The water cycle
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Copyright University Corporation for Atmospheric Research
Earth's Water Cycle
Water is always on the move. Rain falling where you live may have been water in the ocean just days before. And the water you see in a river or stream may have been snow on a high mountaintop.
Water can be in the atmosphere, on the land, in the ocean, and even underground. It is recycled over and over through the water cycle. In the cycle, water changes state between liquid, solid (ice), and gas (water vapor).
Most water vapor gets into the atmosphere by a process called evaporation. This process turns the water that is at the top of the ocean, rivers, and lakes into water vapor in the atmosphere using energy from the Sun. Water vapor can also form from snow and ice through the process of sublimation and can evaporate from plants by a process called transpiration.
The water vapor rises in the atmosphere and cools, forming tiny water droplets by a process called condensation. Those water droplets make up clouds. If those tiny water droplets combine with each other they grow larger and eventually become too heavy to stay in the air. Then they fall to the ground as rain, snow, and other types of precipitation.
Most of the precipitation that falls becomes a part of the ocean or part of rivers, lakes, and streams that eventually lead to the ocean. Some of the snow and ice that falls as precipitation stays at the Earth surface in glaciers and other types of ice. Some of the precipitation seeps into the ground and becomes a part of the groundwater.
Water stays in certain places longer than others. A drop of water may spend over 3,000 years in the ocean before moving on to another part of the water cycle while a drop of water spends an average of just eight days in the atmosphere before falling back to Earth.
Last modified January 6, 2009 by Lisa Gardiner.
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Ok, everyone, that’s a wrap!
After 207 days in the field, 254 flights, and data collected at 45 terrestrial sites and 24 aquatic sites, the National Ecological Observatory Network’s Airborne Observation Platform’s “peak greenness” flight campaign is coming to a close for 2017.
From the northern-most point on the Alaska coast to the Florida peninsula and everything in between, two flight crews collected remote sensing data while dodging hurricanes, witnessing the midnight sun, and taking in some of the nation’s most spectacular landscapes. Propellers failed and rodents chewed through ground cables, but the airborne operations team worked tirelessly across the continent throughout our busiest season to date!
Many airborne data products are already processed and available, with more being published all the time. Airborne data is free to request and use: http://www.neonscience.org/data.
In addition to the network of NEON sites flown each year, we are excited to announce that the AOP Assignable Asset is about to come online, available for principal investigator research starting in 2018. For more information, visit http://www.neonscience.org/assignable-assets.
Many thanks to NEON’s AOP team, domain contacts, science collaborators, and the numerous staff from various park agencies, non-profits, universities, and airports that helped make this all possible.
We look forward to working with you as we soar into next field season!
-Heather Rogers, Flight Operations, Airborne Observation Platform (AOP) for the NEON project, operated by Battelle.