In the Lab

NOAA Tower To Monitor Air
A new sensor in what will be a broad nationwide network for tracking carbon is now monitoring the air over Colorado’s Front Range, the National Oceanic & Atmospheric Administration (NOAA) announced on July 31. A 1,000-foot-high tower east of Erie is one of 12 tall towers being instrumented by NOAA to capture the regional ebb and flow of atmospheric carbon.

This network of sensors monitors the natural carbon cycle and fossil fuel emissions, which help drive climate change. NOAA’s Earth System Research Lab (ESRL) in Boulder, Colo., is developing the tower network across the nation as part of its global observations of carboncycle gases.

“Boulder and other cities are spending money to reduce their fossil fuel emissions. They need accurate data to know what is working and what is not,” said ESRL scientist Arlyn Andrews. Cities and states have relied on proxy data, such as point-source inventories, gasoline sales records, and other tallies to estimate fossil fuel emissions, but there has been no objective way to verify what is released into the atmosphere.

The tower instruments in Erie are expected to give scientists the detailed information they need to tell how the region’s carbon dioxide is affected by forests, crops, or an upwind Front Range city. Finding carbon monoxide in the same air parcel, for example, is a clue that the carbon dioxide source is a high-traffic urban area, since carbon monoxide is produced through combustion.

As other towers in the network collect similar regional details from around the country, the data will be fed into ESRL’s online Carbon Tracker site, a powerful data framework unveiled earlier this year. For more information, contact ESRL at www.esrl.noaa.gov.

Device to Allow Drivers To Monitor Emissions
Future drivers may only have to glance at the dashboard to see the pollution spewing out of their vehicle’s exhausts.

A team from The University of Manchester has constructed a laser measuring device capable of recording levels of carbon dioxide, carbon monoxide and methane from directly inside an exhaust system, according to an Aug. 5 announcement by the university. Once optimized, the process could be incorporated into onboard diagnostic systems that would monitor emissions as vehicles drive along — and potentially help people reduce their emissions by adjusting their driving style.

Reporting in the Optical Society of America’s journal Applied Optics, academics claim this approach is faster and more sensitive than the extractive techniques normally used to monitor emissions.

The University of Manchester team employed a device known as a “near-IR diode laser sensor” to measure the variation in gas concentration during changes in the operating conditions of a Rover engine, such as increasing and decreasing the throttle, adjusting the air to fuel ratio, and start-up.

The team stated that the components for the device are readily available and the near-IR technology allows highly accurate readings to be taken and also cuts out interference.

In the studies reported in Applied Optics, the near-IR device used two diode lasers operating at different frequencies; one detecting carbon monoxide and carbon dioxide and the other detecting methane.

The next steps will be to fully quantify the technique and add more lasers for other key emissions such as nitrogen oxide, nitrogen dioxide and specific hydrocarbons.

For more information, contact Philip Martin, www.ceas.manchester.ac.uk/

This article originally appeared in the 10/01/2007 issue of Environmental Protection.

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