Model performance in spatiotemporal patterns of precipitation: New methods for identifying value added by a regional climate model

Abstract A new approach of coordinated global and regional climate modeling is presented. It is applied to the Canadian Centre for Climate Modelling and Analysis Regional Climate Model (CanRCM4) and its parent global climate model CanESM2. CanRCM4 was developed specifically to downscale climate predictions and climate projections made by its parent global model. The close association of a regional climate model (RCM) with a parent global climate model (GCM) offers novel avenues of model development and application that are not typically available to independent regional climate modeling centers. For example, when CanRCM4 is driven by its parent model, driving information for all of its prognostic variables is available (including aerosols and chemical species), significantly improving the quality of their simulation. Additionally, CanRCM4 can be driven by its parent model for all downscaling applications by employing a spectral nudging procedure in CanESM2 designed to constrain its evolution to follow any large-scale driving data. Coordination offers benefit to the development of physical parameterizations and provides an objective means to evaluate the scalability of such parameterizations across a range of spatial resolutions. Finally, coordinating regional and global modeling efforts helps to highlight the importance of assessing RCMs’ value added relative to their driving global models. As a first step in this direction, a framework for identifying appreciable differences in RCM versus GCM climate change results is proposed and applied to CanRCM4 and CanESM2.

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Evaluation of an ensemble of regional climate model simulations over South America driven by the ERA-Interim reanalysis: model performance and uncertainties

Climate Dynamics ◽

10.1007/s00382-013-1667-2 ◽

2013 ◽

Vol 41 (5-6) ◽

pp. 1139-1157 ◽

Cited By ~ 100

Author(s):

Silvina A. Solman ◽

E. Sanchez ◽

P. Samuelsson ◽

R. P. da Rocha ◽

L. Li ◽

...

Keyword(s):

South America ◽

Regional Climate Model ◽

Climate Model ◽

Regional Climate ◽

Model Performance ◽

Model Simulations ◽

Climate Model Simulations

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Regional climate-model performance in Greenland firn derived from in situ observations

Geological Survey of Denmark and Greenland Bulletin ◽

10.34194/geusb.v35.4943 ◽

1969 ◽

Vol 35 ◽

pp. 75-78 ◽

Cited By ~ 1

Author(s):

Charalampos Charalampidis ◽

Dirk Van As ◽

Peter L. Langen ◽

Robert S. Fausto ◽

Baptiste Vandecrux ◽

...

Keyword(s):

Regional Climate Model ◽

Climate Model ◽

Regional Climate ◽

Ice Sheet ◽

Model Performance ◽

Mass Conservation ◽

Mass Budget ◽

Run Off ◽

In Situ Observations

Recent record-warm summers in Greenland (Khan et al. 2015) have started affecting the higher regions of the ice sheet (i.e. the accumulation area), where increased melt has altered the properties of firn (i.e. multi-year snow). At high altitudes, meltwater percolates in the porous snow and firn, where it refreezes. The result is mass conservation, as the refrozen meltwater is essentially stored (Harper et al. 2012). However, in some regions increased meltwater refreezing in shallow firn has created thick ice layers. These ice layers act as a lid, and can inhibit meltwater percolation to greater depths, causing it to run off instead (Machguth et al. 2016). Meltwater at the surface also results in more absorbed sunlight, and hence increased melt in the accumulation area (Charalampidis et al. 2015). These relatively poorly understood processes are important for ice-sheet mass-budget projections.

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Validation of a High-Resolution Version of the Regional Climate Model RegCM3 over the Carpathian Basin

Journal of Hydrometeorology ◽

10.1175/2010jhm1234.1 ◽

2011 ◽

Vol 12 (1) ◽

pp. 84-100 ◽

Cited By ~ 46

Author(s):

Csaba Torma ◽

Erika Coppola ◽

Filippo Giorgi ◽

Judit Bartholy ◽

Rita Pongrácz

Keyword(s):

