Journal articles: 'RegCM'

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Browne, Nana A. K., and Mouhamadou B. Sylla. "Regional Climate Model Sensitivity to Domain Size for the Simulation of the West African Summer Monsoon Rainfall." International Journal of Geophysics 2012 (2012): 1–17. http://dx.doi.org/10.1155/2012/625831.

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We use the International Centre for Theoretical Physics (ICTP) Regional Climate Model (RegCM3) to study the impact of different domain sizes on the simulation of the West African summer monsoon rainfall and circulation features. RegCM3 simulates drier conditions over the default domain (RegCM-D1) and its westward extension (RegCM-D2), much less dryness over the eastward extended domain (RegCM-D3) and excessive wetness in the domain extended northward into the extratropical regions (RegCM-D4). This overestimation is related to the existence of larger source of humidity due to the inclusion of a more significant portion of the Atlantic Ocean and to a weakening of the African Easterly Jet (AEJ), which both favor stronger westerlies advecting moisture towards the land. The best performance is, however, captured in the RegCM-D3 experiment, and this originates from a simulation of moderate westerly moisture fluxes along with a stronger AEJ and occurrences of more frequent African Easterly Waves (AEWs). Therefore, the choice of the domain for regional climate model simulation of the West African summer monsoon rainfall is of critical importance, and caution needs to be taken to account for the main regional forcings including mostly the necessary humidity sources of the tropical Atlantic Ocean and the AEWs genesis region upstream of Sudanese Highlands.

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Shi, Ying, Miao Yu, Amir Erfanian, and Guiling Wang. "Modeling the Dynamic Vegetation–Climate System over China Using a Coupled Regional Model." Journal of Climate 31, no. 15 (August 2018): 6027–49. http://dx.doi.org/10.1175/jcli-d-17-0191.1.

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Using the Regional Climate Model (RegCM) coupled with the Community Land Model (CLM) including modules of carbon–nitrogen cycling (CN) and vegetation dynamics (DV), this study evaluates the performance of the model with different capacity of representing vegetation processes in simulating the present-day climate over China based on three 21-yr simulations driven with boundary conditions from the ERA-Interim reanalysis data during 1989–2009. For each plant functional type (PFT), the plant pheonology, density, and fractional coverage in RegCM-CLM are all prescribed as static from year to year; RegCM-CLM-CN prescribes static fractional coverage but predicts plant phenology and density, and RegCM-CLM-CN-DV predicts plant phenology, density, and fractional coverage. Compared against the observational data, all three simulations reproduce the present-day climate well, including the wind fields, temperature and precipitation seasonal cycles, extremes, and interannual variabilities. Relative to RegCM-CLM, both RegCM-CLM-CN and RegCM-CLM-CN-DV perform better in simulating the interannual variability of temperature and spatial distribution of mean precipitation, but produce larger biases in the mean temperature field. RegCM-CLM-CN overestimates leaf area index (LAI), which enhances the cold biases and alleviates the dry biases found in RegCM-CLM. RegCM-CLM-CN-DV underestimates vegetation cover and/or stature, and hence overestimates surface albedo, which enhances the wintertime cold and dry biases found in RegM-CLM. During summer, RegCM-CLM-CN-DV overestimates LAI in south and east China, which enhances the cold biases through increased evaporative cooling; in the west where evaporation is low, the albedo effect of the underestimated vegetation cover is still dominant, leading to enhanced cold biases relative to RegCM-CLM.

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Potop, Vera, Constanta Boroneant, and Mihaela Caian. "Assessing the changes in drought conditions during summer in the Republic of Moldova based on RegCM simulations." Journal of Economic Development, Environment and People 2, no. 3 (September 30, 2013): 63. http://dx.doi.org/10.26458/jedep.v2i3.44.

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We assess the changes in drought conditions during summer in the Republic of Moldova based on the Standardized Precipitation Index (SPI) calculated from monthly precipitation data simulated by the regional climatic model RegCM3. The RegCM simulations were conducted at a horizontal resolution of 10 km in the framework of EU-FP6 project -CECILIA. The domain was centered over Romania at 46°N, 25°E and included the Republic of Moldova.

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O'Brien, T. A., P. Y. Chuang, L. C. Sloan, I. C. Faloona, and D. L. Rossiter. "Coupling a new turbulence parametrization to RegCM adds realistic stratocumulus clouds." Geoscientific Model Development 5, no. 4 (August 3, 2012): 989–1008. http://dx.doi.org/10.5194/gmd-5-989-2012.

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Abstract. To model stratocumulus clouds in the regional climate model, RegCM4.1, the University of Washington (UW) turbulence parametrization has been coupled to RegCM. We describe improvements in RegCM's coastal and near-coastal climatology, including improvements in the representation of stratiform clouds. By comparing output from a 27-yr (1982–2009) simulation of the climate of western North America to a wide variety of observational data (station data, satellite data, and aircraft in situ data), we show the following: (1) RegCM-UW is appropriate for use in general regional climate studies, and (2) the UW model distinctly improves the representation of the marine boundary layer in RegCM. These model–data comparisons also show that RegCM-UW has a slight cold bias, a (wet) precipitation bias, a systematic low bias in the vertically-integrated liquid water content near the coast, and a high bias in the fractional cloud coverage. The model represents well the diurnal, monthly, and interannual variability in low clouds. These results show RegCM-UW as a nascent mesoscale stratocumulus model that is appropriate for stratocumulus investigations at scales ranging from hourly to decadal. The source code for RegCM-UW is publicly available, under the GNU license, through the International Centre for Theoretical Physics.

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O'Brien, T. A., P. Y. Chuang, L. C. Sloan, I. C. Faloona, and D. L. Rossiter. "Coupling a new turbulence parametrization to RegCM adds realistic stratocumulus clouds." Geoscientific Model Development Discussions 4, no. 4 (December 9, 2011): 3437–84. http://dx.doi.org/10.5194/gmdd-4-3437-2011.

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Abstract. To model stratocumulus clouds in the regional climate model, RegCM4.1, the University of Washington (UW) turbulence parametrization has been coupled to RegCM. We describe improvements in RegCM's coastal and near-coastal climatology, including improvements in the representation of stratiform clouds. By comparing output from a 27-yr (1982–2009) simulation of the climate of Western North America to a wide variety of observational data (station data, satellite data, and aircraft in situ data), we show the following: (1) RegCM-UW is appropriate for use in general regional climate studies, and (2) the UW model distinctly improves the representation of the marine boundary layer in RegCM. These model-data comparisons also show that RegCM-UW has slight cold bias, a (wet) precipitation bias, a systematic low bias in the vertically-integrated liquid water content near the coast, and a high bias in the fractional cloud coverage. The model represents well the diurnal, monthly, and interannual variability in low clouds. These results show RegCM-UW as a nascent mesoscale stratocumulus model that is appropriate for stratocumulus investigations at scales ranging from hourly to decadal. The source code for RegCM-UW is publicly available, under the GNU license, through the International Centre for Theoretical Physics.

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ElBessa, Mohamed, Saad Mesbah Abdelrahman, Kareem Tonbol, and Mohamed Shaltout. "Dynamical Downscaling of Surface Air Temperature and Wind Field Variabilities over the Southeastern Levantine Basin, Mediterranean Sea." Climate 9, no. 10 (October 11, 2021): 150. http://dx.doi.org/10.3390/cli9100150.

