Table 2.
Slopes and SDs of the lines of linear least squares fit for the Southern Ocean monthly sea ice extents, both for the 40-y record, 1979–2018, and, in parentheses, for the 36-y record, 1979–2014
| Month | Slope, 103 km2⋅y−1 | R | Slope, % per decade |
| January | 10.4 ± 9.0 (18.4 ± 8.8) | 1.15 (2.10) | 2.2 ± 1.9 (3.9 ± 1.9) |
| February | 5.0 ± 5.8 (13.2 ± 5.8) | 0.87 (2.25) | 1.7 ± 2.0 (4.6 ± 2.0) |
| March | 11.3 ± 7.3 (20.6 ± 7.3) | 1.54 (2.83) | 3.0 ± 1.9 (5.6 ± 2.0) |
| April | 15.7 ± 9.5 (24.8 ± 9.5) | 1.66 (2.60) | 2.4 ± 1.4 (3.8 ± 1.5) |
| May | 17.3 ± 8.7 (27.9 ± 8.4) | 1.99 (3.33) | 1.8 ± 0.9 (2.9 ± 0.9) |
| June | 16.9 ± 7.4 (26.9 ± 7.4) | 2.29 (3.62) | 1.3 ± 0.6 (2.1 ± 0.6) |
| July | 13.5 ± 5.5 (20.4 ± 5.7) | 2.44 (3.55) | 0.9 ± 0.4 (1.3 ± 0.4) |
| August | 11.4 ± 5.0 (20.1 ± 5.3) | 2.29 (3.80) | 0.7 ± 0.3 (1.2 ± 0.3) |
| September | 10.4 ± 5.8 (23.0 ± 5.7) | 1.80 (4.03) | 0.6 ± 0.3 (1.3 ± 0.3) |
| October | 11.8 ± 5.3 (22.4 ± 5.2) | 2.23 (4.30) | 0.7 ± 0.3 (1.3 ± 0.3) |
| November | 1.1 ± 6.7 (16.2 ± 5.5) | 0.17 (2.94) | 0.1 ± 0.4 (1.0 ± 0.4) |
| December | 10.0 ± 10.9 (34.1 ± 9.9) | 0.93 (3.46) | 1.0 ± 1.1 (3.5 ± 1.0) |
The slopes and SDs are listed both as the areal loss each year and as the percentage of the ice cover lost each decade. The R column gives the ratio of the slope magnitude for the areal loss to its SD, as a rough indicator of statistical significance, both for the 40-y record and for the 36-y record. Statistical significance at the 95% level or above is indicated in the R column by italics and statistical significance at the 99% level or above is indicated by boldface.