21 research outputs found
Projected changes in extreme temperature and precipitation indices over CORDEX-MENA domain
In this study, projected changes in climate extreme indices defined by the Expert Team on Climate Change Detection and Indices were investigated over Middle East and North Africa. Changes in the daily maximum and minimum temperature-and precipitation-based extreme indices were analyzed for the end of the 21st century compared to the reference period 1971–2000 using regional climate model simulations. Regional climate model, RegCM4.4 was used to downscale two different global climate model outputs to 50 km resolution under RCP4.5 and RCP8.5 scenarios. Results generally indicate an intensification of temperature-and precipitation-based extreme indices with increasing radiative forcing. In particular, an increase in annual minimum of daily minimum temperatures is more pronounced over the northern part of Mediterranean Basin and tropics. High increase in warm nights and warm spell duration all over the region with a pronounced increase in tropics are projected for the period of 2071–2100 together with decrease or no change in cold extremes. According to the results, a decrease in total wet-day precipitation and increase in dry spells are expected for the end of the century.Publisher's Versio
Analysing projected changes in future air temperature and precipitation climatology of Turkey by using RegCM4.3.5 climate simulations
Bu çalışmada 1970-2000 dönemi günümüz iklimine göre 2070-2100 dönemi için Türkiye’nin ortalama hava sıcaklığı ve yağış klimatolojilerindeki değişikler, bölgesel iklim modeli simülasyonları (benzetim) kullanılarak öngörüldü. Günümüz ve gelecek iklim koşullarının model kestirimlerinin yapılması için, International Centre for Theoretical Physics (ICTP) bölgesel iklim modeli RegCM4.3.5 kullanıldı. Met Office Hadley Merkezi’nin HadGEM2 küresel iklim modeli, Türkiye ve çevresi için alt ölçeklendirme yöntemi ile çalışıldı. Gelecekte Türkiye’nin iklim değişkenlerinde oluşacak değişimleri incelemek için, küresel iklim modelinin RCP4.5 ve RCP8.5 salım senaryoları çıktıları kullanıldı. Model çıktılarına göre, Türkiye’de ortalama hava sıcaklıklarında 3 °C ile 7 °C arasında değişen artışlar olacaktır. Sıcaklık artışı, sıcak mevsimlerde soğuk mevsimlere göre daha fazla olacaktır. Bölgesel iklim modeli sonuçlarına göre, Türkiye’nin yağış klimatolojisinde ise, –0.8 mm/gün ile 1.2 mm/gün arasında değişen değişimler beklenmektedir.In this work, future changes for the period of 2070-2100 in mean air temperature and precipitation climatology of Turkey with respect to present climate (1971 to 2000) were projected by using regional climate model simulations. Regional Climate Model (RegCM4.3.5) of International Centre for Theoretical Physics (ICTP) was used for projections of future and present climate conditions. HadGEM2 (Hadley Global Environment Model 2) global climate model of Met Office Hadley Centre was downscaled for Turkey and its surrounding region. In this study, RCP4.5 and RCP8.5 emission scenarios were studied in order to investigate future changes of some climate variables in Turkey. According to the model results, there will be an increase of between 3 °C and 7 °C in mean air temperatures of Turkey. This warming will be more severe in warm seasons than cold seasons. Changes varying from –0.8 mm/day to 1.2 mm/day in precipitation climatology of Turkey are expected according to the regional climate model results.Publisher's Versio
Impact of climate change on natural snow reliability, snowmaking capacities, and wind conditions of ski Resorts in Northeast Turkey: a dynamical downscaling approach
Many ski resorts worldwide are going through deteriorating snow cover conditions due to anthropogenic warming trends. As the natural and the artificially supported, i.e., technical, snow reliability of ski resorts diminish, the industry approaches a deadlock. For this reason, impact assessment studies have become vital for understanding vulnerability of ski tourism. This study considers three resorts at one of the rapidly emerging ski destinations, Northeast Turkey, for snow reliability analyses. Initially one global circulation model is dynamically downscaled by using the regional climate model RegCM4.4 for 1971-2000 and 2021-2050 periods along the RCP4.5 greenhouse gas concentration pathway. Next, the projected climate outputs are converted into indicators of natural snow reliability, snowmaking capacity, and wind conditions. The results show an overall decline in the frequencies of naturally snow reliable days and snowmaking capacities between the two periods. Despite the decrease, only the lower altitudes of one ski resort would face the risk of losing natural snow reliability and snowmaking could still compensate for forming the base layer before the critical New Year's week. On the other hand, adverse high wind conditions improve as to reduce the number of lift closure days at all resorts. Overall, this particular region seems to be relatively resilient against climate change.Publisher's Versio
The Worldwide C3S CORDEX Grand Ensemble: A Major Contribution to Assess Regional Climate Change in the IPCC AR6 Atlas
The worldwide C3S CORDEX grand ensemble: A major contribution to assess regional climate change in the IPCC AR6 Atlas
peer reviewedAbstract
The collaboration between the Coordinated Regional Climate Downscaling Experiment (CORDEX) and the Earth System Grid Federation (ESGF) provides open access to an unprecedented ensemble of Regional Climate Model (RCM) simulations, across the 14 CORDEX continental-scale domains, with global coverage. These simulations have been used as a new line of evidence to assess regional climate projections in the latest contribution of the Working Group I (WGI) to the IPCC Sixth Assessment Report (AR6), particularly in the regional chapters and the Atlas.
