Related Papers
Future Changes in Precipitation Extremes Over East Africa Based on CMIP6 Projections
2021 •
Hassen Babaousmail
Characterization of Historical Trends of Droughts and Pluvial Scenarios over Kenya, East Africa
Hassen Babaousmail
This work examines drought and pluvial events based on Standardized Precipitation-Evapotranspiration Index (SPEI) over Kenya from 1981 to 2016. Spatiotemporal analysis of dry and wet events is conducted for 3 and 12-month SPEI. The drought incidences were observed during the period 1984, 1987, 2000, 2006, 2009, 2015, and 2016 for SPEI-3 whilst the SPEI-12 demonstrated the manifestation of drought during the year 2000 and 2006. SPEI clearly shows the wettest period, 1997 and 1998 coinciding with the El Nino event in both time steps. SPEI -3 shows a reduction in moderate drought events while severe and extreme cases were on increase towards the end of the twentieth century. Conversely, SPEI-12 depicts an overall severe drought occurrence over the study location with observed intensity of -1.54 and cumulative frequency of 64 months during the study period. The trend of wet events is upwards in the western and central highlands while the rest of the regions show increase in dry events d...
Detection and Attribution of Lake Victoria’s Water-Level Fluctuations in a Changing Climate
2021 •
Maurice Nyadawa
This study investigated the influence of land-use and precipitation change and variability on Lake Victoria’s water-level fluctuations. Extreme precipitation events, corresponding to extreme water-levels, over the lake and its catchment area were identified and their return periods estimated by fitting them into a generalized extreme value (GEV) distribution. Using general circulation models from the 6th phase of the Coupled Model Intercomparison Project (CMIP6)’s Detection & Attribution Model Intercomparison Project (DAMIP), an assessment of the potential contribution of human-induced climate change on the observed precipitation patterns over the study area was done. The greatest precipitation anomalies for the period 1900-2020 were recorded in 1961’s October-December (OND) season and 2019’s June-August (JJA) and OND seasons, corresponding to the period when the highest water-levels were recorded in Lake Victoria. While land-use change in the study domain was observed, extended and...
Future Changes in Seasonal Temperature Over Pakistan in CMIP6
Victor Ongoma
The present study analyzed seasonal (i.e., Dec-Jan [DJF] and June – August [JJA]) temperature change for the near (2025-2054) and far future (2070-2099) under SSP245, SSP370, and SSP585 scenarios over Pakistan. The anomalies, Mann-Kendall trend tests, Sequential Mann-Kendall trend test (SQMK), and probability density frequency (PDF) analysis were used to investigate future mean temperature variations. The DJF season projected higher increase in temperature in the northern (3.8 oC, 5.1 oC and 6.5 oC), followed by central regions (3.8 oC, 4.9 oC and 6.4 oC) under SSP245, SSP370 and SSP585 scenarios, respectively. The central region is likely to record significant increase in JJA (3.0 oC, 4.4 oC and 5.4 oC) mean temperature in far future under the given SSP scenarios. Compared to historical (PDF), the far future DJF temperature changes revealed significant higher warming over northern, central and then over southern regions under most of SSP scenarios. The southern regions are projecte...
Atmospheric Research
Historical evaluations and simulations of precipitation over East Africa from Rossby centre regional climate model
2020 •
Moses Ojara
Projected Changes in Rainfall Over Uganda Based on CMIP6 Models
2022 •
Richard Mumo
Information about likely future patterns of climate variables is important in climate change mitigation and adaptation efforts. This study investigates future (2021–2100) changes in rainfall based on CMIP6 datasets over Uganda. The projection period was divided into two sub-periods: 2021–2060 (near future) and 2061–2100 (far future), relative to the baseline period (1985–2014). Two emission scenarios: SSP2-4.5 and SSP5-8.5, were considered. The results reveal a larger decrease (increase) in rainfall during March – April (November – December) under both SSPs. Moreover, an enhanced decline (increase) is projected under SSP2-4.5 (SSP5-8.5). The spatial distribution of future changes in seasonal rainfall reveals a decrease in MAM rainfall in the near future over most parts of the country under both emission scenarios. However, a recovery is exhibited towards the end of the century with more increase in the south-western parts of the country, and a higher magnitude under SSP5-8.5. In con...
Weather Research and Forecasting Model Sensitivity to Choice of Parameterization over Ethiopia
2022 •
Andualem S Shiferaw
Comparison of multimodel ensembles of global and regional climate models projections for extreme precipitation over four major river basins in southern Africa. Part I: Assessment of the historical simulations
Dieudonne faka
This study assesses the performance of large ensembles of global (CMIP5, CMIP6) and regional (CORDEX, CORE) climate models in simulating extreme precipitation over four major river basins (Limpopo, Okavango, Orange and Zambezi) in southern Africa during the period 1983–2005. The ability of the model ensembles to simulate seasonal extreme precipitation indices is assessed using three high-resolution satellite-based datasets. The results show that all ensembles overestimate the annual cycle of mean precipitation over all basins, although the intermodal spread is large, with CORDEX being the closest to the observed values. Generally, all ensembles overestimate the mean and interannual variability of rainy days (RR1), maximum consecutive wet days (CWD), and heavy and very heavy precipitation days (R10mm and R20mm respectively) over all basins during all three seasons. Simple daily rainfall intensity (SDII) and the number of consecutive dry days (CDD) are generally underestimated. The lo...
Projected Changes in Meteorological Drought Over East Africa Inferred from Bias-Adjusted CMIP6 Models
2021 •
Victor Dike
The ongoing global warming has caused unprecedented changes in the climate system, leading to climate change and increase in drought occurrence, duration, severity and intensity. This research uses the sixth phase of Coupled Model Intercomparison Project (CMIP6) data to investigate the projected changes in drought events over East Africa (EA) under four Shared Socioeconomic Pathway (SSP) emission scenarios (SSP1-2.6, SSP2-4.5, SSP3-4.0 and SSP5-8.5). Drought is quantified using the standardized precipitation index (SPI) considering different measures: drought duration (DD), drought frequency (DF), drought severity (DS) and drought intensity (DI). The CMIP6 data are first bias-corrected using a quantile mapping method, with the Climatic Research Unit (CRU)’s precipitation data as the observation. Evaluating the accuracy and reliability of historical data before and after correction demonstrates the importance of such approach. The projection results show that a drying pattern is expe...
Climatic Change
Assessing uncertainties in the regional projections of precipitation in CORDEX-AFRICA
2020 •
N'Datchoh Evelyne Touré
Over the past decades, large variations of precipitation were observed in Africa, which often led to dramatic consequences for local society and economy. To avoid such disasters in the future, it is crucial to better anticipate the expected changes, especially in the current context of climate change and population growth. To this date, however, projections of precipitation over Africa are still associated with very large uncertainties. To better understand how this uncertainty can be reduced, this study uses an advanced Bayesian analysis of variance (ANOVA) method to characterize, for the first time in the regional climate projections of CORDEX-AFRICA, the different sources of uncertainty associated with the projections of precipitation over Africa.By 2090, the ensemble mean precipitation is projected to increase over the Horn of Africa from September to May and over the eastern Sahel and Guinea Coast from June to November. It is projected to decrease over the northern coast and so...