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The characteristics of near surface air temperature and wind field over the Southeastern Levantine (SEL) sub-basin during the period 1979–2018 were simulated. The simulation was carried out using a dynamical downscaling approach, which requires running a regional climate model system (RegCM-SVN6994) on the study domain, using lower-resolution climate data (i.e., the fifth generation of ECMWF atmospheric reanalysis of the global climate ERA5 datasets) as boundary conditions. The quality of the RegCM-SVN simulation was first verified by comparing its simulations with ERA5 for the studied region from 1979 to 2018, and then with the available five WMO weather stations from 2007 to 2018. The dynamical downscaling results proved that RegCM-SVN in its current configuration successfully simulated the observed surface air temperature and wind field. Moreover, RegCM-SVN was proved to provide similar or even better accuracy (during extreme events) than ERA5 in simulating both surface air temperature and wind speed. The simulated annual mean T2m by RegCM-SVN (from 1979 to 2018) was 20.9 °C, with a positive warming trend of 0.44 °C/decade over the study area. Moreover, the annual mean wind speed by RegCM-SVN was 4.17 m/s, demonstrating an annual negative trend of wind speed over 92% of the study area. Surface air temperatures over SEL mostly occurred within the range of 4–31 °C; however, surface wind speed rarely exceeded 10 m/s. During the study period, the seasonal features of T2m showed a general warming trend along the four seasons and showed a wind speed decreasing trend during spring and summer. The results of the RegCM-SVN simulation constitute useful information that could be utilized to fully describe the study area in terms of other atmospheric parameters.

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Shalaby, A., A. S. Zakey, A. B. Tawfik, F. Solmon, F. Giorgi, F. Stordal, S. Sillman, R. A. Zaveri, and A. L. Steiner. "Implementation and evaluation of online gas-phase chemistry within a regional climate model (RegCM-CHEM4)." Geoscientific Model Development 5, no. 3 (May 22, 2012): 741–60. http://dx.doi.org/10.5194/gmd-5-741-2012.

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Abstract. The RegCM-CHEM4 is a new online climate-chemistry model based on the International Centre for Theoretical Physics (ICTP) regional climate model (RegCM4). Tropospheric gas-phase chemistry is integrated into the climate model using the condensed version of the Carbon Bond Mechanism (CBM-Z; Zaveri and Peters, 1999) with a fast solver based on radical balances. We evaluate the model over continental Europe for two different time scales: (1) an event-based analysis of the ozone episode associated with the heat wave of August 2003 and (2) a climatological analysis of a six-year simulation (2000–2005). For the episode analysis, model simulations show good agreement with European Monitoring and Evaluation Programme (EMEP) observations of hourly ozone over different regions in Europe and capture ozone concentrations during and after the summer 2003 heat wave event. For long-term climate simulations, the model captures the seasonal cycle of ozone concentrations with some over prediction of ozone concentrations in non-heat wave summers. Overall, the ozone and ozone precursor evaluation shows the feasibility of using RegCM-CHEM4 for decadal-length simulations of chemistry-climate interactions.

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Shalaby, A. K., A. S. Zakey, A. B. Tawfik, F. Solmon, F. Giorgi, F. Stordal, S. Sillman, R. A. Zaveri, and A. L. Steiner. "Implementation and evaluation of online gas-phase chemistry within a regional climate model (RegCM-CHEM4)." Geoscientific Model Development Discussions 5, no. 1 (January 17, 2012): 149–88. http://dx.doi.org/10.5194/gmdd-5-149-2012.

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Abstract. The RegCM-CHEM4 is a new online climate-chemistry model based on the International Centre for Theoretical Physics (ICTP) regional climate model (RegCM4). Tropospheric gas-phase chemistry is integrated into the climate model using the condensed version of the Carbon Bond Mechanism (CBM-Z; Zaveri and Peters, 1999) with a fast solver based on radical balances. We evaluate the model over Continental Europe for two different time scales: (1) an event-based analysis of the ozone episode associated with the heat wave of August 2003 and (2) a climatological analysis of a six-year simulation (2000–2005). For the episode analysis, model simulations show good agreement with European Monitoring and Evaluation Program (EMEP) observations of hourly ozone over different regions in Europe and capture ozone concentrations during and after the August 2003 heat wave event. For long-term climate simulations, the model captures the seasonal cycle of ozone concentrations with some over prediction of ozone concentrations in non-heat wave summers. Overall, the ozone and ozone precursor evaluation shows the feasibility of using RegCM-CHEM4 for decadal-length simulations of chemistry-climate interactions.

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Coppola, Erika, Paolo Stocchi, Emanuela Pichelli, Jose Abraham Torres Alavez, Russell Glazer, Graziano Giuliani, Fabio Di Sante, Rita Nogherotto, and Filippo Giorgi. "Non-Hydrostatic RegCM4 (RegCM4-NH): model description and case studies over multiple domains." Geoscientific Model Development 14, no. 12 (December 21, 2021): 7705–23. http://dx.doi.org/10.5194/gmd-14-7705-2021.

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Abstract. We describe the development of a non-hydrostatic version of the regional climate model RegCM4, called RegCM4-NH, for use at convection-permitting resolutions. The non-hydrostatic dynamical core of the Mesoscale Model MM5 is introduced in the RegCM4, with some modifications to increase stability and applicability of the model to long-term climate simulations. Newly available explicit microphysics schemes are also described, and three case studies of intense convection events are carried out in order to illustrate the performance of the model. They are all run at a convection-permitting grid spacing of 3 km over domains in northern California, Texas and the Lake Victoria region, without the use of parameterized cumulus convection. A substantial improvement is found in several aspects of the simulations compared to corresponding coarser-resolution (12 km) runs completed with the hydrostatic version of the model employing parameterized convection. RegCM4-NH is currently being used in different projects for regional climate simulations at convection-permitting resolutions and is intended to be a resource for users of the RegCM modeling system.

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Sangelantoni, Ferretti, and Redaelli. "Toward a Regional-Scale Seasonal Climate Prediction System over Central Italy based on Dynamical Downscaling." Climate 7, no. 10 (October 5, 2019): 120. http://dx.doi.org/10.3390/cli7100120.

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Anticipating seasonal climate anomalies is essential for defining short-term adaptation measures. To be actionable, many stakeholders require seasonal forecasts at the regional scale to be properly coupled to region-specific vulnerabilities. In this study, we present and preliminarily evaluate a regional-scale Seasonal Forecast System (SFS) over Central Italy. This system relies on a double dynamical downscaling performed through the Regional-scale Climate Model (RCM) RegCM4.1. A twelve-member ensemble of the NCEP-CFSv2 provides driving fields for the RegCM. In the first step, the RegCM dynamically downscales NCEP-CFSv2 predictions from a resolution of 100 to 60 km over Europe (RegCM-d1). This first downscaling drives a second downscaling over Central Italy at 12 km (RegCM-d2). To investigate the added value of the downscaled forecasts compared to the driving NCEP-CFSv2, we evaluate the driving CFS, and the two downscaled SFSs over the same (inner) domain. Evaluation involves winter temperatures and precipitations over a climatological period (1982–2003). Evaluation for mean bias, statistical distribution, inter-annual anomaly variability, and hit-rate of anomalous seasons are shown and discussed. Results highlight temperature physical values reproduction benefiting from the downscaling. Downscaled inter-annual variability and probabilistic metrics show improvement mainly at forecast lead-time 1. Downscaled precipitation shows an improved spatial distribution with an undegraded but not improved seasonal forecast quality.

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Reboita, Michelle Simões, Cássia Gabriele Dias, Lívia Márcia Mosso Dutra, Rosmeri Porfírio da Rocha, and Marta Llopart. "Previsão Climática Sazonal para o Brasil Obtida Através de Modelos Climáticos Globais e Regional." Revista Brasileira de Meteorologia 33, no. 2 (June 2018): 207–24. http://dx.doi.org/10.1590/0102-7786332001.

