Author Correction: Summertime increases in upper-ocean stratification and mixed-layer depth (Nature, (2021), 591, 7851, (592-598), 10.1038/s41586-021-03303-x)

Abstract

In this Article, the code used to compute stratification values omitted the gravitational acceleration coefficient. All values for mean stratification or change in stratification should have been multiplied by the appropriate coefficient (9.81 m s-2); the values on colour scale bars of Figs. 2a–d, 3a, b, Extended Data Figs. 4e–h, 5a, b, 9a, and on the x axes in Fig. 3a, b, have therefore been increased by an order of magnitude. In the Abstract, the text ‘we find that the summertime density contrast increased by 8.9 ± 2.7 per cent per decade (10-6–10-5 per second squared per decade, depending on region)’ has been changed to ‘we find that the summertime density contrast increased by 8.9 ± 2.7 per cent per decade (10-5–10-4 per second squared per decade, depending on region)’. In the section titled ‘Seasonal pycnocline changes’, the text ‘Summertime pycnocline stratification has increased worldwide across all ocean basins since 1970, at a rate ranging from 10-6 s-2 dec-1 to 10-5 s-2 dec-1 (Fig. 3b). Trends display a marked regional pattern, with greater trends in the tropics (about 10-5 s-2) than at high latitudes (about 10-6 s-2). Consistent with pycnocline stratification, the 0–200 m stratification also shows a global increase, although at a lower rate, ranging from 10-7 s-2 dec-1 to 10-6 s-2 dec-1 (Fig. 3a).’ has been changed to ‘Summertime pycnocline stratification has increased worldwide across all ocean basins since 1970, at a rate ranging from 10-5 s-2 dec-1 to 10-4 s-2 dec-1 (Fig. 3b). Trends display a marked regional pattern, with greater trends in the tropics (about 10-4 s-2) than at high latitudes (about 10-5 s-2). Consistent with pycnocline stratification, the 0–200 m stratification also shows a global increase, although at a lower rate, ranging from 10-6 s-2 dec-1 to 10-5 s-2 dec-1 (Fig. 3a)’. We thank L. Cheng, K. E. Trenberth, M. E. Mann, J. Abraham, J. Zhu and G. Li for identifying these errors. The original Article has been corrected online.