Table 2.

Correlations between measured and retrieved snow depths

Month	Overall Rs (−)	Rs (−) between mountain ranges	Rs (−) within mountain ranges
December	0.67 (<0.01)	0.96 (<0.01)	0.58 (<0.01)
January	0.72 (<0.01)	0.93 (<0.01)	0.60 (0.02)
February	0.76 (<0.01)	0.92 (<0.01)	0.72 (<0.01)
March	0.69 (<0.01)	0.85 (<0.01)	0.67 (<0.01)
April	0.72 (<0.01)	0.84 (<0.01)	0.60 (0.04)

Spatial correlations (R_s; dimensionless) and their statistical significance level (p; in parentheses) are shown for monthly-averaged Sentinel−1 and in situ snow depth from December 2017 through April 2018. To calculate the overall R_s, all available measurements across the Northern Hemisphere are used. The R_s between mountain ranges is calculated from snow depths averaged per mountain range for the 11 ranges shown in Fig. 1b. The R_s within mountain ranges is the average of the spatial correlations within each of these ranges