Altitude of Sun at equinox = 90 - 43.53 = 46.47º.

 I = I0(sin q)e-0.3567/sinq

 = 1.35(sin 46.47)e-0.3567/sin 46.47 = 0.60 W/m2

 At the equator:
I = 0.7 X 1.35 = 0.945 W/m2

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