanography Centre, Southampton22, Old Dominion University23, Oregon Health & Science University24, National Oceanography Centre25, Plymouth Marine Laboratory26, University of Copenhagen27, Lamont–Doherty Earth Observatory28, University of Texas at Austin29, University of Miami30
TL;DR: This database is limited spatially, lacking large regions of the ocean especially in the Indian Ocean, but can nevertheless be used to study spatial and temporal distributions and variations of marine N2 fixation, to validate geochemical estimates and to parameterize and validate biogeochemical models.
Abstract: . Marine N2 fixing microorganisms, termed diazotrophs, are a key functional group in marine pelagic ecosystems. The biological fixation of dinitrogen (N2) to bioavailable nitrogen provides an important new source of nitrogen for pelagic marine ecosystems and influences primary productivity and organic matter export to the deep ocean. As one of a series of efforts to collect biomass and rates specific to different phytoplankton functional groups, we have constructed a database on diazotrophic organisms in the global pelagic upper ocean by compiling about 12 000 direct field measurements of cyanobacterial diazotroph abundances (based on microscopic cell counts or qPCR assays targeting the nifH genes) and N2 fixation rates. Biomass conversion factors are estimated based on cell sizes to convert abundance data to diazotrophic biomass. The database is limited spatially, lacking large regions of the ocean especially in the Indian Ocean. The data are approximately log-normal distributed, and large variances exist in most sub-databases with non-zero values differing 5 to 8 orders of magnitude. Reporting the geometric mean and the range of one geometric standard error below and above the geometric mean, the pelagic N2 fixation rate in the global ocean is estimated to be 62 (52–73) Tg N yr−1 and the pelagic diazotrophic biomass in the global ocean is estimated to be 2.1 (1.4–3.1) Tg C from cell counts and to 89 (43–150) Tg C from nifH-based abundances. Reporting the arithmetic mean and one standard error instead, these three global estimates are 140 p 9.2 Tg N yr−1, 18 p 1.8 Tg C and 590 p 70 Tg C, respectively. Uncertainties related to biomass conversion factors can change the estimate of geometric mean pelagic diazotrophic biomass in the global ocean by about p70%. It was recently established that the most commonly applied method used to measure N2 fixation has underestimated the true rates. As a result, one can expect that future rate measurements will shift the mean N2 fixation rate upward and may result in significantly higher estimates for the global N2 fixation. The evolving database can nevertheless be used to study spatial and temporal distributions and variations of marine N2 fixation, to validate geochemical estimates and to parameterize and validate biogeochemical models, keeping in mind that future rate measurements may rise in the future. The database is stored in PANGAEA ( doi:10.1594/PANGAEA.774851 ).
319 citations
••
TL;DR: In this paper, an aerosol sampling performed in the French Riviera between August and September 2003 indicated that iron concentrations in 2003 were significantly higher than in previous years, while continuous pyrogenic emissions are suspected to be the cause of high Fe concentrations.
Abstract: [1] While the Mediterranean region is typified by frequent summer fires, the 2003 heat wave that hit Europe, and France in particular, made this season longer causing devastating fires. Aerosol sampling performed in the French Riviera between August and September 2003 indicated that iron concentrations in 2003 were significantly higher than in previous years. Continuous pyrogenic emissions are suspected to be the cause of high Fe concentrations. When these particles were dissolved in seawater, 2% of the total iron content was found in solution. This amount could be significant for the water column on a regional scale. Indeed, these fires might explain the observed dissolved iron enrichment of the surface mixed layer (+0.4 nM) measured in the Ligurian Sea during August. In contrast to a locally significant effect, pyrogenic inputs have little impact on the global Fe budget since they represent at most 10% of desert dust inputs.
170 citations
Cited by
More filters
••
2,261 citations
••
01 Jan 2014TL;DR: For base year 2010, anthropogenic activities created ~210 (190 to 230) TgN of reactive nitrogen Nr from N2 as discussed by the authors, which is at least 2 times larger than the rate of natural terrestrial creation of ~58 Tg N (50 to 100 Tg nr yr−1) (Table 6.9, Section 1a).
