Change in Hawaii's winds threatens water supply

HONOLULU -- Part of what makes living in Hawaii so pleasant is the gentle breeze. Arriving from the northeast, it's light enough that it is barely noticeable but strong enough to chase away the humidity.

Nowadays, experts say, these breezes, called trade winds, are declining, a drop that's slowly changing life across the islands.

The effects can be seen from the relatively minor, such as residents unaccustomed to the humidity complaining about the weather and having to use their fans and air conditioning more often, to the more consequential, including winds being too weak to blow away volcanic smog.

The winds also help bring the rains, and their decline means less water. It's one reason officials are moving to restore the health of the mountainous forests that hold the state's water supply and encourage water conservation.

It's not clear what's behind the shift in the winds.

"People always try to ask me: 'Is this caused by global warming?' But I have no idea," said University of Hawaii at Manoa meteorologist Pao-shin Chu.

Chu suggested a graduate student look into it. The resulting study, published last fall in the Journal of Geophysical Research, showed a decades-long decline, including a 28 percent drop in northeast trade wind days at Honolulu's airport since the early 1970s.-- AP