Numerical weather prediction and climate modelling: Challenges and opportunities for improving climate services delivery in Southern Africa

Meque, Arlindo; Gamedze, Sunshine; Moitlhobogi, Thembani; Booneeady, P; Samuel, Sydney; Mpalang, Letlhogonolo

doi:10.1016/j.cliser.2021.100243

Cited by 12 publications

(12 citation statements)

References 28 publications

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“…They illustrate that a variety of activities are needed to achieve a comprehensive understanding of climate variability and change. Improving data availability and exchange will not only support the understanding of climate trends, but will also support applications as especially numerical weather forecasting (Meque et al, 2021). The combination of observations and numerical models also allows to generate longterm climate reanalysis datasets that provide realistic threedimensional fields of past weather and are therefore used in a wide range of applications.…”

Section: Discussionmentioning

confidence: 99%

Contributions to the Improvement of Climate Data Availability and Quality for Sub-Saharan Africa

et al. 2022

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Reliable weather observations are the basis to assess climate change and variability. Compared to other regions of the world, long time series of weather observations are sparse in many countries of Sub-Saharan Africa. Various activities at national or international level are ongoing to improve the availability and quality of climate databases. Here, we present ongoing international contributions with a focus on representative examples hosted at Germany's national meteorological service DWD (Deutscher Wetterdienst). The international exchange of monthly climate reports (CLIMAT) is monitored within the Monitoring Centre of the GCOS Surface Network (Global Climate Observing System). In that context also quality control is performed and data are made publicly available. Recent climate observations can be complemented by digitization of historical hand-written weather observations which are available in distributed archives. International data centers, such as the Global Precipitation Climatology Centre (GPCC), collect international data. They perform quality-control of these observations and provide derived products in support of global and regional climate assessments. These activities can also contribute to the improvement of national climate databases, as e.g., demonstrated in a cooperation among selected countries with the SASSCAL initiative (Southern African Science Service Centre for Climate Change and Adaptive Land Management). Satellite-based observations are an additional source that can provide climatological information for selected parameters. In particular, the METEOSAT satellite series provides valuable data for the African continent. The Satellite Application Facility on Climate Monitoring (CM SAF) provides high resolution climate data covering the last decades derived from observations of such meteorological satellites. Based on these examples the paper illustrates the variety of ongoing international efforts in support of regional observation-based climate information, but also identifies the needs for further activities.

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Section: Discussionmentioning

confidence: 99%

Contributions to the Improvement of Climate Data Availability and Quality for Sub-Saharan Africa

et al. 2022

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“…This leads us to the third, and probably the most prominent driver of the underdeveloped MLT CIS in Africa, which relates to capacity gaps within national institutions responsible for CIS development. African NMHS are said to lack computing equipment and technical expertise to generate downscale MLT climate information thus limiting their generation of climate change projections and products for different users (Griggs et al., 2021; Meque et al., 2021). In places where MLT CIS is emerging, institutional capacity gaps further prevent the integration of MLT CIS into pre‐existing S2S CIS.…”

Section: Status Of Holistic Cis In Africamentioning

confidence: 99%

“…This means that previous and ongoing work to address the S2S technological and capacity barriers already contributes towards addressing the same barriers for MLT CIS. Hence, although many NMHS in Africa are still limited by their low computing capabilities (Meque et al., 2021), the gains made from development of S2S CIS can still be used to accelerate MLT CIS. Today, the climate scientists recommend that national institutions transition from independent generation of climate projections, and instead tap into already existing resources such as CORDEX to advance MLT CIS.…”

Section: Status Of Holistic Cis In Africamentioning

confidence: 99%

Develop medium‐ to long‐term climate information services to enhance comprehensive climate risk management in Africa

