Electromagnetic Waves

On a particular day, the sun delivers an average power of $\left(\frac{6}{\pi} \times 10^3\right) \frac{\mathrm{W}}{\mathrm{m}^2}$ to the top of earth's atmosphere. Find the amplitude of magnetic field for the electromagnetic waves above atmosphere.

(Take, $\mu_0=4 \pi \times 10^{-7}$ SI unit)