Eddy Covariance: Measuring an Ecosystem's Breath

Summary

Eddy covariance is a scientific method that measures the exchange of gases like CO2 between ecosystems and the atmosphere. It utilizes anemometers and infrared gas analyzers to capture data, which is then processed to estimate gas fluxes. This method is crucial for understanding CO2 trends and aiding in the development of climate change models. The data collected is shared globally through FluxNet, contributing to a comprehensive understanding of atmospheric gas concentrations.

Takeaways

• 🌿 Eddy covariance is a scientific method for measuring CO2 emissions and gas exchanges in ecosystems.
• 🔍 It helps scientists forecast long-term trends in CO2 and greenhouse gases, similar to weather forecasting.
• 📊 Policymakers use the data to draft legislation to address climate change and improve quality of life.
• 🌀 An eddy is a circular motion of air caused by temperature fluctuations, which is key to measuring gas fluxes.
• 🌡 Covariance involves measuring changes in gas concentration and wind direction simultaneously.
• 🛰️ Eddy covariance is measured using anemometers and infrared gas analyzers mounted on towers.
• 📈 Data is collected thousands of times per minute and processed through complex equations to estimate gas fluxes.
• 🌳 Two primary observations are used: fluctuations around the mean and trends in gas concentration within a defined area.
• 🌍 Eddy covariance data contributes to FluxNet, an international database for global climate models.
• 🌱 It is crucial for understanding CO2 uptake by photosynthesis and emissions from various natural and human sources.
• 🔗 Eddy covariance data is publicly accessible, aiding in the development of climate change models and strategies.

Q & A

What is the eddy covariance method?

Eddy covariance is a scientific method used to measure the exchange of CO2 and other gases between soil, vegetation, and the air in an ecosystem. It helps in understanding an ecosystem's 'breathing' by quantifying gas fluxes or changes.

How does the eddy covariance method contribute to climate change research?

The eddy covariance method provides data that helps scientists develop models to forecast long-term trends in CO2 and greenhouse gas concentrations, which is crucial for understanding and addressing climate change.

What are the two main instruments used in eddy covariance measurements?

The two main instruments used are an anemometer, which measures wind speed and direction, and an infrared gas analyzer, which measures gas concentrations in the air.

How is the data collected from eddy covariance measurements processed?

The data, collected thousands of times per minute, is processed through a complex series of equations. After several assumptions, it yields estimates of the movement of gas into or out of an ecosystem.

What is the significance of the term 'eddy' in the context of eddy covariance?

In eddy covariance, 'eddy' refers to the circular motion of air created by temperature fluctuations. These fluctuations lead to the creation of wind and the eddies that scientists measure.

What does the term 'covariance' imply in the context of eddy covariance?

Covariance in eddy covariance refers to the simultaneous measurement of the change in the concentration of a gas and the direction of the swirling wind.

How are the two types of observations used to approximate gas exchange in eddy covariance?

The two types of observations involve calculating gas fluctuations around the mean and the trend of gas concentration measurements within a defined area, such as a box placed over the ecosystem.

What is the role of the international database FluxNet in eddy covariance data?

FluxNet is an international database to which researchers and organizations contribute eddy covariance data. It facilitates the use of this data to contribute to global models at various time scales.

Why are eddy covariance measurements important for understanding atmospheric concentrations?

Eddy covariance measurements are important because they provide the most conclusive method for measuring the intake of CO2 and other gases by photosynthesis and their emission into the atmosphere from various sources.

How can policymakers use the data from eddy covariance measurements?

Policymakers can use the data from eddy covariance measurements to draft legislation to address issues related to greenhouse gas emissions and improve people's quality of life.

Where can one access eddy covariance and other related data?

Eddy covariance and other related data can be accessed freely at the NEON Science website.

Outlines

00:00

🌿 Understanding Eddy Covariance for CO2 Emissions

Eddy covariance is a scientific method used to measure CO2 and other gas exchanges between an ecosystem and the atmosphere. It's crucial for developing models that predict long-term trends in greenhouse gas concentrations, aiding policymakers in drafting legislation to address climate change. The method involves measuring the circular motion of air, known as eddies, created by temperature fluctuations, and the change in gas concentration, or 'variance'. High-tech equipment like anemometers and infrared gas analyzers are used to collect data, which is then processed through complex equations to estimate gas fluxes. This data is shared globally through databases like FluxNet, contributing to a comprehensive understanding of atmospheric gas trends.

