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| Titel |
Helicopter survey of methane and carbon dioxide sources on the Laptev Sea shelf near the Lena River Delta |
| VerfasserIn |
A. Salyuk, I. Semiletov, V. Nesterov, N. Shakhova |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250026313
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| Zusammenfassung |
| Carbon dioxide and methane have recently been recognized not only as key sources but also
as great tracers of global climate change.
The release of CH4 and CO2 from geological and biological sources on the Laptev Sea
shelf was investigated during a flight on the helicopter Mi-8 20 September 2006 organized by
POI FEB RAS. Gas concentrations were measured on the height of about 100 m
over sea surface on the route more than 1200 km long and area over 40 000 km2
using Fast CH4 analyzer LosGatos DLT-100 and CO2 and H2O analyzer Li-8100
(LiCor). Vertical structure of atmosphere were investigated in 5 points with different
air-sea interaction environment with maximal height up to 2 000 m in northernmost
point.
Our data reveal that Arctic air-sea exchange processes have a substantial impact on
overlying atmospheric CH4 and CO2 composition. Enhanced concentrations of CH4 were
measured along the entire helicopter route (>1.85 ppm Latitudinal mean average), reaching
up to 1.97 ppm (6.5% increase) in particular areas. Some anomalies in air CH4 were spatially
correlated with anomalies in distribution of dissolved CH4 in water which could be
associated with fault zones and Lena River discharge. Vertical profiles of methane and
carbon dioxide exhibit a significant increase near the sea surface, what prove later
as a source of CH4 and CO2 into the atmosphere. Possibly massive escape both
of these gases may be related additionally with already intensified autumn ocean
convection.
Offshore helicopter survey near the Lena River Delta show that the Laptev
Sea surface is a strong source of carbon dioxide and methane into the atmosphere.
Aircraft survey may be used for mapping of the methane anomalies on the shelf. |
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