注入海中的马更些河，加拿大 The Mackenzie River in Canada emptying into the Beaufort Sea (© Norman Kuring, GSFC/NASA/USGS Landsat)

注入海中的马更些河，加拿大 The Mackenzie River in Canada emptying into the Beaufort Sea (© Norman Kuring, GSFC/NASA/USGS Landsat)

World Rivers Day

Today we're recognizing World Rivers Day, a celebration of our planet's waterways. The event branched off in 2005 from its source, BC Rivers Day, which has been observed by British Columbians in Canada since 1980. The annual event is now celebrated on the fourth Sunday of September by millions of people in more than 100 countries. It is a day that raises public awareness about rivers around the world and encourages their conservation.

Our photo, captured by NASA's Earth-imaging Landsat 8 satellite, shows part of the Mackenzie River delta and the river's turbid waters as they flow from the far north of Canada and Alaska into the Beaufort Sea in the Arctic Ocean. The Mackenzie River—the longest river in Canada and second-largest drainage basin of any North American river after the Mississippi–plays a vital role in modulating the Arctic climate as warmer fresh water mixes with colder seawater.

世界河流日

今天，我们要纪念世界河流日，这是一个庆祝地球水路的节日。这一活动于2005年从其源头——不列颠哥伦比亚河日开始，自1980年以来，加拿大的不列颠哥伦比亚人就一直在观察这一活动。现在，100多个国家的数百万人在9月的第四个星期日庆祝这项一年一度的活动。这一天提高了公众对世界各地河流的认识，并鼓励保护河流。

我们的照片由美国宇航局地球成像陆地卫星8号（Landsat 8）卫星拍摄，显示了麦肯齐河三角洲的一部分和河流的浑浊水域，它们从加拿大和阿拉斯加的最北部流入北冰洋的波弗特海。麦肯齐河是加拿大最长的河流，也是仅次于密西西比河的北美第二大流域，在调节北极气候方面起着至关重要的作用，因为温暖的淡水与寒冷的海水混合。