Friday, April 15, 2016

Episode 312 (4-18-16): Student's Research Digs into Streamside Soils, Rainfall Rates, and Greenhouse Gases

CLICK HERE to listen to episode audio (4:52)

Transcript of audio, notes on the audio, photos, and additional information follow below.

All Web addresses mentioned were functional as of 4-15-16.


From the Cumberland Gap to the Atlantic Ocean, this is Virginia Water Radio for the week of April 18, 2016.

This week, we feature another in a series of episodes on water research by Virginia students. To start, have a listen for about 15 seconds to these analytical-device mystery sounds, and see if you can guess what kind of atmospheric gases this device is designed to measure. And here’s a hint: what lets the light in but doesn’t let the heat out?

SOUNDS - ~15 sec

If you guessed, greenhouse gases, you’re right! You heard sounds from a special kind of spectrometer that uses lasers to measure levels of carbon dioxide, methane, and nitrous oxide, three key greenhouse gases—that is, gases that transmit solar radiation but absorb heat energy radiated back from the earth’s surface, similar to the way glass in a greenhouse works. Scientists studying current and predicted changes in the earth’s climate focus lots of attention on these greenhouse gases, particularly on their levels, sources, storage, and interactions with temperature and precipitation in ecosystems.

Soil ecosystems are one major area of scientific focus. For example, the American Society of Agronomy currently states, “Far too little is known about how management influences soil organic carbon accumulation and greenhouse gas emissions under a diversity of environmental conditions around the world.”

Potential effects on soil greenhouse gases from predicted changes in rainfall intensity—that is, the amount and timing of rainfall—were the focus of research by Tyler Weiglein, a 2015 graduate from Civil and Environmental Engineering at Virginia Tech, and one of four Virginia students who received research grants in 2014 from the Virginia Water Resources Research Center. Let’s listen for about 50 seconds as Tyler describes his research methods.

GUEST VOICE - ~ 51 sec

“We’re here in the Water Quality Lab in the Department of Biological Systems Engineering at Virginia Tech. And right here is a Picarro Cavity Ring-down Spectrometer. It’s used to measure carbon dioxide, methane, and nitrous oxide, three key greenhouse gases. And I used this for my undergraduate research to look at how rainfall frequency and magnitude would affect soil greenhouse gas emissions. Inside the chambers were soil samples that were taken from the Stroubles Creek floodplain, in Blacksburg, Va., near the Virginia Tech campus. And these soil samples were grouped together in treatment groups: each group received the same amount of water, but the timing and magnitude of the water additions was altered to simulate different storm intensities and different storm frequencies.”

By helping clarify possible impacts of rainfall intensity on carbon dioxide and other greenhouse gases in streamside soils, Tyler’s work is part of much broader efforts in Virginia and worldwide to understand better the complicated interactions among climate, atmospheric gases, carbon, and the water cycle.

Thanks to Tyler Weiglein for lending his voice to this episode, and we close with sounds of two aspects of his research: stream flow at Tyler’s research site, and a heavy rainfall. But we’ll just have to imagine the sounds of interactions in the soil among water, organisms, and atmospheric gases!

SOUNDS - ~ 10 sec

For more Virginia water sounds, music, and information, visit us online at, or call us at (540) 231-5463. Virginia Water Radio is produced by the Virginia Water Resources Research Center, part of Virginia Tech’s College of Natural Resources and Environment. Thanks to Stewart Scales for his banjo version of Cripple Creek to open and close the show. In Blacksburg, I’m Alan Raflo, thanking you for listening, and wishing you health, wisdom, and good water.


Audio for this episode was recorded by Virginia Water Radio on April 13, 2016, at the water-quality lab of Virginia Tech’s Biological Systems Engineering Department, and at the Department’s StreamLab research site on Stroubles Creek in Blacksburg, Va.



Photos of aspects of research by Tyler Weiglein on greenhouse gases in streamside soils. 1) Area of Stroubles Creek near Virginia Tech campus where soil was sampled. 2) Transect used to take sampled in streamside area; photo courtesty of Tyler Weiglein. 3) Example of a sample soil core; photo courtesy of Tyler Weiglein. 4) Model of computer screen display of spectrometer analyses of nitrous oxide, carbon dioxide, methane, ammonia, and water.


American Society of Agronomy, Soil Carbon and Greenhouse Gas Emissions Community, online at

Sabrina Kleinman, University of Arizona, “Soils and Climate Change” Mar. 6, 2015), online at

National Oceanic and Atmospheric Administration (NOAA)/National Centers for Environmental Information, “Greenhouse Gases,” online at

Picarro, Inc., “Cavity Ring-Down Spectroscopy,” online at; and “About Picarro,” at

U.S. Environmental Protection Agency (EPA), “Draft Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2014” (February 2016), online at

U.S. EPA, “Overview of Greenhouse Gases,” online at


All Water Radio episodes are listed by category at the Index link above ( See particularly the “Science” category.

Previous episodes on water research by students include the following:
Episode 259, 3-30-15: Red-winged Blackbird Research Follows Connections among Hormones, Avian Malaria, Aquatic Habitats, and Mercury.
Episode 280, 9-7-15: Oysters, Nitrogen, and the Chesapeake Bay – Part 2.
Episode 290, 11-16-15: Antibiotic Resistance Research Follows Genetic Trails in Watersheds.

Previous episodes on connections among air emissions, climate change, and water include the following:
EP230 – 9/8/14: An Introduction to Air Pollution and Water.
EP231 – 9/15/14: Exploring Climate Change Basics, with Examples from Assateague Island National Seashore and Shenandoah National Park.


This episode may help with the following Virginia’s 2010 Science Standards of Learning (SOLs):

Grades K-6 Matter Theme
6.6 – Properties of air (including pressure, temperature, and humidity) and structure/dynamics of earth’s atmosphere.

Life Science Course
LS. 10 - changes over time in ecosystems, communities, and populations, and factors affecting those changes.
LS.11 - relationships between ecosystem dynamics and human activity.

Earth Science Course
ES.11 – origin, evolution, and dynamics of the atmosphere, including human influences on climate.

Biology Course
BIO.8 - dynamic equilibria and interactions within populations, communities, and ecosystems; including nutrient cycling, succession, effects of natural events and human activities, and analysis of the flora, fauna, and microorganisms of Virginia ecosystems.

The episode may also help with the following Virginia 2008 Social Studies SOL:

World Geography Course
WG.2 - how selected physical and ecological processes shape the Earth’s surface, including how humans influence their environment and are influenced by it.

Virginia’s SOLs are available from the Virginia Department of Education, online at