The brightness of the sunlight is attenuated quickly as it passes through the water.

Rousseff said that the intensity of Brazil's downturn caught her by surprise and that she would do "whatever it takes" to attenuate it.

Water will attenuate the signal.

He also pointed to a robust U.S. reconstruction effort in Iraq, which he said is beginning to improve the everyday lives of Iraqis and attenuate public sympathy for the insurgents.