Keywords

💡Eddy Covariance

Eddy covariance is a scientific method used to measure the exchange of gases, such as carbon dioxide (CO2), between the Earth's surface and the atmosphere. It is central to the video's theme as it helps scientists understand how ecosystems 'breathe' by quantifying the fluxes of gases. The method involves measuring the movement of these gases caused by eddies, which are circular motions of air created by temperature fluctuations. The script humorously introduces the term, emphasizing its significance in measuring CO2 emissions and other greenhouse gases, which is crucial for developing models to predict long-term trends and informing policy decisions.

💡CO2 emissions

CO2 emissions refer to the release of carbon dioxide into the atmosphere, which is a key contributor to climate change. In the context of the video, understanding and measuring CO2 emissions at a local ecosystem level is essential for tracking and predicting global climate trends. The script explains how eddy covariance measures these emissions, which is vital for creating accurate climate models and for policymakers to draft legislation aimed at mitigating climate change.

💡Gas fluxes

Gas fluxes are changes in the concentration of gases, particularly CO2, that occur as they move between an ecosystem and the atmosphere. The video emphasizes the importance of quantifying these fluxes to understand the balance between photosynthesis, which absorbs CO2, and respiration or other processes that release it. The script uses the term to illustrate how eddy covariance measures the net movement of CO2 molecules, which is crucial for tracking carbon cycles and the health of ecosystems.

💡Anemometer

An anemometer is a device used to measure wind speed and direction. In the video, it is one of the two key pieces of equipment used in eddy covariance measurements, mounted on towers above areas of interest. The script mentions that the anemometer works in conjunction with an infrared gas analyzer to collect data on wind and gas concentrations, which is then used to calculate gas fluxes and understand ecosystem dynamics.

💡Infrared gas analyzer

An infrared gas analyzer is a high-tech instrument that measures the concentration of gases, including CO2, in the air. As explained in the script, it is used alongside an anemometer in eddy covariance setups to collect data on gas concentrations. This data, when combined with wind speed and direction measurements, allows scientists to calculate the flux of gases and monitor the health of ecosystems.

💡FluxNet

FluxNet is an international database that compiles eddy covariance data from various institutions and researchers around the world. The video highlights FluxNet as a critical resource for scientists, as it facilitates the use of eddy covariance data to contribute to global models at different time scales. The script emphasizes the collaborative nature of this database, showcasing how collective data contributes to a broader understanding of climate change and atmospheric gas concentrations.

💡Photosynthesis

Photosynthesis is the process by which plants, algae, and some bacteria convert light energy into chemical energy, using carbon dioxide and water to produce oxygen and glucose. The script mentions photosynthesis in the context of CO2 uptake by plants, which is a crucial part of the carbon cycle. Eddy covariance measurements help scientists understand how much CO2 is absorbed by photosynthesis in different ecosystems, which is essential for modeling and predicting climate change.

💡Respiration

Respiration is the process by which living organisms release energy stored in organic molecules by breaking them down, releasing carbon dioxide as a byproduct. In the video, respiration is discussed as one of the processes that contribute to CO2 emissions, alongside photosynthesis. Eddy covariance measurements help scientists track the balance between CO2 uptake by photosynthesis and release by respiration, which is vital for understanding ecosystem health and climate change.

💡Permafrost

Permafrost refers to soil that remains frozen for at least two consecutive years. The script mentions thawing permafrost as a source of CO2 emissions, highlighting the interconnectedness of various natural processes with climate change. As permafrost thaws, it releases trapped CO2 and methane, contributing to atmospheric greenhouse gas concentrations. Eddy covariance measurements can help monitor these emissions and their impact on the climate.

💡Policymakers

Policymakers are individuals or groups responsible for creating and implementing laws and regulations. The video script discusses how eddy covariance data can inform policymakers, enabling them to draft legislation aimed at addressing climate change and improving environmental quality. By providing accurate measurements of CO2 emissions and gas fluxes, eddy covariance contributes to the scientific basis for policy decisions.

Highlights

Scientists use eddy covariance to measure CO2 emissions for local ecosystems.

Eddy covariance measures an ecosystem's 'breathing', the exchange of CO2 and other gases.

Data helps develop models forecasting long-term trends in CO2 and greenhouse gases.

