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What Does Two Decades of Rain and Snow Show Us?

You are seeing the culmination of almost twenty years of rain and snow, all at once.

For the first time, we have combined and remastered the satellite measurements from two of our precipitation spacecraft to create our most detailed picture of our planet’s rain and snowfall. This new record will help scientists better understand normal and extreme rain and snowfall around the world and how these weather events may change in a warming climate. 

The Most Extreme Places on Earth

Using this new two-decade record, we can see the most extreme places on Earth. 

The wettest places on our planet occur over oceans. These extremely wet locations tend to be very concentrated and over small regions.

A region off the coast of Indonesia receives on average 279 inches of rain per year.

An area off the coast of Colombia sees on average 360 inches of rain per year.

The driest places on Earth are more widespread. Two of the driest places on Earth are also next to cold ocean waters. In these parts of the ocean, it rains as little as it does in the desert – they’re also known as ocean deserts! 

Just two thousand miles to the south of Colombia is one of the driest areas, the Atacama Desert in Chile that receives on average 0.64 inches of rain per year.

Across the Atlantic Ocean, Namibia experiences on average 0.49 inches of rain a year and Egypt gets on average 0.04 inches of rain per year.

Global Patterns

As we move from January to December, we can see the seasons shift across the world.

During the summer in the Northern Hemisphere, massive monsoons move over India and Southeast Asia.

We can also see dynamic swirling patterns in the Southern Ocean, which scientists consider one of our planet’s last great unknowns.

Close-up Patterns

This new record also reveals typical patterns of rain and snow at different times of the day – a pattern known as the diurnal cycle. 

As the Sun heats up Earth’s surface during the day, rainfall occurs over land. In Florida, sea breezes from the Gulf of Mexico and Atlantic Ocean feed the storms causing them to peak in the afternoon. At night, storms move over the ocean.

In the winter months in the U.S. west coast, the coastal regions generally receive similar amounts of rain and snow throughout the day. Here, precipitation is driven less from the daily heating of the Sun and more from the Pacific Ocean bringing in atmospheric rivers – corridors of intense water vapor in the atmosphere.

This new record marks a major milestone in the effort to generate a long-term record of rain and snow. Not only does this long record improve our understanding of rain and snow as our planet changes, but it is a vital tool for other agencies and researchers to understand and predict floods, landslides, disease outbreaks and agricultural production.

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