A Kárpát-medence domborzatának csapadékváltozásban betöltött szerepének vizsgálata regionális klímamodellek segítségével

Az éghajlati modellek fontos szerepet töltenek be a jövőbeli antropogén kényszerek várható éghajlati hatásainak vizsgálatában. Napjainkban a globális klímakutatás elsődleges eszközei a globális klímamodellek (GCM), melyek leggyakrabban használt horizontális térbeli felbontása: 100‒300 km. Azonban a globális klímamodellek lehetőségei a relatív durva felbontásukból adódóan regionális szinten igen korlátozottnak (szub-kontinentális szinten) tekinthető. A GCM eredményekben az éghajlati változók leírása igen sok bizonytalansággal terhelt, kiváltképp a csapadék vonatkozásában. A numerikus előrejelző körökben jól ismert beágyazásos módszer során a globális modellbe illesztett (befészkelt, beágyazott) korlátos tartományú modell végzi el a globális klímamodell eredményeinek regionális szintre való leskálázását. Az első sikeres, beágyazáson alapuló regionális klímamodell (RCM) kísérletet az Amerikai Egyesült Államok nyugati partjára, 60 km-es rácsfelbontás mellett végezték el (Dickinson et al., 1989). Az elmúlt évtizedekben esettanulmányoktól kezdve paleoklimato-lógiai vizsgálatokon át, a jövőre vonatkozó klimatológiai kutatásokig, valamint évszakos előrejelzésekig egyaránt alkalmaztak RCM-ket. Azonban a regionális klíma előrejelzésekben egyaránt meglévő bizonytalanságok vizsgálata ezen előrejelzések csoportos kiértékelését követelik meg (Beniston et al., 2007). Az elmúlt közel két évtized során Európa térségére több olyan nemzetközi program látott napvilágot, melyek során a regionális klímaváltozás vizsgálata RCM szimulációk segítségével történt: PRUDENCE (Predicting of Regional Scenarios and Uncertainties for Defining European Climate Change Risks and Effects, 2001‒2004; Christensen & Christensen, 2007); ENSEMBLES (Ensembles-Based Predicitions of Climate Changes and Their Impacts, 2004‒2009; Hewit & Griggs, 2004); CECILIA (2006‒2009; Halenka, 2007). Az egyik legújabb nemzetközi kezdeményezés során (Coordinated Regional climate Downscaling Experiment, CORDEX; Giorgi et al., 2009), a Föld minden kontinensére rendelkezésre állnak RCM szimulációk (többnyire az 1950‒2100 időszakra vonatkozóan). A CORDEX keretén belül az EURO-CORDEX (Jacob et al., 2014) és Med-CORDEX (Ruti et al., 2015) nemzetközi programoknak köszönhetőn példa nélküli mértékben hozzáférhetők 50 km és 12 km felbontás mellett klímaszimulációk a Kárpát-medencét teljes terjedelmében magában foglaló európai régióra. Ezen szimulációk szolgáltatják az alapját a Kárpát-medence térségére végzett kutatásaimnak

Temperature characteristics over the Carpathian Basin ‐ projected changes of climate indices at regional and local scale based on bias‐adjusted CORDEX simulations

The present research focuses on temperature change signals over the Carpathian Basin with a special focus on selected lowland and mountainous subregions. High-resolution (0.11 degrees) EURO-and Med-CORDEX regional climate model (RCM) simulations of near-surface air temperature are analysed based on raw and bias-adjusted data. The mini-ensemble consists of eight RCM simulations driven by five different general circulation models for the period 1976-2099 under the high-end RCP8.5 scenario. The high-resolution, homogenized and quality controlled CARPATCLIM was used as a reference dataset. The selected subregions cover eight municipalities located at diverse altitudes: Bratislava, Budapest, Brassov, Debrecen, Hoverla, Novi Sad, Pecs and Poprad. The following climate indices are assessed: summer days, ice days, frost days, tropical nights, the coldest day, the warmest day, the coldest night and the warmest night. In general, for the reference period (1976-2005) bias adjusted RCM data showed almost perfect match with observations. Accordingly, no best performing RCM is found for all indices. The ensemble mean of the bias-adjusted RCM simulations projects an increase (decrease) of 32% and 112% (18% and 25%) in the annual number of summer days and tropical nights (frost days and ice days) for the period 2021-2050. For 2070-2099 we can expect more frequent tropical nights (about five times) with respect to the reference period and the frequency of frost days can be halved. Profound warming manifests in the increase of the warmest temperature of day of up to 2-3 degrees C by the near future and of 5-7 degrees C by the end of the 21st century, which means the absolute maximum temperature can reach 44-47 degrees C for the period 2070-2099. Our results also highlight the need for bias-adjusted data adapted by different sectors (human health, agriculture, transport, disaster management, heritage conservation) under the national adaptation strategies

Mistral and Tramontane wind systems in climate simulations from 1950 to 2100

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Recent increases in winter snowfall provide resilience to very small glaciers in the Julian Alps, Europe

