Extended Data Fig. 3: Calibrated hydroclimate records with insolation gradient and ice sheet area.
From: Mid-latitude net precipitation decreased with Arctic warming during the Holocene
a, Northern Hemisphere annual mean latitudinal insolation gradient14 and Laurentide Ice Sheet (LIS) area18. b, Calibrated hydroclimate records (n = 15, blue) with a fitted regression model using the annual insolation gradient and the LIS area. Shading represents the 95% bootstrapped uncertainty estimates (see Methods). Fitted dashed line is a simple linear model and the solid line includes an autoregressive (ar1) term for the residuals to account for autocorrelation in the hydroclimate records. The fitted solid line indicates that the mean hydroclimate change represents an increase in net precipitation of 16.8 ± 7 mm per 0.01 W m−2 per degree of latitude decrease in the annual insolation gradient since 8 ka. Earlier amplification of the dryness in these records can probably be attributed to ice-sheet effects. c, Spatial distribution of calibrated hydroclimate records. The map was generated using code and associated data from ref. 30.
