Mesoscale Processes

What is the role of mesoscale activity on regulating energy-matter transfer and on the dynamics of ecosystems in oceanic waters?

Mesoscale eddies are characteristic of the southeastern Pacific (SEP) and connect areas with coastal upwelling with oligotrophic oceanic waters, as well as meso- and epipelagic domains. The eddies create unique and relatively isolated environments with distinct biological communities and chemical conditions, depending on the nature of the water trapped, the characteristics and path of the eddies and their interactions with winds and topography. Seamounts, submarine mountain ranges and oceanic islands in the southeastern Pacific can also create or strengthen mesoscale activity and consequently increase biological production around them. Our hypothesis is that mesoscale eddies that are generated in the costal area create conditions of deficient O2/low pH in the open sea (or the opposite in areas with minimal oxygen), with corresponding changes in the structure of communities and biochemical cycles, and that differ significantly from those found in adjacent oceanic waters. To address this research theme, we will carry a field experiment to study the characteristics and evolution of mesoscale eddies generated in the sea beyond central Chile (~36 ºS) and that are propagated to the northwest, reaching to around the Juan Fernández Archipelago. The field experiment will include time-series observations by satellite teledetection (e.g. ocean altimetry and color), an anchorage in the vicinity of the Juan Fernández Archipelago, and sections with a sailplane, as well as cruises oriented to processes. To study the evolution of the physical-chemical and biological conditions of one of these eddies we will visit it on three occasions as it advances from the coast to the open ocean. On this occasion we assess changes in chemical characteristics (e.g. dissolved organic carbon and organic particulates and dissolved inorganic matter, O2, pH/pCO2 and nutrients), community structures, gene expression and biogeochemical activity (e.g. primary production, nitrogen fixation, respiration and others) within and beyond the eddies. As well, we will carry out onboard perturbation experiments; applying individual and multiple stress factor in contrasting waters. Using numeric experiments, we will analyze the structure of these eddies and they ways in which they are generated and transported, in particular in the minimum oxygen zones (ZMO) around oceanic islands and submarine associated with the submarine Nazca and Juan Fernández mountain ranges.



Meet our researchers


Front-Eddy Influence on Water Column Properties, Phytoplankton Community Structure, and Cross-Shelf Exchange of Diatom Taxa in the Shelf-Slope Area off Concepción (∼36–37°S)

Journal of Geophysical Research: Oceans

doi:10.1002/2017JC013111Tuesday, November 21, 2017

Morales, C.E.Anabalón, V.Bento, JoaquimHormazábal, S.Cornejo D'Ottone, M.Correa- Ramirez, MarcoSilva, Nelson

Underwater glider observations in the oxygen minimum zone off central Chile

Bulletin of the American Meteorological Society | Volume 97, Issue 10, Pages 1783-1789

doi:10.1175/BAMS-D-14-00040.1Tuesday, November 22, 2016

The influence of anoxia and substrate availability on N2O cycling by denitrification in the upper boundary of the oxygen minimum zone off northern Chile

Journal of Marine Research | Volume 73, Issue 6, Pages 185-205

doi:10.1357/002224015817391285Sunday, November 1, 2015

Castro-González, M.Farías, L.

Interannual variability of the subsurface eddy field in the Southeast Pacific

Journal of Geophysical Research: Oceans | Volume 120, Issue 7, Pages 4907-4924

doi:10.1002/2014JC010265Tuesday, June 16, 2015

Combes, V.Hormazábal, S.Di Lorenzo, E.

Presence of nitrous oxide hotspots in the coastal upwelling area off central Chile: an analysis of temporal variability based on ten years of a biogeochemical time series

Environmental Research Letters | Volume 10, Issue 4, Pages 1-13

doi:10.1088/1748-9326/10/4/044017Friday, April 24, 2015

Farías, L.Besoain, V.García-Loyola, S.

Intra-seasonal variation and its effects on copepod community structure off Central/southern Chile (2002-2009)

Hydrobiologia | Volume 758, Issue 1, Pages 61-74

doi:10.1007/s10750-015-2265-6Sunday, April 12, 2015

Mesoscale variability in the habitat of the Humboldt Current krill, spring 2007

Journal of Geophysical Research: Oceans | Volume 120, Issue 4, Pages 2769-2783

doi:10.1002/2014JC010460Saturday, April 11, 2015

Life-cycle modification in open oceans accounts for genome variability in a cosmopolitan phytoplankton

ISME Journal | Volume 9, Pages 1365-1377

doi:10.1038/ismej.2014.221Wednesday, April 1, 2015

Von Dassow, P.Johns, U.Ogata, H.Probert, I.Mahdi Bendif, E.Kegel, U.J.Audic, S.Da Silva, C.Claverie, J.M.Doney, S.Glover, D.M.Herrera, Y.Lescot, M.Garet-Delmas, M.L.De Vargas, C.

Egg production and hatching success of Calanus chilensis and Acartia tonsa in the northern Chile upwelling zone (23°S), Humboldt Current System

Journal of Marine Systems | Volume 148, Pages 200-212

doi:10.1016/j.jmarsys.2015.03.007Saturday, March 21, 2015

Phytoplankton phenology in the coastal upwelling region off central-southern Chile (35S–38S): Time-space variability, coupling to environmental factors, and sources of uncertainty in the estimates

Journal of Geophysical Research: Oceans | Volume 120, Issue 2, Pages 813-831

doi:10.1002/2014JC010330Thursday, February 12, 2015

An unaccounted for N2O sink in the surface water of the eastern subtropical South Pacific: Physical versus biological mechanisms

Progress in Oceanography | Volume 137, Pages 12-23

doi:10.1016/j.pocean.2014.12.016Thursday, January 8, 2015

Other research lines

Universidad de ConcepciónPontificia Universidad Católica de ChileMinisterio de Economía, Fomento y TurismoIniciativa Científica Milenio
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