Weather and Water Cycle
What is the interaction between the earth's weather and
The water cycle is a major factor in both weather and climate.
Unfortunately, the water cycle is both the most dominant and the most
complex of all the atmospheric gas cycles for a number of reasons: 1. It
occurs as solid, liquid, and vapor. It is transported through the cycle
faster than other cycles, such as CO2 or CH4. In the form of clouds its
reflectivity/absorption of sunlight is not well understood. The monitoring
of the atmospheric content is spotty -- that is there is no satellite
monitoring that overlaps, so instruments cannot be intercalibrated. In
short, despite a lot of rhetoric about global climate change this major
factor is not factored into the analysis in any serious way.
The weather is dependent on water. Therefore, the water cycle
is vitally important to producing weather. Even more important
is how the water is distributed on the Earth's surface and in
the atmosphere. So, the strength of the water cycle depends
on the region in which you are interested.
For instance, in most of North America, precipitation from clouds
falls through the atmosphere, with some of it being evaporated into
the air and the rest falling onto the ground or onto a water body
or river. Some of the water runs off of the ground into rivers
and lakes and some is absorbed by the soil. Some of the water that
goes into the soil ends up in underground reservoirs or flows
underground great distances and can come out of the ground from springs.
Evaporation from the ground, lakes, and rivers into the air
eventually ends up in clouds. As the water condenses into the water
droplets that form clouds, it releases heat, which can, in extreme cases,
fuel thunderstorms and hurricanes.
Normal weather systems are dependent on water. You can see this from
the lack of significant weather systems in areas of the world that are
very dry, such as the southwestern part of the USA, the Sahara desert
in northern Africa, the Near East, and central Australia.
Water really makes things happen when it comes to weather.
David R. Cook
Atmospheric Physics and Chemistry Section
Environmental Research Division
Argonne National Laboratory
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Update: June 2012