Towards an integrated observation and modeling system in the New York Bight using variational methods. Part I : 4DVAR data assimilation
MetadataShow full item record
Four-dimensional Variational data assimilation (4DVAR) in the Regional Ocean Modeling System (ROMS) is used to produce a best-estimate analysis of ocean circulation in the New York Bight during spring 2006 by assimilating observations collected by a variety of instruments during an intensive field program. An incremental approach is applied in an overlapped cycling system with 3-day data assimilation window to adjust model initial conditions. The model-observation mismatch for all observed variables is reduced substantially. Comparisons between model forecast and independent observations show improved forecast skill for about 15 days for temperature and salinity, and 2 to 3 days for velocity. Tests assimilating only certain subsets of the data indicate that assimilating satellite sea surface temperature improves the forecast of surface and subsurface temperature but worsens the salinity forecast. Assimilating in situ temperature and salinity from gliders improves the salinity forecast but has little effect on temperature. Assimilating HF-radar surface current data improves the velocity forecast by 1-2 days yet worsens the forecast of subsurface temperature. During some time periods the convergence for velocity is poor as a result of the data assimilation system being unable to reduce errors in the applied winds because surface forcing is not among the control variables. This study demonstrates the capability of 4DVAR data assimilation system to reduce model-observation mismatch and improve forecasts in the coastal ocean, and highlights the value of accurate meteorological forcing.
Author Posting. © The Author(s), 2010. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Ocean Modelling 35 (2010): 119-133, doi:10.1016/j.ocemod.2010.08.003.
Showing items related by title, author, creator and subject.
The seasonal nitrogen cycle in Wilkinson Basin, Gulf of Maine, as estimated by 1-D biological model optimization Anderson, Laurence A. (2009-04-22)The objective of this study was to fit a simple ecosystem model to climatological nitrogen cycle data in the Gulf of Maine, in order to calibrate the biological model for use in future 3-D modelling studies. First ...
He, Ruoying; McGillicuddy, Dennis J.; Lynch, Daniel R.; Smith, Keston W.; Stock, Charles A.; Manning, James P. (American Geophysical Union, 2005-10-12)A data assimilative model hindcast of the Gulf of Maine (GOM) coastal circulation during an 11 day field survey in early summer 2003 is presented. In situ observations include surface winds, coastal sea levels, and shelf ...
Booth, Mary S.; Stark, John M.; Rastetter, Edward B. (Ecological Society of America, 2005-05)Isotope pool dilution studies are increasingly reported in the soils and ecology literature as a means of measuring gross rates of nitrogen (N) mineralization, nitrification, and inorganic N assimilation in soils. We ...