The WASCAL high-resolution regional climate simulation ensemble for West Africa: concept, dissemination, assessment

Abstract. Climate change and constant population growth pose severe challenges to 21st century rural Africa. Within the framework of the West African Science Service Center on Climate Change and Adapted Land Use (WASCAL), an ensemble of high-resolution regional climate change scenarios for the greater West African region are provided to support the development of effective adaptation and mitigation measures. This contribution presents the overall concept of the WASCAL regional climate simulations as well as detailed information on the experiment design, and provides information on the format and dissemination of the available data. All data is made available to the public at the CERA long-term archive of the German Climate Computing Center (DKRZ) with a subset available at the PANGAEA Data Publisher for Earth & Environmental Science portal (https://doi.pangaea.de/10.1594/PANGAEA.880512). Regional climate projections are generated at high (12 km) and intermediate (60 km) resolution using the Weather Research & Forecasting Model (WRF). The simulations cover the validation period 1980–2010 and the two future periods 2020–2050 and 2070–2100. A brief comparison to observations and two climate change scenarios from the CORDEX initiative is presented to provide guidance on the data set to future users and to assess their climate change signal. Under the RCP4.5 scenario, the results suggest an increase in temperature by 1.5 °C at the Coast of Guinea and by up to 3 °C in the northern Sahel by the end of the 21st century, in line with existing climate projections for the region. They also project an increase in precipitation by up to 300 mm per year along the Coast of Guinea, by up to 150 mm per year in the Soudano region adjacent in the North, and almost no change in precipitation in the Sahel. This stands in contrast to existing regional climate projections, which predict increasingly drier conditions. The high spatial and temporal resolution of the data, the extensive list of output variables, the large computational domain and the long time periods covered make this data set a unique resource for follow-up analyses and impact modelling studies over the greater West African region. The comprehensive documentation and standardisation of the data facilitate and encourage its use within and outside of the WASCAL community.

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The WASCAL high-resolution regional climate simulation ensemble for West Africa: concept, dissemination and assessment

Earth System Science Data ◽

10.5194/essd-10-815-2018 ◽

2018 ◽

Vol 10 (2) ◽

pp. 815-835 ◽

Cited By ~ 5

Author(s):

Dominikus Heinzeller ◽

Diarra Dieng ◽

Gerhard Smiatek ◽

Christiana Olusegun ◽

Cornelia Klein ◽

...

Keyword(s):

Climate Change ◽

High Resolution ◽

Regional Climate ◽

West African ◽

Climate Projections ◽

Climate Change Scenarios ◽

African Region ◽

Data Set ◽

West African Region ◽

Regional Climate Projections

Abstract. Climate change and constant population growth pose severe challenges to 21st century rural Africa. Within the framework of the West African Science Service Center on Climate Change and Adapted Land Use (WASCAL), an ensemble of high-resolution regional climate change scenarios for the greater West African region is provided to support the development of effective adaptation and mitigation measures. This contribution presents the overall concept of the WASCAL regional climate simulations, as well as detailed information on the experimental design, and provides information on the format and dissemination of the available data. All data are made available to the public at the CERA long-term archive of the German Climate Computing Center (DKRZ) with a subset available at the PANGAEA Data Publisher for Earth & Environmental Science portal (https://doi.pangaea.de/10.1594/PANGAEA.880512). A brief assessment of the data are presented to provide guidance for future users. Regional climate projections are generated at high (12 km) and intermediate (60 km) resolution using the Weather Research and Forecasting Model (WRF). The simulations cover the validation period 1980–2010 and the two future periods 2020–2050 and 2070–2100. A brief comparison to observations and two climate change scenarios from the Coordinated Regional Downscaling Experiment (CORDEX) initiative is presented to provide guidance on the data set to future users and to assess their climate change signal. Under the RCP4.5 (Representative Concentration Pathway 4.5) scenario, the results suggest an increase in temperature by 1.5 ∘C at the coast of Guinea and by up to 3 ∘C in the northern Sahel by the end of the 21st century, in line with existing climate projections for the region. They also project an increase in precipitation by up to 300 mm per year along the coast of Guinea, by up to 150 mm per year in the Soudano region adjacent in the north and almost no change in precipitation in the Sahel. This stands in contrast to existing regional climate projections, which predict increasingly drier conditions. The high spatial and temporal resolution of the data, the extensive list of output variables, the large computational domain and the long time periods covered make this data set a unique resource for follow-up analyses and impact modelling studies over the greater West African region. The comprehensive documentation and standardisation of the data facilitate and encourage their use within and outside of the WASCAL community.

