Study finds increase in phytoplankton, which absorb CO2.
Normal levels of phytoplankton found in brown water near Matanzas.
A lab test of brown water sampled near the Matanzas Inlet ruled out an overabundance of microscopic plants called phytoplankton as a cause of the discoloration.
Phytoplankton off New Zealand.
Today's global warming news is about phytoplankton .
No phytoplankton , no marine life.
For now, our oceans are still teeming with phytoplankton .
Vital ocean phytoplankton a casualty of global warming.
A new study suggests that a global rise in ocean temperatures has cut the number of phytoplankton , which are the bedrock of the food chain, by 40 percent since 1950.
Decline in oceans' phytoplankton alarms scientists / Experts pondering whether reduction of marine plant life is linked to warming of the seas.
A microscope reveals marine diatom cells, which are an important group of phytoplankton in the oceans.
Scientists report finding a massive bloom of phytoplankton hidden under Arctic ice, suggesting that, as the ice thins and melts, the region is becoming vastly more biologically productive.
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Zooplankton (lower curve) has more intense variability in small-scales than phytoplankton (upper curve), as observed in experiments.
Stochastic population dynamics in turbulent fields
We denote by N (r, t) and P (r, t) the phytoplankton and zooplankton concentrations, respectively.
Stochastic population dynamics in turbulent fields
The equations are discretized on a two-dimensional mesh with periodic boundary conditions and solved with a fourth order Runge-Kutta method for the deterministic phytoplankton growth and with the Milstein scheme for stochastic differential equations for the zooplankton growth .
Stochastic population dynamics in turbulent fields
The initial condition is given by homogeneous populations of zooplankton and phytoplankton at their stable equilibrium which corresponds to Neq = 1.0 and Peq = 0.225 for the parameter values as in Fig. 2.
Stochastic population dynamics in turbulent fields
In Fig. 5, we display the typical phytoplankton and zooplankton patterns that emerge from the model.
Stochastic population dynamics in turbulent fields
The time correlations of the zooplankton is more rapidly decreasing than that of phytoplankton, since the noise introduced in the zooplankton growth is delta correlated in time.
Stochastic population dynamics in turbulent fields
The phytoplankton concentration, on the other hand, is only indirectly affected by this uncorrelated noise, through the nonlinear population dynamics and convection.
Stochastic population dynamics in turbulent fields
The phytoplankton patterns generally resemble a tracer pattern, with the difference that the latter becomes static in the long time limit.
Stochastic population dynamics in turbulent fields
Again, due to the presence of a noise term that is uncorrelated in space, the zooplankton correlations decay faster than the phytoplankton correlations.
Stochastic population dynamics in turbulent fields
FIG. 7: Time correlation functions for phytoplankton and zooplankton obtained after the system is allowed to relax for a long time (τ = 2500).
Stochastic population dynamics in turbulent fields
After this transient period, the time correlation function of a tracer is equal to 1, which indicates that the pattern has become stationary (not shown). C (t) represents the concentration of phytoplankton for the upper curve and of zooplankton for the lower curve.
Stochastic population dynamics in turbulent fields
FIG. 8: Spatial correlation functions for plankton. C (x) represents the concentration of phytoplankton and of zooplankton.
Stochastic population dynamics in turbulent fields
The zooplankton correlation function (broken line) decays more rapidly than the phytoplankton correlation function (continuous line).
Stochastic population dynamics in turbulent fields
Inset: semi-log plot shows that the phytoplankton correlation has an initial exponential decay.
Stochastic population dynamics in turbulent fields
FIG. 9: Variance spectra for phytoplankton and zooplankton, obtained from an average over 250 horizontal and 250 vertical transects of the system.
Stochastic population dynamics in turbulent fields
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