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| Titel |
NDIR surface in situ and FTIR remote sensing measurements at the Jungfraujoch see different CO trends |
| VerfasserIn |
Bart Dils, Junbo Cui, Stephan Henne, Emmanuel Mahieu, Martin Steinbacher, Martine De Mazière |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250057851
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| Zusammenfassung |
| Carbon monoxide (CO) is mainly produced by incomplete combustion of carbon-containing
materials (fossil fuels or biomass) and plays an important role in atmospheric chemistry. Its
reaction with OH is widely considered as its most important sink, and at the same
time it is also the dominant reaction partner for OH (barring strongly polluted or
forested areas). As such CO has a strong indirect impact on the growth rates of many
important greenhouse gases such as CH4 and O3. It also has a direct influence on CO2
through its oxidation. Therefore obtaining accurate long-term measurements of
tropospheric CO concentrations is important, as it improves our understanding of the
earth’s present and future atmosphere. While the usage of space-borne instruments
such as MOPITT, SCIAMACHY and IASI has become increasingly important for
measuring the atmospheric composition on a global scale, their use for long term
trend analysis is often complicated by system degradation and bias shifts. Thus
ground-based measurements are crucial for providing very accurate data with high temporal
resolution over extended periods of time, ideally suited for trend analysis and validation
purposes. To optimally use the available information, there is, within the atmospheric
research community, a strong interest in integrated datasets, combining data from
several measurement techniques. Alas, this integration is often hindered by the
different characteristics of the data sets, inherent to the measurement techniques
used.
Here, two carbon monoxide time series (1997 till 2007) acquired at the high-Alpine
research station Jungfraujoch with two well-established measurement techniques, namely
in-situ surface concentration measurements using Non-Dispersive Infrared Absorption
technology (NDIR), and remote sensing measurements using solar absorption Fourier
transform Infrared Spectrometry (FTIR), have been compared. We show that, even if both
techniques are able to measure free tropospheric CO concentrations and if factors such as
humidity, atmospheric boundary layer intrusions and temporal overlap effects are taken into
account, significant differences in their overall trend are observed. Lagranto trajectory model
data are used to assess whether these observations can be explained by considering that
various source regions contribute differently to both datasets and have different emission
trends. |
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