Conclusion
During this lesson we discuss some causes of complexity in environmental systems. We showed that the wide range of scales involved in the system makes its characterization difficult not just in term modeling but also in term of measurement and observation. We highlight the variability at different scales of some geophysical fields, this variability is generally caused by a non-linear effects. We gave some source of this non-linearity. Before starting discussion some governing equations which describe the evolution of the system, we introduce the differential equations and classifications (ODEs and PDEs). We introduce the Navier-Stokes equations and highlight the difficulties to solve them. The symmetries of governing equations can be used as a power full tool in order to characterize the behavior of complex systems. We end this lesson with a set of exercises and their solutions.