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Simulating future precipitation extremes in a complex Alpine catchment

Natural Hazards and Earth System Science ◽

10.5194/nhess-13-263-2013 ◽

2013 ◽

Vol 13 (2) ◽

pp. 263-277 ◽

Cited By ~ 9

Author(s):

C. Dobler ◽

G. Bürger ◽

J. Stötter

Keyword(s):

Climate Change ◽

Large Scale ◽

Climate Models ◽

Regional Climate ◽

Regional Climate Models ◽

Precipitation Extremes ◽

Climate Projections ◽

Research Station ◽

Climate Change Scenarios ◽

Station Data

Abstract. The objectives of the present investigation are (i) to study the effects of climate change on precipitation extremes and (ii) to assess the uncertainty in the climate projections. The investigation is performed on the Lech catchment, located in the Northern Limestone Alps. In order to estimate the uncertainty in the climate projections, two statistical downscaling models as well as a number of global and regional climate models were considered. The downscaling models applied are the Expanded Downscaling (XDS) technique and the Long Ashton Research Station Weather Generator (LARS-WG). The XDS model, which is driven by analyzed or simulated large-scale synoptic fields, has been calibrated using ECMWF-interim reanalysis data and local station data. LARS-WG is controlled through stochastic parameters representing local precipitation variability, which are calibrated from station data only. Changes in precipitation mean and variability as simulated by climate models were then used to perturb the parameters of LARS-WG in order to generate climate change scenarios. In our study we use climate simulations based on the A1B emission scenario. The results show that both downscaling models perform well in reproducing observed precipitation extremes. In general, the results demonstrate that the projections are highly variable. The choice of both the GCM and the downscaling method are found to be essential sources of uncertainty. For spring and autumn, a slight tendency toward an increase in the intensity of future precipitation extremes is obtained, as a number of simulations show statistically significant increases in the intensity of 90th and 99th percentiles of precipitation on wet days as well as the 5- and 20-yr return values.

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Ensemble Projections of Regional Climatic Changes over Ontario, Canada

Journal of Climate ◽

10.1175/jcli-d-15-0185.1 ◽

2015 ◽

Vol 28 (18) ◽

pp. 7327-7346 ◽

Cited By ~ 29

Author(s):

Xiuquan Wang ◽

Guohe Huang ◽

Jinliang Liu ◽

Zhong Li ◽

Shan Zhao

Keyword(s):

Climate Change ◽

Global Warming ◽

Regional Climate ◽

Climatic Changes ◽

Climate Projections ◽

Climate Change Scenarios ◽

Local Climate ◽

Ensemble Simulations ◽

Extreme Precipitation Events ◽

Data Portal

Abstract In this study, high-resolution climate projections over Ontario, Canada, are developed through an ensemble modeling approach to provide reliable and ready-to-use climate scenarios for assessing plausible effects of future climatic changes at local scales. The Providing Regional Climates for Impacts Studies (PRECIS) regional modeling system is adopted to conduct ensemble simulations in a continuous run from 1950 to 2099, driven by the boundary conditions from a HadCM3-based perturbed physics ensemble. Simulations of temperature and precipitation for the baseline period are first compared to the observed values to validate the performance of the ensemble in capturing the current climatology over Ontario. Future projections for the 2030s, 2050s, and 2080s are then analyzed to help understand plausible changes in its local climate in response to global warming. The analysis indicates that there is likely to be an obvious warming trend with time over the entire province. The increase in average temperature is likely to be varying within [2.6, 2.7]°C in the 2030s, [4.0, 4.7]°C in the 2050s, and [5.9, 7.4]°C in the 2080s. Likewise, the annual total precipitation is projected to increase by [4.5, 7.1]% in the 2030s, [4.6, 10.2]% in the 2050s, and [3.2, 17.5]% in the 2080s. Furthermore, projections of rainfall intensity–duration–frequency (IDF) curves are developed to help understand the effects of global warming on extreme precipitation events. The results suggest that there is likely to be an overall increase in the intensity of rainfall storms. Finally, a data portal named Ontario Climate Change Data Portal (CCDP) is developed to ensure decision-makers and impact researchers have easy and intuitive access to the refined regional climate change scenarios.

