1. Saji, N. H., Goswami, B. N., Vinayachandran, P. N. & Yamagata, T. A dipole mode in the tropical Indian Ocean. Nature 401, 360–363 (1999).

2. Webster, P. J., Moore, A. M., Loschnigg, J. P. & Leben, R. R. Coupled ocean–atmosphere dynamics in the Indian Ocean during 1997–98. Nature 401, 356–360 (1999).

3. Cai, W. et al. Projected response of the Indian Ocean Dipole to greenhouse warming. Nat. Geosci. 6, 999–1007 (2013).

4. Han, W. et al. Indian Ocean decadal variability: a review. Bull. Am. Meteorol. Soc. 95, 1679–1703 (2014).

5. Abram, N. J., Gagan, M. K., Cole, J. E., Hantoro, W. S. & Mudelsee, M. Recent intensification of tropical climate variability in the Indian Ocean. Nat. Geosci. 1, 849–853 (2008).

6. Cai, W. et al. Increased frequency of extreme Indian Ocean Dipole events due to greenhouse warming. Nature 510, 254–258 (2014).

7. Weller, E. & Cai, W. Realism of the Indian Ocean Dipole in CMIP5 models: the implications for climate projections. J. Clim. 26, 6649–6659 (2013).

8. Cai, W. et al. Pantropical climate interactions. Science 363, eaav4236 (2019).

9. Ummenhofer, C. C. et al. What causes southeast Australia’s worst droughts? Geophys. Res. Lett. 36, L04706 (2009).

10. Cai, W., Cowan, T. & Raupach, M. Positive Indian Ocean Dipole events precondition southeast Australia bushfires. Geophys. Res. Lett. 36, (2009).

11. Abram, N. J., Gagan, M. K., McCulloch, M. T., Chappell, J. & Hantoro, W. S. Coral reef death during the 1997 Indian Ocean dipole linked to Indonesian wildfires. Science 301, 952–955 (2003).

12. Hashizume, M., Chaves, L. F. & Minakawa, N. Indian Ocean Dipole drives malaria resurgence in East African highlands. Sci. Rep. 2, 269 (2012).

13. Cai, W., Sullivan, A. & Cowan, T. Climate change contributes to more frequent consecutive positive Indian Ocean Dipole events. Geophys. Res. Lett. 36, L23704 (2009).

14. Cai, W. et al. Stabilised frequency of extreme positive Indian Ocean Dipole under 1.5 °C warming. Nat. Commun. 9, 1419 (2018).

15. Stevenson, S., Fox-Kemper, B., Jochum, M., Rajagopalan, B. & Yeager, S. G. ENSO model validation using wavelet probability analysis. J. Clim. 23, 5540–5547 (2010).

16. Wittenberg, A. T. Are historical records sufficient to constrain ENSO simulations? Geophys. Res. Lett. 36, L12702 (2009).

17. Meyers, G., McIntosh, P., Pigot, L. & Pook, M. The years of El Niño, La Niña, and interactions with the tropical Indian Ocean. J. Clim. 20, 2872–2880 (2007).

18. Abram, N. J. et al. Optimized coral reconstructions of the Indian Ocean Dipole: an assessment of location and length considerations. Paleoceanography 30, 1391–1405 (2015).

19. Thompson, D. M., Ault, T. R., Evans, M. N., Cole, J. E. & Emile-Geay, J. Comparison of observed and simulated tropical climate trends using a forward model of coral δ18O. Geophys. Res. Lett. 38, L14706 (2011); correction 38, L19705 (2011).

20. Konecky, B. L., Noone, D. C. & Cobb, K. M. The influence of competing hydroclimate processes on stable isotope ratios in tropical rainfall. Geophys. Res. Lett. 46, 1622–1633 (2019).

21. Cobb, K. M., Charles, C. D., Cheng, H. & Edwards, R. L. El Nino/Southern Oscillation and tropical Pacific climate during the last millennium. Nature 424, 271–276 (2003).

22. Abram, N. J. et al. Early onset of industrial-era warming across the oceans and continents. Nature 536, 411–418 (2016).

23. Maher, N., McGregor, S., England, M. H. & Gupta, A. S. Effects of volcanism on tropical variability. Geophys. Res. Lett. 42, 6024–6033 (2015).

24. Sigl, M. et al. Timing and climate forcing of volcanic eruptions for the past 2,500 years. Nature 523, 543–549 (2015).

25. Gergis, J. L. & Fowler, A. M. A history of ENSO events since A.D. 1525: implications for future climate change. Clim. Change 92, 343–387 (2009).

26. Grove, R. & Adamson, G. in El Niño in World History (eds Grove, R. & Adamson, G.) 49–79 (Palgrave Macmillan, 2018).

27. Boomgaard, P. in Asian Population History (eds Liu, T. et al.) 451 (Oxford Univ. Press, 2001).

28. Cobb, K. M. et al. Highly variable El Nino/Southern Oscillation throughout the Holocene. Science 339, 67–70 (2013).

29. Grothe, P. R. et al. Enhanced El Niño-Southern Oscillation variability in recent decades. Geophys. Res. Lett. 46, https://doi.org/10.1029/2019GL083906 (2019).

