Assessing the spatial and temporal characteristics of temperature and rainfall over the central and southern regions of Malawi during the winter season

Abstract

Malawi is a land locked country located within the longitudes 33 degrees to 36 degrees East and latitude 9o 22’ to 17o7’. The total area is 118,480 square km – of which an area of 94,080 square km is occupied by land, and 24,400 square km is covered by water. Malawi has a tropical type of climate with two seasons: Summer (September to April) and winter(May to August). Most of the rainfall comes during the summer season.The features which influence weather during summer season are Congo air mass, Inter-Tropical Convergence Zone (ITCZ), tropical cyclones and topography. Southeasterly trade winds intensify the orographic rainfall in Malawi. Malawi is characterized by different types of topographic features such as mountains, highlands, plains, lakes and rivers. Winter seasons nowadays seem to be different from how they used to be in the past worldwide and Malawi is no exceptional. The assessment of the spatial and temporal characteristics of temperature and rainfall during winter seasons were done, and also examination of the causes of winter rainfall and temperature variability and determine whether these are climate change signals were also done in the Southern and Central Regions of Malawi. Statistical techniques were used to study the spatial and temporal characteristics of both rainfall and temperature over central and southern regions of Malawi. The data was obtained from Department of Climate Change and Meteorological Services (DCCMS) in Malawi for ten stations for the mean monthly temperature and mean monthly rainfall from1961 to 2013 for South and Central Regions of Malawi and was subject to quality control before analysis was carried out. The study found out that most of the data in the selected stations were homogenous as attested by single mass curve. Genstat application was used to analyzing data, t-stat was used to check the trend and Surfer software was used to create maps. The observations were made using graphical method. With time, the trend for maximum and minimum temperatures over the Southern and Central Regions of Malawi during Winter Seasons are showing that they are all increasing gradually. The observation of rainfall showed that the general rainfall trend over time, over the Central and Southern Regions of Malawi is not significant during Winter Seasons.