6477eb2d-1a10-4546-ac30-ce621e7ef9b0 Copernicus Marine Service product specification CMEMS servicedesk.cmems@mercator-ocean.eu http://marine.copernicus.eu/ 2026-03-27T15:17:27.484025Z ISO 19139, MyOcean profile 0.2 2 false EPSG Volume Transport Anomaly in Selected Vertical Sections OMI_CIRCULATION_VOLTRANS_IBI_section_integrated_anomalies 2026-03-31 3.4 2024-11-26 6477eb2d-1a10-4546-ac30-ce621e7ef9b0 '''DEFINITION''' The indicator of Volume Transport Anomaly in Selected Vertical Sections in the Iberia–Biscay–Ireland (IBI) region (OMI_CIRCULATION_VOLTRANS_IBI_section_integrated_anomalies) is defined as the time series of annual mean volume transport calculated across a set of vertical ocean sections. These sections have been selected to represent the temporal variability of key ocean currents within the IBI domain. The monitored ocean currents include the transport towards the North Sea through the Rockall Trough (RTE) (Holliday et al., 2008; Lozier and Stewart, 2008), the Canary Current (CC) (Knoll et al., 2002; Mason et al., 2011), the Azores Current (AC) (Mason et al., 2011), the Algerian Current (ALG) (Tintoré et al., 1988; Benzohra and Millot, 1995; Font et al., 1998), and the net transport along the 48° N latitude parallel (N48) (see OMI figure). To produce ensemble-based results, six datasets provided by the Copernicus Marine Service have been used: * '''IBI-REA''' & '''IBI-INT''': IBI_MULTIYEAR_PHY_005_002 (reanalysis and interim datasets) * '''GLO-REA''': GLOBAL_MULTIYEAR_PHY_001_030 (reanalysis) * '''ARMOR''': MULTIOBS_GLO_PHY_TSUV_3D_MYNRT_015_012 (reprocessed observations) * '''MED-REA''': MEDSEA_MULTIYEAR_PHY_006_004 (reanalysis) * '''NWS-REA''': NWSHELF_MULTIYEAR_PHY_004_009 (reanalysis) The time series displays the ensemble mean (blue line), the ensemble spread (grey shaded area), and the mean transport with reversed sign (red dashed line), which indicates the threshold of anomaly values corresponding to a reversal in the direction of the current transport. In addition, the trend analysis at the 95% confidence level is shown in the bottom-right corner of each diagram. Further details on the product are provided in the corresponding Product User Manual (de Pascual-Collar et al., 2026a) and Quality Information Document (de Pascual-Collar et al., 2026b), as well as in de Pascual-Collar et al., 2024. '''CONTEXT''' The IBI area is a highly complex region characterized by a remarkable variety of ocean currents. Among them, we can highlight those that originate as a result of the closure of the North Atlantic Drift (Mason et al., 2011; Holliday et al., 2008; Peliz et al., 2007; Bower et al., 2002; Knoll et al., 2002; Pérez et al., 2001; Jia, 2000); the subsurface currents flowing northward along the continental slope (de Pascual-Collar et al., 2019; Pascual et al., 2018; Machín et al., 2010; Fricourt et al., 2007; Knoll et al., 2002; Mazé et al., 1997; White & Bowyer, 1997); and the exchange currents occurring in the Strait of Gibraltar and the Alboran Sea (Sotillo et al., 2016; Font et al., 1998; Benzohra & Millot, 1995; Tintoré et al., 1988). The variability of ocean currents in the IBI domain is relevant to the global thermohaline circulation and other climatic and environmental processes. For example, as discussed by Fasullo and Trenberth (2008), subtropical gyres play a crucial role in the meridional energy balance. The poleward salt transport of Mediterranean water, driven by subsurface slope currents, has significant implications for salinity anomalies in the Rockall Trough and the Nordic Seas, as studied by Holliday (2003), Holliday et al. (2008), and Bozec et al. (2011). The Algerian Current serves as the only pathway for Atlantic Water to reach the Western Mediterranean. '''CMEMS KEY FINDINGS''' The volume transport time series reveal periods during which the monitored currents exhibited notably high or low variability. Specifically, the RTE current shows pronounced variability in 2010 