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Resumo Este estudo avalia a destreza de dois modelos climáticos globais (CPTEC e CFSv2) e de um modelo climático regional (RegCM4) em prever o clima sazonal em diferentes regiões do Brasil. O RegCM4 foi dirigido tanto com as saídas do sistema CFSv2 quanto do modelo do CPTEC. Também foram utilizadas duas versões do RegCM: a 4.3 e a 4.5. O RegCM4.3 foi dirigido por seis membros do CFSv2, enquanto o RegCM4.5 foi dirigido por um membro do modelo global do CPTEC. Todas as previsões iniciaram cerca de dois meses antes do trimestre a ser previsto e ao todo foram realizadas 94 simulações com o modelo regional. De forma geral, o RegCM4 adiciona valor às previsões dos modelos climáticos globais, principalmente, quando é aninhado às saídas do modelo do CPTEC. Quando o RegCM4.5 é dirigido por esse modelo global e é utilizada a parametrização de convecção cumulus de Emanuel há uma boa performance do modelo regional na previsão da precipitação e temperatura do ar em quase todo o Brasil.

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Bao, Y., and S. Lü. "Improvement of surface albedo parameterization within a regional climate model (RegCM3)." Hydrology and Earth System Sciences Discussions 6, no. 2 (March 4, 2009): 1651–76. http://dx.doi.org/10.5194/hessd-6-1651-2009.

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Abstract. A parameterization for calculating surface albedo of Solar Zenith Angel (SZA) dependence with coefficient for each vegetation type determined on the Moderate Resolution Imaging Spectro-radiometer (MODIS) reformed by the Bidirectional Reflectance Distribution Function (BRDF) is incorporated within the latest Abdus Salam International Centre for Theoretical Physics (ICTP) Regional Climate Model (RegCM3), and evaluated with a high resolution one-way nesting simulation in China using the Climate Research Unit (CRU) data and the observations from the Field Experiment on Interaction between Land and Atmosphere in Arid Region of Northwest China (NWC-ALIEX). The performance of the SZA method modeling surface characteristic is investigated.Results indicate, RegCM with SZA method (RCM_SZA) considerably improve the cold bias of original RegCM (RCM_ORI) in air surface temperature in East Asia with 1.2 degree increased in summer due to the lower albedo produced by SZA method which makes more solar radiation absorbed by the surface and used for heating the atmosphere near to the surface. The simulated diurnal cycle of ground temperature conforms fairly well to the observation in the nesting simulation in Northwest China, especially during the noon time when the SZA has the lowest value. However, the modification can not obviously affect the East Asia summer monsoon precipitation simulation although RCM_SZA produce more evapo-transpiration in surface with more than 2 Wm−2 increases in simulated latent heat fluxes both in East Asia and in Northwest China compared to RCM_ORI.

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Camara, M., G. Jenkins, and A. Konare. "Impacts of dust on West African climate during 2005 and 2006." Atmospheric Chemistry and Physics Discussions 10, no. 2 (February 5, 2010): 3053–86. http://dx.doi.org/10.5194/acpd-10-3053-2010.

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Abstract. The aim of this study is to understand the impacts of Saharan dust outbreaks on West African climate using a 3-dimensional, hydrostatic, sigma vertical coordinate regional climate model (RegCM). We performed a simulation with the non aerosol version of the model (control case) followed by another simulation using the desert dust module (dust case) implemented in RegCM which includes emission, transport, gravitational settling, wet and dry removal and calculation of dust optical properties for 2005 and 2006. Dynamic and thermodynamic parameters obtained from both versions of the model are intercompared and validated with NCEP/NCAR reanalysis, African Monsoon Multidisciplinary Analysis (AMMA) program data and the Global Precipitation Climatology Project (GPCP) rainfall products. The spatial and temporal distribution of the Aerosol optical depth derived from the desert dust run is compared to available observed aerosol data such as the Aerosol Robotic Network (AERONET) program and satellites data. Using radiosounding data and RegCM outputs, a case study of a strong dust outbreak showed the presence of a stable environment at Dakar, Sal and Nouadhibou stations.

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Nguyen-Xuan, Thanh, Liying Qiu, Eun-Soon Im, Jina Hur, and Kyo-Moon Shim. "Sensitivity of Summer Precipitation over Korea to Convective Parameterizations in the RegCM4: An Updated Assessment." Advances in Meteorology 2020 (April 27, 2020): 1–15. http://dx.doi.org/10.1155/2020/1329071.

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This study investigates the performance of the latest version of RegCM4 in simulating summer precipitation over South Korea, comparing nine sensitivity experiments with different combinations of convective parameterization schemes (CPSs) between land and ocean. In addition to the gross pattern of seasonal and monthly mean precipitation, the northward propagation of the intense precipitation band and statistics from extreme daily precipitation are thoroughly evaluated against gridded and in situ station observations. The comparative analysis of 10-year simulations demonstrates that no CPS shows superiority in both quantitative and qualitative aspects. Furthermore, a nontrivial discrepancy among the different observation datasets makes a robust assessment of model performance difficult. Regardless of the CPS over the ocean, the simulations with the Kain–Fritsch scheme over land show a severe dry bias, whereas the simulations with the Tiedtke scheme over land suffer from a limited accuracy in reproducing spatial distributions due to the excessive orographic precipitation. In general, the simulations with the Emanuel scheme over land are better at capturing the major characteristics of summer precipitation over South Korea, despite not all statistical metrics showing the best performance. When applying the Emanuel scheme to both land and the ocean, precipitation tends to be slightly overestimated. This deficiency can be alleviated by using either the Tiedtke or Kain–Fritsch schemes over the ocean instead. As few studies have applied and evaluated the Tiedtke and Kain–Fritsch schemes to the Korean region within the RegCM framework, and this study introduces the potential of these new CPSs compared with the more frequently selected Emanuel scheme, which is particularly beneficial to RegCM users.

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Malavelle, F., M. Mallet, V. Pont, C. Liousse, and F. Solmon. "Long-term simulations (2001–2006) of biomass burning and mineral dust optical properties over West Africa: comparisons with new satellite retrievals." Atmospheric Chemistry and Physics Discussions 11, no. 10 (October 25, 2011): 28587–626. http://dx.doi.org/10.5194/acpd-11-28587-2011.

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Abstract. The West African region is characterized by large concentrations of smoke and biomass burning aerosols, which could significantly modify the regional radiative budget and the hydrological cycle. Here, we propose long-term (2001–2006) RegCM simulations of aerosol optical properties over West Africa together with their spectral dependences. Results of simulations are evaluated at local and regional scale by using surface network (AERONET/PHOTON) and remote sensing observations (MODIS, MISR, OMI) especially during the dry season, December-January-February, DJF. New original satellite retrievals are tested and compared to RegCM simulations. Concerning AOD, we obtain values in agreement with AERONET/PHOTON observations at the local scale but some differences clearly appear between simulated AOD and regional MISR, OMI and MODIS view, especially over (1) the central Africa and (2) the gulf of Guinea during DJF. Concerning simulated SSA (for visible wavelengths), our results display (1) comparable values with level 2 AERONET/PHOTON local observations together with (2) non negligible differences with satellite (MODIS Deep blue, OMI and MISR products) observations. In most cases, satellite SSA is found to be higher than those simulated by RegCM and retrieved through AERONET/PHOTON network. In parallel, we also note significant differences on retrieved SSA from each satellite (OMI, MISR, MODIS Deep Blue) remote sensing techniques over this specific region. Finally, our work highlights that the spectral dependence of aerosol optical properties is a useful parameter to adapt so that modeled simulations should be be better evaluated and constrained.

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Lu, Chen, Guohe Huang, Guoqing Wang, Jianyun Zhang, Xiuquan Wang, and Tangnyu Song. "Long-Term Projection of Water Cycle Changes over China Using RegCM." Remote Sensing 13, no. 19 (September 25, 2021): 3832. http://dx.doi.org/10.3390/rs13193832.

