V. Botte et A. Kay, A numerical study of plankton population dynamics in a deep lake during the passage of the Spring thermal bar, J MAR SYST, 26(3-4), 2000, pp. 367-386
An N-P-Z plankton model has been included in a finite volume formulation of
the Navier-Stokes equations and has been used to predict the effect of the
spring warming and the thermal bar on the plankton ecosystem of a section
of the Central Basin of Lake Baikal. The results presented show that the cu
rrents converging towards the thermal bar generate a maximum in the phytopl
ankton population at the location of the thermal bar, while the boundary be
tween the unstable near-surface region and the stably stratified lower part
of the lake acts as a barrier to the diffusion of the plankton population
towards deeper regions. The enlargement of the unstable area during the war
ming of the lake has been found to have a major effect on the distribution
of the phytoplankton, with enhanced vertical diffusion balancing the growth
near the surface and preventing the phytoplankton population from reaching
bloom values, and consequently inhibiting any development of the zooplankt
on population. It has also been found that the vertical component of the Co
riolis force could allow the currents generated by the thermal bar to reach
the deeper part of the lake. (C) 2000 Elsevier Science B.V. All rights res
erved.