Impact of data assimilation on Eulerian versus Lagrangian estimates of upper ocean transport

• Published in: Journal of Geophysical Research: Oceans
• Main Authors: Sperrevik, Ann Kristin, Rohrs, Johannes, Christensen, Kai Hakon
• Language: unknown
• Published: 2022
• Subjects: 54 ENVIRONMENTAL SCIENCES; Norway; Northern Norway
• Online Access: http://www.osti.gov/servlets/purl/1461513; https://www.osti.gov/biblio/1461513; https://doi.org/10.1002/2016JC012640

Using four-dimensional variational analysis, we produce an estimate of the state of a coastalregion in Northern Norway during the late winter and spring in 1984. We use satellite sea surface tempera-ture and in situ observations from a series of intensive field campaigns, and obtain a more realistic distribu-tion of water masses both in the horizontal and the vertical than a pure downscaling approach can achieve.Although the distribution of Eulerian surface current speeds are similar, we find that they are more variableand less dependent on model bathymetry in our reanalysis compared to a hindcast produced using thesame modeling system. Furthermore, Lagrangian drift currents on the other hand are significantly changed, with overallhigher kinetic energy levels in the reanalysis than in the hindcast, particularly in the superinertial frequencyband.