We study here how the model solution behaves for different values of β. In all cases, the populations are uniform (so advection and diffusion are inactive), and we start with Ps0 = 0.5, Pi0 = 0.0, Z0 = 0.0 and V0 = 0.25. See 11.02.2012: First analysis of run 001 for a study of the behavior of the solution for a fixed value of β but various initial conditions for Ps and V.
There are two regimes. For β smaller than 0.12, Ps will obtain its maximum and final value very rapidly (Figs. 1a and c and Figs. 4 and 5), although it takes him longer and longer to reach this value (Fig. 1b). In this regime, the maximum of Pi and V are their initial value and they decay rapidly to zero stays (Figs. 2a and 3a and Figs. 4 and 5).
For β larger than 0.12, the maximum value of Ps decays with β and it is reached at the first oscillation, right at the beginning of the run (Figs. 1a and b and Figs. 6 and 7). Its final value also decays with β. For Ps and V, their maximum values increase with β and these are reached also at the first oscillation at the beginning of the run. Interestingly, their final value peaks for β around 0.35. Finally, the larger β, the smaller the period of oscillations and the slower the solution asymptotes to equilibrium (Figs. 6 and 7).
These results are consistent with Fig. 4 of Rhodes et al. (2008).
Figs. 1a and 1c shows the ratio of the maximum value to the final value. In 11.02.2012: First analysis of run 001, where β = 0.35, it was noticed that the maximum value was about twice the final value. We see by looking at these two figures, that this was somewhat of a coincidence and the relationship between the two quantities are more complicated.
Figure 1: Maximum value of Ps and its timing, final value of Ps and a measure of the convergence of the run.
Figure 2: Maximum value of Pi and its timing, final value of Pi and a measure of the convergence of the run.
Figure 3: Maximum value of V and its timing, final value of V and a measure of the convergence of the run.
Figure 4: Time series of Ps, Pi and V for β = 0.05.
Figure 5: Time series of Ps, Pi and V for β = 0.10.
Figure 6: Time series of Ps, Pi and V for β = 0.25.
Figure 7: Time series of Ps, Pi and V for β = 0.70.
To produce the first three figures, manyruns_2.py in RESEARCH/MODELISATION/marine_viruses/current_version/runs/run_001 has been used and it was plotted with plot_all_outputs.py in RESEARCH/MODELISATION/marine_viruses/current_version/runs/run_001/analysis/manyruns_2. To produce Figs. 4 to 7, we use plot_timeseries_current_run.py in RESEARCH/MODELISATION/marine_viruses/current_version/runs/run_001/analysis/.