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Impact of climate change on hydrological conditions in a tropical West African catchment using an ensemble of climate simulations

Hydrology and Earth System Sciences ◽

10.5194/hess-21-2143-2017 ◽

2017 ◽

Vol 21 (4) ◽

pp. 2143-2161 ◽

Cited By ~ 28

Author(s):

Yacouba Yira ◽

Bernd Diekkrüger ◽

Gero Steup ◽

Aymar Yaovi Bossa

Keyword(s):

Climate Change ◽

Water Resources ◽

Bias Correction ◽

Climate Models ◽

Regional Climate ◽

West African ◽

Climate Projections ◽

Impact Of Climate Change ◽

Budget Analysis ◽

High Uncertainty

Abstract. This study evaluates climate change impacts on water resources using an ensemble of six regional climate models (RCMs)–global climate models (GCMs) in the Dano catchment (Burkina Faso). The applied climate datasets were performed in the framework of the COordinated Regional climate Downscaling Experiment (CORDEX-Africa) project.After evaluation of the historical runs of the climate models' ensemble, a statistical bias correction (empirical quantile mapping) was applied to daily precipitation. Temperature and bias corrected precipitation data from the ensemble of RCMs–GCMs was then used as input for the Water flow and balance Simulation Model (WaSiM) to simulate water balance components.The mean hydrological and climate variables for two periods (1971–2000 and 2021–2050) were compared to assess the potential impact of climate change on water resources up to the middle of the 21st century under two greenhouse gas concentration scenarios, the Representative Concentration Pathways (RCPs) 4.5 and 8.5. The results indicate (i) a clear signal of temperature increase of about 0.1 to 2.6 °C for all members of the RCM–GCM ensemble; (ii) high uncertainty about how the catchment precipitation will evolve over the period 2021–2050; (iii) the applied bias correction method only affected the magnitude of the climate change signal; (iv) individual climate models results lead to opposite discharge change signals; and (v) the results for the RCM–GCM ensemble are too uncertain to give any clear direction for future hydrological development. Therefore, potential increase and decrease in future discharge have to be considered in climate change adaptation strategies in the catchment. The results further underline on the one hand the need for a larger ensemble of projections to properly estimate the impacts of climate change on water resources in the catchment and on the other hand the high uncertainty associated with climate projections for the West African region. A water-energy budget analysis provides further insight into the behavior of the catchment.

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Exposure to climate change in Central Europe: What can be gained from regional climate projections for management decisions of protected areas?

Regional Environmental Change ◽

10.1007/s10113-014-0704-y ◽

2014 ◽

Vol 15 (7) ◽

pp. 1409-1419 ◽

Cited By ~ 8

Author(s):

Judith Stagl ◽

Fred F. Hattermann ◽

Katrin Vohland

Keyword(s):

Climate Change ◽

Protected Areas ◽

Central Europe ◽

Regional Climate ◽

Climate Projections ◽

Management Decisions ◽

Regional Climate Projections

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Evapo-Transpiration calculated from the new regional climate projections data set DRIAS-2020 over France

10.5194/ems2021-109 ◽

2021 ◽

Author(s):

Sébastien Bernus ◽

Lola Corre ◽

Agathe Drouin ◽

Genaro Saavedra Soriano ◽

Pascal Simon ◽

...

Keyword(s):

Relative Humidity ◽

Agricultural Sector ◽

Regional Climate ◽

Specific Humidity ◽

Climate Projections ◽

Visible Radiation ◽

Adaptation Measures ◽

Data Set ◽

Thermal Amplitude ◽

Regional Climate Projections

&#160;Evapo-Transpiration calculated from the new regional climate projections data set DRIAS-2020 over FranceChanges in climatic variables such as temperature, precipitation, relative humidity or solar radiation strongly affect the agricultural sector. Relevant indicators are strongly needed to quantify the expected impacts and implement adaptation measures. Information on the future trend of Evapo-Transpiration (ET) is one of the key issues in order to take up the water management challenge.In 2020, a new set of climate indicators based on regional climate projections corrected over France was produced and published on the French national climate service DRIAS (www.drias-climat.fr) and the associated report was published in January 2021. The latter portal provides climate information in a variety of graphical or numerical forms. The climate projections are based on the EURO-CORDEX ensemble and have been corrected using the ADAMONT method according to the SAFRAN reference data set.ET is calculated from this new data set with the aim of making it freely available on the DRIAS portal. Various calculation methods are used and compared. First, ET is calculated upstream and downstream of the ADAMONT method. Second, different calculation procedures are tested for the FAO recommended formula. One uses the average specific humidity instead of minimum and maximum of daily relative humidity which are not available in all selected models. ET is also calculated using the Hargreaves proxy for the visible radiation based on the square root of the maximum daily thermal amplitude multiplied by a coefficient. Three different values were tested for this coefficient&#160;: 0.16, 0.175 and 0.19.These various ET are then analyzed with a view to quantify the influence of the calculation method on the resulting estimated trends.Authors&#160;: BERNUS S.1, CORRE L.2, DROUIN A.2, SAAVEDRA SORIANO G.3, SIMON P.2, PRATS&#160;S.4, &#160;1 M&#233;t&#233;o-France, Direction de la Climatologie et des Services Climatiques, Toulouse, France, [email protected]2M&#233;t&#233;o-France, Direction de la Climatologie et des Services Climatiques, Toulouse, France, [email protected]3&#201;cole des Mines, Antibes, France, [email protected]4M&#233;t&#233;o-France, Direction des Services M&#233;t&#233;orologiques, Toulouse, France, [email protected]&#160;References&#160;:FAO (1998). Crop evapotranspiration: Guidelines for computing crop water requirements. FAO Irrigation and drainage paper 56, Rome, Italy

