WEBVTT FILE

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Silence

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Music

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Music

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Music

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Music

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Water is the fundamental

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ingredient for life on Earth.

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Looking at our Earth from|space,

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with its vast and deep ocean,|it appears

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as though there is an abundance|of water for our use.

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However, only a small portion

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of Earth's water is accessible|for our needs.

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How much fresh water exists and|where it is

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stored affects us all.

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Nearly two-thirds of this fresh|water is stored

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in the polar ice caps, snow|packs, and glaciers,

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making it inaccessible for long

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periods of time.

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Music

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Music

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Music

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Music

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The water cycle is dynamic

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- it describes the continuous|movement of water

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on, above and below the|surface of the Earth

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and the transitions from one|state

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to another.

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Music

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Sea surface temperature,|surface winds, and air

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temperature influence the rate|of evaporation at the

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ocean surface. In the tropics,

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warm ocean surface temperatures|support high rates

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of evaporation. Wind

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also increases evaporation.

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When the air's temperature

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is warmer, it can hold more|water.

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Music

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Music

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While the atmosphere does not

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store a large quantity of water|compared to the ocean,

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rivers and lakes, it can|transport water

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quickly from one place to|another.

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Low-lying regions of the|atmosphere with high

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moisture and strong winds, can|form "atmospheric

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rivers" to transport water|horizontally.

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Music

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Clouds are formed as water|vapor cools

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and condenses into droplets and|ice crystals.

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Clouds and water vapor act

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as insulators in the atmosphere.

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Clouds help shield the Earth|from the Sun and trap

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heat from below.

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When cloud particles grow large|enough,

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they may fall out as rain or|snow.

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Under the right conditions,|areas of precipitation

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can grow into large storms.

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As storms grow, they transfer

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heat vertically into the upper|atmosphere.

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The migration of storms helps|to distribute heat

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between the equator and poles -|shaping

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winds patterns globally.

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How storms grow and intensify

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depends upon atmospheric|mositure, surface temperatures

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and wind patterns. Precipitation

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is concentrated in some parts|of the world

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and scarce in others. It can|vary substantially

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from season-to-season and from|year-to-year.

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Water that falls on the land|surface as

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precipitation is stored within|snow packs,

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lakes, reservoirs, soils

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and underground aquifers.

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Music

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Water availability varies

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from place-to-place and over|time.

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The availability of water|affects the

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and abundance of vegetation.

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The primary source of food for|animals and people.

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Extreme water

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cycle variability, unusually dry

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or wet conditions, impacts|humans

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worldwide.

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Each year, hazards such as|floods exact costly

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economic and human toll.

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Most of the water that

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falls on to land remains stored|there for weeks

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or more.

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Music

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Snowfall is stored as snow|pack or ice.

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Melt water and rainfall

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are stored in lakes and soils.|Some of the water

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is absorbed by plant roots or|drains into the water table.

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Eventually, the water will|evaporate

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to the atmosphere or return to|the ocean

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in streams and rivers,|providing a source

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of nutrient rich water that|supports ocean life.

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Sensors on a suite of NASA|satellites observe and measure

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water on land, in the ocean and|in the atmosphere.

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These measurements are

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important to understanding the|availability and distribution

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of Earth's water, which is both|vital

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to life and vulnerable to the|impacts

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of climate change and a growing|world population.

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Music

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Beeping sounds

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Beeping sounds

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Beeping sounds

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End