et al. 2023

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Increasing climate change risks in Africa, emerging from global warming and their interaction with non‐climate risks such as market, have increased the need for comprehensive Climate Risk Management (CRM) that considers both climatic and non‐climatic risks and enables actions that address the underlying drivers of vulnerability to these risks. However, comprehensive CRM requires holistic Climate Information Services (CIS), that is, CIS that balances between components focused on provision of short‐ and long‐term climate information for both local and non‐local decision makers. In this article, we ask: to what extent is CIS in Africa holistic? We review recent and ongoing CIS interventions in Africa to determine whether a balance of components between short‐ and long‐term CIS for local and non‐local decision makers is achieved for holistic CIS. We find a focus on provision of short‐term, that is, Sub‐Seasonal‐to‐Seasonal (S2S) CIS for local and non‐local decision makers, with limited focus on medium‐ to long‐term (MLT) CIS, particularly MLT CIS for local decision makers which represents the biggest gap to achieving holistic CIS in Africa. We present a supported case that ensuring holistic CIS in Africa will require a portfolio‐based approach to CIS development, particularly focusing on MLT CIS for local decision makers. We further highlight the need for integration of this MLT CIS for local decision makers into existing CIS. Achieving this will require: (a) experimentation and innovation with different CIS formats, products and timeframes to enable learning and flexibility to achieve desired goals; (b) capacity development of producers and consumers of climate information to ensure that they have the skills and expertise to understand and generate, and articulate needs and consume MLT CIS respectively; and (c) coordinated allocation of financial resources to ensure that all components of the holistic CIS are advanced.

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“…In case of the former i.e., NWP, the South African Weather Service (SAWS) employs the UK Met Office (Met Office) Unified Model (UM) as its main operational system [18,19], which replaced the National Centers for Environmental Prediction (NCEP) regional Eta Model [20,21]. Other NWP models used in southern Africa for operational purposes are the Consortium for Small Scale Modeling (COSMO) and the Weather Research and Forecasting (WRF) [22,23]. The three models were compared in a recent study when simulating HIW events in South Africa, and all three captured the selected events [24].…”

Section: Introductionmentioning

confidence: 99%

Rainfall Simulations of High-Impact Weather in South Africa with the Conformal Cubic Atmospheric Model (CCAM)

et al. 2022

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Warnings of severe weather with a lead time longer that two hours require the use of skillful numerical weather prediction (NWP) models. In this study, we test the performance of the Commonwealth Scientific and Industrial Research Organisation (CSIRO) Conformal Cubic Atmospheric Model (CCAM) in simulating six high-impact weather events, with a focus on rainfall predictions in South Africa. The selected events are tropical cyclone Dineo (16 February 2017), the Cape storm (7 June 2017), the 2017 Kwa-Zulu Natal (KZN) floods (10 October 2017), the 2019 KZN floods (22 April 2019), the 2019 KZN tornadoes (12 November 2019) and the 2020 Johannesburg floods (5 October 2020). Three configurations of CCAM were compared: a 9 km grid length (MN9km) over southern Africa nudged within the Global Forecast System (GFS) simulations, and a 3 km grid length over South Africa (MN3km) nudged within the 9 km CCAM simulations. The last configuration is CCAM running with a grid length of 3 km over South Africa, which is nudged within the GFS (SN3km). The GFS is available with a grid length of 0.25°, and therefore, the configurations allow us to test if there is benefit in the intermediate nudging at 9 km as well as the effects of resolution on rainfall simulations. The South African Weather Service (SAWS) station rainfall dataset is used for verification purposes. All three configurations of CCAM are generally able to capture the spatial pattern of rainfall associated with each of the events. However, the maximum rainfall associated with two of the heaviest rainfall events is underestimated by CCAM with more than 100 mm. CCAM simulations also have some shortcomings with capturing the location of heavy rainfall inland and along the northeast coast of the country. Similar shortcomings were found with other NWP models used in southern Africa for operational forecasting purposes by previous studies. CCAM generally simulates a larger rainfall area than observed, resulting in more stations reporting rainfall. Regarding the different configurations, they are more similar to one another than observations, however, with some suggestion that MN3km outperforms other configurations, in particular with capturing the most extreme events. The performance of CCAM in the convective scales is encouraging, and further studies will be conducted to identify areas of possible improvement.

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Numerical weather prediction and climate modelling: Challenges and opportunities for improving climate services delivery in Southern Africa

Cited by 12 publications

References 28 publications

Contributions to the Improvement of Climate Data Availability and Quality for Sub-Saharan Africa

Contributions to the Improvement of Climate Data Availability and Quality for Sub-Saharan Africa

Develop medium‐ to long‐term climate information services to enhance comprehensive climate risk management in Africa

Rainfall Simulations of High-Impact Weather in South Africa with the Conformal Cubic Atmospheric Model (CCAM)

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