The temperature variability was studied using linear regression models, Man-Kendall (M-K) rank statistics, mean monthly and annual temperature anomalies, number of hot and cold days and nights per annum. The temperatu...The temperature variability was studied using linear regression models, Man-Kendall (M-K) rank statistics, mean monthly and annual temperature anomalies, number of hot and cold days and nights per annum. The temperature time series (mean, minimum and maximum) has shown a warming trend of the local air during last two decades. The maximum and minimum of the monthly mean temperatures of 23.35°C and 13.25°C were observed in June and January, respectively. Similarly, the maximum and minimum temperature ranges of 13.4°C and 8.2°C were found in December and June. The ratios between the hottest and coldest month’s monthly mean maximum and monthly mean minimum temperatures were 1.039 and 1.033, respectively. The best fit linear line showed an increase of 0.048°C per annum in the annual mean temperature with a coefficient of determination of 52%. An overall increase of 1.01°C was found between 1985. The Mann-Kendall rank statistics test confirmed the warming trends of the local atmospheric environment of Abha city.展开更多
The extreme temperature trends are analyzed for a meteorological data collection station in Jeddah, Saudi Arabia over approximately last four decades stretching between years 1970 and 2006. The long-term change in tem...The extreme temperature trends are analyzed for a meteorological data collection station in Jeddah, Saudi Arabia over approximately last four decades stretching between years 1970 and 2006. The long-term change in temperature has been assessed by Mann-Kendell rank statistics and linear trend analysis. The study also includes the estimation of hot and cold days and nights frequencies and finally the temperature anomalies on yearly basis. The ratio between the seasonal mean temperatures (Tmmean) of the daily mean of hottest (July) and coldest (January) months was 1.032. Similarly the ratios between the seasonal mean temperature of daily maximum (Tmmax) of hottest and coldest months was 1.033 while for seasonal mean temperature of daily minimum (Tmmin) was 1.030. Significant increase was observed in hot days per year and relatively smaller decrease in hot nights. Significant increase in summer time temperatures was confirmed by both linear regression analysis and M-K rank statistics. The monthly and annual mean maximum temperatures have increased more than the mean and mean minimum temperatures.展开更多
文摘The temperature variability was studied using linear regression models, Man-Kendall (M-K) rank statistics, mean monthly and annual temperature anomalies, number of hot and cold days and nights per annum. The temperature time series (mean, minimum and maximum) has shown a warming trend of the local air during last two decades. The maximum and minimum of the monthly mean temperatures of 23.35°C and 13.25°C were observed in June and January, respectively. Similarly, the maximum and minimum temperature ranges of 13.4°C and 8.2°C were found in December and June. The ratios between the hottest and coldest month’s monthly mean maximum and monthly mean minimum temperatures were 1.039 and 1.033, respectively. The best fit linear line showed an increase of 0.048°C per annum in the annual mean temperature with a coefficient of determination of 52%. An overall increase of 1.01°C was found between 1985. The Mann-Kendall rank statistics test confirmed the warming trends of the local atmospheric environment of Abha city.
文摘The extreme temperature trends are analyzed for a meteorological data collection station in Jeddah, Saudi Arabia over approximately last four decades stretching between years 1970 and 2006. The long-term change in temperature has been assessed by Mann-Kendell rank statistics and linear trend analysis. The study also includes the estimation of hot and cold days and nights frequencies and finally the temperature anomalies on yearly basis. The ratio between the seasonal mean temperatures (Tmmean) of the daily mean of hottest (July) and coldest (January) months was 1.032. Similarly the ratios between the seasonal mean temperature of daily maximum (Tmmax) of hottest and coldest months was 1.033 while for seasonal mean temperature of daily minimum (Tmmin) was 1.030. Significant increase was observed in hot days per year and relatively smaller decrease in hot nights. Significant increase in summer time temperatures was confirmed by both linear regression analysis and M-K rank statistics. The monthly and annual mean maximum temperatures have increased more than the mean and mean minimum temperatures.
