Everyone knows how the work week can take a toll on employees, but new research suggests the five-day slog may have even broader impacts--on climate.

    After examining more than 40 years of temperature data taken from roughly 10,000 surface stations, researchers from the National Oceanic and Atmospheric Administration and from the University of Reading in the U.K. found that temperature differences between day and night appear to follow distinct five-days-on, two-days-off patterns.

    The scientists checked the data for all possible natural influences such as the lunar cycle as well as random variations and found neither to be at play. The only factor that could be causing the fluctuations was the Monday-through-Friday grind, they concluded in a recently published report in the Proceedings of the National Academy of Sciences.

    "There is nothing in nature that should cause these data to be different," said Piers M de F. Forster, a meteorologist based at the University of Reading, England, who co-authored the study with NOAA's Susan Solomon. "So whatever the cause we find has to be something that we're changing, ourselves."

    The meteorologists propose the differences in average temperatures between Saturdays as opposed to Thursdays, for example, may stem from workweek-induced pollution. Forster explains that during the workweek more people commute and more factories are in operation. Both contribute to the amount of particle pollution in the air.

    Particles can influence cloud cover, but the kind of particles released into the atmosphere can lead to different changes, says Forster.

    Lighter particles provide a surface for cloud droplets to form. This leads to an increase in cloud cover, which, in turn, can lead to an increase in temperature since clouds have an insulating effect.

    人們普遍了解工作日是如何影響上班族的，然而最新研究表明這五天的勞作對氣候的影響更加顯著。

    英國國家海洋及大氣管理局和英國國立瑞丁大學的研究員分析了約一萬個地面氣象站40多年來采集的氣溫數據。他們發現晝夜溫差出現明顯的五天大兩天小的變化規律。

    科學家們檢查了所有可能造成這種變化的自然因素，例如月亮運行周期和隨機的變化，結果發現二者都不起作用。他們在最近召開的全國科學院研討會上發表的報告中總結說：唯一可能解釋這種溫差變化的就是人們從周一到周五的辛苦勞作。

    英國國立瑞丁大學的氣象學家皮爾斯·福雷斯特和國家海洋及大氣管理局的蘇姍·所羅門合作主持了這項研究。福雷斯特說：“自然界中沒有什么能夠造成這些數據差異，所以不管原因是什么，它一定與我們自己正在改變的某種東西有關。”

    氣象學家們提出平均氣溫的差異可能是工作日中產生的污染造成的，例如周六和周四相比，平均氣溫就有一定的差異。福雷斯特解釋說在五天工作日中，乘車上下班的人多，進行生產的工廠也多，這都會增加空氣中的微粒含量，對大氣造成污染。

    微粒會影響云量，但是釋放到大氣中的不同顆粒會造成不同的變化，福雷斯特說。

    較輕的微粒能夠提供云滴形成所需要的界面，這樣會增加云量，進而導致氣溫的升高，因為云有保溫的作用。