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E
cosystems
As a result, observations from space do not adequately
cover some important carbon source and sink areas.
In order to solve these above-mentioned problems,
Meisei Electric has developed a low-cost, easy-to-operate,
all-weather sonde to measure vertical CO
2
distribution,
and is developing a low-cost and robust CO
2
column
densitometer by using an optical fiber etalon (Fiber Etalon
Solar measurement for Carbon dioxide, or FES-C).
Instrument development
Meisei Electric received financial support from the Japan
Science and Technology Agency (JST) between 2008 and
2010, to develop a CO
2
sonde that can measure the verti-
cal profile of CO
2
under the research area titled ‘Small
measurement device for CO
2
monitoring’. This CO
2
sonde has already achieved about 1 part per million
(ppm) accuracy (one standard deviation), independent
of the observation site, time and weather. The sonde
went into practical use in 2012, and improvements to
make measurements possible in the tropopause (10-–15
km) are in progress.
Meisei Electric has also been participating in the
‘Development of automatic optical CO
2
instrument aimed
at the global standard’ project, which runs from 2011 to
2013, with the support of JST. The advantages of the FES-C
and whose CO
2
emissions are growing most alarmingly. This
method can be applied to the weak but widely spread sink/source,
forest or grassland, for example, and for less non-predictable local
emissions such as forest fires. World Meteorological Organization
has made great efforts to establish a CO
2
observation network
to fill these gaps, and we applaud their commitment. With their
continued support, the impact of CO
2
emissions on local habi-
tats can be more clearly planned, and this vital component better
integrated into local climate forecasts. If those who continue to
increase their emissions were made more clear of the effects locally
on their climate by way of greater incidence of weather related
disasters or greater challenges in agriculture, water management
and health, then it may even convince them sooner of the impor-
tance of reducing their emissions.
On the other hand, satellite observations such as the Greenhouse
Gases Observing Satellite are already operating and similar satellites
are planned by the United States, Europe and China. Satellite obser-
vations have the advantage that high-density observations can be
made over the entire world; however, no measurements can be made
in areas under cloud cover, and even on clear days, measurement
accuracy is reduced in the presence of aerosols and cirrus. Aerosol is
emitted, along with CO
2
, from cities and factories, and it is difficult to
evaluate the amount of emission reduction there. Moreover, the large
forest areas, which are major CO
2
sinks, are frequently covered by
clouds because of the active transpiration of water vapour from trees.
0
2000
4000
6000
8000
10000
385 390 395 400 405 410 415 420
Altitude [m]
CO
2
concentration [ppm]
CO
2
-60 -40 -20 0 20 40 60 80 100
Temperature [
ϒ
C] / Humidity [%RH]
Temperature
Humidity
Vertical profiles of CO
2
, temperature and humidity measured by the CO
2
sonde launched at 14:30 LT on 26 November 2011 at Moriya Ibaragi, Japan
Source: Meisei Electric