I have simulated a birdcage MRI coil with circular polarization. When the B1+ and B1- fields are represented with arrows, the vectors are directed along the B0 direction (z-direction) instead of along directions perpendicular to B0 (in the XY plane). However, the H field, when represented with arrows, is shown correctly, with its dominant components directed along the X and Y directions. Why do the B1+ and B1- fields not seem to be correctly represented by the arrows?