VOA常速英语2013--热浪期的协同作用导致城市酷热（在线收听）

Heat Waves Make Cities Swelter Synergistically 热浪期的协同作用导致城市酷热

No wonder it’s gonna be a hot time in the old town tonight. Cities can be anywhere from two to 20 degrees Fahrenheit hotter than nearby countryside, due to what’s known as the "urban heat island" effect. But when heat waves roll through, they interact synergistically with the urban heat island—boosting temperatures even higher than you might expect.

今晚的老城将迎来一个炎热的夜晚，这并不奇怪。因为众所周知的“城市热岛效应”，城市的温度会比其临近的乡村高2至20华氏度。但当热浪期来袭之时，由于其与热岛效应的协同作用，气温甚至能比你所能预想到的更高。

Researchers used a June 2008 heat wave in Baltimore as a case study. They compared temperatures downtown to those near the Baltimore/Washington International Airport—a residential, half-forested area. Using modeling software, they found that temperatures downtown weren't simply a sum of the urban heat island and the heat wave—they were three and a half degrees hotter than that. The results appear in the Journal of Applied Meteorology and Climatology. [Dan Li and Elie Bou-Zeid, Synergistic Interactions between Urban Heat Islands and Heat Waves: the Impact in Cities is Larger than the Sum of its Parts

研究人员选取2008年六月发生在巴尔的摩的热浪期作为案例来研究。他们比较了市中心地区和巴尔的摩/华盛顿国际机场附近某些地区的气温，其中后者是半数为森林所覆盖的居民区。使用模拟软件研究后，他们发现，市中心的气温并不仅仅是城市热岛效应和热浪期两种效应带来的升温值的简单叠加——而是比这个值高了约3.5华氏度。该项研究结果发表在《应用气象与气候学》杂志上。[Dan Li and Elie Bou-Zeid，城市热岛效应与热浪期的协同增效作用：其对城市的总影响大于二者各自影响之和]

Urban areas are carpeted in asphalt and concrete, which don't hold water like soil and vegetation do. So while the countryside sweats during a heat wave, cooling itself through evaporation, the city just bakes. But researchers say there's a simple solution to beat the heat: install green roofs, and plant some trees. Which would help the concrete jungle live up to the second half of its name.

城市的地表都覆盖着沥青和混凝土，它们并不像土壤和植被那样，能够保存水分。因此当热浪期来临时，乡村可以通过水分蒸发来降温，而城市只能被活活烘烤。但研究人员说，有个很简单的途径来解决这个高温难题：打造绿色屋顶，同时多种树。这样一来，城市的混凝土丛林也将更能对得起其名字中的“丛林”二字。

—Christopher Intagliata

——克里斯托弗-英塔格丽塔