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The global water cycle is becoming more intense in a warming climate, leading to extreme rainstorms and floods. In addition, the delicate balance of precipitation, evapotranspiration, and runoff affects the variations in soil moisture, which is of vital importance to agriculture. A systematic examination of climate change impacts on these variables may help provide scientific foundations for the design of relevant adaptation and mitigation measures. In this study, long-term variations in the water cycle over China are explored using the Regional Climate Model system (RegCM) developed by the International Centre for Theoretical Physics. Model performance is validated through comparing the simulation results with remote sensing data and gridded observations. The results show that RegCM can reasonably capture the spatial and seasonal variations in three dominant variables for the water cycle (i.e., precipitation, evapotranspiration, and runoff). Long-term projections of these three variables are developed by driving RegCM with boundary conditions of the Geophysical Fluid Dynamics Laboratory Earth System Model under the Representative Concentration Pathways (RCPs). The results show that increased annual average precipitation and evapotranspiration can be found in most parts of the domain, while a smaller part of the domain is projected with increased runoff. Statistically significant increasing trends (at a significant level of 0.05) can be detected for annual precipitation and evapotranspiration, which are 0.02 and 0.01 mm/day per decade, respectively, under RCP4.5 and are both 0.03 mm/day per decade under RCP8.5. There is no significant trend in future annual runoff anomalies. The variations in the three variables mainly occur in the wet season, in which precipitation and evapotranspiration increase and runoff decreases. The projected changes in precipitation minus evapotranspiration are larger than those in runoff, implying a possible decrease in soil moisture.

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Vondou, Derbetini A., Zephirin D. Yepdo, Tanessong Romeo Steve, Tchakoutio Sandjon Alain, and Lucie Djiotang Tchotchou. "Diurnal cycle of rainfall over Central Africa simulated by RegCM." Modeling Earth Systems and Environment 3, no. 3 (July 29, 2017): 1055–64. http://dx.doi.org/10.1007/s40808-017-0352-6.

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Khoperskov, Alexander, Konstantin Firsov, Alexander Titov, and Aleksey Razmolov. "Deployment of the Regional Climate Model for the South of Russia Based on RegCM 4.5." Mathematical Physics and Computer Simulation, no. 3 (August 2019): 67–94. http://dx.doi.org/10.15688/mpcm.jvolsu.2019.3.6.

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Qian, Jian-Hua, Filippo Giorgi, and Michael S. Fox-Rabinovitz. "Regional stretched grid generation and its application to the NCAR RegCM." Journal of Geophysical Research: Atmospheres 104, no. D6 (March 1, 1999): 6501–13. http://dx.doi.org/10.1029/98jd02649.

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Gao, Xuejie, and Filippo Giorgi. "Use of the RegCM System over East Asia: Review and Perspectives." Engineering 3, no. 5 (October 2017): 766–72. http://dx.doi.org/10.1016/j.eng.2017.05.019.

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Zakey, A. S., F. Solmon, and F. Giorgi. "Development and testing of a desert dust module in a regional climate model." Atmospheric Chemistry and Physics Discussions 6, no. 2 (March 10, 2006): 1749–92. http://dx.doi.org/10.5194/acpd-6-1749-2006.

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Abstract. We develop a desert dust module and implement it within a regional climate model (RegCM). The dust module includes emission, transport, gravitational settling, wet and dry removal and calculations of dust optical properties. The coupled RegCM-dust model is applied to the simulation of two dust episodes over the Sahara region (a northeastern Africa dust outbreak, and a west Africa-Atlantic dust outbreak observed during the SHADE "Saharan Dust Experiment") as well as a three month simulation over an extended domain covering the Africa-Europe sector. Comparison with satellite and insitu (for SHADE) measurements shows that the model captures the main spatial (both horizontal and vertical) and temporal features of the dust distribution. The main model deficiency occurred in the SHADE case, when the model failed to accurately simulate the development of a mesoscale low associated with an easterly wave that contributed to the generation of the dust outbreak. The model appears suitable to conduct long term simulations of the effects of Saharan dust on African and European climate.

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Zakey, A. S., F. Solmon, and F. Giorgi. "Implementation and testing of a desert dust module in a regional climate model." Atmospheric Chemistry and Physics 6, no. 12 (October 19, 2006): 4687–704. http://dx.doi.org/10.5194/acp-6-4687-2006.

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Abstract. In an effort to improve our understanding of aerosol impacts on climate, we implement a desert dust module within a regional climate model (RegCM). The dust module includes emission, transport, gravitational settling, wet and dry removal and calculations of dust optical properties. The coupled RegCM-dust model is used to simulate two dust episodes observed over the Sahara region (a northeastern Africa dust outbreak, and a west Africa-Atlantic dust outbreak observed during the SHADE "Saharan Dust Experiment"), as well as a three month simulation over an extended domain covering the Africa-Europe sector. Comparisons with satellite and local aerosol optical depth measurements shows that the model captures the main spatial (both horizontal and vertical) and temporal features of the dust distribution. The main model deficiency occurs in the representation of certain dynamical patterns observed during the SHADE case which is associated with an active easterly wave that contributed to the generation of the dust outbreak. The model appears suitable to conduct long term simulations of the effects of Saharan dust on African and European climate.

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Reboita, Michelle Simões, Rosmeri Porfírio da Rocha, Christie André de Souza, Thales Chile Baldoni, Pedro Lucas Lopes da Silveira Silva, and Glauber Willian S. Ferreira. "Future Projections of Extreme Precipitation Climate Indices over South America Based on CORDEX-CORE Multimodel Ensemble." Atmosphere 13, no. 9 (September 9, 2022): 1463. http://dx.doi.org/10.3390/atmos13091463.

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Climate change is undeniable, and its effects, like droughts and intense precipitation, evidence this reality. However, many questions remain unanswered, such as climate extremes’ future frequency and intensity. International collaboration projects such as the Coordinated Regional Climate Downscaling Experiment (CORDEX)-Coordinated Output for Regional Evaluations (CORE) have emerged to address these questions, creating protocols to facilitate the intercomparison among simulations obtained by different regional climate models (RCMs). Given this context, this study aims to describe the projected changes in the extreme precipitation events over the South America domain by using a set of projections of three RCMs (Eta, RegCM, and REMO) under the CORDEX-CORE framework (except Eta). These models were nested in different global climate models (GCMs) from Coupled Model Intercomparison Project phase 5 (CMIP5) under the RCP8.5 scenario and integrated with a grid space of 25 km. In addition, six climate indices (PRCPTOT, SDII, R95p, P95, CDD, and CWD) were computed by season for the historical period (1995–2014) and four future time-slices (2020–2039, 2040–2059, 2060–2079, and 2080–2099). For brevity, this study focuses on the austral summer. RCMs are generally capable of representing the spatial pattern of climate indices but with differences in intensity. The ensemble with all RCMs shows a slightly better spatial correlation with the reference data than the ensemble of each RCM. The signal of the projections is similar between RegCM and REMO and, in general, opposite to Eta (mainly in the South Atlantic Convergence Zone region). Of the six climate indices analyzed, the ensemble performed with the three RCMs projects statistically significant negative (positive) trends for four indices in the Amazon (La Plata Basin), indicating a signal of dry (wet) conditions increasing towards the end of the century. Furthermore, both regions have significant positive (negative) trends of consecutive dry (wet) days. The region with higher uncertainties lies over southeastern Brazil, where Eta projects a dry climate and RegCM and REMO, a wet one.