and during 2014–2015; the N48 section between 2012 and 2014; the ALG current in 2006 and 2017; the AC current between 2005–2007 and in 2021; and the CC current between 2005–2007. Furthermore, certain periods display anomalies of sufficient magnitude (in absolute value) to indicate a reversal in the net transport direction of the current. This is the case for the ALG current in 2017 and 2024 (with net transport towards the west), and for the CC current in 2010 (with net transport towards the north). Trend analysis over the period 1993–2023 does not reveal any statistically significant trends for the monitored currents. However, the confidence interval for the trend in the ALG section is close to rejecting the null hypothesis of no trend. '''DOI (product):''' https://doi.org/10.48670/mds-00351 E.U. Copernicus Marine Service Information IBI-NOLOGIN-MADRID-ES P0M0D0H/P0M0D0H N/A https://documentation.marine.copernicus.eu/IMG/OMI_CIRCULATION_VOLTRANS_IBI_section_integrated_anomalies.png Oceanographic geographical features GEMET - INSPIRE themes, version 1.0 2018-07-27 geonetwork.thesaurus.external.theme.httpinspireeceuropaeutheme-theme in-situ-observation numerical-model Discipline 2025-12-09 geonetwork.thesaurus.local.discipline.myocean.discipline volume_transport_anomaly_across_monitoring_section Climate and Forecast Standard Names 2017-04-04 geonetwork.thesaurus.external.parameter.myocean.ocean-variables multi-year Temporal scale 2025-12-09 geonetwork.thesaurus.local.temporal-scale.myocean.temporal-scale marine-resources coastal-marine-environment marine-safety weather-climate-and-seasonal-forecasting Area of benefit 2025-12-09 geonetwork.thesaurus.local.area-of-benefit.myocean.area-of-benefit iberian-biscay-irish-seas Reference Geographical Areas 2025-12-09 geonetwork.thesaurus.local.reference-geographical-area.myocean.reference-geographical-area N/A Processing level 2025-12-09 geonetwork.thesaurus.local.processing-level.myocean.processing-level Not Applicable Model assimilation 2016-02-03 geonetwork.thesaurus.external.theme.myocean.model-assimilation See Copernicus Marine Environment Monitoring Service Data commitments and licence at: http://marine.copernicus.eu/web/27-service-commitments-and-licence.php No limitations on public access Benzohra, M., Millot, C.: Characteristics and circulation of the surface and intermediate water masses off Algeria. Deep Sea Research Part I: Oceanographic Research Papers, 42(10), 1803-1830, https://doi.org/10.1016/0967-0637(95)00043-6, 1995. 2019-05-08 Bower, A. S., Le Cann, B., Rossby, T., Zenk, T., Gould, J., Speer, K., Richardson, P. L., Prater, M. D., Zhang, H.-M.: Directly measured mid-depth circulation in the northeastern North Atlantic Ocean: Nature, 419, 6907, 603–607, https://doi.org/10.1038/nature01078, 2002. 2019-05-08 Bozec, A., Lozier, M. S., Chasignet, E. P., Halliwel, G. R.: On the variability of the Mediterranean Outflow Water in the North Atlantic from 1948 to 2006, J. Geophys. Res.-Oceans, 116, C09033, https://doi.org/10.1029/2011JC007191, 2011. 2019-05-08 Fasullo, J. T., Trenberth, K. E.: The annual cycle of the energy budget. Part II: Meridional structures and poleward transports. Journal of Climate, 21(10), 2313-2325, https://doi.org/10.1175/2007JCLI1936.1, 2008. 2019-05-08 Font, J., Millot, C., Salas, J., Juliá, A., Chic, O.: The drift of Modified Atlantic Water from the Alboran Sea to the eastern Mediterranean, Scientia Marina, 62-3, https://doi.org/10.3989/scimar.1998.62n3211, 1998. 2019-05-08 Friocourt Y, Levier B, Speich S, Blanke B, Drijfhout SS. A regional numerical ocean model of the circulation in the Bay of Biscay, J. Geophys. Res.,112:C09008, https://doi.org/10.1029/2006JC003935, 2007. 2019-05-08 Holliday, N. P., Hughes, S. L., Bacon, S., Beszczynska-Möller, A., Hansen, B., Lavín, A., Loeng, H., Mork, K. A., Østerhus, S., Sherwin, T., Walczowski, W.: Reversal of the 1960s to 1990s freshening trend in the northeast North Atlantic and Nordic Seas, Geophys. Res. Lett., 35, L03614, https://doi.org/10.1029/2007GL032675, 2008. 