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Economic impacts of drought risks for water utilities through Severity-Duration-Frequency framework under climate change scenarios

10.5194/hess-2017-615 ◽

2017 ◽

Cited By ~ 4

Author(s):

Diego A. Guzmám ◽

Guilherme S. Mohor ◽

Denise Taffarello ◽

Eduardo M. Mendiondo

Keyword(s):

Climate Change ◽

Risk Aversion ◽

Economic Impacts ◽

Regional Climate ◽

Water Utilities ◽

Climate Projections ◽

Climate Change Scenarios ◽

Model Framework ◽

Water Utility ◽

Drought Resilience

Abstract. Climate variability and increasing water demands prioritize the need to implement planning strategies for urban water security in the long and medium term. However, actions to manage the drought risk impacts entail great complexity, such as the calculation of economic losses derived from the combination of severity, duration and frequency under uncertainties in the climate projections. Thus, new approaches of risk aversion are needed, as an integrated framework for resilience gap assessment, for water utilities to cope with droughts, thereby linking drivers of climate, hydrology and human demands. This paper aims to present the economic impacts of risk aversion for water utilities through a framework linking severity, duration and frequency (SDF) of droughts under climate change scenarios. This new model framework addresses the opportunity cost that represent the preparedness for risk aversion to cope with potential future impacts of droughts, involving a set of options for planning of water resources, under different demands and climate projections. The methodology integrates the hydrological simulation procedures, under radiative climate forcing scenarios RCP 4.5 and 8.5, from a regional climate model Eta-INPE, with time horizons of 2007–2040, 2041–2070, and 2071–2099, linked to Water Evaluation and Planning system (WEAP) hydrologic model and under stationary and non-stationary water supply demand assumptions. The model framework is applied to the Cantareira Water Supply System for Sao Paulo Metropolitan Region, Brazil, with severe vulnerability to droughts. By using hydrological simulations with WEAP, driven by Eta-INPE Regional Climatic Model base line scenarios (1962–2005), were characterized the SDF curves. On the one hand, water tariff price associated to calibrated and modelled scenarios constitute supply/demand proxies of the water warranty time delimited by drought duration. Then, profit loss analysis scenarios are assessed for the regional water utility. On the other hand, for drought resilience gap, results show water utility profit losses per period between 1.3 % and 10.3 % of the regional GDP in 2016. Although future economic impacts vary in a same order, non-stationary demand trends impose larger differences in the drought resilience gap, when the future securitization are linked to regional climate outputs.

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Impacts of climate change on the water regime of the Inn River basin – extracting adaptation-relevant information from climate model ensembles and impact modelling

Advances in Geosciences ◽

10.5194/adgeo-32-99-2012 ◽

2012 ◽

Vol 32 ◽

pp. 99-107 ◽

Cited By ~ 3

Author(s):

J. Korck ◽

J. Danneberg ◽

W. Willems

Keyword(s):

Climate Change ◽

River Basin ◽

Regional Climate ◽

Relevant Information ◽

High Flow ◽

Low Flow ◽

Climate Projections ◽

Study Region ◽

Regional Climate Projections ◽

Impacts Of Climate Change

Abstract. The Inn River basin is a highly relevant study region in terms of potential hydrological impacts of climate change and cross boundary water management tasks in the Alpine Space. Regional analyses in this catchment were performed within the EU co-funded project AdaptAlp. Objective of the study was to gain scientifically based knowledge about impacts of climate change on the water balance and runoff regime for the Inn River basin, this being fundamental for the derivation of adaptation measures. An ensemble of regional climate projections is formed by combinations of global and regional climate models on the basis of both statistical and bias-corrected dynamical downscaling procedures. Several available reference climate datasets for the study region are taken into account. As impact model, the process-oriented hydrological model WaSiM-ETH is set up. As expected, regional climate projections indicate temperature increases for the future in the study area. Projections of precipitation change are less homogenous, especially regarding winter months, though most indicate a decrease in the summer. Hydrological simulation results point towards climate induced changes in the water regime of the study region. The analysis of hydrological projections at both ends of the ensemble bandwidth is a source of adaptation relevant information regarding low-flow and high-flow conditions. According to a "drought-prone scenario", mean monthly low flow could decrease up to −40% in the time frame of 2071–2100. A "high-flow-increase-scenario" points towards an increase in mean monthly high flow in the order of +50% in the winter, whilst showing a decrease in autumn.

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