%0 Journal Article
%T Analysis and Comparison of Trends in Extreme Temperature Indices in Riyadh City, Kingdom of Saudi Arabia, 1985每2010
%A Ali S. Alghamdi
%A Todd W. Moore
%J Journal of Climatology
%D 2014
%R 10.1155/2014/560985
%X This study employed the time series of thirteen extreme temperature indices over the period 1985每2010 to analyze and compare temporal trends at two weather stations in Riyadh city, Saudi Arabia. The trend analysis showed warming of the local air for the city. Significant increasing trends were found in annual average maximum and minimum temperatures, maximum of minimum temperature, warm nights, and warm days for an urban and a rural station. Significant decreasing trends were detected in the number of cool nights and cool days at both stations. Comparison of the trends suggests that, in general, the station closer to the city center warmed at a slower rate than the rural station. Significant differences were found in a lot of the extreme temperature indices, suggesting that urbanization and other factors may have had negative effects on the rate of warming at the urban station. 1. Introduction A better understanding of trends in local extreme temperature has potential benefits to many practical problems. Increasing extremely high temperatures, for example, directly affect energy consumption [1]. In summer 2010, which was the warmest season in Saudi Arabia＊s record with temperatures reaching 52∼C in Jeddah city, eight power plants throughout Saudi Arabia were forced to shut down, resulting in a loss of power in several cities [2], leaving people exposed and vulnerable to the extreme temperature. If observed trends indicate that such extreme temperatures are becoming more frequent, energy providers may be able to adapt their electricity supply to minimize the likelihood of widespread power outage. Evidence that localized high temperatures are becoming less frequent, on the other hand, along with assessment of possible causes of the cooling, can be used to develop and implement urban planning strategies to mitigate local- and larger-scale warming [3每5]. Multiple recent studies have been dedicated to gaining a better understanding of mean and extreme temperature patterns and trends in Saudi Arabia (e.g., [2, 6每12]). One study [7] reported that annual mean air temperature in Saudi Arabia increased at an average rate of 0.60∼Cˋdecadeˋ1 over the period 1978每2009 and another one [8] showed that the increasing trend was robust across the seasons, although the rate of change did vary seasonally. Annual maximum and minimum temperature also increased over the period 1978每2009 [8]. Other extreme temperature indices, such as extremely hot days (maximum temperature >90th percentile), warm spells (6 consecutive days when maximum temperature >90th percentile), and
%U http://www.hindawi.com/journals/jcli/2014/560985/