SSS 2010-04-28(在线收听) |
If you've ever driven up to a mountain pass, you know that the higher you climb, the colder it gets. But on clear, calm days, it can actually (be) colder in the valleys. That's because under high-pressure systems, cold air slides down mountain slopes and pools down below. In the Oregon Cascades, ridgeline temperatures have clocked in at 27 degrees Fahrenheit warmer than those in a valley 2,600 feet below. So what happens when you take this variability and subject it to climate change? Well, a moderate estimate from the IPCC says western Oregon could warm 5 degrees Fahrenheit over the next century. But that's probably more accurate for the valleys—ridgetop temperatures could rise as much as 14 degrees, according to research in the International Journal of Climatology. Oregon is projected to have more high-pressure days as the climate changes. That means more cold air pooling in the valleys and more extreme temperature differences, which could disrupt the local ecosystem. We tend to think of climate change as a global or regional phenomenon. But, as this research suggests, you have to also think locally. Thanks for the minute for Scientific American's 60-Second Science. I'm Christopher Intagliata. |
原文地址:http://www.tingroom.com/lesson/sasss/2010/4/101758.html |