2019-05-08 Holliday, N. P.: Air‐sea interactionand circulation changes in the north- east Atlantic, J. Geophys. Res., 108(C8), 3259, https://doi.org/10.1029/2002JC001344, 2003. 2019-05-08 Jia, Y.: Formation of an Azores Current Due to Mediterranean Overflow in a Modeling Study of the North Atlantic. J. Phys. Oceanogr., 30, 9, 2342–2358, https://doi.org/10.1175/1520-0485(2000)030<2342:FOAACD>2.0.CO;2, 2000. 2019-05-08 Knoll, M., Hernández-Guerra, A., Lenz, B., López Laatzen, F., Machı́n, F., Müller, T. J., Siedler, G.: The Eastern Boundary Current system between the Canary Islands and the African Coast, Deep-Sea Research. 49-17, 3427-3440, https://doi.org/10.1016/S0967-0645(02)00105-4, 2002. 2019-05-08 Lozier, M. S., Stewart, N. M.: On the temporally varying penetration ofMediterranean overflowwaters and eastward penetration ofLabrador Sea Water, J. Phys. Oceanogr., 38,2097–2103, https://doi.org/10.1175/2008JPO3908.1, 2008. 2019-05-08 Machín, F., Pelegrí, J. L., Fraile-Nuez, E., Vélez-Belchí, P., López-Laatzen, F., Hernández-Guerra, A., Seasonal Flow Reversals of Intermediate Waters in the Canary Current System East of the Canary Islands. J. Phys. Oceanogr, 40, 1902–1909, https://doi.org/10.1175/2010JPO4320.1, 2010. 2019-05-08 Mason, E., Colas, F., Molemaker, J., Shchepetkin, A. F., Troupin, C., McWilliams, J. C., Sangra, P.: Seasonal variability of the Canary Current: A numerical study. Journal of Geophysical Research: Oceans, 116(C6), https://doi.org/10.1029/2010JC006665, 2011. 2019-05-08 Mazé, J. P., Arhan, M., Mercier, H., Volume budget of the eastern boundary layer off the Iberian Peninsula, Deep-Sea Research. 1997, 44(9-10), 1543-1574, https://doi.org/10.1016/S0967-0637(97)00038-1, 1997. 2019-05-08 Pascual, A., Levier ,B., Sotillo, M., Verbrugge, N., Aznar, R., Le Cann, B.: Characterization of Mediterranean Outflow Water in the Iberia-Gulf of Biscay-Ireland region. In: von Schuckmann et al. (2018) The Copernicus Marine Environment Monitoring Service Ocean State Report, Journal of Operational Oceanography, 11:sup1, S1-S142, https://doi.org/10.1080/1755876X.2018.1489208, 2018. 2019-05-08 de Pascual-Collar, A., Aznar, R., Levirer, B., Sotillo, M.: EU Copernicus Marine Service Product User Manual for OMI_CURRENTS_VOLTRANS_section_integrated_anomalies. Issue 1.1, Mercator Ocean International, https://catalogue.marine.copernicus.eu/documents/PUM/CMEMS-IBI-OMI-PUM-CIRCULATION-VOLTRANS_section_integrated_anomalies.pdf, 2026a. 2019-05-08 de Pascual-Collar, A., Aznar, R., Levirer, B., Sotillo, M. G., Ciliberti, S.: EU Copernicus Marine Service Product Quality Information Document for Global Reanalysis Products, OMI_CURRENTS_VOLTRANS_section_integrated_anomalies, Issue 1.1, Mercator Ocean International, https://catalogue.marine.copernicus.eu/documents/QUID/CMEMS-IBI-OMI-QUID-CIRCULATION-VOLTRANS_section_integrated_anomalies.pdf, 2026b. 2019-05-08 de Pascual-Collar, Á., Aznar, R., Levier, B., and Sotillo, M. G.: Monitoring main ocean currents of the Iberia–Biscay–Ireland region, in: 8th edition of the Copernicus Ocean State Report (OSR8), edited by: von Schuckmann, K., Moreira, L., Grégoire, M., Marcos, M., Staneva, J., Brasseur, P., Garric, G., Lionello, P., Karstensen, J., and Neukermans, G., Copernicus Publications, State Planet, 4-osr8, 5, https://doi.org/10.5194/sp-4-osr8-5-2024, 2024. 2019-05-08 de Pascual-Collar, A., Sotillo, M. G., Levier, B., Aznar, R., Lorente, P., Amo-Baladrón, A., Álvarez-Fanjul E.: Regional circulation patterns of Mediterranean Outflow Water near the Iberian and African continental slopes. Ocean Sci., 15, 565–582. https://doi.org/10.5194/os-15-565-2019, 2019. 2019-05-08 Peliz, A., Dubert, J., Marchesiello, P., Teles‐Machado, A.: Surface circulation in the Gulf of Cadiz: Model and mean flow structure. Journal of Geophysical Research: Oceans, 112, C11, https://doi.org/10.1029/2007JC004159, 2007. 