Particle distribution in repeated ocean sections and sediment resuspension

This is the first compilation of an expansive data base of transmissometer data on a decadal period of time. More than 7376 stations have been analyzed for “cp” value, a proxy for particle concentrations, by Gardner and co-workers (2018, see reference below). Full water-column sections confirm that particle concentrations are higher in surface waters, decrease rapidly below 200 m, most often down to the seafloor. However, cloudy near-bottom waters, known as “benthic nepheloid layers”, are generated by sediment erosion and resuspension at specific geographic areas. These locations are directly linked to energetic surface dynamics that produce regions of high Eddy Kinetic Energy (EKE). More fascinating, however, is the decadal persistence of this close surface-to-deep connection. We invite you to read this very interesting article!

18 Gardner2Figures: (A) Map of log of surface eddy kinetic energy (modified from Dixon et al., 2011) with cp transects indicated. (B) Section of cp (proxy for particle concentration) along 53° W in spring, 2012 in the Western North Atlantic. Black contours are dissolved oxygen (µmol kg-1). Click here to view the figure larger.

Reference:

Gardner, W. D., Mishonov, A. V., & Richardson, M. J. (2018). Decadal Comparisons of Particulate Matter in Repeat Transects in the Atlantic, Pacific, and Indian Ocean Basins. Geophysical Research Letters. http://doi.org/10.1002/2017GL076571

Latest highlights

Anthropogenic iron impact on the surface productivity in the Pacific Transition Zone

Hawco and colleagues investigated the influence of industrial emissions on oceanic iron supply and its ecological consequences in the North Pacific.

Trace metal effluxes from Peruvian shelf sediments

Liu and co-authors compared four methods to estimate dissolved iron fluxes from Peruvian shelf sediments, revealing large variability.

Coupling copper and neodymium data highlights the importance of the margin sources for the copper oceanic cycle

Lemaitre and co-workers analysed the dissolved concentrations and isotopes along the GEOVIDE (GA01) section in the North Atlantic Ocean.

High levels of anthropogenic lead in the Indian Ocean

Yadav and her colleagues provide comprehensive insights into the distribution and sources of dissolved lead in the Indian Ocean.

Rechercher