atmosphere

PAESTA Podcast Series: Episode 4 - What is a Watershed?

You Asked, We Answered!

Transcript for the podcast

We all live in a watershed – think of it as your ecological address, and no matter where you are on land, any water that falls in that same location has a drainage destination determined by elevation and landforms. A watershed is an area of land where the surface water (including lakes, streams, reservoirs, and wetlands) and the underlying groundwater flows from a higher to lower elevation. Streams and rainfall within a watershed will typically drain to a common outlet, such as the outflow of a reservoir, mouth of a bay, or any point along a stream channel. The word watershed is sometimes used interchangeably with drainage basin or catchment.

PAESTA Podcast Series: Episode 3 - How do Scientists Measure Rainfall?

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Transcript for the podcast

Many schools will have a rain gauge installed, where students can measure and record the amount of rain that falls each day. But scientists do not measure precipitation on the ground – they measure precipitation from space, using a combination of active and passive remote-sensing techniques, improving the spatial and temporal coverage of precipitation observations on a global scale.  You see, reliable ground-based precipitation measurements are difficult to obtain because most of the world is covered by water, and many countries do not have precise rain measuring equipment (such as rain gauges and radar). Precipitation is also difficult to measure because precipitation systems can be somewhat random and can evolve very rapidly. During a storm, precipitation amounts can vary greatly over a very small area and over a short time span.

PAESTA Podcast Series: Episode 1 - How Do We Know CO2 is Increasing?

Atmospheric CO2 at Mauna Loa Observatory

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Transcript for the podcast

We know that atmospheric levels of carbon dioxide have been increasing because we have the data! The story of collecting CO2 data begins in 1958, when a geochemist from the Scripps Institution of Oceanography, Dr. Charles Keeling, started collecting measurements of carbon dioxide in the atmosphere at an observatory located over 11,000 feet in elevation on the Mauna Loa volcano on the big island of Hawaii. These systematic measurements Dr. Keeling started have become the most widely recognized record of human impact on Earth, linking rising levels of carbon dioxide from the burning of fossil fuels to the warming of the planet.