caa a22 4500 605473226 CHVBK 20210128100342.0 cr unu---uuuuu 210128e20150201xx s 000 0 eng 10.1007/s00382-014-2173-x doi (NATIONALLICENCE)springer-10.1007/s00382-014-2173-x Possible North Atlantic origin for changes in ENSO properties during the 1970s [Elektronische Daten] [Mihai Dima, Gerrit Lohmann, Norel Rimbu] The most intense El Niño episodes in more than a century occurred after the 1970s climate shift. Previous studies show that the characteristics of the El Niño-Southern Oscillation (ENSO) phenomenon changed synchronously with the shift, but the associated causes are not fully understood. An analysis of the observed tropical Pacific sea surface temperature (SST) anomalies shows that their increase in the eastern part of the basin after the 1970s is not related to the canonical ENSO pattern, but to the tropical Pacific meridional mode (TPMM). We present observational evidence which supports the hypothesis that the change in the TPMM was triggered by the great salinity anomaly (GSA), which manifested in the North Atlantic during the late 1960s. The GSA induced a weak Labrador convection and a SST dipole south of Greenland. The associated atmospheric structure includes a North Pacific Oscillation sea level pressure dipole in the Pacific sector. This excites the TPMM which contributes to the intense El Niño events and to the enhanced ENSO's asymmetry, observed after the shift. Our results imply that, if the GSA has not an anthropic origin, as was suggested, then the tropical Pacific climate shift has a natural origin. This is supported by the end of the North Atlantic regime in the 1990s and by the rebound of the tropical Pacific after 1998. Springer-Verlag Berlin Heidelberg, 2014 ENSO nationallicence Great salinity anomaly nationallicence Climate shift nationallicence Dima Mihai Faculty of Physics, University of Bucharest, Bucharest, Romania aut Lohmann Gerrit Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany aut Rimbu Norel Faculty of Physics, University of Bucharest, Bucharest, Romania aut Climate Dynamics Springer Berlin Heidelberg 44/3-4(2015-02-01), 925-935 0930-7575 44:3-4<925 2015 44 382 https://doi.org/10.1007/s00382-014-2173-x text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00382-014-2173-x text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Dima Mihai Faculty of Physics, University of Bucharest, Bucharest, Romania aut NATIONALLICENCE 700 1- Lohmann Gerrit Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany aut NATIONALLICENCE 700 1- Rimbu Norel Faculty of Physics, University of Bucharest, Bucharest, Romania aut NATIONALLICENCE 773 0- Climate Dynamics Springer Berlin Heidelberg 44/3-4(2015-02-01), 925-935 0930-7575 44:3-4<925 2015 44 382