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Precipitation during the Ethiopian Kiremt (June–September) season has exhibited significant interannual and multi‐decadal variability over the 20th and early 21st century. We investigate the temporal variability in the strength of the teleconnections between sea‐surface temperatures in key global oceanic regions, including the Tropical Pacific, Indian Ocean, and Tropical Atlantic, and Kiremt season precipitation at sub‐seasonal, interannual and multi‐decadal time scales. We also investigate the influence of the Madden‐Julian Oscillation (MJO). We perform a systematic analysis of 112‐year long (1901–2012) precipitation in the northern region of East Africa including the southern and central regions of Ethiopia and uncover interesting spatial, temporal and sub‐seasonal variability, and teleconnection patterns. Precipitation anomalies during wet and dry years extend throughout Northern Africa and also, during September extends over Indian subcontinent, suggesting large‐scale variability of wet/dry patterns. Wet (dry) years are accompanied by La Nina like (El Nino like) conditions in the tropical Pacific and extending into Atlantic and Indian Oceans. Through Bayesian dynamical linear modelling we find that temporal changes in seasonal precipitation correspond to changes in the strengths of sea surface temperature teleconnections, and that the relative strengths of these teleconnections rather than one dominant teleconnection influences precipitation variability. During three precipitation epochs in this region, the mid‐century pluvial, the late‐century drought, and the early 21st century, we find that changes in precipitation are related to changes in the main dynamical features of precipitation. These findings suggest that Kiremt season precipitation is in a new regime, and is of key interest to the agricultural and water resources communities who rely on accurate forecasts of precipitation to make operational decisions. [ABSTRACT FROM AUTHOR]

East Africa is one of the most vulnerable regions of Africa to extreme weather and climate events. Regional and local information on climate extremes is critical for monitoring and managing the impacts and developing sustainable adaptation measures. However, this type of information is not readily available at the necessary spatial resolution. Therefore, here we test trends and variability of temperature (1979–2010) and precipitation (1981–2016) extremes in East Africa, particularly Ethiopia, Kenya, and Tanzania, at a spatial resolution of 0.1 and 0.05°, respectively, using the indices defined by the Expert Team on Climate Change Detection and Indices (ETCCDI). We use gridded data sets with high accuracy and resolution from the Terrestrial Hydrology Research Group, University of Princeton and Climate Hazards Group InfraRed Precipitation with Station data (CHIRPS). Trends of 19 indices are computed by fitting a linear model and using the nonparametric Mann–Kendall test and the magnitude of change is computed using the Sen's slope method. The results show an increasing trend in monthly maximum and minimum values of daily maximum and minimum temperature in large parts of the region. This is accompanied by significant increasing trends in warm nights (TN90p), warm days (TX90p), warm spell duration index (WSDI), and summer days index (SU). In addition, cold days (TX10p) and cold nights (TN10p) showed a significant decreasing trend. In general, the results show an increasing tendency in temperatures extremes, which is in line with rising global mean temperature. In addition, most of the temperature extremes observed after 2000 are warmer than the long‐term mean (1979–2010). Precipitation indices, on the other hand, showed increasing and decreasing trends in Ethiopia, Kenya, and Tanzania, but no general pattern. The outcomes enable identifying hot spot areas and planning of adaptation and mitigation measures at much finer spatial scale than previously possible. Significant changes in monthly maximum values of daily maximum (TXx) and minimum (TNx) and monthly minimum values of daily maximum (TXn) and minimum (TNn) temperature are observed in large parts of East Africa. This change is accompanied by significant increasing trends in warm indices (e.g., warm nights and warm days) and decrease in cold indices (e.g., cold nights and days). Observed temperature extremes after 2000 are warmer than the base period (1981–2010). [ABSTRACT FROM AUTHOR]

ABSTRACT This study examines the performance of multimodel numerical simulations and multiobservational databases focusing on seasonal cycles and spatial variations of precipitation over Ethiopia. Seven regional climate models ( RCMs) driven by the European Center for Medium Range Weather Forecasting ( ECMWF) Interim reanalysis ( ERA-Interim) and generated in the framework of COordinated Regional climate Downscaling EXperiment ( CORDEX) project, and four observational databases computed using different interpolation techniques and blending strategies were evaluated against typical observational database produced by Climate Research Unit ( CRU) over Ethiopia on monthly basis. All were produced at 48.8 km grid resolution for the period 1989-2008. The preliminary results showed that ensembles [multimodel ensemble ( MME) + multiobservational ensemble ( MOE)] were as good as CRU in reproducing the temporal variability and the geographical distribution of precipitation. Comparison of seasonal means and temporal correlation results revealed that there were good agreements between ensembles and CRU at each grid point and in close proximity to each other. Results of rotated principal components ( RPCs), rotated empirical orthogonal functions ( REOFs), and the associated power spectra showed that every ensemble's element was able to simulate the seasonal cycles and homogeneous precipitation zones of CRU reasonably well. Excessive and deficient rainfall periods, which were seen in every ensemble's RPCs, matched CRU historical records. [ABSTRACT FROM AUTHOR]

ABSTRACT Ethiopia has wide eco-environmental diversity ranging from extreme heat at one of the lowest places in the world to one of the coolest summits in Africa. Associated with this environmental diversity and climate change, climatic extremes are expected to change over time and also vary across eco-environments in the country. This study was conducted to examine the trends of past precipitation and temperature extremes over three eco-environments in Ethiopia. The study involved analysis of 20 extreme indices computed from daily temperature and precipitation data spanning over 42 years (1967-2008). The climate data were obtained from 11 stations selected from three major eco-environments (pastoral, agropastoral and highland). The results indicated positive trends for maximum value of the maximum temperature ( TXx), warm days ( TX90p), warm nights ( TN90p) and warm spell duration indicators ( WSDI) and negative trends for cool days ( TX10p), cool nights ( TN10p) and cold spell duration indicators ( CSDI) in more than 8 of the 11 stations studied. However, most of the trends were not significant at many of the stations and the significant trends were not uniquely differentiated by eco-environments. Unlike temperature extremes, precipitation extreme trends showed high variability among nearby stations within eco-environments and were not significant at many of the stations studied. It is concluded that trends of temperature and precipitation extremes vary considerably among stations located within a given eco-environment indicating that the response of local climate to global warming could be different in physiographically diverse regions. [ABSTRACT FROM AUTHOR]