Policymakers use this data to draft legislation addressing environmental issues.

Eddy covariance quantifies gas fluxes by measuring gas movement between ecosystems and the atmosphere.

An eddy is a circular motion of air created by temperature fluctuations.

Covariance involves measuring changes in gas concentration and wind direction simultaneously.

Two main instruments used are an anemometer and an infrared gas analyzer.

Data is collected thousands of times per minute and processed through complex equations.

Two types of observations are used: fluctuations around the mean and trends in gas concentration.

Eddy covariance reveals how much CO2 is reused by organisms and released into the atmosphere.

The system measures net flux of gas molecules over a defined volume and time.

Eddy covariance data is collected globally and contributes to the international FluxNet database.

These measurements are crucial for understanding CO2 intake by photosynthesis and emissions from various sources.

Data supports the development of accurate climate change models and forecasting greenhouse gas concentrations.

Eddy covariance and related data are available for public use at NEON Science dot org.

Transcripts

(music)

Have you ever wondered how scientists measure

CO2 emissions for local ecosystems here on earth?

(error beep)

Well, one way is a well defined scientific method known as eddy covariance.

(laugh) No, not that Eddie!

Eddy covariance is how we measure an ecosystem's breathing.

It’s CO2 and other gasses that are exchanged between soil, vegetation, and the air

in an ecosystem.

The data it provides help scientists develop models that forecast long-term trends in CO2 and greenhouse gasses,

much like the National Weather Service forecasts the short-term weather.

This data will allow policymakers to draft legislation to address pressing issues and

improve people's quality of life.

Eddy covariance quantifies gas fluxes, or changes,

by directly measuring the movement of gasses,

like CO2, between an ecosystem and the atmosphere.

To simplify it, let's look at both words.

An eddy is a circular motion of air created by temperature fluctuations.

At night, without the sun, the air is cool and relatively stable.

With the raising of the sun, the earth and air temperature begins to climb.

This constant night and day fluctuation creates the wind we feel

and the eddies of air that scientists measure.

Covariance has two parts:

"co" meaning together and

"variance" meaning change.

This means simultaneously measuring the change between the concentration of a gas and the

direction of swirling wind.

Eddy covariance is primarily measured by two pieces of high tech gadgetry,

mounted on tripods and towers above areas of interest,

like forests, lakes or agricultural areas.

The anemometer measures wind speed and direction.

The infrared gas analyzer measures gas concentrations in the air.

The data are collected simultaneously, thousands of times per minute.

The wind and gas concentration data go into a complex series of equations that,

after several assumptions, yield estimates of the movement of gas into or out of an ecosystem.

Two types of observations are primarily used to approximate the gas exchange.

Imagine we place a box over the ecosystem,

the gas moving in and out of the top of the box is calculated as fluctuations around the mean.

The gas accumulated inside the box is calculated from

the trend of gas concentration measurements in that area.

When calculated over time, we can see trends that reveal how much CO2, and other gases,

are being reused by earth’s organisms and how much is released into the atmosphere.

To really simplify, the system works by measuring how many gas molecules pass through a defined

volume over a specific time.

For example, the system might capture a measurement of 7 CO2 molecules being carried upward towards

the atmosphere by an eddy, then, in the next moment, only 5 of those molecules are recorded

traveling downward toward the ground.

Then we know that the net flux, over this specific time period is equal to 2 molecules

of CO2 being emitted into the atmosphere. [adios, buh-bye]

It isn’t your everyday Eddie that compiles this stuff.

Eddy covariance data are collected by individual researchers and organizations around the globe,

including the National Ecological Observatory Network.

And what’s really cool is that all these institutions contribute

to an international database, FluxNet,

to facilitate the use of eddy covariance data to contribute to global models at many time scales.

Eddy covariance measurements are really important because they are the most conclusive method

for measuring how much CO2, and other gases, are taken in by photosynthesis,

and also emitted into earth’s atmosphere from things like respiration,

geologic emissions,

thawing permafrost, and

human activity.

Documenting these gas exchanges is important to understand trends in atmospheric concentrations.

They allow for the development of accurate models to forecast greenhouse gas concentrations

and other factors of climate change on our planet.

So next time you think about how scientists measure CO2 and greenhouse emissions at a local level

just remember Eddy… [heh]

Eddy Covariance! [laugh]

Eddy covariance and other data are freely available at NEON Science dot org.