idw – Informationsdienst Wissenschaft
Nachrichten, Termine, Experten
Nachrichten, Termine, Experten
Referent: Dr. Mati Kahru, Scripps Institution of Oceanography, University of California, San Diego, USA
The influence of decreasing Arctic sea-ice on net primary production (NPP) in the Arctic Ocean has been considered in multiple publications but is not well constrained due to the potentially large errors in satellite algorithms. In particular, the Arctic Ocean is rich in colored dissolved organic matter (CDOM) that interferes with the detection of chlorophyll-a concentration in the standard band-ratio algorithm, the primary input to NPP models. We used the quasi-analytic algorithm (QAA, Lee et al. 2002) that separates absorption by phytoplankton from absorption by CDOM and detrital matter. We merged satellite data from multiple satellite sensors and created a 19-year time series (1997-2015) of NPP.
During this period both the estimated annual total and the summer monthly maximum pan-Arctic NPP increased by about 47% while the specific productivity per open water area has decreased by 12.9% during the same period. Positive monthly anomalies in NPP are highly correlated with positive anomalies in open water during the summer months. Following the earlier ice retreat, the start of the high-productivity season has become earlier, e.g. in northern Barents Sea at a mean rate of -3.0 day/year and the length of the high-productivity period has increased from 15 days in 1998 to 62 days in 2015. While in some areas the termination of the productive season has been extended, allowed by the delayed ice formation, the termination has also become earlier in the northern Barents Sea, likely due to limited nutrients.
Information on participating / attending:
Date:
06/15/2016 14:00 - 06/15/2016
Event venue:
Alfred-Wegener-Institut, Hörsaal, Columbusstraße / Am Alten Hafen 26
27568 Bremerhaven
Bremen
Germany
Target group:
Scientists and scholars, Students
Relevance:
regional
Subject areas:
Biology, Geosciences, Oceanology / climate
Types of events:
Presentation / colloquium / lecture
Entry:
04/07/2016
Sender/author:
Ralf Röchert
Department:
Kommunikation und Medien
Event is free:
yes
Language of the text:
German
URL of this event: http://idw-online.de/en/event53921
You can combine search terms with and, or and/or not, e.g. Philo not logy.
You can use brackets to separate combinations from each other, e.g. (Philo not logy) or (Psycho and logy).
Coherent groups of words will be located as complete phrases if you put them into quotation marks, e.g. “Federal Republic of Germany”.
You can also use the advanced search without entering search terms. It will then follow the criteria you have selected (e.g. country or subject area).
If you have not selected any criteria in a given category, the entire category will be searched (e.g. all subject areas or all countries).
