Bridging the scale gap: obtaining high-resolution stochastic simulations of gridded daily precipitation in a future climate

Abstract. Climate change impact assessment related to floods, infrastructure networks, and water resource management applications requires realistic simulations of high-resolution gridded precipitation series under a future climate. This paper proposes to produce such simulations by combining a weather generator for high-resolution gridded daily precipitation, trained on a historical observation-based gridded data product, with coarser-scale climate change information obtained using a regional climate model. The climate change information can be added to various components of the weather generator, related to both the probability of precipitation as well as the amount of precipitation on wet days. The information is added in a transparent manner, allowing for an assessment of the plausibility of the added information. In a case study of nine hydrological catchments in central Norway with the study areas covering 1000–5500 km2, daily simulations are obtained on a 1 km grid for a period of 19 years. The method yields simulations with realistic temporal and spatial structures and outperforms empirical quantile delta mapping in terms of marginal performance.

Download Full-text

Bridging the scale gap: Obtaining high-resolution stochastic simulations of gridded daily precipitation in a future climate

10.5194/hess-2020-673 ◽

2021 ◽

Author(s):

Qifen Yuan ◽

Thordis L. Thorarinsdottir ◽

Stein Beldring ◽

Wai Kwok Wong ◽

Chong-Yu Xu

Keyword(s):

Climate Change ◽

High Resolution ◽

Climate Model ◽

Daily Precipitation ◽

Regional Climate ◽

Weather Generator ◽

Future Climate ◽

Stochastic Simulations ◽

Climate Change Information ◽

Historical Observation

Abstract. Climate change impact assessment related to floods, infrastructure networks and water resources management applications requires realistic simulations of high-resolution gridded precipitation series under a future climate. This paper proposes to produce such simulations by combining a weather generator for high-resolution gridded daily precipitation, trained on historical observation-based gridded data product, with coarser scale climate change information obtained using a regional climate model. The climate change information can be added to various components of the weather generator, related to both the probability of precipitation as well as the amount of precipitation on wet days. The information is added in a transparent manner, allowing for an assessment of the plausibility of the added information. In a case study of nine hydrological catchments in central Norway with the study areas covering 1000–5500 km2, daily simulations are obtained on a 1 km grid for a period of 19 years. The method yields simulations with realistic temporal and spatial structures and outperforms empirical quantile delta mapping in terms of marginal performance.

Download Full-text

Assessing mean climate change signals in the global CORDEX-CORE ensemble

10.5194/dkt-12-61 ◽

2020 ◽

Author(s):

Claas Teichmann ◽

Daniela Jacob ◽

Armelle Reca Remedio ◽

Thomas Remke ◽

Lars Buntemeyer ◽

...

Keyword(s):

Climate Change ◽

High Resolution ◽

Climate Model ◽

Global Climate ◽

Global Climate Model ◽

Regional Climate ◽

Future Climate Change ◽

Climate Services ◽

Climate Change Information ◽

Mean Climate

The Coordinated Output for Regional Evaluations (CORE) simulation ensemble is an effort of the WCRP CORDEX community to provide high resolution regional climate change information for the major inhabited areas of the world and thus to generate the solid scientific basis for further research related to vulnerability, impact, adaptation and climate services (VIACS). This is especially important in those areas in which so far only few high-resolution simulations or only global comparatively coarse simulations were available. The driving simulations were selected to cover the spread of high, medium and low climate sensitivity at a global scale. Initially, the two RCMs REMO and RegCM4 were used to downscale these data global climate model output to a resolution of 0.22&#176; (about 25km) while it is intended that the CORDEX CORE ensemble can then be extended by additional regional simulations to further increase the ensemble size and thus the representation of possible future climate change pathways. The aim of this study is to investigate and document the climate change information provided by the current CORDEX CORE ensemble with respect to mean climate change in different regions and in comparison to previously existing global climate information, especially those global climate simulations used as boundary forcing for CORDEX CORE, but also in comparison to the entire AR5-GCM ensemble. The analysis focuses on the representation of the AR5-GCM range of climate change signals by the CORDEX CORE ensemble with respect to mean temperature and precipitation changes and corresponding shifts in the annual cycles in the new AR6 IPCC physical reference regions. This also provides an indication for CORDEX CORE suitability for VIACS applications in each region.

