tw.m

kappa     = 0.41;
const_a   = 5.0;
epsilon   = 0.0003;
z_pos     = z_dat*0.001 + epsilon;         % z_pos is in m

zw  = polyfit(z_pos(1:3),u0(1:3),2)
tw_slope = rho_air*nu*zw(2)