Table 1.
Change in Climate model variables with the northward expansion of trees
| Month |
Variable Name |
Units |
Fixed Ocean |
Interactive Ocean |
||||||||||
| Land | Ocean | Land | Ocean | |||||||||||
| April | C-FO | ΔV-FO | p | C-FO | ΔV-FO | p | C-IO | ΔV - IO | p | C-IO | ΔV - IO | p | ||
| Surf. Air Temp. | K | 265.04 | 0.98 | 0.0070 | 260.76 | 0.28 | 0.5043 | 265.56 | 1.48 | 0.0038 | 261.46 | 1.46 | 0.0044 | |
| Water Vapor | Kgm-2 | 6.09 | 0.03 | 0.9000 | 5.54 | 0.20 | 0.2890 | 6.21 | 0.32 | 0.1633 | 5.69 | 0.39 | 0.0438 | |
| Low Cloud | fraction | 0.58 | -0.03 | 0.4483 | 0.63 | -0.02 | 0.6728 | 0.58 | -0.05 | 0.3287 | 0.64 | -0.02 | 0.5771 | |
| Albedo | albedo | 0.51 | -0.07 | 0.0013 | 0.60 | -0.004 | 0.7917 | 0.50 | -0.08 | 0.2556 | 0.59 | -0.01 | 0.8429 | |
| Latent Heat | Wm-2 | 10.07 | 1.39 | 0.0305 | 17.00 | -2.59 | 0.0000 | 10.19 | 1.52 | 0.0202 | 16.28 | 0.65 | 0.1430 | |
| Sensible Heat | Wm-2 | 12.15 | 1.30 | 0.0570 | 15.08 | -3.29 | 0.0000 | 11.75 | 0.81 | 0.2229 | 14.60 | -1.86 | 0.0033 | |
| Ice Fraction | fraction | na | na | na | 0.70 | 0.00 | 1.0000 | na | na | na | 0.70 | -0.01 | 0.8755 | |
| Precipitation | 10-8 m s-1 | 1.37 | -0.03 | 1.0000 | 1.08 | 0.03 | 1.0000 | 1.38 | -0.03 | 1.0000 | 1.16 | 0.00 | 1.0000 | |
| Eff. Water Import | kg s-1 | na | na | na | 304.37 | -20.25 | 0.0000 | na | na | na | 300.69 | 0.09 | 0.9736 | |
| Transpiration | Wm-2 | 0.95 | 0.16 | 0.4582 | na | na | na | 1.12 | 0.20 | 0.4184 | na | na | na | |
| July | ||||||||||||||
| Surf. Air Temp. | K | 284.88 | 0.51 | 0.2236 | 277.49 | 0.09 | 0.8375 | 284.98 | 1.09 | 0.0455 | 277.63 | 0.82 | 0.1794 | |
| Water Vapor | Kgm-2 | 19.35 | 0.38 | 0.1316 | 17.21 | 0.20 | 0.2850 | 19.38 | 0.89 | 0.0047 | 17.53 | 0.50 | 0.0289 | |
| Low Cloud | fraction | 0.49 | -0.02 | 0.5910 | 0.75 | -0.01 | 0.7834 | 0.48 | -0.02 | 0.6227 | 0.75 | -0.02 | 0.7138 | |
| Albedo | albedo | 0.24 | -0.01 | 0.4898 | 0.23 | 0.00 | 0.9501 | 0.24 | -0.01 | 0.8149 | 0.23 | -0.02 | 0.6458 | |
| Latent Heat | Wm-2 | 43.34 | 4.16 | 0.0000 | 12.49 | -1.10 | 0.0051 | 44.20 | 5.29 | 0.0000 | 12.92 | 2.66 | 0.0000 | |
| Sensible Heat | Wm-2 | 19.98 | 1.00 | 0.2169 | 4.34 | -0.23 | 0.6746 | 20.13 | 0.52 | 0.4956 | 4.17 | 1.19 | 0.0558 | |
| Ice Fraction | fraction | na | na | na | 0.36 | 0.00 | 1.0000 | na | na | na | 0.36 | -0.05 | 0.4100 | |
| Precipitation | 10-8 m s-1 | 2.53 | 0.03 | 1.0000 | 1.17 | -0.05 | 1.0000 | 2.46 | 0.13 | 0.9999 | 1.22 | -0.01 | 1.0000 | |
| Eff. Water Import | kg s-1 | na | na | na | 321.72 | 1.07 | 0.6725 | na | na | na | 313.68 | -8.38 | 0.0030 | |
| Transpiration | Wm-2 | 17.16 | 4.61 | 0.0000 | na | na | na | 17.65 | 5.55 | 0.0000 | na | na | na | |
Variables of interest are shown from the four global climate model runs. Values are reported as the mean of the control run (C-FO and C-IO), the anomaly (ΔV-FO or ΔV - IO), and p-value of significance for spatial averages over either land (1.3 × 108 km2) or ocean (3.4 × 108 km2) area north of 60 °N. P-values of 0.05 or less indicate significance of at least 95% confidence and are shown in bold. The exception is effective water import (see Methods) which is an estimate of the monthly average of atmospheric water vapor imported northward over the 60 °N latitude line.