Click For Photo: https://www.sciencedaily.com/images/2019/03/190318132607_1_540x360.jpg
This discovery -- appearing in Nature Geoscience -- will enable scientists to develop more accurate models of the role that mountain streams play in global biogeochemical fluxes. Considering that more than 30% of the Earth's surface is covered by mountains, the ramifications of this discovery are considerable.
The study was conducted at EPFL's Stream Biofilm and Ecosystem Research Laboratory (SBER), within the School of Architecture, Civil and Environmental Engineering (ENAC).
Ecosystems - World - Oceans - Streams - Lakes
In aquatic ecosystems, such as the world's oceans, streams and lakes, numerous aquatic organisms, ranging from bacteria to fish, respire oxygen and exhale CO2. These gases must therefore be continually "exchanged" from the atmosphere to the water and vice-versa. Because mountain streams often flow over steep drops and rugged terrain, this creates a lot of turbulence and causes air bubbles to be trapped in the water, appearing white (aka 'white water').
These bubbles accelerate the gas exchange. Strikingly, the same mechanism is at work when white-capped waves appear on the surface of rough seas. Until now, scientists have ignored the contribution from air bubbles and have used the same approach to calculate gas exchange velocities in mountain streams than in calm lowland streams.
Terrain - Gas - Exchange - Mountain - Streams
It is intuitive that the rugged terrain would influence gas exchange in mountain streams, but no evidence had been collected to test this hypothesis...
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