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. Does it mean “describe” or “trace the outline of”?
Could someone kindly enlighten me on this?