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1 April 2014 - Johnny A. Johannessen on satellite retrieval of surface current

posted Feb 21, 2014, 1:48 AM by Knut-Frode Dagestad   [ updated Aug 3, 2014, 5:09 AM ]
Tuesday 1 April 2014, Prof. Johnny A. Johannessen from Nansen Environmental and Remote Sensing Center (NERSC) will give us an overview of "Satellite sensor synergy for retrieval of surface current"

Time: 17:00-17:45
Place: East wing auditorium, Geophysical Institute, University of Bergen

After the talk, discussions will continue over a beer or coffee at Cafe Chaos (5 min by foot).

The talk is free of charge, but please register by sending an email to knutfd@met.no
Both members and non-members are welcome!

To become a member of BGF and enjoy reduced fees for some of our events, please register here.


Abstract:
New knowledge of the global ocean surface dynamics emerged over the last 10 - 15 years reveal an ocean filled with a large number of various mesoscale (~100 km) and sub-mesoscale (<~10 km) meandering surface current features and eddies. However we are still faced with challenges when it comes to accurate quantification of the surface current associated with these mesoscale to sub-mesoscale features, and nor is it always possible to provide forecasts of the exact locations and evolution of the frontal features and eddies with sufficient accuracy. This deficiency results primarily from inability to adequately characterize the upper ocean dynamics. This is partly resulting from a lack of regular high-quality in-situ observations with sufficient temporal and spatial resolution. However, more consistent quantitative use of satellite observations is also required to advance the understanding and reduce the knowledge gaps of the ocean surface current and upper layer dynamics at the mesoscale to sub-mesoscale.

Direct and indirect estimates of the surface current and higher level derived quantities such as frontal boundaries can be derived using a variety of satellite sensors including altimetry, gravimetry, SAR, scatterometry, optical sensing and passive microwaves. Each of these satellite based measurement techniques has their specific strength and limitations. By development and use of systematic data merging and sensor synergy combined with advanced processing tools and simulation models, the complementary strength of each sensing technique can be optimized. In so doing the knowledge gaps and deficiencies are relaxed and the final estimate of the surface current and higher level derived products (e.g. frontal boundaries) will be more consistent, regular and reliable.

This presentation will shed more light on this using a variety of examples from a range of different current regimes and geographical areas.



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