English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

A series of observing system simulation experiments\ud(OSSEs) is carried out with a global data assimilation system at\ud1∕4° resolution using simulated data derived from a\ud1∕12° resolution free-run simulation. The objective is to not only quantify\udhow well multiple altimeter missions and Argo profiling floats can constrain\udthe global ocean analysis and 7-day forecast at 1∕4° resolution\udbut also to better understand the sensitivity of results to data\udassimilation techniques used in Mercator Ocean operational systems. The impact\udof multiple altimeter data is clearly evidenced even at a 1∕4°\udresolution. Seven-day forecasts of sea level and ocean currents are\udsignificantly improved when moving from one altimeter to two altimeters not\udonly on the sea level, but also on the 3-D thermohaline structure and\udcurrents. In high-eddy-energy regions, sea level and surface current 7-day\udforecast errors when assimilating one altimeter data set are respectively\ud20 and 45 % of the error of the simulation without assimilation. Seven-day\udforecasts of sea level and ocean currents continue to be improved when\udmoving from one altimeter to two altimeters with a relative error reduction\udof almost 30 %. The addition of a third altimeter still improves the 7-day\udforecasts even at this medium 1∕4° resolution and brings an\udadditional relative error reduction of about 10 %. The error level of the\udanalysis with one altimeter is close to the 7-day forecast error level when\udtwo or three altimeter data sets are assimilated. Assimilating altimeter\uddata also improves the representation of the 3-D ocean fields. The addition\udof Argo has a major impact on improving temperature and demonstrates the\udessential role of Argo together with altimetry in constraining a global data\udassimilation system. Salinity fields are only marginally improved. Results\udderived from these OSSEs are consistent with those derived from experiments\udwith real data (observing system evaluations, OSEs) but they allow for more\uddetailed characterisation of errors on analyses and 7-day forecasts. Both\udOSEs and OSSEs should be systematically used and intercompared to test data\udassimilation systems and quantify the impact of existing observing systems

Assessing the impact of multiple altimeter missions and Argo in a global eddy-permitting data assimilation system