OUTPACE long duration stations: physical variability, context of biogeochemical sampling, and evaluation of sampling strategy
|Author(s)||de Verneil Alain1, 4, Rousselet Louise1, Doglioli Andrea M.1, Petrenko Anne A.1, Maes Christophe2, Bouruet-Aubertot Pascale3, Moutin Thierry1|
|Affiliation(s)||1 : Aix Marseille Univ, Univ Toulon, CNRS, IRD,MIO UM 110, F-13288 Marseille, France.
2 : UBO, CNRS, LOPS, Ifremer,IRD,IUEM, F-29280 Brest, France.
3 : Univ Paris 06, Sorbonne Univ, UPMC, CNRS IRD MNHN,LOCEAN, Paris, France.
4 : New York Univ Abu Dhabi, Ctr Prototype Climate Modeling, Abu Dhabi, U Arab Emirates.
|Source||Biogeosciences (1726-4170) (Copernicus Gesellschaft Mbh), 2018-04 , Vol. 15 , N. 7 , P. 2125-2147|
|WOS© Times Cited||12|
|Note||Special issue Interactions between planktonic organisms and biogeochemical cycles across trophic and N2 fixation gradients in the western tropical South Pacific Ocean: a multidisciplinary approach (OUTPACE experiment) Editor(s): T. Moutin, S. Bonnet, K. Richards, D. G. Capone, E. Marañón, and L. Mémery|
Research cruises to quantify biogeochemical fluxes in the ocean require taking measurements at stations lasting at least several days. A popular experimental design is the quasi-Lagrangian drifter, with in situ incubations that follow the flow of water over time. The ship then tracks the drifter because subsequent measurements are supposed to remain in the same water environment. An outstanding question is how to best determine whether this is true. During the Oligotrophy to UlTra-oligotrophy PACific Experiment (OUTPACE) cruise, from 18 February to 3 April 2015 in the western tropical South Pacific, three separate stations of long duration (five days) over the upper 500 m were conducted in this quasi-Lagrangian sampling scheme. Here we present physical data to provide context for these three stations and to assess whether the sampling strategy worked, i.e. that indeed a single body of water was sampled. After analyzing tracer variability and local water circulation at each station, we argue that, while no realization will be truly Lagrangian, all long duration three stations were conducted in their own sufficiently self-similar physical environment during OUTPACE. By directly addressing the concerns raised by these quasi-Lagrangian sampling platforms, a protocol of best practices can begin to be formulated so that future research campaigns include the complementary datasets and analyses presented here to verify the appropriate use of the drifter platform.