Very small glaciers (<0.5 km2) account for more than 80% of the total number of glaciers and more than 15% of the total glacier area in the European Alps. This study seeks to better understand the impact of extreme snowfall events on the resilience of very small glaciers and ice patches in the southeastern European Alps, an area with the highest mean annual precipitation in the entire Alpine chain. Mean annual precipitation here is up to 3300 mm water equivalent, and the winter snow accumulation is approximately 6.80 m at 1800 m asl averaged over the period 1979–2018. As a consequence, very small glaciers and ice/firn patches are still present in this area at rather low altitudes (1830–2340 m). We performed repeated geodetic mass balance measurements on 14 ice bodies during the period 2006–2018 and the results show an increase greater than 10% increase in ice volume over this period. This is in accordance with several extreme winter snow accumulations in the 2000s, promoting a positive mass balance in the following years. The long-term evolution of these very small glaciers and ice bodies matches well with changes in mean temperature of the ablation season linked to variability of Atlantic Multidecadal Oscillation. Nevertheless, the recent behaviour of such residual ice masses in this area where orographic precipitation represents an important component of weather amplification is somehow different to most of the Alps. We analysed synoptic meteorological conditions leading to the exceptional snowy winters in the 2000s, which appear to be related to the influence and modification of atmospheric planetary waves and Arctic Amplification, with further positive feedbacks due to change in local sea surface temperature and its interactions with low level flows and the orography. Although further summer warming is expected in the next decades, we conclude that modification of storm tracks and more frequent occurrence of extreme snowfall events during winter are crucial in ensuring the resilience of small glacial remnants in maritime alpine sectors

DNA methylation clock DNAmFitAge shows regular exercise is associated with slower aging and systemic adaptation

DNAmPhenoAge, DNAmGrimAge, and the newly developed DNAmFitAge are DNA methylation (DNAm)-based biomarkers that reflect the individual aging process. Here, we examine the relationship between physical fitness and DNAm-based biomarkers in adults aged 33–88 with a wide range of physical fitness (including athletes with long-term training history). Higher levels of VO 2 max ( ρ = 0.2, p = 6.4E − 4, r = 0.19, p = 1.2E − 3), Jumpmax ( p = 0.11, p = 5.5E − 2, r = 0.13, p = 2.8E − 2), Gripmax ( ρ = 0.17, p = 3.5E − 3, r = 0.16, p = 5.6E − 3), and HDL levels ( ρ = 0.18, p = 1.95E − 3, r = 0.19, p = 1.1E − 3) are associated with better verbal short-term memory. In addition, verbal short-term memory is associated with decelerated aging assessed with the new DNAm biomarker FitAgeAcceleration ( ρ : − 0.18, p = 0.0017). DNAmFitAge can distinguish high-fitness individuals from low/medium-fitness individuals better than existing DNAm biomarkers and estimates a younger biological age in the high-fit males and females (1.5 and 2.0 years younger, respectively). Our research shows that regular physical exercise contributes to observable physiological and methylation differences which are beneficial to the aging process. DNAmFitAge has now emerged as a new biological marker of quality of life

Detailed validation of EURO-CORDEX and Med-CORDEX regional climate model ensembles over the Carpathian Region

Present study evaluates the ability of the ERA-Interim-driven regional climate model (RCM) simulations conducted in the framework of the Coordinated Regional Climate Downscaling Experiment (CORDEX) in describing precipitation and temperature climatic conditions over the Carpathian Region. In total, nine RCM simulations were assessed from EURO-CORDEX and Med-CORDEX (at 0.44° and 0.11° nominal resolutions) against the CARPATCLIM high resolution gridded observational database. Present work focuses on the mean, minimum, and maximum near-surface air temperature and precipitation. The study shows the performance of the members of RCM ensembles in representing the basic spatiotemporal patterns of the climate over the Carpathian Region for the period of 1989–2008. Different metrics covering from daily to monthly and from seasonal to annual time scales are analyzed over the region of interest: spatial patterns of seasonal mean temperature and precipitation, annual cycle of precipitation, monthly mean temperature bias, as well as climate indices, including CDD (consecutive dry days), R95, FD (frost days, when Tmin25 °C). The results confirm the distinct capabilities of RCMs in capturing the local features of the climatic conditions of the Carpathian Region. This work is in favor to select RCMs with reasonable performance over the Carpathian Region, based on which a high-resolution bias-adjusted climatic database can be established for future risk assessment and impact studies

Ragweed pollen production and dispersion modelling within a regional climate system, calibration and application over Europe

International audienceCommon 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 hay fever 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 this online approach 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 the lack of information on ragweed density distribution, a calibration based on airborne pollen observations is used. Accordingly a cross validation is conducted and shows reasonable error and sensitivity of the calibration. 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 and the model is better constrained. From these simulations health risks associated to common ragweed pollen spread are 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