GLORIA

GEOMAR Library Ocean Research Information Access

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Wiley  (4)
Material
Publisher
  • Wiley  (4)
Language
Years
Subjects(RVK)
  • 1
    Online Resource
    Online Resource
    Wiley ; 2015
    In:  Quarterly Journal of the Royal Meteorological Society Vol. 141, No. 686 ( 2015-01), p. 166-181
    In: Quarterly Journal of the Royal Meteorological Society, Wiley, Vol. 141, No. 686 ( 2015-01), p. 166-181
    Abstract: We present results from a new synthesis (GECCO2) which covers the years 1948 to 2011 employing a similar configuration of the Massachusetts Institute of Technology general circulation model as the previous 50‐year (1952 to 2001) GECCO synthesis. In GECCO2, the resolution was increased; it now includes the Arctic Ocean and a dynamic/thermodynamic sea ice model. The synthesis uses the adjoint method to bring the model into consistency with available hydrographic and satellite data as well as prior estimates of surface fluxes. In comparison to GECCO, GECCO2 provides a better agreement with the assimilated data, however the estimated flux adjustments remain similar to GECCO. Global heat content changes are in agreement with recent observational estimates and the estimate of the global heat flux is close to a radiative forcing estimate. Both show a clear effect of the radiative forcing from volcanic eruptions and a weak relation to ENSO events. In contrast to GECCO, the importance of the Denmark Strait overflow for the variability of the Atlantic Meridional Overturning Circulation (AMOC) is replaced in GECCO2 by water mass transformation in the subpolar gyre, which is shown to be part of the thermohaline circulation if the overturning is defined as a function of density. Heat and freshwater transport estimates in the Atlantic are more consistent with previous estimates than the unconstrained run. Decomposing heat and freshwater transports into overturning and gyre components by averaging on density coordinates demonstrates that in these coordinates the contribution from the gyre circulation largely disappears for heat transport and is reduced for the freshwater transport.
    Type of Medium: Online Resource
    ISSN: 0035-9009 , 1477-870X
    URL: Issue
    RVK:
    RVK:
    Language: English
    Publisher: Wiley
    Publication Date: 2015
    detail.hit.zdb_id: 3142-2
    detail.hit.zdb_id: 2089168-4
    SSG: 14
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 2
    Online Resource
    Online Resource
    Wiley ; 2021
    In:  Quarterly Journal of the Royal Meteorological Society Vol. 147, No. 736 ( 2021-04), p. 1908-1929
    In: Quarterly Journal of the Royal Meteorological Society, Wiley, Vol. 147, No. 736 ( 2021-04), p. 1908-1929
    Abstract: We present an Arctic ocean–sea ice reanalysis covering the period 2007–2016 based on the adjoint approach of the Estimating the Circulation and Climate of the Ocean (ECCO) consortium. The spatiotemporal variation of Arctic sea surface temperature (SST), sea ice concentration (SIC), and sea ice thickness (SIT) is substantially improved after the assimilation of ocean and sea ice observations. By assimilating additional World Ocean Atlas 2018 (WOA18) hydrographic data, the freshwater content of the Canadian Basin becomes closer to the observations and translates into changes of the ocean circulation and of transports through the Fram and Davis straits. This new reanalysis compares well with previous filter‐based (TOPAZ4) and nudging‐based (PIOMAS) reanalyses regarding SIC and SST. Benefiting from using the adjoint of the sea ice model, our reanalysis is superior to the ECCOv4r4 product considering sea ice parameters. However, the mean state and variability of the freshwater content and the transport properties of our reanalysis remain different from TOPAZ4 and ECCOv4r4, likely because of a lack of hydrographic observations.
