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Full-Text Articles in Physical Sciences and Mathematics
A Multiscale Approach To High-Resolution Ocean Profile Observations Within A 4dvar Analysis System, Matthew J. Carrier, John J. Osborne, Hans E. Ngodock, Scott R. Smith, Innocent Souopgui, Joseph M. D'Addezio
A Multiscale Approach To High-Resolution Ocean Profile Observations Within A 4dvar Analysis System, Matthew J. Carrier, John J. Osborne, Hans E. Ngodock, Scott R. Smith, Innocent Souopgui, Joseph M. D'Addezio
Faculty Publications
Most ocean data assimilation systems are tuned to process and assimilate observations to constrain features on the order of the mesoscale and larger. Typically this involves removal of observations or computing averaged observations. This procedure, while necessary, eliminates many observations from the analysis step and can reduce the overall effectiveness of a particular observing platform. Simply including these observations is not an option as doing so can produce an overdetermined, ill-conditioned problem that is more difficult to solve. An approach, presented here, aims to avoid such issues while at the same time increasing the number of observations within the assimilation. …
On The Approximation Of The Inverse Error Covariances Of High-Resolution Satellite Altimetry Data, Max Yaremchuk, Joseph M. D'Addezio, Gleb Panteleev, Gregg Jacobs
On The Approximation Of The Inverse Error Covariances Of High-Resolution Satellite Altimetry Data, Max Yaremchuk, Joseph M. D'Addezio, Gleb Panteleev, Gregg Jacobs
Faculty Publications
© 2018 Royal Meteorological Society High-resolution (swath) altimeter missions scheduled to monitor the ocean surface in the near future have observation-error covariances (OECs) with slowly decaying off-diagonal elements. This property presents a challenge for the majority of the data assimilation algorithms which were designed under the assumption of the diagonal OECs being easily inverted. In this note, we present a method of approximating the inverse of a dense OEC by a sparse matrix represented by the polynomial of spatially inhomogeneous differential operators, whose coefficients are optimized to fit the target OEC by minimizing a quadratic cost function. Explicit expressions for …
Examining The Potential Impact Of Swot Observations In An Ocean Analysis-Forecasting System, Matthew Carrier, Hans E. Ngodock, Scott R. Smith, Innocent Souopgui, Brent Bartels
Examining The Potential Impact Of Swot Observations In An Ocean Analysis-Forecasting System, Matthew Carrier, Hans E. Ngodock, Scott R. Smith, Innocent Souopgui, Brent Bartels
Faculty Publications
NASA's Surface Water and Ocean Topography (SWOT) satellite, scheduled for launch in 2020, will provide observations of sea surface height anomaly (SSHA) at a significantly higher spatial resolution than current satellite altimeters. This new observation type is expected to improve the ocean model mesoscale circulation. The potential improvement that SWOT will provide is investigated in this work by way of twin-data assimilation experiments using the Navy Coastal Ocean Model four-dimensional variational data assimilation (NCOM-4DVAR) system in its weak constraint formulation. Simulated SWOT observations are sampled from an ocean model run (referred to as the "nature" run) using an observation-simulator program …