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Song, Tangnyu, Guohe Huang, Guoqing Wang, Yongping Li, Xiuquan Wang, Chen Lu, and Zhenyao Shen. "Bayesian model averaging of the RegCM temperature projections: a Canadian case study." Journal of Water and Climate Change 13, no. 2 (October 26, 2021): 771–85. http://dx.doi.org/10.2166/wcc.2021.393.

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Abstract The choices of physical schemes coupled in the Regional Climate Model version 4 (RegCM4), the input general circulation model (GCM) results, and the emission scenarios may cause considerable uncertainties in future temperature projections. Therefore, the ensemble approach, which can be used to reflect these uncertainties, is highly desired. In this study, the probabilistic projections for future temperature are generated at 88 Canadian climate stations based on the developed RegCM4 ensemble and obtained Bayesian model averaging (BMA) weights. The BMA weights indicate that the RegCM4 coupled with the holtslag PBL scheme driven by the HadGEM can provide relatively reliable temperature projections at most climate stations. It is also suggested that the BMA approach is effective in simulating temperature over middle and eastern Canada through taking advantage of each ensemble member. However, the effectiveness of the BMA method is limited when all the models in the ensemble cannot simulate the temperature robustly. The projected results demonstrate that the temperature will increase continuously in the future, while the temperature increase under RCP8.5 will be significantly larger than that under RCP4.5.

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Nogherotto, Rita, Adrian Mark Tompkins, Graziano Giuliani, Erika Coppola, and Filippo Giorgi. "Numerical framework and performance of the new multiple-phase cloud microphysics scheme in RegCM4.5: precipitation, cloud microphysics, and cloud radiative effects." Geoscientific Model Development 9, no. 7 (July 27, 2016): 2533–47. http://dx.doi.org/10.5194/gmd-9-2533-2016.

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Abstract. We implement and evaluate a new parameterization scheme for stratiform cloud microphysics and precipitation within regional climate model RegCM4. This new parameterization is based on a multiple-phase one-moment cloud microphysics scheme built upon the implicit numerical framework recently developed and implemented in the ECMWF operational forecasting model. The parameterization solves five prognostic equations for water vapour, cloud liquid water, rain, cloud ice, and snow mixing ratios. Compared to the pre-existing scheme, it allows a proper treatment of mixed-phase clouds and a more physically realistic representation of cloud microphysics and precipitation. Various fields from a 10-year long integration of RegCM4 run in tropical band mode with the new scheme are compared with their counterparts using the previous cloud scheme and are evaluated against satellite observations. In addition, an assessment using the Cloud Feedback Model Intercomparison Project (CFMIP) Observational Simulator Package (COSP) for a 1-year sub-period provides additional information for evaluating the cloud optical properties against satellite data. The new microphysics parameterization yields an improved simulation of cloud fields, and in particular it removes the overestimation of upper level cloud characteristics of the previous scheme, increasing the agreement with observations and leading to an amelioration of a long-standing problem in the RegCM system. The vertical cloud profile produced by the new scheme leads to a considerably improvement of the representation of the longwave and shortwave components of the cloud radiative forcing.

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Katragkou, E., P. Zanis, I. Tegoulias, D. Melas, I. Kioutsioukis, B. C. Krüger, P. Huszar, T. Halenka, and S. Rauscher. "Decadal regional air quality simulations over Europe in present climate: near surface ozone sensitivity to external meteorological forcing." Atmospheric Chemistry and Physics 10, no. 23 (December 13, 2010): 11805–21. http://dx.doi.org/10.5194/acp-10-11805-2010.

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Abstract. Regional climate-air quality decadal simulations over Europe were carried out with the RegCM3/CAMx modeling system for the time slice 1991–2000, in order to study the impact of different meteorological forcing on surface ozone. The RegCM3 regional climate model was firstly constrained by the ERA40 reanalysis dataset which is considered as an experiment with perfect meteorological boundary conditions and then it was constrained by the global circulation model ECHAM5. A number of meteorological parameters were examined including the 500 mb geopotential height, solar radiation, temperature, cloud liquid water path, planetary boundary layer height and surface wind. The different RegCM meteorological forcing resulted in changes of near surface ozone over Europe ranging between ± 4 ppb for winter and summer. The area showing the greatest sensitivity in O3 during winter is central and southern Europe while in summer central north continental Europe. The different meteorological forcing impacts on the atmospheric circulation, which in turn affects cloudiness and solar radiation, temperature, wind patterns and the meteorology depended biogenic emissions. For comparison reasons, the impact of chemical boundary conditions on surface ozone was additionally examined with a series of sensitivity studies, indicating that surface ozone changes are comparable to those caused by the different meteorological forcing. These findings suggest that, when it comes to regional climate-air quality simulations, the selection of external meteorological forcing can be as important as the selection of adequate chemical lateral boundary conditions.

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Amoussou, Ernest, Hervé Awoye, Henri S. Totin Vodounon, Salomon Obahoundje, Pierre Camberlin, Arona Diedhiou, Kouakou Kouadio, Gil Mahé, Constant Houndénou, and Michel Boko. "Climate and Extreme Rainfall Events in the Mono River Basin (West Africa): Investigating Future Changes with Regional Climate Models." Water 12, no. 3 (March 16, 2020): 833. http://dx.doi.org/10.3390/w12030833.

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This study characterizes the future changes in extreme rainfall and air temperature in the Mono river basin where the main economic activity is weather dependent and local populations are highly vulnerable to natural hazards, including flood inundations. Daily precipitation and temperature from observational datasets and Regional Climate Models (RCMs) output from REMO, RegCM, HadRM3, and RCA were used to analyze climatic variations in space and time, and fit a GEV model to investigate the extreme rainfalls and their return periods. The results indicate that the realism of the simulated climate in this domain is mainly controlled by the choice of the RCMs. These RCMs projected a 1 to 1.5 °C temperature increase by 2050 while the projected trends for cumulated precipitation are null or very moderate and diverge among models. Contrasting results were obtained for the intense rainfall events, with RegCM and HadRM3 pointing to a significant increase in the intensity of extreme rainfall events. The GEV model is well suited for the prediction of heavy rainfall events although there are uncertainties beyond the 90th percentile. The annual maxima of daily precipitation will also increase by 2050 and could be of benefit to the ecosystem services and socioeconomic activities in the Mono river basin but could also be a threat.

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Patarčić, Mirta, and Čedo Branković. "Skill of 2-m Temperature Seasonal Forecasts over Europe in ECMWF and RegCM Models." Monthly Weather Review 140, no. 4 (April 2012): 1326–46. http://dx.doi.org/10.1175/mwr-d-11-00104.1.

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Various measures of forecast quality are analyzed for 2-m temperature seasonal forecasts over Europe from global and regional model ensembles for winter and summer seasons during the period 1991 to 2001. The 50-km Regional Climate Model (RegCM3) is used to dynamically downscale nine-member ensembles of ECMWF global experimental seasonal forecasts. Three sets of RegCM3 experiments with different soil moisture initializations are performed: the RegCM3 default initial soil moisture, initial soil moisture taken from ECMWF seasonal forecasts, and initial soil moisture obtained from RegCM3 ECMWF interim Re-Analysis (ERA-Interim)-driven integrations (RegCM3 climatology). Both deterministic and probabilistic skill metrics are estimated. The better-resolved spatial scales in near-surface temperature by RegCM3 do not necessarily lead to the improved regional model skill in the regions where systematic errors are large. The impact of initial soil moisture on RegCM3 forecast skill is seen in summer in the southern part of the integration domain. When regional model soil moisture was initialized from ECMWF seasonal forecasts, systematic errors were reduced and deterministic skill was enhanced relative to the other RegCM3 experiments. The Brier skill score for rare cold anomalies in this experiment is comparable to that of the global model, whereas in other experiments it is significantly smaller than in global model. There is no major impact of soil moisture initialization on forecast skill in winter. However, some significant improvements in RegCM3 probabilistic skill scores for positive anomalies in winter are found in the central part of the domain where RegCM3 systematic errors are smaller than in global model.

