Variability properties of daily and monthly observed near‐surface temperatures in Uganda: 1960–2008

Abstract

Variability and trends in daily and monthly near-surface temperatures in Uganda, collected over the period 1960 to 2008 (49 years), are analyzed. For this purpose daily observational temperature records from eight selected stations in Uganda were acquired from the Uganda Meteorological Department (UMD). Data collected by the UMD are quality controlled through a rigorous process before being archived. The data received were tested for homogeneity, gaps were filled and simple correlation analyses were used for validation during the analysis.Statistical techniques (Mann-Kendall and linear regression) were employed to analyze temperature variability and to obtain temperature trends. Findings indicate that intra-annual temperature shows reduced variability over recent decades, but which is not statistically significant. An examination of intra-monthly trends in daily maximum and minimum 2 temperatures revealed a general decline of intra-annual variance of monthly temperature means.Results also demonstrated that maximum temperatures are more variable compared to minimum temperatures in Uganda. An increasing trend in hot days, hot nights, warm nights and warm spells were also detected. At seven of the stations, annual temperature range and diurnal temperature range trends were found to be negative. The finding that intra-annual and intramonthly variance is declining suggests that fewer anomalously extreme temperature episodes occur. The gap between maximum and minimum extremes is reducing, which supports the observation that minimum temperatures are on the increase Key words: Uganda, climate change, Mann-Kendall test, trend analysis, temperature variability. IntroductionThe climate science community agrees that changes in the frequency and intensity of climate events are likely to impact nature and society in future (Zhang et al, 2005;Easterling et al, 2003).Unfortunately, such changes are not well documented for some parts of the world, which raises concern amongst scientists, (Easterling et al., 2003;Mahli and Wright, 2004;New et al., 2006;Thornton et al., 2007). This is despite of the anticipation that climate change might have a profound effect on developing countries, of which many are located in Africa. Some studies that have documented changes in climate and climate variability and their impacts for Africa include:New et al., Kruger and Shongwe, (2004);Mahe et al., (2001);King'uyu et al., (2000), amongst others. The few regional studies conducted in Africa revealed that observed changes in climate are not spatially uniform (Kizza et al., 2009;Mubiru et al., 2009;Schreck and Semazzi, 2004;Nicholson, 1996;Basalirwa, 1995;Ogallo, 1993;Rodhe andVirji, 1976 andSamson, 1952) because of geographical and land-surface variations. Nevertheless, profiling these changes has enhanced the understanding of climate in the continent, and contributed to more informed decisions on, and respondes to, climate change.Studies on near-surface temperature changes conducted in Africa, and elsewhere in the world, have demonstrated...

Climate change and variability: a review of what is known and ought to be known for Uganda

“…There is now evidence that the country as a whole is experiencing observable shifts in rainfall and temperatures (Kizza et al, 2009;DEWPoint, 2012;FEWSNET, 2012;Mubiru et al, 2012;Kilimani, 2013;Nsubuga et al, 2014a;GOU, 2015). Less information is available on other variables such as wind, solar hours and humidity among others.…”

“…A study by Mubiru et al (2012), indicates that farmers in Uganda characterize the rains during the MAM season to be short, localized and with occasional hot and dry spells. Dry spells are reported by Nsubuga et al (2014a) to be increasing in Uganda. This climate variability has been detected in fluctuations in the water resources, e.g.…”

“…Analysis indicated that rainfall, for example at the Kakooge station, has varied more over the past 30 years (1980-2009) than before (e.g. 1940-1969), consequently implying that the central region is at risk of experiencing more droughts in the future (Nsubuga et al, 2014a). The USAID (2013) report contains a comprehensive analysis of the general characteristics of the observed climate over Uganda.…”

“…Considerable work has been done at a national level (Anyah and Semazzi, 2004;Osbahr et al, 2011;Nsubuga et al, 2011Nsubuga et al, , 2014aNsubuga et al, , 2014bNsubuga et al, , 2014cNsubuga et al, , 2015Bomuhangi et al, 2016), which has revealed various climatic changes in Uganda. The present work attempts to review various works in peer-reviewed articles and other forms of publication which have documented climate change in Uganda.…”

Detection of trends in days with extreme temperatures in Iran from 1961 to 2010

“…Partal and Kahya 2006;Partal and Küçük 2006; Modarres and de Paulo Rodrigues da Silva 2007;Adamowski et al 2009Adamowski et al , 2010del Río et al 2011;Dinpashoh et al 2011; Tabari and Hosseinzadeh Talaee 2011;Tabari et al 2011a;Nalley et al 2012Nalley et al , 2013Shadmani et al 2012; Wang et al 2012a, b;Yang et al 2012;Duhan and Pandey 2013;Safeeq et al 2013;Shi et al 2013;Nsubuga et al 2014;Pingale et al 2014;Araghi et al 2015). By applying this test on a time series, one can detect the existence and significance of any trend in the data.…”