Precipitation Measurement Missions

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Weather & Climate

Weather and climate describe the world outside the window - whether it’s hot or cold, humid or dry, sunny or cloudy. Weather is the short term conditions present in the moment that let people know what to wear today and whether or not to bring an umbrella. Climate describes the long term conditions that let people know what clothes to keep in their wardrobe all year long and whether they need to own snow boots, flip flops or both.

Various types of extreme weather around the world.

Both weather and climate are the result of the interaction of several Earth systems:

the movement of moisture in the water cycle that evaporates ocean water into the air where it condenses into travelling clouds or storms that eventually cause rain or snow;
the movement of heat that begins at the sun-soaked equator and moves warm air toward the north and south poles;
the movement of the oceans that takes icy-cold water from the poles to the tropics, warming or cooling the air above the water.

These and many other factors, including greenhouse gases in the atmosphere, combine to form the high and low pressure systems you hear about on the weather report, and over time add up to the climate of the location you live in.

To understand the complex interactions and patterns of weather and climate, scientists collect as much observational data as they can on precipitation, temperatures, humidity, and other atmospheric conditions. They then use that data and the relationships between the different pieces to create computer models of local, regional, or even global weather and climate.