What does “delineate” mean in this context?

Question

I was reading a Scientific American story, “Controversial Spewed Iron Experiment Succeeds as Carbon Sink” (by David Biello), when I came across this sentence:

“The problem for scientists is that oceanic waters tend to mix, which makes monitoring and delineating an experiment in the ocean challenging.”

I'm wondering what “delineate” means in this context. I think I grasp the general idea of this sentence, but it is the exact meaning of the word that has been troubling me.

Could someone kindly enlighten me on this?

Thanks!

Answer 1

I think this would me more on topic at English.SE, but (from Merriam-Webster):

Delineate:

1 a : to indicate or represent by drawn or painted lines
    b : to mark the outline of

2 : to describe, portray, or set forth with accuracy or in detail — de·lin·ea·tor noun

In this case, it could be either meaning that is used. Either 2, as Richard Smith said in his answer, to define the experiment's parameters in general, or 1b, to mark, limit a specific area of the ocean in which the experiment will be done. Obviously, delimiting an area in a body of liquid is not very easy.

Answer 2

To delineate an experiment is to describe precisely the conditions and the states of all the parameters.

So in your sentence it probably means a scientist might struggle to keep track of all the confounding factors (changing salinity, composition, dissolved gases, particulates, pH, temp, etc.) which might affect an experiment in such a dynamic system as the ocean.