Interdecadal Changes in the Freeze Depth and Period of Frozen Soil on the Three Rivers Source Region in China from 1960 to 2014

Table 5

Correlation coefficients for freeze depth and forcing variables, freeze first date and forcing variables, freeze last date and forcing variables, and freeze duration and forcing variables for the three different time periods on the TRSR 9 stations (Figure 1). Significance levels: ; .

	1960–2014	1985–2014	2000–2014
Freeze depth and forcing variables
Air temperature	−0.88	−0.89	−0.83
Thawing index	−0.75	−0.78	−0.72
Maximum snow depth	0.04	0.06	−0.34
Annual precipitation	−0.15	−0.40	−0.53
Spring precipitation	−0.27	−0.27	−0.39
Summer precipitation	−0.08	0.30	−0.39
Freeze first date	−0.52	−0.60	−0.56
Freeze first date and forcing variables
Air temperature	0.68	0.70	0.54
Thawing index	0.68	0.70	0.59
Annual precipitation	0.28	0.28	0.16
Autumn precipitation	0.34	0.50	0.37
Freeze last date and forcing variables
Air temperature	−0.85	−0.83	−0.64
Thawing index	−0.81	−0.79	−0.45
Maximum snow depth	0.10	0.20	−0.41
Annual precipitation	−0.28	−0.38	−0.40
Spring precipitation	−0.41	−0.32	−0.50
Summer precipitation	−0.17	−0.29	−0.32
Freeze depth	0.75	0.71	0.58
Freeze duration and forcing variables
Air temperature	−0.83	−0.83	−0.62
Thawing index	−0.80	−0.81	−0.52
Maximum snow depth	0.08	0.26	−0.25
Annual precipitation	−0.27	−0.33	−0.27
Autumn precipitation	0.01	−0.20	0.277
Spring precipitation	−0.41	−0.28	−0.44
Summer precipitation	−0.12	−0.21	−0.15
Freeze depth	0.69	0.71	0.61