Download Full-text

Projection of Future Climate Change over Japan in Ensemble Simulations with a High-Resolution Regional Climate Model

SOLA ◽

10.2151/sola.2015-022 ◽

2015 ◽

Vol 11 (0) ◽

pp. 90-94 ◽

Cited By ~ 17

Author(s):

Akihiko Murata ◽

Hidetaka Sasaki ◽

Hiroaki Kawase ◽

Masaya Nosaka ◽

Mitsuo Oh'izumi ◽

...

Keyword(s):

Climate Change ◽

High Resolution ◽

Regional Climate Model ◽

Climate Model ◽

Regional Climate ◽

Future Climate ◽

Future Climate Change ◽

Ensemble Simulations

Download Full-text

Regionalization of Climate Change Simulations over the Eastern Mediterranean

Journal of Climate ◽

10.1175/2008jcli1807.1 ◽

2009 ◽

Vol 22 (8) ◽

pp. 1944-1961 ◽

Cited By ~ 75

Author(s):

Bariş Önol ◽

Fredrick H. M. Semazzi

Keyword(s):

Climate Change ◽

Regional Climate Model ◽

Temperature Increase ◽

Climate Model ◽

Eastern Mediterranean ◽

Regional Climate ◽

Future Climate ◽

Climate Change Projections ◽

Model Simulations ◽

The Future

Abstract In this study, the potential role of global warming in modulating the future climate over the eastern Mediterranean (EM) region has been investigated. The primary vehicle of this investigation is the Abdus Salam International Centre for Theoretical Physics Regional Climate Model version 3 (ICTP-RegCM3), which was used to downscale the present and future climate scenario simulations generated by the NASA’s finite-volume GCM (fvGCM). The present-day (1961–90; RF) simulations and the future climate change projections (2071–2100; A2) are based on the Intergovernmental Panel on Climate Change (IPCC) greenhouse gas (GHG) emissions. During the Northern Hemispheric winter season, the general increase in precipitation over the northern sector of the EM region is present both in the fvGCM and RegCM3 model simulations. The regional model simulations reveal a significant increase (10%–50%) in winter precipitation over the Carpathian Mountains and along the east coast of the Black Sea, over the Kackar Mountains, and over the Caucasus Mountains. The large decrease in precipitation over the southeastern Turkey region that recharges the Euphrates and Tigris River basins could become a major source of concern for the countries downstream of this region. The model results also indicate that the autumn rains, which are primarily confined over Turkey for the current climate, will expand into Syria and Iraq in the future, which is consistent with the corresponding changes in the circulation pattern. The climate change over EM tends to manifest itself in terms of the modulation of North Atlantic Oscillation. During summer, temperature increase is as large as 7°C over the Balkan countries while changes for the rest of the region are in the range of 3°–4°C. Overall the temperature increase in summer is much greater than the corresponding changes during winter. Presentation of the climate change projections in terms of individual country averages is highly advantageous for the practical interpretation of the results. The consistence of the country averages for the RF RegCM3 projections with the corresponding averaged station data is compelling evidence of the added value of regional climate model downscaling.

Download Full-text

Regional Climate Model Emulator based on Deep Learning: Concept and First Evaluation of a Novel Hybrid Downscaling Approach

10.21203/rs.3.rs-725819/v1 ◽

2021 ◽

Author(s):

Antoine Doury ◽

Samuel Somot ◽

Sébastien Gadat ◽

Aurélien Ribes ◽

Lola Corre

Keyword(s):

Climate Change ◽

Network Architecture ◽

Large Scale ◽

Climate Models ◽

Climate Model ◽

Regional Climate ◽

Regional Climate Models ◽

Future Climate ◽

Near Surface ◽

The Way

Abstract Providing reliable information on climate change at local scale remains a challenge of first importance for impact studies and policymakers. Here, we propose a novel hybrid downscaling method combining the strengths of both empirical statistical downscaling methods and Regional Climate Models (RCMs). The aim of this tool is to enlarge the size of high-resolution RCM simulation ensembles at low cost.We build a statistical RCM-emulator by estimating the downscaling function included in the RCM. This framework allows us to learn the relationship between large-scale predictors and a local surface variable of interest over the RCM domain in present and future climate. Furthermore, the emulator relies on a neural network architecture, which grants computational efficiency. The RCM-emulator developed in this study is trained to produce daily maps of the near-surface temperature at the RCM resolution (12km). The emulator demonstrates an excellent ability to reproduce the complex spatial structure and daily variability simulated by the RCM and in particular the way the RCM refines locally the low-resolution climate patterns. Training in future climate appears to be a key feature of our emulator. Moreover, there is a huge computational benefit in running the emulator rather than the RCM, since training the emulator takes about 2 hours on GPU, and the prediction is nearly instantaneous. However, further work is needed to improve the way the RCM-emulator reproduces some of the temperature extremes, the intensity of climate change, and to extend the proposed methodology to different regions, GCMs, RCMs, and variables of interest.