High Resolution ◽

Regional Climate Model ◽

Climate Model ◽

Regional Climate ◽

Model Performance ◽

Region Of Interest ◽

Carpathian Basin ◽

Temperature And Precipitation ◽

Area Of Interest ◽

Wide Range

Abstract This paper presents a validation study for a high-resolution version of the Regional Climate Model version 3 (RegCM3) over the Carpathian basin and its surroundings. The horizontal grid spacing of the model is 10 km—the highest reached by RegCM3. The ability of the model to capture temporal and spatial variability of temperature and precipitation over the region of interest is evaluated using metrics spanning a wide range of temporal (daily to climatology) and spatial (inner domain average to local) scales against different observational datasets. The simulated period is 1961–90. RegCM3 shows small temperature biases but a general overestimation of precipitation, especially in winter; although, this overestimate may be artificially enhanced by uncertainties in observations. The precipitation bias over the Hungarian territory, the authors’ main area of interest, is mostly less than 20%. The model captures well the observed late twentieth-century decadal-to-interannual and interseasonal variability. On short time scales, simulated daily temperature and precipitation show a high correlation with observations, with a correlation coefficient of 0.9 for temperature and 0.6 for precipitation. Comparison with two Hungarian station time series shows that the model performance does not degrade when going to the 10-km gridpoint scale. Finally, the model reproduces the spatial distribution of dry and wet spells over the region. Overall, it is assessed that this high-resolution version of RegCM3 is of sufficiently good quality to perform climate change experiments over the Carpathian region—and, in particular, the Hungarian territory—for application to impact and adaptation studies.

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An analysis of regional climate model performance over the tropical Americas. Part II: simulating subseasonal variability of precipitation associated with ENSO forcing

Tellus A Dynamic Meteorology and Oceanography ◽

10.1111/j.1600-0870.2008.00387.x ◽

2009 ◽

Vol 61 (3) ◽

pp. 343-356 ◽

Cited By ~ 7

Author(s):

Etienne Tourigny ◽

Colin Jones

Keyword(s):

Regional Climate Model ◽

Climate Model ◽

Regional Climate ◽

Model Performance ◽

Subseasonal Variability

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Sensitivity studies with the Regional Climate Model COSMO-CLM 5.0 over the CORDEX Central Asia Domain

10.5194/gmd-2019-22 ◽

2019 ◽

Author(s):

Emmanuele Russo ◽

Ingo Kirchner ◽

Stephan Pfahl ◽

Martijn Schaap ◽

Ulrich Cubasch

Keyword(s):

Regional Climate Model ◽

Central Asia ◽

Climate Models ◽

Climate Model ◽

Reference Model ◽

Developing Economies ◽

Regional Climate ◽

Model Performance ◽

Mitigation Strategies ◽

Climate Projections

Abstract. Due to its extension, geography and the presence of several under-developed or developing economies, the Central Asia domain of the Coordinated Regional climate Downscaling Experiment (CORDEX) is one of the most vulnerable regions on Earth to the effects of climate changes. Reliable information on potential future changes with high spatial resolution acquire significant importance for the development of effective adaptation and mitigation strategies for the region. In this context, Regional Climate Models (RCMs) play a fundamental role. In this paper, the results of a set of sensitivity experiments with the regional climate model COSMO-CLM version 5.0, for the Central Asia CORDEX domain, are presented. Starting from a reference model setup, general model performance is evaluated for present-days, testing the effects of a set of singular physical parameterizations and their mutual interaction on the simulation of monthly and seasonal values of three variables that are important for impact studies: 2-meter temperature, precipitation and diurnal temperature range. The final goal of this study is two-fold: having a general overview of model performance and its uncertainties for the considered region and determining at the same time an optimal model configuration. Results show that the model presents remarkable deficiencies over different areas of the domain. The combined change of the albedo taking into consideration the ratio of forest fractions and the soil conductivity taking into account the ratio of liquid water and ice in the soil, allows to achieve the best improvements in model performance in terms of climatological means. Importantly, the model seems to be particularly sensitive to those parameterizations that deal with soil and surface features, and that could positively affect the repartition of incoming radiation. The results for the mean climate appear to be independent of the observational dataset used for evaluation and of the boundary data employed to force the simulations. On the other hand, due to the large uncertainties in the variability estimates from observations, the use of different boundaries and the model internal variability, it has not been possible to rank the different simulations according to their representation of the monthly variability. This work is the first ever sensitivity study of an RCM for the CORDEX Central Asia domain and its results are of fundamental importance for further model development and for future climate projections over the area.

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