Arctic Ocean Ice Melt From Warm Mackenzie River Flows

These images show sea surface temperatures of the Beaufort Sea where Canada's Mackenzie River discharges into the Arctic Ocean, as measured by the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument on NASA's Terra spacecraft. The image at left was obtained June 14, 2012, before discharged waters from the Mackenzie River (located in the bottom center of the image) broke through the adjacent sea ice barrier (shown in light blue) stuck along the shore of the Mackenzie River delta. The image at right, acquired July 5, 2012, shows the extensive intrusion of heat carried by the river waters once they breached the sea ice barrier (shown in yellow, orange and red). Scientists saw an increase of 11.7 degrees Fahrenheit (6.5 degrees Celsius) in the surface temperature of the open water, which enhanced sea ice melt.

Image credit: NASA

Note: For more information, see PIA18035: Warm Rivers Play Role in Arctic Sea Ice Melt (Animation) and NASA: Warm Rivers Play Role in Arctic Sea Ice Melt.

Botswana's Okavango Delta

This image is a compilation of three images from Envisat’s radar and shows where southwestern Africa’s Okavango River empties into the inland Okavango Delta in northern Botswana. The Okavango River originates in Angola, forms part of the Angola Namibia border and then ends in northern Botswana. Here, it has formed a depression in the semi-arid Kalahari basin. Appearing purple at the center of the image is Chief’s Island. In the lower-right portion of the image we can see a large cluster of radar reflections from the town of Maun. At the top of the image, a triangle with similar coloring to the delta can be seen. This is a swamp area and national park located mostly in Namibia.

This image is featured on the Earth from Space video program.

Image credit: ESA

Camargue Delta, France

This image from ALOS shows southern France and the divide of the Rhone River: the 'Grand Rhône' flows down the center of the image while the 'Petit Rhône' is visible to the west. This divide at the French city of Arles forms the Camargue delta region. In the upper right corner of the image, we can see the Alpilles mountains. The green area south of the mountains is a large nature reserve.

This image is a compilation of three radar passes on 14 May 2008, 20 May 2010 and 5 July 2010. Each is assigned a color (red, green or blue) and combined to produce this representation. The colors reveal changes in the surface between the satellite’s passes.

Photo credit: JAXA, ESA

Mississippi River Delta

This Landsat image of 3 October 2011 shows the Mississippi River Delta, where the largest river in the United States empties into the Gulf of Mexico. In this false-color image, land vegetation appears pink, while the sediment in the surrounding waters are bright blue and green.

Photo credit: USGS/ESA