Here, we present the work done in the framework of the Copernicus Climate Change Service (C3S) to assemble a consistent worldwide CORDEX grand ensemble, aligned with the deadlines and activities of IPCC AR6. This work addressed the uneven and heterogeneous availability of CORDEX ESGF data by supporting publication in CORDEX domains with few archived simulations and performing quality control. It also addressed the lack of comprehensive documentation by compiling information from all contributing regional models, allowing for an informed use of data. In addition to presenting the worldwide CORDEX dataset, we assess here its consistency for precipitation and temperature by comparing climate change signals in regions with overlapping CORDEX domains, obtaining overall coincident regional climate change signals. The C3S CORDEX dataset has been used for the assessment of regional climate change in the IPCC AR6 (and for the interactive Atlas) and is available through the Copernicus Climate Data Store (CDS)
A Statistical Analysis of the Robustness of Alternate Genetic Coding Tables
The rules that specify how the information contained in DNA is translated into amino acid “language†during protein synthesis are called “the genetic codeâ€Â, commonly called the “Standard†or “Universal†Genetic Code Table. As a matter of fact, this coding table is not at all “universalâ€Â: in addition to different genetic code tables used by different organisms, even within the same organism the nuclear and mitochondrial genes may be subject to two different coding tables. Results In an attempt to understand the advantages and disadvantages these coding tables may bring to an organism, we have decided to analyze various coding tables on genes subject to mutations, and have estimated how these genes “survive†over generations. We have used this as indicative of the “evolutionary†success of that particular coding table. We find that the “standard†genetic code is not actually the most robust of all coding tables, and interestingly, Flatworm Mitochondrial Code (FMC) appears to be the highest ranking coding table given our assumptions. Conclusions It is commonly hypothesized that the more robust a genetic code, the better suited it is for maintenance of the genome. Our study shows that, given the assumptions in our model, Standard Genetic Code is quite poor when compared to other alternate code tables in terms of robustness. This brings about the question of why Standard Code has been so widely accepted by a wider variety of organisms instead of FMC, which needs to be addressed for a thorough understanding of genetic code evolution
Simulation of temperature and precipitation climatology for the Central Asia CORDEX domain using RegCM 4.0
The 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.Publisher's Versio
Investigation of projected changes for near future air temperature and precipitation climatology of Turkey and surrounding regions by using the regional climate model RegCM4.3.5
Bu çalışmada 1970 – 2000 referans dönemi iklimine göre 2020 – 2050 dönemi için Türkiye’nin ortalama hava sıcaklığı ve yağış klimatolojilerinde öngörülen değişiklikler, bölgesel iklim modeli benzetimleri kullanılarak araştırıldı. Yakın gelecekteki iklim koşullarında öngörülen değişimleri incelemek için Uluslararası Teorik Fizik Merkezi’ne ait olan RegCM4.3.5 isimli bölgesel iklim modeli üç farklı küresel modelden yararlanılarak koşuldu. Max Planck Meteoroloji Enstitüsü’ne ait MPI-ESM-MR, Met Office Hadley Merkezi’ne ait HadGEM2 ve Amerikan Ulusal Okyanus ve Atmosfer Dairesi Jeofiziksel Akışkanlar Dinamiği Laboratuvarı’na ait GFDL-ESM2M modelleri Türkiye ve çevresi için dinamik olarak 50 km’ye alt ölçeklendirildi. Öngörüler, Hükümetlerarası İklim Değişikliği Paneli’nin (IPCC) RCP4.5 ve RCP8.5 salım senaryolarına göre gerçekleştirildi. Model sonuçlarına göre, Türkiye’de ortalama hava sıcaklıklarında 1970 – 2000 dönemine göre 2020 – 2050 döneminde 0.5 °C ile 4 °C arasında değişen artışlar olacaktır. Bu artış, sıcak mevsimlerde soğuk mevsimlere göre daha fazla olacaktır. Türkiye’nin yağış klimatolojisinde ise, bölgesel iklim modeli sonuçlarına göre, özellikle ülkenin Akdeniz ikliminin egemen olduğu batı ve güney bölgelerinde ve tüm mevsimlerde, yaklaşık 0.4 mm/gün ile 1.2 mm/gün arasında değişen belirgin yağış azalışlarının oluşması beklenir.In this study, projected future changes for the period of 2020 – 2050 in mean air temperature and precipitation climatology and year-to-year variability with respect to the control period of 1970 – 2000 were investigated for the domain of Turkey via regional climate model simulations. In order to investigate the projected changes in near future climate conditions, Regional Climate Model (RegCM4.3.5) of ICTP (International Centre for Theoretical Physics) was driven by three different global climate models. HadGEM2 global climate model of the Met Office Hadley Centre, MPI-ESM-MR global climate model of the Max Planck Institute for Meteorology, GFDL-ESM2M global climate model of the National Oceanic and Atmospheric Administration Geophysical Fluid Dynamics Laboratory were dynamically downscaled to 50 km for Turkey and its surrounding region. The projections were performed based on the RCP4.5 and the RCP8.5 emission scenarios of the Intergovernmental Panel on Climate Change (IPCC). According to the model results, there will be an increase between 0.5 °C and 4 °C in mean air temperatures of Turkey for the period of 2020 – 2050 with respect to the period of 1970 – 2000. This warming will be more severe in warm seasons than cold seasons. Precipitation decreases varying from approximately 0.4 mm/day to 1.2 mm/day in precipitation climatology of Turkey are expected to occur in all seasons particularly over the southern and western regions of the country dominated by the Mediterranean climate, according to the regional climate model results.Publisher's Versio