Mechanisms of Pollutant Exchange at Soil-Vegetation-Atmosphere Interfaces and Atmospheric Fate
The presence in the atmosphere of pollutants emitted from agriculture or impacting crop production, their concentration levels and their residence time depend on a series of physical, chemical and biological processes. This chapter describes the basic mechanisms and the main factors involved in air pollutant emissions and fate in agricultural systems. These include emissions to the atmosphere from fields or livestock husbandry, atmospheric transfers at various scales – from the proximity of the sources to regional and global scales –, atmospheric chemistry and deposition to ecosystem. These concepts are necessary to understand the context and various choices that can be made in terms of measuring air concentrations and emission/deposition fluxes and of modelling emissions, atmospheric fate – dispersion, transport, degradation – and deposition. The knowledge on these processes contributes to modelling the impact of agricultural sources on air quality and the impact of air pollution on ecosystems. It also helps identify levers for mitigating emissions from agriculture and impacts of air pollution on crops.
(pp. 61-96, 22/01/2020)
ECOSYS, INRAE, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, SADAPT, INRAE, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Non-hydrostatic, non-linear processes in the surf zone
• Sub-surface pressure and lidar data are used to study the non-linear and nonhydrostatic character of surf zone waves • Non-hydrostatic effects are strong even in the inner surf zone, where broken waves are sharp-crested and have a steep front • Oscillatory flow under broken waves is dominated by irrotational motions
(Journal of Geophysical Research. Oceans. vol. 125, n° 2169-9275, 18/01/2020)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Experimental study of the formation of organosulfates from $\alpha$-Pinene oxidation. 2. Time evolution and effect of particle acidity
The present work is an extensive laboratory study of organosulfate (OS) formation from the reaction of α-pinene oxidation products or proxies with acidified ammonium sulfate aerosols in three different acidity conditions (NH$_4$)$_2$SO$_4$ 0.06 M; (NH$_4$)$_2$SO$_4$/H$_2$SO$_4$ 0.06 M/0.005 M; (NH$_4$)$_2$SO$_4$/H$_2$SO$_4$ 0.03 M/0.05 M). The kinetics of the reactions of $\alpha$-pinene, $\alpha$-pinene oxide, isopinocampheol, pinanediol, and myrtenal with ammonium sulfate particles were studied using a quasi-static reactor. The reaction of $\alpha$-pinene oxide with the highly acidic ammonium sulfate particles was determined to be 7, 10, 21, and 24 times faster than for isopinocampheol, $\alpha$-pinene, pinanedial, and myrtenal, respectively, for an OS precursor concentration of 1 ppm and after 1 h reaction time. The effective rate coefficients for OS formation from $\alpha$-pinene oxide were determined to be 2 orders of magnitude higher in highly acidic conditions than for the two other acidity conditions. For $\alpha$-pinene oxide reactions with highly acidic ammonium sulfate particles, OS formation was observed to increase linearly with (i) the time of reaction up to 400 min ($r^2$= > 0.95) and (ii) α-pinene oxide gas-phase concentration. However, OS formation from $\alpha$-pinene oxide reactions with slightly acidic or pure ammonium sulfate particles was limited, with a plateau ([OS]max = 0.62 ± 0.03 $\mu$g) reached after around 15–20 min. Organosulfate dimers (m/z 401 and m/z 481) were detected not only with highly acidic particles but also with slightly acidic and pure ammonium sulfate particles, indicating that oligomerization processes do not require strong acidity conditions. Dehydration products of organosulfates ($m/z$ 231 and $m/z$ 383) were observed only under highly acidic conditions, indicating the key role of H$_2$SO$_4$ on the dehydration of organosulfates and the formation of olefins in the atmosphere. Finally, this kinetic study was completed with simulation chamber experiments in which the mass concentration of organosulfates was shown to depend on the available sulfate amount present in the particle phase ($r^2$ = 0.96). In conclusion, this relative comparison between five organosulfate precursors shows that epoxide was the most efficient reactant to form organosulfates via heterogeneous gas–particle reactions and illustrates how gas–particle reactions may play an important role in OS formation and hence in the atmospheric fate of organic carbon. The kinetic data presented in this work provide strong support to organosulfate formation mechanisms proposed in part 1 ( J. Phys. Chem. A 2016, 120, 7909−7923).
