Figure 4
From: North-south dipole in winter hydroclimate in the western United States during the last deglaciation
TraCE-21k climate model analyses for HS1 (17.00 ka) and B/A (14.36 ka) periods. December-February zonal averaged vertical motion (Pa s−1) for HS1 (a), B/A (c), and their difference (HS1 minus B/A) (e) shown by brown (positive, downward motion) to green (negative, upward motion) filled contours. December-February storm track activity (s−2) over the Pacific Ocean for HS1 (b), B/A (d) shown by blue filled contours. Storm track differences for (HS1-B/A) (f) shown by brown (negative, B/A greater than HS1) to green (positive, HS1 greater than B/A) filled contours. NCEP/NCAR89 1981–2010 averages for December-February vertical motion and storm track activity are shown as labeled open contours in the same units for each plot (a–d) (negative values are dashed in (a,c)). Statistically significant differences between the gridpoints at the alpha = 0.01 level are noted by stippling. Difference in vertical motions (g) and storm track activity (h) between the B/A from TraCE-21k output and the modern reanalysis observations89 are displayed as (g,h) above for zonal averaged vertical motion and storm track activity, respectively.