Abstract: For base year 2010, anthropogenic activities created ~210 (190 to 230) TgN of reactive nitrogen Nr from N2. This human-caused creation of reactive nitrogen in 2010 is at least 2 times larger than the rate of natural terrestrial creation of ~58 TgN (50 to 100 TgN yr−1) (Table 6.9, Section 1a). Note that the estimate of natural terrestrial biological fixation (58 TgN yr−1) is lower than former estimates (100 TgN yr−1, Galloway et al., 2004), but the ranges overlap, 50 to 100 TgN yr−1 vs. 90 to 120 TgN yr−1, respectively). Of this created reactive nitrogen, NOx and NH3 emissions from anthropogenic sources are about fourfold greater than natural emissions (Table 6.9, Section 1b). A greater portion of the NH3 emissions is deposited to the continents rather than to the oceans, relative to the deposition of NOy, due to the longer atmospheric residence time of the latter. These deposition estimates are lower limits, as they do not include organic nitrogen species. New model and measurement information (Kanakidou et al., 2012) suggests that incomplete inclusion of emissions and atmospheric chemistry of reduced and oxidized organic nitrogen components in current models may lead to systematic underestimates of total global reactive nitrogen deposition by up to 35% (Table 6.9, Section 1c). Discharge of reactive nitrogen to the coastal oceans is ~45 TgN yr−1 (Table 6.9, Section 1d). Denitrification converts Nr back to atmospheric N2. The current estimate for the production of atmospheric N2 is 110 TgN yr−1 (Bouwman et al., 2013).
1,967 citations
••
National Center for Atmospheric Research1, University of Illinois at Urbana–Champaign2, German Aerospace Center3, Earth System Research Laboratory4, Centre national de la recherche scientifique5, Cooperative Institute for Research in Environmental Sciences6, Forschungszentrum Jülich7, International Institute for Applied Systems Analysis8, Manchester Metropolitan University9, Goddard Institute for Space Studies10, Joint Global Change Research Institute11, Netherlands Environmental Assessment Agency12, Cornell University13, Desert Research Institute14, Geophysical Fluid Dynamics Laboratory15
TL;DR: In this paper, the authors present a new dataset of gridded emissions covering the historical period (1850-2000) in decadal increments at a horizontal resolution of 0.5° in latitude and longitude.
Abstract: We present and discuss a new dataset of gridded emissions covering the historical period (1850–2000) in decadal increments at a horizontal resolution of 0.5° in latitude and longitude. The primary purpose of this inventory is to provide consistent gridded emissions of reactive gases and aerosols for use in chemistry model simulations needed by climate models for the Climate Model Intercomparison Program #5 (CMIP5) in support of the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5). Our best estimate for the year 2000 inventory represents a combination of existing regional and global inventories to capture the best information available at this point; 40 regions and 12 sectors are used to combine the various sources. The historical reconstruction of each emitted compound, for each region and sector, is then forced to agree with our 2000 estimate, ensuring continuity between past and 2000 emissions. Simulations from two chemistry-climate models is used to test the ability of the emission dataset described here to capture long-term changes in atmospheric ozone, carbon monoxide and aerosol distributions. The simulated long-term change in the Northern mid-latitudes surface and mid-troposphere ozone is not quite as rapid as observed. However, stations outside this latitude band show much better agreement in both present-day and long-term trend. The model simulations indicate that the concentration of carbon monoxide is underestimated at the Mace Head station; however, the long-term trend over the limited observational period seems to be reasonably well captured. The simulated sulfate and black carbon deposition over Greenland is in very good agreement with the ice-core observations spanning the simulation period. Finally, aerosol optical depth and additional aerosol diagnostics are shown to be in good agreement with previously published estimates and observations.
1,953 citations
••
TL;DR: The physics of aeolian saltation, the formation and development of sand dunes and ripples, the physics of dust aerosol emission, the weather phenomena that trigger dust storms, and the lifting of dust by dust devils and other small-scale vortices are reviewed.
Abstract: The transport of sand and dust by wind is a potent erosional force, creates sand dunes and ripples, and loads the atmosphere with suspended dust aerosols This article presents an extensive review of the physics of wind-blown sand and dust on Earth and Mars Specifically, we review the physics of aeolian saltation, the formation and development of sand dunes and ripples, the physics of dust aerosol emission, the weather phenomena that trigger dust storms, and the lifting of dust by dust devils and other small-scale vortices We also discuss the physics of wind-blown sand and dune formation on Venus and Titan
1,175 citations