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Sangelantoni, Lorenzo, Antonio Ricchi, Rossella Ferretti, and Gianluca Redaelli. "Dynamical Downscaling in Seasonal Climate Forecasts: Comparison between RegCM- and WRF-Based Approaches." Atmosphere 12, no. 6 (June 10, 2021): 757. http://dx.doi.org/10.3390/atmos12060757.

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The purpose of the present study is to assess the large-scale signal modulation produced by two dynamically downscaled Seasonal Forecasting Systems (SFSs) and investigate if additional predictive skill can be achieved, compared to the driving global-scale Climate Forecast System (CFS). The two downscaled SFSs are evaluated and compared in terms of physical values and anomaly interannual variability. Downscaled SFSs consist of two two-step dynamical downscaled ensembles of NCEP-CFSv2 re-forecasts. In the first step, the CFS field is downscaled from 100 km to 60 km over Southern Europe (D01). The second downscaling, driven by the corresponding D01, is performed at 12 km over Central Italy (D02). Downscaling is performed using two different Regional Climate Models (RCMs): RegCM v.4 and WRF 3.9.1.1. SFS skills are assessed over a period of 21 winter seasons (1982–2002), by means of deterministic and probabilistic approach and with a metric specifically designed to isolate downscaling signal over different percentiles of distribution. Considering the temperature fields and both deterministic and probabilistic metrics, regional-scale SFSs consistently improve the original CFS Seasonal Anomaly Signal (SAS). For the precipitation, the added value of downscaled SFSs is mainly limited to the topography driven refinement of precipitation field, whereas the SAS is mainly “inherited” by the driving CFS. The regional-scale SFSs do not seem to benefit from the second downscaling (D01 to D02) in terms of SAS improvement. Finally, WRF and RegCM show substantial differences in both SAS and climatologically averaged fields, highlighting a different impact of the common SST driving field.

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Adhikari, Neeraj, and Kundan Lal Shrestha. "Impact of Climate Change on Wind Energy Generation in Kagbeni, Nepal using RegCM." Journal of the Institute of Engineering 15, no. 3 (October 9, 2020): 16–20. http://dx.doi.org/10.3126/jie.v15i3.31903.

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Renewable energies, the promising technologies for the mitigation of climate change, are strongly climate dependent. This research was done to study the impact of climate change on energy generation from wind resources in Kagbeni, Nepal, where the present wind speed and wind power density at 75 m agl are 8.15 m/s and 851 W/m2 respectively. In this research, RegCM-4.4.1 regional climate model was used to downscale the future wind resources with a resolution of 10 km x 10 km. The model was validated in the region using five year observed wind resources from 2001-2005 and further it was used to downscale the wind resources for time period of 2030-2050 using HadGEM2 GCM output of scenario RCP 4.5. This research predicts a 5.3% increase in the wind speed with 13.4% increase in the wind power density at 75 m agl for the time period of 2030-2050. The turbine selected was SUZLON S-52 having hub height of 75 m with 600 KW power rating. The capacity factor of the turbine for the time period of 2030-2050 increases by 15% compared to base year 2001-2005.

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Muhammadh, K. M., M. M. M. Mafas, and S. B. Weerakoon. "Rainfall forecast in the Upper Mahaweli basin in Sri Lanka using RegCM model." Journal of Physics: Conference Series 822 (April 11, 2017): 012075. http://dx.doi.org/10.1088/1742-6596/822/1/012075.

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Lu, Chen, Guohe Huang, and Xiuquan Wang. "Projected changes in temperature, precipitation, and their extremes over China through the RegCM." Climate Dynamics 53, no. 9-10 (July 27, 2019): 5859–80. http://dx.doi.org/10.1007/s00382-019-04899-7.

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Turuncoglu, U. U., G. Giuliani, N. Elguindi, and F. Giorgi. "Modeling the Caspian Sea and its catchment area using a coupled regional atmosphere-ocean model (RegCM-ROMS): model design and preliminary results." Geoscientific Model Development Discussions 5, no. 4 (November 26, 2012): 3907–55. http://dx.doi.org/10.5194/gmdd-5-3907-2012.

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Abstract. We describe the development of a coupled regional atmosphere-ocean model (RegCM-ROMS) and its implementation over the Caspian Sea basin. The coupled model is run for the period 1999–2008 (after a spin up of 4 yr) and it is compared to corresponding stand alone model simulations and a simulation in which a distributed 1d lake model is run for the Caspian Sea. All model versions show a good performance in reproducing the climatology of the Caspian Sea basin, with relatively minor differences across them. The coupled ROMS produces realistic, although somewhat overestimated, lake surface temperatures (LSTs), with a considerable improvement compared to the use of the simpler coupled lake model. Simulated near surface salinity and sea currents are also realistic, although the upwelling over the eastern coastal regions is underestimated. The distribution of sea ice over the shallow northern shelf of the Caspian Sea and its seasonal evolution are well reproduced. ROMS also calculates the Caspian Sea Level (CSL), showing that for the present experiment excessive evaporation over the lake area leads to a drift in estimated CSL. Despite this problem which requires further analysis due to many uncertainties in the estimation of CSL, overall the coupled RegCM-ROMS system shows encouraging results in reproducing both the climatology of the region and the basic characteristics of the Caspian Sea.

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Koné, Brahima, Arona Diedhiou, N'datchoh Evelyne Touré, Mouhamadou Bamba Sylla, Filippo Giorgi, Sandrine Anquetin, Adama Bamba, Adama Diawara, and Arsene Toka Kobea. "Sensitivity study of the regional climate model RegCM4 to different convective schemes over West Africa." Earth System Dynamics 9, no. 4 (November 9, 2018): 1261–78. http://dx.doi.org/10.5194/esd-9-1261-2018.

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Abstract. The latest version of RegCM4 with CLM4.5 as a land surface scheme was used to assess the performance and sensitivity of the simulated West African climate system to different convection schemes. The sensitivity studies were performed over the West African domain from November 2002 to December 2004 at a spatial resolution of 50 km × 50 km and involved five convective schemes: (i) Emanuel; (ii) Grell; (iii) Emanuel over land and Grell over ocean (Mix1); (iv) Grell over land and Emanuel over ocean (Mix2); and (v) Tiedtke. All simulations were forced with ERA-Interim data. Validation of surface temperature at 2 m and precipitation were conducted using data from the Climate Research Unit (CRU), Global Precipitation Climatology Project (GPCP) and the Tropical Rainfall Measurement Mission (TRMM) during June to September (rainy season), while the simulated atmospheric dynamic was compared to ERA-Interim data. It is worth noting that the few previous similar sensitivity studies conducted in the region were performed using BATS as a land surface scheme and involved less convective schemes. Compared with the previous version of RegCM, RegCM4-CLM also shows a general cold bias over West Africa whatever the convective scheme used. This cold bias is more reduced when using the Emanuel convective scheme. In terms of precipitation, the dominant feature in model simulations is a dry bias that is better reduced when using the Emanuel convective scheme. Considering the good performance with respect to a quantitative evaluation of the temperature and precipitation simulations over the entire West African domain and its subregions, the Emanuel convective scheme is recommended for the study of the West African climate system.

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Dash, Sushilv Kumar, Sagnik Dey, Popat Salunke, Mamta Dalal, Vaishali Saraswat, Sourangsu Chowdhury, and Rohit Kumar Chowdhury. "Comparative Study of Heat Indices in India Based on Observed and Model Simulated Data." Current World Environment 12, no. 3 (December 25, 2017): 530–46. http://dx.doi.org/10.12944/cwe.12.3.06.

