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| Titel |
Simulated and observed trends in key variables of the Arctic marine carbon cycle |
| VerfasserIn |
Nadine Goris, Christoph Heinze, Siv Lauvset, Dmitry Petrenko, Dmitry Pozdnyakov, Jörg Schwinger |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250081718
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| Zusammenfassung |
| For the Arctic region, a thorough monitoring of the marine carbon cycle is important, as the
general “polar amplification” of climate change also translates into the biogeochemical realm.
As compared to the global ocean, the sink for human-produced CO2 is fairly small in the
Arctic Ocean itself. Nevertheless, it is important to follow up this Arctic sink as a further
control of the regional carbon budget and to record changes in the marine carbon cycle on the
way towards a “blue Arctic”. Since observations on the Arctic are rare, the EU FP7
MONARCH-A project tries to enable adequate descriptions of the status and evolution of the
Arctic region Earth system components by generating time series of observation datasets
and model hindcasts. In terms of the marine carbon cycle, this analysis focuses
mainly on the key variables pCO2 and primary productivity. For oceanic pCO2, the
comprehensive data-sets SOCAT and LDEO were combined, while measurements of
atmospheric CO2 were collected from the GLOBALVIEW-CO2 data integration project.
Monthly Primary Production fields were retrieved from the sensors MODIS and
SeaWiFs. In order to get an overall picture of the behavior and trends of those key
variables, in addition the physical-biogeochemical model MICOM-HAMOCC-M was
employed.
The investigation showed that both oceanic and atmospheric pCO2 are consistent
variables which have a regular annual cycle and a similar behaviour all over the
Arctic for both model and data. In contrast, primary production shows an irregular
annual cycle in both range and form, varying over the Arctic. While a few well
distributed measurement stations with continuous observations are sufficient to get a
comprehensive picture for consistent variables like pCO2, it is relatively difficult
and costly to get a comprehensive record of non-consistent variables. Since the
provided data-set for primary production covers a relatively short time-scale, it was
neither possible to confidently validate the model nor to determine significant trends.
Widespread measurements for at least 40 years are needed to capture both different
regional behavior and associated trends stressing the value of the existing spatially
comprehensive Arctic datasets of primary production and the importance of continuing the
sensor-retrievals in the following years. The measurement stations of atmospheric CO2
provide a good characterization of CO2 with continuous measurement on a few, well
distributed locations and allow for a confident data-model comparison all over the Arctic,
while the coverage of the LDEO/SOCAT database allows for confident statements
about the trends of oceanic pCO2 in the region between 60oW and 30oE. Here, the
validated model MICOM-HAMOCC-M simulates a fast rising oceanic CO2 partial
pressure leading to an accelerated decrease in ocean CO2 uptake in the Arctic. |
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