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Impact of data assimilation on E ulerian versus L agrangian estimates of upper ocean transport
Author(s) -
Sperrevik Ann Kristin,
Röhrs Johannes,
Christensen Kai Håkon
Publication year - 2017
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
eISSN - 2169-9291
pISSN - 2169-9275
DOI - 10.1002/2016jc012640
Subject(s) - hindcast , environmental science , eulerian path , climatology , bathymetry , data assimilation , lagrangian , meteorology , physics , atmospheric sciences , geology , mathematics , oceanography
Using four‐dimensional variational analysis, we produce an estimate of the state of a coastal region in Northern Norway during the late winter and spring in 1984. We use satellite sea surface temperature and in situ observations from a series of intensive field campaigns, and obtain a more realistic distribution 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 variable and less dependent on model bathymetry in our reanalysis compared to a hindcast produced using the same modeling system. Lagrangian drift currents on the other hand are significantly changed, with overall higher kinetic energy levels in the reanalysis than in the hindcast, particularly in the superinertial frequency band.