Evaluation of precipitation simulations in <scp>CMIP6</scp> models over Uganda

Ngoma, Hamida; Wang, Wen; Ayugi, Brian; Babaousmail, Hassen; Karim, Rizwan; Ongoma, Victor

doi:10.1002/joc.7098

Cited by 77 publications

(50 citation statements)

References 88 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The two main projections utilized are drawn from Tier 1 ScenarioMIP: SSP2-4.5 and SSP5-8.5. Following the recommendations of previous studies (e.g., [57,[81][82][83][84][85]), this employs MME of CMIP6 for projection of extreme events over the study area. Many studies have remarked on the robustness of MME as compared to individual models due to cancellation of intermodel biases [59].…”

Section: Discussionmentioning

confidence: 99%

“…Presence of complex topography has considerable influence on the variation of extreme events and impacted regions [66,83]. For instance, the presence of large inland water bodies-i.e., Lake Victoria, which is the largest freshwater lake in Africa and second in the world, covering about 68,000 km 2 and bordering three countries, Uganda (45%), Tanzania (49%), and Kenya (6%)-have a significant influence on the incidences of extreme events [84]. Additionally, high elevation areas (i.e., Mt.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Future Changes in Precipitation Extremes over East Africa Based on CMIP6 Models

Ayugi

Dike

Ngoma

et al. 2021

Water

Self Cite

View full text Add to dashboard Cite

This paper presents an analysis of projected precipitation extremes over the East African region. The study employs six indices defined by the Expert Team on Climate Change Detection Indices to evaluate extreme precipitation. Observed datasets and Coupled Model Intercomparison Project Phase six (CMIP6) simulations are employed to assess the changes during the two main rainfall seasons: March to May (MAM) and October to December (OND). The results show an increase in consecutive dry days (CDD) and decrease in consecutive wet days (CWD) towards the end of the 21st century (2081–2100) relative to the baseline period (1995–2014) in both seasons. Moreover, simple daily intensity (SDII), very wet days (R95 p), very heavy precipitation >20 mm (R20 mm), and total wet-day precipitation (PRCPTOT) demonstrate significant changes during OND compared to the MAM season. The spatial variation for extreme incidences shows likely intensification over Uganda and most parts of Kenya, while a reduction is observed over the Tanzania region. The increase in projected extremes may pose a serious threat to the sustainability of societal infrastructure and ecosystem wellbeing. The results from these analyses present an opportunity to understand the emergence of extreme events and the capability of model outputs from CMIP6 in estimating the projected changes. More studies are recommended to examine the underlying physical features modulating the occurrence of extreme incidences projected for relevant policies.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Future Changes in Precipitation Extremes over East Africa Based on CMIP6 Models

Ayugi

Dike

Ngoma

et al. 2021

Water

Self Cite

View full text Add to dashboard Cite

show abstract

“…While we used biascorrected CMIP6 simulations to examine the future changes in precipitation and PET over WMZs across Uganda, the results should be interpreted with caution due to few limitations. Existing studies have pointed out the simulated precipitation over Uganda and the Greater Horn of Africa depends on the boundary layers, the model horizontal resolution, and the parameterization schemes [51][52][53][54]. In fact, in a recent study over East Africa [55] established that the biases in GCMs are not fully corrected to resemble observed patterns, despite the implementation of various robust statistical methods such as quantile approach.…”

Section: Discussionmentioning

confidence: 99%

Observed and Future Precipitation and Evapotranspiration in Water Management Zones of Uganda: CMIP6 Projections

