Answer
$54^{\circ}$
Work Step by Step
We can find the angle of incidence as
$n_{air}sin\theta_i=n_{ice}sin\theta_2$
This can be rearranged as:
$\theta_i=sin^{-1}(\frac{n_{ice}}{n_{air}}sin\theta_2)$
$\theta_i=sin^{-1}(\frac{1.31}{1.00}sin38^{\circ})=54^{\circ}$
