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| Titel |
CO2 emissions driven by wind are produced at global scale |
| VerfasserIn |
M. Rosario Moya, Enrique P. Sánchez-Cañete, Andrew S. Kowalski, Penelope Serrano-Ortíz, Ana Lopez-Ballesteros, Cecilio Oyonarte, Francisco Domingo |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250145767
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| Publikation (Nr.) |
 EGU/EGU2017-9737.pdf |
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| Zusammenfassung |
| As an important tool for understanding and monitoring ecosystem dynamics at ecosystem
level, the eddy covariance (EC) technique allows the assessment of the diurnal and seasonal
variation of the net ecosystem exchange (NEE). Despite the high temporal resolution
data, there are still many processes (in addition to photosynthesis and respiration)
that, although they are being monitored, have been neglected. Only a few authors
have studied anomalous CO2 emissions (non biological), and have related them
to soil ventilation, photodegradation or geochemical processes. The aims of this
study are: 1) to identify anomalous daytime CO2 emissions in different ecosystems
distributed around the world, 2) to determine the meteorological variables that influence
these emissions, and 3) to explore the potential processes which can be involved.
We have studied EC data together with other meteorological ancillary variables
obtained from the FLUXNET database and have found more than 50 sites with
anomalous CO2 emissions in different ecosystem types such as grasslands, croplands or
savannas. Data were filtered according to the FLUXNET quality control flags (only
data with maximum quality were used, i.e. control flag equal to 0) and daytime
(shortwave radiation incoming > 50 W m−2). Partial Spearman correlation analyses
were performed between NEE and ancillary data: air temperature, vapour pressure
deficit, soil temperature, precipitation, atmospheric pressure, soil water content,
incoming photosynthetic photon flux density, friction velocity and net radiation. When
necessary, ancillary variables were gap-filled using the MDS method (Reichstein et al.
2005).
Preliminary results showed strong and highly significant correlations between
friction velocity and anomalous CO2 emissions, suggesting that these emissions were
mainly produced by ventilation events. Anomalous CO2 emissions were found
mainly in arid ecosystems and sites with hot and dry summers. We suggest that
anomalous CO2 emissions occur globally and therefore, their contribution to the
global NEE requires further investigation in order to better understand its drivers. |
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