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It has been reported that the occurrence of "Heat wave" conditions is increasing in different parts of the world. This increase in heat extremes is expected to lead to increasing levels of discomfort to the human beings. In addition, there are loss of working hours, adverse health impacts and deaths depending on the severity and duration of the heat extremes. It is well known that meteorologically it is not merely the rise in temperature which causes human discomfort. Temperature coupled with high humidity, low wind and impervious clothing form major causes of discomfort. Above all, the type of physical activities being undertaken in these adverse conditions is one of the important factors to decide the stress and strain encountered by a person. Studies on biometeorology have been carried out by several scientists for over a century and a number of heat indices have been developed which quantify the level of discomfort or heat stress in their working environments. Today, observed meteorological parameters as well as corresponding model outputs are freely available from several sources which can be used for estimating the values of heat indices at any location. Both dynamical and statistical downscaling methods are very useful in this regard. In this study, some of the commonly used heat indices have been calculated for the four major cities of Delhi, Mumbai, Chennai and Kolkata using daily observed parameters from the India Meteorological Department (IMD) for the period 1975 to 2005. Same indices are also calculated based on the simulated values from the Regional Climate Model (RegCM) of the Abdus Salam International Centre for Theoretical Physics (ICTP) over the same period. The RegCM simulated fields have been obtained from the COordinated Regional Downscaling EXperiments (CORDEX) over the South Asia domain. Comparison of characteristics of the four selected indices based on IMD observed data and RegCM simulations leads to the inference that there are several similarities between the two sets of data in terms of their annual cycles and inter-annual variations. This exercise conclusively shows the advantages of dynamical downscaling. Further, results of this study encourage for a comprehensive work in the future for the country wide mapping and projection of heat indices based on model simulations, development of suitable heat indices and classification of comfort classes for their use in warning system for human health related issues in India.

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Anav, Alessandro, Adriana Carillo, Massimiliano Palma, Maria Vittoria Struglia, Ufuk Utku Turuncoglu, and Gianmaria Sannino. "The ENEA-REG system (v1.0), a multi-component regional Earth system model: sensitivity to different atmospheric components over the Med-CORDEX (Coordinated Regional Climate Downscaling Experiment) region." Geoscientific Model Development 14, no. 7 (July 2, 2021): 4159–85. http://dx.doi.org/10.5194/gmd-14-4159-2021.

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Abstract. In this study, a new regional Earth system model is developed and applied to the Med-CORDEX (Coordinated Regional Climate Downscaling Experiment) region. The ENEA-REG system is made up of two interchangeable regional climate models as atmospheric components (RegCM, REGional Climate Model, and WRF, Weather Research and Forecasting), a river model (Hydrological Discharge, HD), and an ocean model (Massachusetts Institute of Technology General Circulation Model, MITgcm); processes taking place at the land surface are represented within the atmospheric models with the possibility to use several land surface schemes of different complexity. The coupling between these components is performed through the RegESM driver. Here, we present and describe our regional Earth system model and evaluate its components using a multidecadal hindcast simulation over the period 1980–2013 driven by ERA-Interim reanalysis. We show that the atmospheric components correctly reproduce both large-scale and local features of the Euro-Mediterranean climate, although we found some remarkable biases: in particular, WRF has a significant cold bias during winter over the northeastern bound of the domain and a warm bias in the whole continental Europe during summer, while RegCM overestimates the wind speed over the Mediterranean Sea. Similarly, the ocean component correctly reproduces the analyzed ocean properties with performances comparable to the state-of-art coupled regional models contributing to the Med-CORDEX initiative. Our regional Earth system model allows studying the Euro-Mediterranean climate system and can be applied to both hindcast and scenario simulations.

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Espinoza, Nikolai S., Carlos A. C. dos Santos, Madson T. Silva, Helber B. Gomes, Rosaria R. Ferreira, Maria L. da Silva, Cláudio M. Santos e Silva, et al. "Landslides Triggered by the May 2017 Extreme Rainfall Event in the East Coast Northeast of Brazil." Atmosphere 12, no. 10 (September 27, 2021): 1261. http://dx.doi.org/10.3390/atmos12101261.

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Given the increasing occurrence of landslides on the East Coast Northeast of Brazil (ECNEB), it is essential to understand its conditions and triggering factors because meteorological anomalies triggered by a landslide will threaten life and property in the region. In this sense, this research aimed to diagnose the meteorological conditions that triggered landslides in the ECNEB in May 2017, evaluate the terrain’s intrinsic conditions using elevation, slope, and susceptibility parameters and determine critical precipitation thresholds for the city with the highest number of landslide risk areas in the region. A dynamic downscaling experiment was carried out using the Regional Climate Model (RegCM) to verify the ability of this model to represent rainfall over the ECNEB. The results from the intrinsic factors showed that the ECNEB is highly susceptible to landslides with various high-risk sectors for landslides to the population. The extreme rainfall event was associated with the convergence of humidity at low levels over the ocean, which contributed to landslides in the ECNEB, mainly in the State of Pernambuco, where 67 landslides were registered. The RegCM numerical simulation underestimated the high daily rainfall signal seen on the Tropical Rainfall Measuring Mission satellite. It is suggested that sensitivity tests can be performed using other physical parameters to find the best model configuration for the ECNEB. This work recommends that exploring the relationship between precipitation and landslides will provide objective criteria for assessing risk areas by contributing to the predictability of disasters in this region.

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Nabat, P., F. Solmon, M. Mallet, J. F. Kok, and S. Somot. "Dust emission size distribution impact on aerosol budget and radiative forcing over the Mediterranean region: a regional climate model approach." Atmospheric Chemistry and Physics Discussions 12, no. 7 (July 19, 2012): 17835–86. http://dx.doi.org/10.5194/acpd-12-17835-2012.

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Abstract. The present study investigates the dust emission and load over the Mediterranean basin using the coupled-chemistry-aerosol regional climate model RegCM-4. The first step of this work focuses on dust particle emission size distribution modeling. We compare a parameterization in which the emission is based on the individual kinetic energy of the aggregates striking the surface to a recent parameterization based on an analogy with the fragmentation of brittle materials. The main difference between the two dust schemes concerns the mass proportion of fine aerosol which is reduced in the case of the new dust parameterization, with consequences for optical properties. At the episodic scale, comparisons between RegCM-4 simulations, satellite and ground-based data show a clear improvement using the new dust distribution in terms of Aerosol Optical Depth (AOD) values and geographic gradients. These results are confirmed at the seasonal scale for the investigated year 2008. A multi-annual simulation is finally carried out using the new dust distribution over the period 2000–2009. This change of dust distribution has sensitive impacts on the simulated regional dust budget, notably dry dust deposition and the regional direct aerosol radiative forcing over the Mediterranean basin. This could clearly modify the possible effects of dust aerosols on the biogeochemical activity and climate of the Mediterranean basin. In particular, we find that the new size distribution produces a higher dust deposition flux, and smaller top of atmosphere (TOA) dust radiative cooling.

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Chervenkov, Hristo, Vladimir Ivanov, Georgi Gadzhev, and Kostadin Ganev. "Sensitivity Study of Different RegCM4.4 Model Set-Ups – Recent Results from the TVRegCM Experiment." Cybernetics and Information Technologies 17, no. 5 (December 20, 2017): 17–26. http://dx.doi.org/10.1515/cait-2017-0051.

