Matches in SemOpenAlex for { <https://semopenalex.org/work/W1557191712> ?p ?o ?g. }
Showing items 1 to 99 of
99
with 100 items per page.
- W1557191712 endingPage "293" @default.
- W1557191712 startingPage "271" @default.
- W1557191712 abstract "The El Niño Southern Oscillation (ENSO) phenomena is the major source of interannual climatic variability in the Tropics. It results primarily from ocean-atmosphere interactions in the tropical Pacific. Over the past decade as part of the Tropical Oceans Global Atmosphere Experiment (TOGA) considerable progress was made in implementing observing systems to document this variability, developing a hierarchy of models, statistical as well as dynamical, to study its physics, and to implement routine experimental forecasts for aspects of ENSO related variability. During the past decade at the National Meteorological Center (NMC), presently the National Centers for Environmental Prediction (NCEP), a unified system for seasonal climate prediction was developed. This consisted of the routine assimilation of the in situ thermal data sets collected by TOGA into an ocean general circulation model to provide analyses for real time climate diagnostics and to provide ocean initial conditions for forecasts and a coupled ocean—atmosphere general circulation forecast model. Conceptually similar systems are currently being implemented at a number of other Centers internationally. A basic requirement for climate diagnostics and prediction is the best definition of the state of the ocean. In the Tropics where the ocean is strongly and directly forced, a model simulation forced with observed stress fields combined with in situ observations through data assimilation, can give a good estimate. These modelbased analyses can provide the basis for diagnostic studies, verification of model simulations and forecasts, and the initial conditions for the forecasts. Comparisons of simulations using existing wind stress products and models to analyses produced using data assimilation show large differences indicating that models and stress fields can still be improved. Without data assimilation model simulations contain significant errors both in their mean spatial structure and also in their low frequency variability. The thermocline topography in the mean is too weak, especially south of the equator where the subtropical gyre is not well defined. Experiments with several different wind products suggest that this is more a result of model rather than forcing field errors. Simulations without data assimilation are also unable to capture the full amplitude and structure of the low frequency variations associated with El Niño. Data assimilation can overcome many of these deficiencies. Even with assimilation, incremental improvements in analysis accuracy are further achieved when better wind forcing is used. However, large corrections can also alter strict dynamical balances. One impact of this is that the near equatorial currents in the western Pacific in NCEP's model-based analyses appear unrealistic. An improved estimation of the low frequency variability of the ocean should lead to higher skill levels in forecasts. This appears to be the case but the results are seasonally dependent. Forecasts initiated from late spring to fall for two versions of the NCEP forecast model show improved skill when data assimilation is used to derive the initial conditions. However, little positive impact is found for forecasts initiated in the winter months. If data assimilation is needed to correct for large errors, then in the forecast mode, where assimilation is not possible, the corrections, especially to the mean field, can lead to large systematic forecast errors. Future skill improvements will result from improvements in the forcing fields and ocean model used in the initialization, and improvements to the coupled forecast model. Indications from experiments at NCEP are that the largest impact on forecast skill is from improvements in the coupled ocean-atmosphere model used in the forecasts. The central role of data assimilation is in producing the best analyses that can be used for improving the ocean models and forcing fields." @default.
- W1557191712 created "2016-06-24" @default.
- W1557191712 creator A5001184000 @default.
- W1557191712 creator A5016028348 @default.
- W1557191712 date "1996-01-01" @default.
- W1557191712 modified "2023-09-22" @default.
- W1557191712 title "Ocean data assimilation as a component of a climate forecast system" @default.
- W1557191712 cites W1969597986 @default.
- W1557191712 cites W1981669700 @default.
- W1557191712 cites W1982161546 @default.
- W1557191712 cites W1986907421 @default.
- W1557191712 cites W1993512681 @default.
- W1557191712 cites W1998085623 @default.
- W1557191712 cites W2009428490 @default.
- W1557191712 cites W2013455123 @default.
- W1557191712 cites W2015378001 @default.
- W1557191712 cites W2016189350 @default.
- W1557191712 cites W2029396219 @default.
- W1557191712 cites W2031127053 @default.
- W1557191712 cites W2032440285 @default.
- W1557191712 cites W2037416330 @default.
- W1557191712 cites W2040006260 @default.