Download Full-text

Evaluation of extreme precipitation over the Nordic region using a convection-permitting regional climate model

10.5194/egusphere-egu2020-10506 ◽

2020 ◽

Author(s):

Erika Toivonen ◽

Danijel Belušić ◽

Emma Dybro Thomassen ◽

Peter Berg ◽

Ole Bøssing Christensen ◽

...

Keyword(s):

High Resolution ◽

Regional Climate Model ◽

Extreme Precipitation ◽

Climate Model ◽

Daily Precipitation ◽

Regional Climate ◽

Precipitation Extremes ◽

Nordic Region ◽

Mesh Resolution ◽

Grid Mesh

Extreme precipitation events have a major impact upon our society. Although many studies have indicated that it is likely that the frequency of such events will increase in a warmer climate, little has been done to assess changes in extreme precipitation at a sub-daily scale. Recently, there is more and more evidence that high-resolution convection-permitting models (CPMs) (grid-mesh typically < 4 km) can represent especially short-duration precipitation extremes more accurately when compared with coarser-resolution regional climate models (RCMs).This study investigates sub-daily and daily precipitation characteristics based on hourly output data from the HARMONIE-Climate model at 3-km and 12-km grid-mesh resolution over the Nordic region between 1998 and 2018. The RCM modelling chain uses the ERA-Interim reanalysis to drive a 12-km grid-mesh simulation which is further downscaled to 3-km grid-mesh resolution using a non-hydrostatic model set-up.The statistical properties of the modeled extreme precipitation are compared to several sub-daily and daily observational products, including gridded and in-situ gauge data, from April to September. We investigate the skill of the model to represent different aspects of the frequency and intensity of extreme precipitation as well as intensity&#8211;duration&#8211;frequency (IDF) curves that are commonly used to investigate short duration extremes from an urban planning perspective. The high grid resolution combined with the 20-year-long simulation period allows for a robust assessment at a climatological time scale and enables us to examine the added value of high-resolution CPM in reproducing precipitation extremes over the Nordic region. Based on the tentative results, the high-resolution CPM can realistically capture the characteristics of precipitation extremes, for instance, in terms of improved diurnal cycle and maximum intensities of sub-daily precipitation.

Download Full-text

Projected climate change over Kuwait simulated using a WRF high resolution regional climate model

10.5194/egusphere-egu2020-1867 ◽

2020 ◽

Author(s):

Hussain Alsarraf

Keyword(s):

Climate Change ◽

High Resolution ◽

Regional Climate Model ◽

Arabian Peninsula ◽

Climate Model ◽

Regional Climate ◽

Dynamic Downscaling ◽

Model Simulations ◽

Average Maximum ◽

The Impact

The purpose of this study is to examine the impact of climate change on the changes on summer surface temperatures between present (2000-2010) and future (2050-2060) over the Arabian Peninsula and Kuwait. In this study, the influence of climate change in the Arabian Peninsula and especially in Kuwait was investigated by high resolution (36, 12, and 4 km grid spacing) dynamic downscaling from the Community Climate System Model CCSM4 using the WRF Weather Research and Forecasting model. The downscaling results were first validated by comparing National Centers for Environmental Prediction NCEP model outputs with the observational data. The global climate change dynamic downscaling model was run using WRF regional climate model simulations (2000-2010) and future projections (2050-2060). The influence of climate change in the Arabian Peninsula can be projected from the differences between the two period&#8217;s model simulations. The regional model simulations of the average maximum surface temperature in summertime predicted an increase from 1&#9702;C to 3 &#9702;C over the summertime in Kuwait by midcentury.&#160;

Download Full-text

Climate change in China in the 21st century as simulated by a high resolution regional climate model

Chinese Science Bulletin ◽

10.1007/s11434-011-4935-8 ◽

2012 ◽

Vol 57 (10) ◽

pp. 1188-1195 ◽

Cited By ~ 109

Author(s):

XueJie Gao ◽

Ying Shi ◽

DongFeng Zhang ◽

Filippo Giorgi

Keyword(s):

Climate Change ◽

High Resolution ◽

Regional Climate Model ◽

21St Century ◽

Climate Model ◽

Regional Climate

Download Full-text

High-resolution Med-CORDEX regional climate model simulations for hydrological impact studies: a first evaluation in Morocco