et al. 2021

Self Cite

View full text Add to dashboard Cite

We used CMIP6 GCMs to quantify climate change impacts on precipitation and potential evapotranspiration (PET) across water management zones (WMZs) in Uganda. Future changes are assessed based on four Shared Socioeconomic Pathways (SSP) scenarios including SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5 over the periods 2021–2040, 2041–2060, 2061–2080, and 2081–2100. Both precipitation and PET are generally projected to increase across all the WMZs. Annual PET in the 2030s, 2050s, 2070s, 2090s will increase in the ranges 1.1–4.0%, 4.8–7.9%, 5.1–11.8%, and 5.3–17.1%, respectively. For the respective periods, annual precipitation will increase in the ranges 4.0–7.8%, 7.8–12.5%, 7.9–19.9%, and 6.9–26.3%. The lower and upper limits of these change ranges for both precipitation and PET are, respectively, derived under SSP1-2.6 and SSP5-8.5 scenarios. Climate change will impact on PET or precipitation disproportionately across the WMZs. While the eastern WMZ (Kyoga) will experience the largest projected precipitation increase especially towards the end of the century, the southern WMZ (Victoria) exhibited the largest PET increase. Our findings are relevant for understanding hydrological impacts of climate change across Uganda, in the background of global warming. Thus, the water sector should devise and implement adaptation measures to impede future socioeconomic and environmental crises in the country.

show abstract

“…The student t test is used to calculate significant values at the 99% confidence interval. As noted by other CMIP6 model simulation evaluation studies (e.g., Akinsanola et al, 2021;Ngoma et al, 2021), CMIP6 model simulations generally show biases in representing regional precipitation patterns. For the current study domain, biases shown could be resulting from, among other factors, local climate and mesoscale convective systems (Ridder et al, 2021) and the general complexity of East Africa's large-scale controlled climate (Li et al, 2016;Nicholson, 2017).…”

Section: Methodsmentioning

confidence: 50%

Future Precipitation Patterns in the Lake Victoria Basin Using CMIP6 Projections

Ogega¹,

Scoccimarro²,

Endris³

et al. 2021

Preprint

View full text Add to dashboard Cite

In late/early 2019/2020, unprecedented high-water-levels were observed in Lake Victoria causing massive flooding in the low-lying lake-adjacent areas and disrupting human and natural systems in the Lake Victoria Basin (LVB). The high lake water-level coincided with unusually heavy and prolonged 2019 June to December precipitation in the LVB. The current study estimates future precipitation patterns over the LVB using HighResMIP and ScenarioMIP general circulation model (GCM) simulations from the 6th phase of the Coupled Model Intercomparison Project (CMIP6). Results show that HighResMIP and ScenarioMIP simulations can adequately reproduce LVB’s precipitation patterns – albeit with location-specific biases. Generally, the GCM simulations tend to over-estimate precipitation patterns over Lake Victoria while under-estimating precipitation patterns over the lake-adjacent areas. Projections show significant future precipitation changes over the LVB relative to the 1970-1999 baseline, with more pronounced changes over the lake than in lake-adjacent areas. Overall, mean annual precipitation is projected to increase by about 18% and 31% by the end of the century, under SSP2-4.5 and SSP5-8.5 scenarios, respectively. Additionally, mean daily precipitation intensity (SDII) is projected to increase by up-to 14% while the maximum 5-day precipitation values (RX5Day) increase by up-to 71% under the SSP5-8.5 scenario. Heavy precipitation events, represented by the width of the right tail distribution of precipitation (99p-90p), are projected to increase by 50% and 94% under SSP2-4.5 and SSP5-8.5, respectively. Given that direct precipitation accounts for about 80% of Lake Victoria’s water budget, the lake’s future water-level fluctuations are likely to be more rampant and unpredictable under the changing climate. Hence, enhanced production and use of climate services is recommended to minimize the risk posed by potentially high water-level fluctuations in Lake Victoria and, ultimately, enhance the socio-economic safety of communities in the LVB.

show abstract

Evaluation of precipitation simulations in CMIP6 models over Uganda

Cited by 77 publications

References 88 publications

Future Changes in Precipitation Extremes over East Africa Based on CMIP6 Models

Future Changes in Precipitation Extremes over East Africa Based on CMIP6 Models

Observed and Future Precipitation and Evapotranspiration in Water Management Zones of Uganda: CMIP6 Projections

Future Precipitation Patterns in the Lake Victoria Basin Using CMIP6 Projections

Contact Info

Product

Resources

About