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In the published paper, the quality of the figures has been compromised and so the figures with higher resolution have been added here.
Figure 1. (a) CMIP5 ensemble mean of future versus present-day changes in 700 hPa zonal wind. (b) Cross-section of zonal wind changes averaged over the North Atlantic sector (50°W/40°E). (c) Latitude versus time change in 700 hPa zonal wind over the North Atlantic sector (50°W/40°E). (d)–(f) are the corresponding fields in CESM-LENS. Season is ONDJFM. Shading indicates anomalies that are significant at the 95% confidence level. Climatology is shown in green contours: 3 m s−1 interval on (a) and (d), 5 m s−1 interval on (b) and (e), sector zonal average in right panels of (c) and (f).
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Figure 2. (a) Timeseries of the ONDJFM zonal index over the North Atlantic sector (50°W/40°E) in CMIP5 (green) and CESM-LENS (orange). Solid line is the ensemble mean, the envelope shows ±1 standard deviation spread between the models/members. The right panel shows the future versus present-day relative changes in %, with the ±1 standard deviation spread. A star indicates that the change is significant at the 90% confidence level. (b) Same as (a) but for sinuosity (relative future versus present-day changes are given, in %). (c) Same as (a) but for the blocking index. (d) Same as (a) but for the jet width index (future versus present-day changes are given in degree of latitude). ZON is computed from monthly data downloaded for the whole period. SIN, BLO and JWI are computed from daily data downloaded for two time slices.
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Figure 3. (a) CMIP5 ensemble mean of future versus present-day changes in ONDJFM zonal mean temperature. Shading indicates anomalies that are significant at the 95% confidence level. (b) Timeseries of ONDJFM UTW in CMIP5 (green) and CESM-LENS (orange). Solid line is the ensemble mean, the envelope shows ±1 standard deviation spread between the models/members. The right panel barplot shows the future versus present-day changes, with the ±1 standard deviation spread. A star indicates that the change is significant at the 90% confidence level. (c) Same as (b) but for AA. (d) Same as (b) but for RUTAW.
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Figure 4. Scatterplots of ONDJFM future versus present-day changes in CMIP5 (numbers, see list in table S1) and CESM-LENS (grey dots) for: (a) BLO versus UPTG; (b) SIN versus UPTG; (c) ZON versus RUTAW; (d) JWI versus RUTAW. Results from three regression analyses are shown. The red solid lines and upper-left correlation coefficients (red) are for a standard regression analysis on CMIP5. The black solid lines and upper-centre correlation coefficients (black) are for an error-in-variable regression analysis on CMIP5, using the CESM-LENS spread as errors on variables X and Y. The solid black curves gives a confidence interval for uncertainties due to both sampling error and internal variability. The dashed black curves are for uncertainties due to internal variability only (see appendix). The upper-right correlation is for a standard regression analysis on CESM-LENS.
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Figure 5. (a) Composite of ONDJFM change in winter zonal wind over the North Atlantic sector for CMIP5 models with a high RUTAW ('UTW effect'). Shading indicate anomalies that are significant at the 95% confidence level. Climatology is in green contours (5 m s−1 interval). (b) Same as (a) but for CMIP5 models with a low RUTAW ('AA effect'). (c) Difference between (a) and (b), i.e. high minus low RUTAW models. (d)–(f) Same as (a)–(c) but for zonal wind at 700 hPa (climatology: 6 m s−1 interval). (g)–(i) Same as (d)–(f) but for 2 m temperature. (j)–(l) Same as (d)–(f) but for cold days intensity.
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