30. Stuecker, M. F. et al. Revisiting ENSO/Indian Ocean Dipole phase relationships. Geophys. Res. Lett. 44, 2481–2492 (2017).

31. Rustic, G. T., Koutavas, A., Marchitto, T. M. & Linsley, B. K. Dynamical excitation of the tropical Pacific Ocean and ENSO variability by Little Ice Age cooling. Science 350, 1537–1541 (2015).

32. Dätwyler, C., Abram, N. J., Grosjean, M., Wahl, E. R. & Neukom, R. El Niño–Southern Oscillation variability, teleconnection changes and responses to large volcanic eruptions since AD 1000. Int. J. Clim. 39, 2711–2724 (2019).

33. Freund, M. B. et al. Higher frequency of Central Pacific El Nino events in recent decades relative to past centuries. Nat. Geosci. 12, 450–455 (2019).

34. Tierney, J. E., Smerdon, J. E., Anchukaitis, K. J. & Seager, R. Multidecadal variability in East African hydroclimate controlled by the Indian Ocean. Nature 493, 389–392 (2013).

35. Goodkin, N. F. et al. East Asian monsoon variability since the sixteenth century. Geophys. Res. Lett. 46, 4790–4798 (2019).

36. Denniston, R. F. et al. Expansion and contraction of the Indo-Pacific tropical rain belt over the last three millennia. Sci. Rep. 6, 34485 (2016).

37. Yan, H. et al. Dynamics of the intertropical convergence zone over the western Pacific during the Little Ice Age. Nat. Geosci. 8, 315 (2015).

38. Yancheva, G. et al. Influence of the intertropical convergence zone on the East Asian monsoon. Nature 445, 74–77 (2007).

39. Ma, T. et al. East Asian winter monsoon impacts the ENSO-related teleconnections and North American seasonal air temperature prediction. Sci. Rep. 8, 6547 (2018).

40. Zhang, P. et al. A test of climate, sun, and culture relationships from an 1810-year Chinese cave record. Science 322, 940–942 (2008).

41. Otto-Bliesner, B. L. et al. Climate variability and change since 850 CE: an ensemble approach with the Community Earth System Model. Bull. Am. Meteorol. Soc. 97, 735–754 (2016).

42. Thirumalai, K., DiNezio, P. N., Tierney, J. E., Puy, M. & Mohtadi, M. An El Niño mode in the glacial Indian Ocean? Paleoceanogr. Paleoclimatol. 34, 1316–1327 (2019).

43. Holland, P. R., Bracegirdle, T. J., Dutrieux, P., Jenkins, A. & Steig, E. J. West Antarctic ice loss influenced by internal climate variability and anthropogenic forcing. Nat. Geosci. 12, 718–724 (2019).

44. Purich, A. & England, M. H. Tropical teleconnections to Antarctic sea ice during austral spring 2016 in coupled pacemaker experiments. Geophys. Res. Lett. 46, 6848–6858 (2019).

45. Henley, B. J. et al. A tripole index for the Interdecadal Pacific Oscillation. Clim. Dyn. 45, 3077 (2015).

46. Ummenhofer, C. C., Biastoch, A. & Böning, C. W. Multidecadal Indian Ocean variability linked to the Pacific and implications for preconditioning Indian Ocean Dipole events. J. Clim. 30, 1739–1751 (2017).

47. Zhang, L., Du, Y. & Cai, W. Low-frequency variability and the unusual Indian Ocean Dipole events in 2015 and 2016. Geophys. Res. Lett. 45, 1040–1048 (2018).

48. Abram, N. J. et al. Seasonal characteristics of the Indian Ocean Dipole during the Holocene epoch. Nature 445, 299–302 (2007).

49. Guemas, V. et al. The Indian Ocean: the region of highest skill worldwide in decadal climate prediction. J. Clim. 26, 726–739 (2013).

50. PAGES 2K Consortium. Global multi-decadal variability in global temperature reconstructions and simulations over the Common Era. Nat. Geosci. 12, 643–649 (2019).

51. Reynolds, R. W., Rayner, N. A., Smith, T. M., Stokes, D. C. & Wang, W. An improved in situ and satellite SST analysis for climate. J. Clim. 15, 1609–1625 (2002).

52. Adler, R. et al. The Global Precipitation Climatology Project (GPCP) monthly analysis (new version 2.3) and a review of 2017 global precipitation. Atmosphere 9, 138 (2018).

53. Sieh, K. et al. Earthquake supercycles inferred from sea-level changes recorded in the corals of west Sumatra. Science 322, 1674–1678 (2008).

54. Natawidjaja, D. H. et al. Source parameters of the great Sumatran megathrust earthquakes of 1797 and 1833 inferred from coral microatolls. J. Geophys. Res. Solid Earth 111, B06403 (2006).

