c$)$ Now use FDD$,$ BDD$,$ or CDD $($whichever is appropriate$)$ to find the $1$st and $2$nd

derivative of Temperature $($T$)$ with respect to depth $(z)$ with $O(h^2).$

Plot these results separately, and locate the thermocline from $d^2\frac{T}{d}{z}^2$ plot. $($Formulations

for FDD$,$ BDD$,$ and CDD are given in Figures $21\mathrm{.}3,21\mathrm{.}4,$ and $21\mathrm{.}5,$ respectively$).$

Remember Thermocline is at a depth where $(d^2\frac{T}{d}{z}^2)=0.$