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Abstract The oncoming climate changes will exert influence on the ecosystems, on all branches of the international economy, and on the quality of life. Global Circulation Models (GCMs) are the most widespread and successful tools employed for both numerical weather forecast and climate research since the 1980s. However, growing demands on accurate and reliable information on regional and sub-regional scale are not directly met by relatively coarse resolution global models, mainly due to the excessive costs affiliated with the use of the model in very high resolution. Regional Climate Models (RCMs) are important instruments used for downscaling climate simulations from GCMs. Main aim of the numerical experiment Tuning an Validation of Regional Climate Model (RegCM-TVRegCM) is to quantify the impact of some tunable factors in the RegCM set-up on the model outputs. Thus, on the first stage of the study, the skill of 20 different model configurations in representing the basic spatial and temporal patterns of the Southeast European (SE) climate for the period 1999-2009, is evaluated. Based on these outcomes, the present work is dedicated on more detailed inspection of the model set-ups with recognizable better performance. The Pearson’s correlation coefficient between the time series of the temperature and precipitation of the 6 most promising model set-ups and the E-OBS on monthly basis are calculated. The main conclusion is that this test does not reveal single one model set-up that definitely over performs the other considered ones.

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Vo Van, Hoa, Tien Du Duc, Hung Mai Khanh, Lars Robert Hole, Duc Tran Anh, Huyen Luong Thi Thanh, and Quan Dang Dinh. "Assessment of Seasonal Winter Temperature Forecast Errors in the RegCM Model over Northern Vietnam." Climate 8, no. 6 (June 14, 2020): 77. http://dx.doi.org/10.3390/cli8060077.

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This study verified the seasonal six-month forecasts for winter temperatures for northern Vietnam in 1998–2018 using a regional climate model (RegCM4) with the boundary conditions of the climate forecast system Version 2 (CFSv2) from the National Centers for Environmental Prediction (NCEP). First, different physical schemes (land-surface process, cumulus, and radiation parameterizations) in RegCM4 were applied to generate 12 single forecasts. Second, the simple ensemble forecasts were generated through the combinations of those different physical formulations. Three subclimate regions (R1, R2, R3) of northern Vietnam were separately tested with surface observations and a reanalysis dataset (Japanese 55-year reanalysis (JRA55)). The highest sensitivity to the mean monthly temperature forecasts was shown by the land-surface parameterizations (the biosphere−atmosphere transfer scheme (BATS) and community land model version 4.5 (CLM)). The BATS forecast groups tended to provide forecasts with lower temperatures than the actual observations, while the CLM forecast groups tended to overestimate the temperatures. The forecast errors from single forecasts could be clearly reduced with ensemble mean forecasts, but ensemble spreads were less than those root-mean-square errors (RMSEs). This indicated that the ensemble forecast was underdispersed and that the direct forecast from RegCM4 needed more postprocessing.

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Liu, L., F. Solmon, R. Vautard, L. Hamaoui-Laguel, Cs Zs Torma, and F. Giorgi. "Estimates of common ragweed pollen emission and dispersion over Europe using RegCM-pollen model." Biogeosciences Discussions 12, no. 21 (November 3, 2015): 17595–641. http://dx.doi.org/10.5194/bgd-12-17595-2015.

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Abstract. Common ragweed (Ambrosia artemisiifolia L.) is a highly allergenic and invasive plant in Europe. Its pollen can be transported over large distances and has been recognized as a significant cause of hayfever and asthma (D'Amato et al., 2007; Burbach et al., 2009). To simulate production and dispersion of common ragweed pollen, we implement a pollen emission and transport module in the Regional Climate Model (RegCM) version 4 using the framework of the Community Land Model (CLM) version 4.5. In the online model environment where climate is integrated with dispersion and vegetation production, pollen emissions are calculated based on the modelling of plant distribution, pollen production, species-specific phenology, flowering probability, and flux response to meteorological conditions. A pollen tracer model is used to describe pollen advective transport, turbulent mixing, dry and wet deposition. The model is then applied and evaluated on a European domain for the period 2000–2010. To reduce the large uncertainties notably due to ragweed density distribution on pollen emission, a calibration based on airborne pollen observations is used. Resulting simulations show that the model captures the gross features of the pollen concentrations found in Europe, and reproduce reasonably both the spatial and temporal patterns of flowering season and associated pollen concentrations measured over Europe. The model can explain 68.6, 39.2, and 34.3 % of the observed variance in starting, central, and ending dates of the pollen season with associated root mean square error (RMSE) equal to 4.7, 3.9, and 7.0 days, respectively. The correlation between simulated and observed daily concentrations time series reaches 0.69. Statistical scores show that the model performs better over the central Europe source region where pollen loads are larger. From these simulations health risks associated common ragweed pollen spread are then evaluated through calculation of exposure time above health-relevant threshold levels. The total risk area with concentration above 5 grains m−3 takes up 29.5 % of domain. The longest exposure time occurs on Pannonian Plain, where the number of days per year with the daily concentration above 20 grains m−3 exceeds 30.

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Shah, Ruchita, Rohit Srivastava, and Rohit Srivastava. "Evaluation of RegCM 4.4 to Get Cloud and Monsoon Features with Seasons over India." International Journal of Environmental Science and Development 9, no. 10 (2018): 303–7. http://dx.doi.org/10.18178/ijesd.2018.9.10.1118.

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RAHMAN, Md MIZANUR, Md NAZRUL ISLAM, AHSAN UDDIN AHMED, and F. GEORGI. "Rainfall and temperature scenarios for Bangladesh for the middle of 21st century using RegCM." Journal of Earth System Science 121, no. 2 (April 2012): 287–95. http://dx.doi.org/10.1007/s12040-012-0159-9.

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Walawender, Ewelina, Rafał Kielar, and Zbigniew Ustrnul. "Use of RegCM gridded dataset for thunderstorm favorable conditions analysis over Poland—climatological approach." Theoretical and Applied Climatology 127, no. 1-2 (September 12, 2015): 229–40. http://dx.doi.org/10.1007/s00704-015-1620-x.

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Bhatla, R., S. Ghosh, B. Mandal, R. K. Mall, and Kuldeep Sharma. "Simulation of Indian summer monsoon onset with different parameterization convection schemes of RegCM-4.3." Atmospheric Research 176-177 (July 2016): 10–18. http://dx.doi.org/10.1016/j.atmosres.2016.02.010.

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Steiner, A. L., J. S. Pal, F. Giorgi, R. E. Dickinson, and W. L. Chameides. "The coupling of the Common Land Model (CLM0) to a regional climate model (RegCM)." Theoretical and Applied Climatology 82, no. 3-4 (May 20, 2005): 225–43. http://dx.doi.org/10.1007/s00704-005-0132-5.

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Mishra, Alok Kumar, Suneet Dwivedi, and Fabio Di Sante. "Performance of the RegCM-MITgcm Coupled Regional Model in Simulating the Indian Summer Monsoon Rainfall." Pure and Applied Geophysics 178, no. 2 (January 25, 2021): 603–17. http://dx.doi.org/10.1007/s00024-020-02648-0.

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Pieczka, Ildikó, Judit Bartholy, Rita Pongrácz, and Karolina Szabóné André. "Validation of RegCM regional and HadGEM global climate models using mean and extreme climatic variables." Időjárás 123, no. 4 (2019): 409–33. http://dx.doi.org/10.28974/idojaras.2019.4.1.

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Ozturk, T., HA Altinsoy, M. Türkeș, and ML Kurnaz. "Simulation of temperature and precipitation climatology for the Central Asia CORDEX domain using RegCM 4.0." Climate Research 52 (March 22, 2012): 63–76. http://dx.doi.org/10.3354/cr01082.

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Abish, B., and K. Arun. "Resolving the weakening of orographic rainfall over India using a regional climate model RegCM 4.5." Atmospheric Research 227 (October 2019): 125–39. http://dx.doi.org/10.1016/j.atmosres.2019.05.003.

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Journal articles on the topic 'RegCM'

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