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.