Temporal Trends and Spatial Patterns of Temperature and Its Extremes over the Beijing-Tianjin Sand Source Region (1960–2014), China

Table 1

Definitions of temperature and extreme indices used in this study.

Type	Index	Descriptive name	Definition	Units
Mean temperature	TA	Annual temperature	Annual mean temperature	°C
		Spring temperature	Mean temperature in spring	°C
		Summer temperature	Mean temperature in summer	°C
		Autumn temperature	Mean temperature in autumn	°C
		Winter temperature	Mean temperature in winter	°C
	TG	Growing season temperature	Mean temperature in growing season	°C
Cold-related indices	TN10p	Cold nights	Percentage of days when TN < 10th percentile	Days
	TX10p	Cold days	Percentage of days when TX < 10th percentile	Days
	CSDI	Cold spell duration indicator	Annual count of days with at least 6 consecutive days when TN < 10th percentile	Days
	TNn	Min Tmin	Monthly minimum value of daily minimum temperature	°C
Warm-related indices	TN90p	Warm nights	Percentage of days when TN > 90th percentile	Days
	TX90p	Warm days	Percentage of days when TX > 90th percentile	Days
	WSDI	Warm spell duration indicator	Annual count of days with at least 6 consecutive days when TX > 90th percentile	Days
	TXx	Max Tmax	Monthly maximum value of daily maximum temperature	°C
Variability indices	DTR	Diurnal temperature range	Monthly mean difference between TX and TN	°C
	GSL	Growing season length	Annual (1st Jan to 31st Dec in NH, 1st July to 30th June in SH) count between first span of at least 6 days with TG > 5°C and first span after July 1 (January 1 in SH) of 6 days with TG < 5°C	Days