Hydrology and Earth System Sciences Discussions ◽

10.5194/hessd-10-5687-2013 ◽

2013 ◽

Vol 10 (5) ◽

pp. 5687-5737 ◽

Cited By ~ 3

Author(s):

Y. Tramblay ◽

D. Ruelland ◽

S. Somot ◽

R. Bouaicha ◽

E. Servat

Keyword(s):

Climate Change ◽

High Resolution ◽

Regional Climate Model ◽

Bias Correction ◽

Hydrological Model ◽

Climate Model ◽

Regional Climate ◽

Impact Studies ◽

Hydrological Impact ◽

Split Sample

Abstract. In the framework of the international CORDEX program, new regional climate model (RCM) simulations at high spatial resolutions are becoming available for the Mediterranean region (Med-CORDEX initiative). This study provides the first evaluation for hydrological impact studies of these high-resolution simulations. Different approaches are compared to analyze the climate change impacts on the hydrology of a catchment located in North Morocco, using a high-resolution RCM (ALADIN-Climate) from the Med-CORDEX initiative at two different spatial resolutions (50 km and 12 km) and for two different Radiative Concentration Pathway scenarios (RCP4.5 and RCP8.5). The main issues addressed in the present study are: (i) what is the impact of increased RCM resolution on present-climate hydrological simulations and on future projections? (ii) Are the bias-correction of the RCM model and the parameters of the hydrological model stationary and transferable to different climatic conditions? (iii) What is the climate and hydrological change signal based on the new Radiative Concentration Pathways scenarios (RCP4.5 and RCP8.5)? Results indicate that high resolution simulations at 12 km better reproduce the seasonal patterns, the seasonal distributions and the extreme events of precipitation. The parameters of the hydrological model, calibrated to reproduce runoff at the monthly time step over the 1984–2010 period, do not show a strong variability between dry and wet calibration periods in a differential split-sample test. However the bias correction of precipitation by quantile-matching does not give satisfactory results in validation using the same differential split-sample testing method. Therefore a quantile-perturbation method that does not rely on any stationarity assumption and produces ensembles of perturbed series of precipitation was introduced. The climate change signal under scenarios 4.5 and 8.5 indicates a decrease of respectively −30% to −57% in surface runoff for the mid-term (2041–2062), when for the same period the projections for precipitation are ranging between −15% and −19% and for temperature between +1.28°C and +1.87°C.

Download Full-text

RCP 8.5 Ghana. High-end climate change impacts on crop production

10.5194/egusphere-egu2020-8955 ◽

2020 ◽

Author(s):

Sylvia Tramberend ◽

Günther Fischer ◽

Harrij van Velthuizen

Keyword(s):

Climate Change ◽

High Resolution ◽

Crop Production ◽

Agricultural Sector ◽

Climate Model ◽

Regional Climate ◽

Climate Change Impacts ◽

Development Planning ◽

Sub Saharan Africa ◽

Sub Saharan

Climate change threatens vulnerable communities in sub-Saharan Africa who face significant challenges for adaptation. Agriculture provides the livelihood for the majority of population. High-resolution assessments of the effects of climate change on crop production are urgently needed for targeted adaptation planning. In Ghana, next to food needs, agriculture plays an important role on international cocoa markets. To this end, we develop and apply a National Agro-Ecological Zoning system (NAEZ Ghana) to analyze the impacts of high-end (RCP8.5) global warming on agricultural production potentials until the end of this century. NAEZ Ghana uses an ensemble of the CORDEX Africa Regional Climate Model, a regional soil map, to assess development trends of crop production potentials for 19 main crops. Results highlight differential impacts across the country. Especially due to the significant increase in the number of days exceeding high-temperature thresholds, rain-fed production of several food and export crops could be reduced significantly compared to the historical 30-year average (1981-2010). Plantain production, an important food crop, could achieve under climate change less than half of its current potential already in the 2050s and less than 10% by the 2080s. Suitable areas for cocoa production decrease strongly resulting in only one third of production potential compared to today. Other crops with detrimental effects of climate change include oil palm, sugarcane, coffee, and rubber. Production of maize, sorghum, and millet cope well with a future warmer climate. The NAEZ Ghana database provides valuable high-resolution information to support agricultural sector development planning and climate change adaptation strategies. The expansion of irrigation development will play a central role in some areas. This requires further research on Ghana&#8217;s linkages between food, water, and energy, taking into account climate and socio-economic changes.

Download Full-text