(Journal of Physical Chemistry A. vol. 124, n° 1089-5639, pp. 409-421, 16/01/2020)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, LISA (UMR_7583), INSU - CNRS, UPEC UP12, CNRS, UPCité, LAC, PSI
Bivalve mollusc circadian clock genes can run at tidal frequency
(Proceedings of the Royal Society B: Biological Sciences. vol. 287, n° 0962-8452, pp. 20192440, 15/01/2020)
CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Confirmation of the exotic status of Marphysa victori Lavesque, Daffe, Bonifácio & Hutchings, 2017 (Annelida) in French waters and synonymy of Marphysa bulla Liu, Hutchings & Kupriyanova, 2018
The bait worm Marphysa victori Lavesque, Daffe, Bonifácio & Hutchings, 2017 was originally described from Arcachon Bay, France. In the original description, the authors suggested that it may have been introduced, although definitive evidence was lacking at the time. In this paper, we confirm that M. victori is an exotic species originating from East Asia, probably a native of China or Japan. This species was most likely introduced into Arcachon Bay in the 1970s with non-native oysters Crassostrea gigas Thunberg, 1793. The Asiatic origin of this species is confirmed based on both morphological and molecular evidence. Comparison of the type specimens of M. victori with those of Marphysa bulla Liu, Hutchings & Kupriyanova, 2018 described from the Yellow Sea, China, showed no morphological or molecular differences and therefore the more recently named M. bulla is relegated to a junior synonym. This is the first example of a large-sized errant invertebrate species being introduced with oysters into Arcachon Bay.
(Aquatic Invasions. vol. 15, n° 1798-6540, pp. 355-366, 01/01/2020)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UMS POREA, INSU - CNRS, CNRS, INRAE
Simulating storm surge and compound flooding events with a creek-to-ocean model: Importance of baroclinic effects
We present a creek-to-ocean 3D baroclinic model based on unstructured grids that aims to unite traditional hydrologic and ocean models in a single modeling platform, by taking full advantage of the polymorphism (i.e. a single model grid can seamlessly morph between full 3D, 2DV, 2DH and quasi-1D configurations). Using Hurricane Irene (2011)’s impact on the Delaware Bay as an example, a seamless 2D–3D model grid is implemented to include the entire US East Coast and Gulf of Mexico with a highly resolved Delaware Bay (down to 20-m resolution). The model is forced by flows from a hydrological model (National Water Model ) at the landward boundary. We demonstrate the model’s accuracy, stability and robustness with the simulation of the storm surge and subsequent river flooding events and compound surges. Through a series of sensitivity tests, we illustrate the importance of including in the simulation the baroclinic effects, as provided by the large-scale Gulf Stream, in order to correctly capture the adjustment process following the main surge and the subsequent compound flooding events. The baroclinicity can explain up to 14% of the elevation error during the adjustment phase after the storm.
(Ocean Modelling. vol. 145, n° 1463-5003, pp. 101526, 01/01/2020)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
The fate of microplastics along salinity gradient and tidal cycles in a well-mixed estuary : a case study of the Seine estuary
While most of the studies focused on microplastic (MP) pollution in both marine and continental environments, estuaries are poorly documented and their role as an important pathway and a physical filter are still unclear. In this study, the fate of MP was investigated along the salinity gradient of the Seine well-mixed estuary and over two tidal cycles. Four sampling surveys were conducted at three stations during the same day (La Bouille-upper estuary, Vieux-Port-middle estuary and La Roque-lower estuary) along the salinity gradient. For each survey, surface water (first 15 cm including the sea surface microlayer - SML) and sub-surface water (first 50 cm excluding SML) were collected using a 300-µm mesh size manta net during the ebb tide. Fragments and microbeads were considered while microfiber pollution was excluded. Concentrations in surface waters were 5 to 6 times higher than those in subsurface waters, due to the significant accumulation of MP in SML. Differences were observed along the salinity gradient with the highest concentrations measured at Vieux-Port station located upstream the maximum turbidity front (MTF) and lower concentrations at La Bouille and La Roque stations. This could be explained by i) the salt intrusion and ii) the accumulation of macrolitters in the vicinity of Vieux-Port. Two tidal cycles were also investigated in La Roque, which is characterized by the presence of the MTF. For both cycles, the vertical distribution was examined by sampling sub-surface water, middle-water column and bottom layer during flood and ebb tides. Results clearly demonstrated a vertical gradient between water collected at the bottom (6 and 10 m) exhibiting the highest concentrations while lowest values were observed in surface water. This gradient can be explained by both the resuspension of bottom sediments, rich in MP, during the flood tide and sedimentation during the long water high period and the ebb tide.
