Using corn to monitor CO2 from decomposition gas

Scientists at the University of California Irvine (UCI) have provided more information about air pollution caused by plants and animals in the United States by analyzing samples of corn leaves collected across 70 different regions. .

The new method of measuring the amount of carbon dioxide emitted from burning coal, oil and natural gas helps atmospheric scientists better understand the contaminated area, how to mix air pollution in the air. Tracking the amount of CO2 emitted from decomposition gas will be necessary because countries around the world are signing a Kyoto Protocol in turn - to reduce greenhouse gas emissions. The United States also signed but still waits for Senate approval.

James Randerson, associate professor of Earth Sciences at UCI and a research associate, said: 'Many countries are facing pressure from monitoring and regulating the amount of CO ₂ emitted from decomposing gas. plants to limit emissions because the greenhouse effect is warming the earth. So this method can help determine how much CO2 from plants and animals decompose in different areas. '

The study was published in the Geophysical Research Journal

Researcher Diana Hsueh on corn field (Photo: University of California - Irvine)

Atmospheric scientists measure the amount of carbon dioxide typically by collecting air samples, but this is the first time that carbon dioxide is released from decomposed gas, delineated by plants. This new method can help supplement the current air sampling method because it actually provides a beneficial way to record the average daytime state after many months. Plants absorb CO ₂ from both the surrounding environment and from decomposing gases and during photosynthesis they become part of plant tissue.

In the summer of 2004, UCI scientists collected corn from 31 states' gardens and farms including Hawaii and Alaska. They choose corn because they are widely grown annually, and their carbon comes from a single growing season. Scientists have avoided key sources of pollution such as high-speed trains and power plants in developing different areas of polluted areas in different states. In the laboratory, they dried samples of corn leaves and leaves, then converted them into graphite with some chemical reactions.

The Graphite was further analyzed in the WM Keck Carbon Cycle Accelerator Mass Spectrometer, a device used to measure rare isotopes of carbon called radioactive carbon. CO2 emitted from decomposition gas does not contain radioactive carbon, so it is easy to distinguish from other sources. By measuring the machine, scientists calculated all the levels of CO ₂ released from decomposition gas at the location where corn samples were collected.

California and Ohio Valley have the most decomposition of CO ₂ , while the Colorado region is the least. Scientists hope to find pollution in California and the western coastal states, but they have discovered the Rocky Mountain Area that currently offers a mobile CO ₂ fence. decomposition gas. Air in the western region including Colorada, Idaho and New Mexico, is the cleanest area, with only 370 parts per million CO2, the air in the Eastern United States of Massachusetts, New Hampshire and New York contains an additional 2.7 parts. million CO ₂ from decomposing gas sources, while the air in Maryland, Ohio, Pennsylvania and West Virginia is twice as much as 4.3 parts per million of CO2 from decomposed gas.

Susan Trumbore, also a professor of earth science and co-research, added: " We can better identify emissions patterns and atmospheric changes in order to regulate the gas source to decompose real life." object. This is a direct way to measure the amount of CO2 released to warm the earth climate. "

Diana Hsueh senior student UCI is also the research director, along with researchers John Southon and Xiaomei Xu, and also Nir Krakauer of California Institute of Technology. The research is supported by the National Science Association and the US aerospace agency.

Anh Phuong