    Type of Medium: Online Resource
    ISSN: 0035-9009 , 1477-870X
    URL: Issue
    RVK:
    RVK:
    Language: English
    Publisher: Wiley
    Publication Date: 2021
    detail.hit.zdb_id: 3142-2
    detail.hit.zdb_id: 2089168-4
    SSG: 14
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 3
    Online Resource
    Online Resource
    Wiley ; 2020
    In:  Quarterly Journal of the Royal Meteorological Society Vol. 146, No. 730 ( 2020-07), p. 2250-2273
    In: Quarterly Journal of the Royal Meteorological Society, Wiley, Vol. 146, No. 730 ( 2020-07), p. 2250-2273
    Abstract: The paper describes an update of the GECCO (German contribution to the Estimating the Circulation and Climate of the Ocean project) ocean synthesis, now in its version 3, and provides an evaluation of the results with assimilated and independent data. GECCO3 covers the 71‐year period 1948–2018 and differs from its predecessor by returning to a single assimilation window instead of partitioning the period in 5‐year‐long overlapping windows which was previously necessary to yield convergence. A solution to the convergence problem is presented. GECCO3 is intended to be used for the initialization of coupled climate models and is configured for the higher‐resolution version of the earth system model (MPI‐ESM) developed at the Max Planck Institute for Meteorology. It uses the bathymetry and grid of the MPI‐ESM with quasi‐uniform resolution of 0.4°, thereby providing the first global eddy‐permitting synthesis based on the adjoint method. The synthesis additionally features the estimation of various mixing parameters and can regionally choose between explicit or parametrized eddy fluxes. Except for the altimeter data in tropical regions, GECCO3 is in better agreement with the assimilated data than GECCO2. The improvements relative to the in situ data partly result from the much larger amount of Argo data, which show lower model–data differences. Global heat content changes are in good agreement with recent estimates, but show uptake almost exclusively in the top 700 m. An alternative version of GECCO3, created by starting from different first‐guess control parameters, was used to evaluate the uncertainty of the estimated parameters and state due to lack of convergence. This estimate suggests a large uncertainty related to the uptake of heat into the lower layers, while estimates of mean meridional transport of heat and freshwater are not affected.
    Type of Medium: Online Resource
    ISSN: 0035-9009 , 1477-870X
    URL: Issue
    RVK:
    RVK:
    Language: English
    Publisher: Wiley
    Publication Date: 2020
    detail.hit.zdb_id: 3142-2
    detail.hit.zdb_id: 2089168-4
    SSG: 14
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 4
    Online Resource
    Online Resource
    Wiley ; 2021
    In:  Quarterly Journal of the Royal Meteorological Society Vol. 147, No. 738 ( 2021-07), p. 2670-2690
    In: Quarterly Journal of the Royal Meteorological Society, Wiley, Vol. 147, No. 738 ( 2021-07), p. 2670-2690
    Abstract: Arctic Ocean Observing System Simulation Experiments (OSSEs) were performed with a pan‐Arctic coupled ocean–sea ice data assimilation system to assess the impacts of assimilating available observations on the Arctic ocean–sea ice state. To this end, the adjoint method with a 3‐year assimilation window was used to assimilate synthetic observations sampled from a 4 km model simulation at the spatio‐temporal distribution of the existing observing system. After data assimilation, the sea ice state, including sea ice concentration (SIC), sea ice thickness (SIT), and sea ice volume (SIV), were significantly improved, benefiting from the high spatio‐temporal coverage of SIC observations and the wintertime SIT observations. In contrast, the ocean state is not very well constrained with the existing hydrographic observing system. An additional 1° × 1° ocean profiling array with a 10‐day sampling frequency was seen to substantially improve the estimated ocean temperature and freshwater content. Data from additional moorings deployed in the Fram Strait and continental slope of the Laptev Sea could also improve the pathway of Atlantic inflow to the Arctic Ocean and the temperature of the Atlantic inflow but degrade the mean volume transport through the Fram Strait. Moreover, estimated exchanges between the Arctic Ocean and the Atlantic Ocean through the Fram Strait, Davis Strait and the St. Anna Trough were found to benefit from the high‐density profiling array.
    Type of Medium: Online Resource
    ISSN: 0035-9009 , 1477-870X
    URL: Issue
    RVK:
    RVK:
    Language: English
    Publisher: Wiley
    Publication Date: 2021
    detail.hit.zdb_id: 3142-2
    detail.hit.zdb_id: 2089168-4
    SSG: 14
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...