(01/01/2020)
GERS-LEE, LEESU, ENPC, UPEC UP12, IFREMER, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Timing and stepwise transitions of the African Humid Period from geochemical proxies in the Nile deep-sea fan sediments
Large fluvial systems, such as the Nile River, allow a basin-scale integrated view of climatological and environmental changes. In this study, we reconstructed the Nile discharge history for the last 20 ka using molecular ratios of glycerol dialkyl glycerol tetraethers (GDGTs) and neodymium (Nd) radiogenic isotopes. By characterizing both the organic and inorganic fractions, we assessed the relevance of the GDGT-based proxies in deltaic environments as tracers of terrigenous origin. A large increase in Nile discharge is documented from 14.8 to 8.4 ka BP reflecting enhanced physical erosion and transport processes from the Ethiopian Traps. We confirmed the primary control of insolation on precipitation on North East Africa through the last 20 ka. The centennial time resolution reached on the sedimentary sequence revealed a step-wise onset and termination of the African Humid Period (AHP) starting at 14.8 ka and ending at 8.4 ka BP, respectively. Our centennial-millennial records allowed furthermore pinpointing the abrupt periods of arid conditions corresponding to the Younger Dryas. These data illustrate the linkage between low and high latitude hydrological variability.
(Quaternary Science Reviews. vol. 228, n° 0277-3791, pp. 106071, 01/01/2020)
LGL-TPE, ENS de Lyon, UCBL, INSU - CNRS, UJM, CNRS, CEREGE, IRD, AMU, CdF (institution), INSU - CNRS, CNRS, INRAE, LOCEAN-CYBIOM, LOCEAN, MNHN, IRD, INSU - CNRS, SU, CNRS, IPSL (FR_636), ENS-PSL, UVSQ, CEA, INSU - CNRS, X, CNES, SU, CNRS, UPCité, NIOZ, INSU - CNRS, UM, CNRS, UA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, CEREGE, IRD, AMU, CdF (institution), INSU - CNRS, CNRS, INRAE, GEOAZUR 7329, INSU - CNRS, UniCA, CNRS, IRD [Occitanie], UniCA
High density polyethylene (HDPE) microplastics impair development and swimming activity of Pacific oyster D-larvae, Crassostrea gigas, depending on particle size
(Environmental Pollution, n° 0269-7491, pp. 113978, 01/01/2020)
LIENSs, INSU - CNRS, ULR, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, EPOC
Trace elements and persistent organic pollutants in chicks of 13 seabird species from Antarctica to the subtropics
Seabirds from remote regions are mainly exposed to environmental contaminants from non-point contamination of their food webs. Pre-fledging seabird chicks are fed by their parents with marine prey captured in the vicinity of breeding colonies. Contaminant concentrations in tissues of pre-fledging chicks can thus be mostly related to local dietary sources, and have the potential to unravel spatial patterns of environmental contamination in marine ecosystems. Here, mercury (Hg), 13 other trace elements, and 18 persistent organic pollutants (POPs) were quantified in blood of chicks across four breeding locations that encompass a large latitudinal range in the southern Indian Ocean (from Antarctica, through subantarctic areas, to the subtropics), over a single breeding season. Thirteen species of penguins, albatrosses and petrels were studied, including endangered and near-threatened species, such as Amsterdam albatrosses and emperor penguins. Blood Hg burdens varied widely between species, with a factor of ~50 between the lowest and highest concentrations (mean ± SD, 0.05 ± 0.01 and 2.66 ± 0.81 µg g−1 dry weight, in thin-billed prions and Amsterdam albatrosses, respectively). Species relying on Antarctic waters for feeding had low Hg exposure. Concentrations of POPs were low in chicks, with the exception of hexachlorobenzene. Contaminant concentrations were mainly explained by species differences, but feeding habitat (inferred from δ13C values) and chicks’ body mass also contributed to explain variation. Collectively, our findings call for further toxicological investigations in Amsterdam albatrosses and small petrel species, because they were exposed to high and diverse sources of contaminants, and in macaroni penguins, which specifically showed very high selenium concentrations. Capsule: Seabird chicks from four distant sites in the southern Indian Ocean had contrasted blood metallic and organic contaminant patterns depending on species, feeding habitat and body mass.
(Environment International. vol. 134, n° 0160-4120, pp. 105225, 01/01/2020)
LIENSs, INSU - CNRS, ULR, CNRS, CEBC, ULR, CNRS, INRAE, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS