edu.ucar.opensky::articles:23844 UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact 2025-12-25T06:42:37.879714 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) https://n2t.org/ark:/85065/d7xw4p42 An EnOI-based data assimilation system with DART for a high-resolution version of the CESM2 ocean component 2020-11-01T00:00:00Z publication https://n2t.org/ark:/85065/d7xw4p42 https://doi.org/10.1029/2020MS002176 Castruccio, Frederic author Karspeck, A. R. author Danabasoglu, Gokhan author Hendricks, J. author Hoar, Timothy J. author Collins, Nancy S. author Anderson, Jeffrey L. author UCAR/NCAR - Library publisher An ensemble optimal interpolation (EnOI) data assimilation system for a high-resolution (0.1 degrees horizontal) version of the Community Earth System Model Version 2 (CESM2) ocean component is presented. For this purpose, a new version of the Data Assimilation Research Testbed (DART Manhattan) that enables large-state data assimilation by distributing state vector information across multiple processors at high resolution is used. The EnOI scheme uses a static (but seasonally varying) 84-member ensemble of precomputed perturbations to approximate samples from the forecast error covariance and utilizes a single model integration to estimate the forecast mean. Satellite altimetry and sea surface temperature observations along with in situ temperature and salinity observations are assimilated. This new data assimilation framework is then used to produce a global high-resolution retrospective analysis for the 2005-2016 period. Not surprisingly, the assimilation is shown to generally improve the time-mean ocean state estimate relative to an identically forced ocean model simulation where no observations are ingested. However, diminished improvements are found in undersampled regions. Lack of adequate salinity observations in the upper ocean actually results in deterioration of salinity there. The EnOI scheme is found to provide a practical and cost-effective alternative to the use of an ensemble of forecasts. UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact PDF Text theme Resource Type 2016-01-01T00:00:00Z publication Copyright author(s). This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License. None eng geoscientificInformation