- W1557191712 cites W2041493260 @default.
- W1557191712 cites W2042465592 @default.
- W1557191712 cites W2045399980 @default.
- W1557191712 cites W2060311778 @default.
- W1557191712 cites W2061942651 @default.
- W1557191712 cites W2062835652 @default.
- W1557191712 cites W2067159744 @default.
- W1557191712 cites W2069867705 @default.
- W1557191712 cites W2070881789 @default.
- W1557191712 cites W2072809701 @default.
- W1557191712 cites W2074192976 @default.
- W1557191712 cites W2075059591 @default.
- W1557191712 cites W2082127163 @default.
- W1557191712 cites W2082173256 @default.
- W1557191712 cites W2085871048 @default.
- W1557191712 cites W2109343241 @default.
- W1557191712 cites W2140602065 @default.
- W1557191712 cites W2172639859 @default.
- W1557191712 cites W2175723489 @default.
- W1557191712 cites W2175816372 @default.
- W1557191712 cites W2334501310 @default.
- W1557191712 cites W2614245765 @default.
- W1557191712 doi "https://doi.org/10.1016/s0422-9894(96)80013-4" @default.
- W1557191712 hasPublicationYear "1996" @default.
- W1557191712 type Work @default.
- W1557191712 sameAs 1557191712 @default.
- W1557191712 citedByCount "4" @default.
- W1557191712 crossrefType "book-chapter" @default.
- W1557191712 hasAuthorship W1557191712A5001184000 @default.
- W1557191712 hasAuthorship W1557191712A5016028348 @default.
- W1557191712 hasConcept C111368507 @default.
- W1557191712 hasConcept C127313418 @default.
- W1557191712 hasConcept C132651083 @default.
- W1557191712 hasConcept C134097258 @default.
- W1557191712 hasConcept C141452985 @default.
- W1557191712 hasConcept C145290371 @default.
- W1557191712 hasConcept C153294291 @default.
- W1557191712 hasConcept C168754636 @default.
- W1557191712 hasConcept C187599188 @default.
- W1557191712 hasConcept C205649164 @default.
- W1557191712 hasConcept C24552861 @default.
- W1557191712 hasConcept C39432304 @default.
- W1557191712 hasConcept C49204034 @default.
- W1557191712 hasConcept C65440619 @default.
- W1557191712 hasConceptScore W1557191712C111368507 @default.
- W1557191712 hasConceptScore W1557191712C127313418 @default.
- W1557191712 hasConceptScore W1557191712C132651083 @default.
- W1557191712 hasConceptScore W1557191712C134097258 @default.
- W1557191712 hasConceptScore W1557191712C141452985 @default.
- W1557191712 hasConceptScore W1557191712C145290371 @default.
- W1557191712 hasConceptScore W1557191712C153294291 @default.
- W1557191712 hasConceptScore W1557191712C168754636 @default.
- W1557191712 hasConceptScore W1557191712C187599188 @default.
- W1557191712 hasConceptScore W1557191712C205649164 @default.
- W1557191712 hasConceptScore W1557191712C24552861 @default.
- W1557191712 hasConceptScore W1557191712C39432304 @default.
- W1557191712 hasConceptScore W1557191712C49204034 @default.
- W1557191712 hasConceptScore W1557191712C65440619 @default.
- W1557191712 hasLocation W15571917121 @default.
- W1557191712 hasOpenAccess W1557191712 @default.
- W1557191712 hasPrimaryLocation W15571917121 @default.
- W1557191712 hasRelatedWork W1557191712 @default.
- W1557191712 hasRelatedWork W1575751383 @default.
- W1557191712 hasRelatedWork W2062534601 @default.
- W1557191712 hasRelatedWork W2090574981 @default.
- W1557191712 hasRelatedWork W2162694184 @default.
- W1557191712 hasRelatedWork W2482309830 @default.
- W1557191712 hasRelatedWork W274542557 @default.
- W1557191712 hasRelatedWork W2811225209 @default.
- W1557191712 hasRelatedWork W2955244819 @default.
- W1557191712 hasRelatedWork W3198983295 @default.
- W1557191712 isParatext "false" @default.
- W1557191712 isRetracted "false" @default.
- W1557191712 magId "1557191712" @default.
- W1557191712 workType "book-chapter" @default.