Changes in Temperature Trends and Extremes over Saudi Arabia for the Period 1978–2019

Table 2

List of extreme indices recommended by the expert team on climate change detection and indices (ETCCDI) used in this study.

Index	Indicator name	Definition	Unit
Absolute indices
TXx	Maximum of maximum temperatures	Monthly maximum value of daily maximum	°C
TNx	Maximum of minimum temperatures	Monthly maximum value of daily minimum	°C
TXn	Minimum of maximum temperatures	Monthly minimum value of daily maximum	°C
TNn	Minimum of minimum temperatures	Monthly minimum value of daily minimum	°C
DTR	Diurnal temperature range	The difference between the maximum and minimum temperature	°C
Relative indices
TX90p	Warm days	Percentage of days when TX > 90th percentile	Days
TX95p	Very warm days	Percentage of days when TX > 95th percentile	Days
TX99p	Extreme warm days	Percentage of days when TX > 99th percentile	Days
TN90p	Warm nights	Percentage of days when TN > 90th percentile	Days
TN90p	Very warm nights	Percentage of days when TN > 90th percentile	Days
TN90p	Extreme warm nights	Percentage of days when TN > 90th percentile	Days
TX10p	Cold days	Percentage of days when TX < 10th percentile	Days
TN10p	Cold nights	Percentage of days when TN < 10th percentile	Days
Duration indices
WSDI	Warm spell duration	Annual count of days with at least 6 consecutive days when TX > 90th percentile	Days
CSDI	Cold spell duration	Annual count of days with at least 6 consecutive days when TN < 10th percentile	Days