But under sea ice, the attenuation coefficient of PAR is little bit different, as the spectrum of the light has been changed by selective absorption through the sea ice.

在海冰覆盖的条件下，PAR的观测结果与无冰海水的PAR有明显差别。由于海冰选择性的吸收，穿透海冰进入海洋的PAR组分已经不同，海水对PAR的衰减系数也会相应变化。