4 sonuçlar
Arama Sonuçları
Listeleniyor 1 - 4 / 4
Yayın Projected changes in temperature and precipitation climatology of Central Asia CORDEX Region 8 by using RegCM4.3.5(Elsevier Ltd, 2017-01-01) Öztürk, Tuğba; Turp, Mustafa Tufan; Türkeş, Murat; Kurnaz, Mehmet LeventThis work investigated projected future changes in seasonal mean air temperature (°C) and precipitation (mm/day) climatology for the three periods of 2011–2040, 2041–2070, and 2071–2100, with respect to the control period of 1971–2000 for the Central Asia domain via regional climate model simulations. In order to investigate the projected changes in near future climate conditions, the Regional Climate Model, RegCM4.3.5 of the International Centre for Theoretical Physics (ICTP) was driven by two different CMIP5 global climate models. The HadGEM2-ES global climate model of the Met Office Hadley Centre and the MPI-ESM-MR global climate model of the Max Planck Institute for Meteorology were downscaled to 50 km for the Coordinated Regional Climate Downscaling Experiment (CORDEX) Region 8. We investigated the seasonal time-scale performance of RegCM4.3.5 in reproducing observed climatology over the domain of the Central Asia by using two different global climate model outputs. For the future climatology of the domain, the regional model projects relatively high warming in the warm season with a decrease in precipitation in almost all parts of the domain. A warming trend is notable, especially for the northern part of the domain during the cold season. The results of our study show that surface air temperatures in the region will increase between 3 °C and about 7 °C on average, according to the emission scenarios for the period of 2071–2100 with respect to past period of 1971–2000. Therefore, the projected warming and decrease in precipitation might adversely affect the ecological and socio-economic systems of this region, which is already a mostly arid and semi-arid environment.Yayın Simulation of temperature and precipitation climatology for the Central Asia CORDEX domain using RegCM 4.0(Inter-Research, 2012) Öztürk, Tuğba; Altınsoy, Hamza; Türkeş, Murat; Kurnaz, Mehmet LeventThe Coordinated Regional Climate Downscaling Experiment (CORDEX) is a framework designed to coordinate international efforts on regional climate simulations. CORDEX domains encompass the majority of land areas of the world. Region 8 of the CORDEX basically covers Central Asia, with the corners of the domain at 54.76 degrees N, 11.05 degrees E; 56.48 degrees N, 139.13 degrees E; 18.34 degrees N, 42.41 degrees E; and 19.39 degrees N, 108.44 degrees E and with a horizontal resolution of 50 km. In the present study, the results of an experiment with the ICTP regional climate RegCM 4.0 model that was run for seasonal mean air temperature and precipitation total series are presented. The experiment consists of one simulation from 1989 to 2010 using ERA-Interim reanalysis data as the boundary condition, another simulation for the period 1970-2000 using the global climate model ECHAM5 A1B scenario data for forcing, and finally a simulation for the period 2070-2100 using the ECHAM5 A1B scenario projection data for forcing. Between these 3 simulations we determined the temperature and precipitation climatology obtained from RegCM 4.0 downscaling for Region 8 of the CORDEX framework. In spite of the diverse topography of the region, the temperature and precipitation climatology obtained by RegCM 4.0 from hindcast data captures the general characteristics of the climate of Central Asia. In winter, the warm temperature bias of the forcing data is slightly decreased by regional downscaling. The influences of the Indian monsoon system are well represented, as this region covers a large area towards the southern boundary of Region 8, even though the focus of this work was to capture the general characteristics of the whole region.Yayın Simulating the climatology of extreme events for the Central Asia domain using the RegCM 4.0 regional climate model(National and Kapodistrian University of Athens, 2012-05) Altınsoy, Hamza; Öztürk, Tuğba; Türkeş, Murat; Kurnaz, Mehmet Levent; Helmis, Konstantinos G.In this work, future changes in the frequency of the seasonal extreme climate events such as number, frequency, duration and intensity of heat waves (five consecutive temperature days above the maximum temperature calendar day 90th percentiles, number of days per year that is above the same percentiles and greatest number of consecutive days above these percentiles) for the period of 2071-2100 over Central Asia (18.56° – 70.13° East and 7.28° - 142.4° North) with respect to the present period of 1971-2000 were studied in detail. Regional Climate Model RegCM4.0 of Abdus Salam International Center for Theoretical Physics (ICTP) with ECHAM5 forcing data was used for hindcast and forecast projection. This region will very likely be affected by heat waves in winter and spring seasons and heat wave frequency, intensity and duration will increase sig-nificantly over the Arabian Peninsula in summer. On the other hand, cold spells will not change as much as heat waves over the region in all seasons.Yayın Simulations of future drought conditions in Central Asia CORDEX Region 8 by using RegCM 4.3.5(2015-01-14) Öztürk, Tuğba; Turp, Mustafa Tufan; Türkeş, Murat; Kurnaz, Mehmet LeventIn this work, projected future changes in mean surface air temperature and precipitation climatology, inter-annual and seasonal variability and climatic aridity/humidity conditions for the period 2070-2100 over the large Central Asia region with respect to present climate (from 1970 to 2000) were simulated based on the RCP4.5 and RCP8.5 emission scenarios. Regional Climate Model (RegCM4.3.5) of the International Centre for Theoretical Physics (ICTP) was used for projections of future and present climate conditions. HadGEM2 global climate model of the Met Office Hadley Centre and MPI-ESM-MR global climate model of the Max Planck Institute for Meteorology were downscaled to 50 km for the CORDEX Region 8. We investigated the seasonal time-scale performance of RegCM4.3.5 in reproducing observed climatology over the domain of Central Asia by using 2 different global climate model outputs. For the future climatology of the domain, the regional model predicts relatively high warming in the warm season and northern part of the domain at cold season with a decrease in precipitation almost all part of the domain. The results of our study show that surface temperatures in the region will increase from 3 °C up to more than 7 °C on average according to the emission scenarios for the period 2070-2100 with respect to past period 1970-2000. Therefore, the projected warming and decrease in precipitation and also resultant or associated increased aridity and more frequent and severe drought events very likely adversely affect the ecological and socio-economic systems of this region, which is already characterised with mostly arid and semi-arid climate and ecosystems.