2019-05-08 Perez, F. F., Castro, C. G., Álvarez-Salgado, X. A., Ríos, A. F.: Coupling between the Iberian basin-scale circulation and the Portugal boundary current system: a chemical study, Deep-Sea Research. I 48,1519 -1533, https://doi.org/10.1016/S0967-0637(00)00101-1, 2001. 2019-05-08 Sotillo, M. G., Amo-Baladrón, A., Padorno, E., Garcia-Ladona, E., Orfila, A., Rodríguez-Rubio, P., Conti, D., Jiménez Madrid, J. A., de los Santos, F. J., Alvarez Fanjul E.: How is the surface Atlantic water inflow through the Gibraltar Strait forecasted? A lagrangian validation of operational oceanographic services in the Alboran Sea and the Western Mediterranean, Deep-Sea Research. 133, 100-117, https://doi.org/10.1016/j.dsr2.2016.05.020, 2016. 2019-05-08 Tintore, J., La Violette, P. E., Blade, I., Cruzado, A.: A study of an intense density front in the eastern Alboran Sea: the Almeria–Oran front. Journal of Physical Oceanography, 18, 10, 1384-1397, https://doi.org/10.1175/1520-0485(1988)018%3C1384:ASOAID%3E2.0.CO;2, 1988. 2019-05-08 White, M., Bowyer, P.: The shelf-edge current north-west of Ireland. Annales Geophysicae 15, 1076–1083. https://doi.org/10.1007/s00585-997-1076-0, 1997. 2019-05-08 6be27b50-be7b-434c-82a0-7f74eeefe3df 301376af-5ab9-4a11-bdb5-05f809228469 4fb4c3ac-ac51-4630-b6bd-4857f6866c77 eng oceans bounding box -19.00 5.00 26.00 56.00 Yearly-mean 1993-01-01 2024-12-31 0 0 display priority: 57500 observation temporal resolution: annual mean vertical level number: 0 false timeseries NetCDF-4 http://stac.marine.copernicus.eu/metadata/OMI_CIRCULATION_VOLTRANS_IBI_section_integrated_anomalies/OMI_CIRCULATION_VOLTRANS_IBI_section_integrated_anomalies_AC_202411/dataset.stac.json WWW:STAC OMI_CIRCULATION_VOLTRANS_IBI_section_integrated_anomalies_AC For accessing native data and Analysis-ready Cloud-optimized data services, consult this STAC metadata endpoint http://stac.marine.copernicus.eu/metadata/OMI_CIRCULATION_VOLTRANS_IBI_section_integrated_anomalies/OMI_CIRCULATION_VOLTRANS_IBI_section_integrated_anomalies_ALC_202411/dataset.stac.json WWW:STAC OMI_CIRCULATION_VOLTRANS_IBI_section_integrated_anomalies_ALC For accessing native data and Analysis-ready Cloud-optimized data services, consult this STAC metadata endpoint http://stac.marine.copernicus.eu/metadata/OMI_CIRCULATION_VOLTRANS_IBI_section_integrated_anomalies/OMI_CIRCULATION_VOLTRANS_IBI_section_integrated_anomalies_CC_202411/dataset.stac.json WWW:STAC OMI_CIRCULATION_VOLTRANS_IBI_section_integrated_anomalies_CC For accessing native data and Analysis-ready Cloud-optimized data services, consult this STAC metadata endpoint http://stac.marine.copernicus.eu/metadata/OMI_CIRCULATION_VOLTRANS_IBI_section_integrated_anomalies/OMI_CIRCULATION_VOLTRANS_IBI_section_integrated_anomalies_N48_202411/dataset.stac.json WWW:STAC OMI_CIRCULATION_VOLTRANS_IBI_section_integrated_anomalies_N48 For accessing native data and Analysis-ready Cloud-optimized data services, consult this STAC metadata endpoint http://stac.marine.copernicus.eu/metadata/OMI_CIRCULATION_VOLTRANS_IBI_section_integrated_anomalies/OMI_CIRCULATION_VOLTRANS_IBI_section_integrated_anomalies_RTE_202411/dataset.stac.json WWW:STAC OMI_CIRCULATION_VOLTRANS_IBI_section_integrated_anomalies_RTE For accessing native data and Analysis-ready Cloud-optimized data services, consult this STAC metadata endpoint COMMISSION REGULATION (EU) No 1089/2010 of 23 November 2010 implementing Directive 2007/2/EC of the European Parliament and of the Council as regards interoperability of spatial data sets and services 2010-12-08 See the referenced specification The myOcean products depends on other products for production or validation. The detailed list of dependencies is given in ISO19115's aggregationInfo (ISO19139 Xpath = "gmd:MD_Metadata/gmd:identificationInfo/gmd:aggregationInfo[./gmd:MD_AggregateInformation/gmd:initiativeType/gmd:DS_InitiativeTypeCode/@codeListValue='upstream-validation' or 'upstream-production']")