Mesoscale Processes

What is the role of mesoscale activity in the regulation of energy-matter transfer and ecosystem dynamics in oceanic waters?

Mesoscale eddies are characteristic of the eastern South Pacific (ESP), connecting coastal upwelling zones with oligotrophic oceanic waters, as well as meso- and epipelagic domains. Eddies create unique and relatively isolated environments where distinctive biological communities and chemical conditions can exist, depending on the nature of the water in the eddies, their characteristics and paths, and their interactions with winds and topography. Seamounts, ocean ridges and oceanic islands in the eastern South Pacific could also produce or strengthen mesoscale activity, thereby increasing surrounding biological production.


The IMO hypothesis is that mesoscale eddies in coastal areas create deficient O2/low pH conditions in the open sea (or the opposite in oxygen minimum zones), with corresponding changes in community structures and with biochemical cycles significantly different from those found in adjacent oceanic waters.  To test this theory, we will carry out a field experiment to study the characteristics and evolution of mesoscale eddies off central Chile (~36 ºS) flowing to the northwest and arriving near the Juan Fernández Archipelago. This field experiment will involve time-series observations by satellite tele-detection (e.g. altimetry and color scanner), an anchorage in the vicinity of the Juan Fernández Archipelago, as well as observations of certain sections using gliders and a research vessel. To study the evolution of the physical-chemical and biological conditions in one of these eddies we will visit it three times as it flows from the coast to the open ocean. On each occasion, we are going to assess changes in chemical characteristics (dissolved organic carbon, organic and inorganic dissolved particles, O2, pH/pCO2, and nutrients), community structures, gene expression and biogeochemical activity (e.g. primary production, nitrogen fixation, respiration, etc.) within and outside the eddies. We will also carry out on-board perturbation experiments, applying individual and multiple stress factors in contrasting waters. Additionally, through numerical experiments, we will analyze the structure of these eddies and the ways in which they are generated and move, particularly in the oxygen minimum zones (OMZs) around oceanic islands and seamounts associated with the Nazca and Juan Fernández ridges.



Meet our researchers


Expanding the conceptual framework of the spatial population structure and life history of jack mackerel in the eastern South Pacific: an oceanic seamount region as potential spawning/nursery habitat

ICES Journal of Marine Science | Volume 74, Issue 9, Pages 2398-2414

doi:10.1093/icesjms/fsx065December, 2017

Parada, C.Gretchina, A.Vásquez, S.Belmadani, A.Combes, V.Ernst, B.Di Lorenzo, E.Porobic, J.Sepúlveda, A.

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 | Volume 122, Issue 11, Pages 8944-8965

doi:10.1002/2017JC013111November, 2017

Morales, C.E.Anabalón, V.Bento, J.P.Hormazábal, S.Cornejo, M.Correa-Ramírez, M.A.Silva, N.

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-14-00040.1October, 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:10.1357/002224015817391285November, 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:10.1002/2014JC010265June, 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:10.1088/1748-9326/10/4/044017April, 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/s10750-015-2265-6April, 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:10.1002/2014JC010460April, 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.2014.221April, 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.2015.03.007March, 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:10.1002/2014JC010330February, 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.2014.12.016January, 2015

Other research lines

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