美国国家航空航天局NASA每日一图-2017年7月12日

Lakes and Rivers Have Ice, Too

On May 29, 2017, the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured this image of ice covering the Amundsen Gulf, Great Bear Lake, and numerous small lakes in the northern reaches of Canada’s Northwest Territories and Nunavut. Sea ice generally forms in the Gulf of Amundsen in December or January and breaks up in June or July. Lake and river ice in this area follow roughly the same pattern, though shallow lakes freeze up earlier in the fall and melt earlier in the spring than larger, deeper lakes.

Icy lakes and rivers make a significant footprint on the Arctic landscape. Though widely dispersed, lakes cover as much as 40 to 50 percent of the land in many parts of the Arctic, and seasonal lake and river ice covers roughly 2 percent of all of Earth’s land surfaces. Since lakes and rivers have the highest evaporation rate of any surface in high latitudes, understanding and monitoring seasonal ice cover is critical to accurately forecasting the weather and understanding regional climate processes.

Lake and river ice also affects the people who live in the Arctic. Seasonal ice roads serve as a key transportation route for many communities. Ice jams can produce sudden and dangerous hazards to hydroelectric power facilities, infrastructure, and human settlements. Changing ice conditions make shipping and boating a challenge. And ice is involved in a range of hydrological processes that can affect the quality of drinking water.

Nonetheless, lake and river ice generally gets the least attention from ice scientists. According to one analysis, scientists publish roughly 50 scientific articles related to lake or river ice each year. In comparison, well over 600 articles get written about glaciers, 500 about snow, 350 about sea ice, and 250 about permafrost.

Annotated Image and References: NASA Earth Observatory

Image Credit: NASA Earth Observatory images by Joshua Stevens, using MODIS data from LANCE/EOSDIS Rapid Response.
Caption: Adam Voiland

Last Updated: July 11, 2017
Editor: Sarah Loff

湖泊和河流也有冰

2017年5月29日,中分辨率成像光谱仪(MODIS)是美国宇航局的Terra卫星拍摄的这张图片,冰覆盖阿蒙森湾,大熊湖,在加拿大的西北地区和努纳武特北部许多小湖泊。海冰一般形成于十二月或一月阿蒙森海湾和打破了在六月或七月。这个地区的湖泊和河流的冰大致相同,尽管浅水湖在秋天更早结冰,而春天比大的更深的湖更早融化。
冰冷的湖泊和河流在北极景观上留下了巨大的足迹。虽然湖泊分布广泛,但在北极的许多地方,湖泊覆盖了多达40到50%的土地,而季节性湖泊和河流冰川覆盖了地球陆地表面的2%。由于湖泊和河流在高纬度地区的地表蒸发率最高,了解和监测季节性冰盖对准确预测天气和了解区域气候过程至关重要。
湖泊和河流的冰也影响到生活在北极的人们。季节性冰路是许多社区的主要交通路线。冰塞会对水电设施、基础设施和人类住区造成突然和危险的危害。改变冰的条件,使航运和划船的挑战。冰参与了一系列影响饮用水水质的水文过程。
尽管如此,冰湖科学家通常很少注意到湖泊和河流的冰。根据一项分析,科学家每年出版大约50篇与湖泊或河流冰有关的科学文章。相比之下,有超过600篇文章是关于冰川的,500是关于雪的,350是关于海冰的,250是关于永久冻土的。
注释图像和参考:美国国家航空航天局地球观测台
图片来源:美国宇航局地球观测图像的Joshua Stevens,用枪/对快速响应的MODIS数据。
描述:Adam Voiland
最后更新:2017年7月11日
编辑:Sarah Loff

评论已关闭