Case Study of a Coastal Jet at Spitsbergen—Comparison of SAR- and Model-Estimated Wind

Anne Dagrun Sandvik University of Bergen, Bergen, Norway

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Birgitte Rugaard Furevik Nansen Environmental and Remote Sensing Center, Bergen, Norway

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Abstract

A combination of in situ ship measurements, synthetic aperture radar (SAR) imagery, and high-resolution numerical modeling was used to investigate a mesoscale coastal jet radiating out from Hinlopenstretet, Norway, on 14 August 1996. In the meteorological analysis, a light breeze and high static stability were found upstream of Svalbard. By studying results of numerical simulations in relation to the topography, upstream stagnation, flow splitting, and downstream jets and wakes were identified. In the Hinlopenstretet area this flow pattern was confirmed by in situ ship measurements and the SAR-estimated wind. Through investigations of sensitivity simulations, it was found that the low-level jet mainly was a result of stratified flow around dynamically steep, isolated topography, while the channeling effect of Hinlopenstretet had a minor influence. In the core of the jet the velocity was increased by a factor of about 3 compared to the upstream velocity.

Corresponding author address: Anne Dagrun Sandvik, University of Bergen, Allegaten 70, N-5007 Bergen, Norway.Email: anne@gfi.uib.no

Abstract

A combination of in situ ship measurements, synthetic aperture radar (SAR) imagery, and high-resolution numerical modeling was used to investigate a mesoscale coastal jet radiating out from Hinlopenstretet, Norway, on 14 August 1996. In the meteorological analysis, a light breeze and high static stability were found upstream of Svalbard. By studying results of numerical simulations in relation to the topography, upstream stagnation, flow splitting, and downstream jets and wakes were identified. In the Hinlopenstretet area this flow pattern was confirmed by in situ ship measurements and the SAR-estimated wind. Through investigations of sensitivity simulations, it was found that the low-level jet mainly was a result of stratified flow around dynamically steep, isolated topography, while the channeling effect of Hinlopenstretet had a minor influence. In the core of the jet the velocity was increased by a factor of about 3 compared to the upstream velocity.

Corresponding author address: Anne Dagrun Sandvik, University of Bergen, Allegaten 70, N-5007 Bergen, Norway.Email: anne@gfi.uib.no

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