55. Zachariasen, J., Sieh, K., Taylor, F. W., Edwards, R. L. & Hantoro, W. S. Submergence and uplift associated with the giant 1833 Sumatran subduction earthquake: evidence from coral microatolls. J. Geophys. Res. Solid Earth 104, 895–919 (1999).

56. McGregor, H. V. & Abram, N. J. Images of diagenetic textures in Porites corals from Papua New Guinea and Indonesia. Geochem. Geophys. Geosyst. 9, Q10013 (2008).

57. DeLong, K. L., Quinn, T. M., Taylor, F. W., Shen, C.-C. & Lin, K. Improving coral-base paleoclimate reconstructions by replicating 350 years of coral Sr/Ca variations. Palaeogeogr. Palaeoclimatol. Palaeoecol. 373, 6–24 (2013).

58. Shen, C.-C. et al. High-precision and high-resolution carbonate 230Th dating by MC-ICP-MS with SEM protocols. Geochim. Cosmochim. Acta 99, 71–86 (2012).

59. Cheng, H. et al. Improvements in 230Th dating, 230Th and 234U half-life values, and U–Th isotopic measurements by multi-collector inductively coupled plasma mass spectrometry. Earth Planet. Sci. Lett. 371–372, 82–91 (2013).

60. Shen, C.-C. et al. Variation of initial 230Th/232Th and limits of high precision U–Th dating of shallow-water corals. Geochim. Cosmochim. Acta 72, 4201–4223 (2008).

61. Philibosian, B. et al. Earthquake supercycles on the Mentawai segment of the Sunda megathrust in the seventeenth century and earlier. J. Geophys. Res. Solid Earth 122, 642–676 (2017).

62. Gagan, M. K. et al. Coral 13C/12C records of vertical seafloor displacement during megathrust earthquakes west of Sumatra. Earth Planet. Sci. Lett. 432, 461–471 (2015).

63. Gao, C., Robock, A. & Ammann, C. Volcanic forcing of climate over the past 1500 years: an improved ice core-based index for climate models. J. Geophys. Res. 113, D23111 (2008).

64. Smith, T. M., Reynolds, R. W., Peterson, T. C. & Lawrimore, J. Improvements to NOAA’s historical merged land-ocean surface temperature analysis (1880-2006). J. Clim. 21, 2283–2296 (2008).

65. Rayner, N. A. et al. Global analyses of sea surface temperature, sea ice, and night marine air temperature since the late nineteenth century. J. Geophys. Res. 108, 4407 (2003).

66. Chan, D., Kent, E. C., Berry, D. I. & Huybers, P. Correcting datasets leads to more homogeneous early-twentieth-century sea surface warming. Nature 571, 393–397 (2019).

67. Philibosian, B. et al. Rupture and variable coupling behavior of the Mentawai segment of the Sunda megathrust during the supercycle culmination of 1797 to 1833. J. Geophys. Res. Solid Earth 119, 7258–7287 (2014).

68. McGregor, H. V., Fischer, M. J., Gagan, M. K., Fink, D. & Woodroffe, C. D. Environmental control of the oxygen isotope composition of Porites coral microatolls. Geochim. Cosmochim. Acta 75, 3930–3944 (2011).

69. Grove, R. & Adamson, G. in El Niño in World History (eds Richard Grove & George Adamson) 81–92 (Palgrave Macmillan, 2018).

70. Natawidjaja, D. H. et al. Paleogeodetic records of seismic and aseismic subduction from central Sumatran microatolls, Indonesia. J. Geophys. Res. Solid Earth 109, B04306 (2004).

71. Plummer, C. T. et al. An independently dated 2000-yr volcanic record from Law Dome, East Antarctica, including a new perspective on the dating of the 1450s CE eruption of Kuwae, Vanuatu. Clim. Past 8, 1929–1940 (2012).

72. Esper, J., Büntgen, U., Hartl-Meier, C., Oppenheimer, C. & Schneider, L. Northern Hemisphere temperature anomalies during the 1450s period of ambiguous volcanic forcing. Bull. Volcanol. 79, 41 (2017).

73. Guillet, S. et al. Climate response to the Samalas volcanic eruption in 1257 revealed by proxy records. Nat. Geosci. 10, 123–128 (2017).

74. Lavigne, F. et al. Source of the great A.D. 1257 mystery eruption unveiled, Samalas volcano, Rinjani Volcanic Complex, Indonesia. Proc. Natl Acad. Sci. USA 110, 16742–16747 (2013).

75. Philibosian, B. et al. An ancient shallow slip event on the Mentawai segment of the Sunda megathrust, Sumatra. J. Geophys. Res. Solid Earth 117, (2012).

76. Lim, E.-P. & Hendon, H. H. Causes and predictability of the negative Indian Ocean Dipole and its impact on La Niña during 2016. Sci. Rep. 7, 12619 (2017).

77. Ren, H.-L. & Jin, F.-F. Niño indices for two types of ENSO. Geophys. Res. Lett. 38, L04704 (2011).