Search

Severe and repeated droughts in Europe have significant impacts on agriculture, transport, energy and healthcare. During the summer of 2003, more than the two-thirds of Europe was under drought. The drought events of 2010 and 2018 were of a similar extent to 2003. An unprecedented stress on water levels throughout the entire EU was created by the combination of severe drought and heat waves during August 2022--the worst drought event in 500 years according to according to the Commission's Joint Research Centre. A raised awareness of drought characteristics is essential for better drought forecasting and monitoring in order to provide reliable adaptation strategies for drought hazard. In this study, the drought over six European stations for the last three decades using the standardized precipitation index (SPI) and the standardized precipitation evapotranspiration index (SPEI) was analyzed. SPI reveals that there are no significant changes in dry and wet conditions, while SPEI shows a significant increase in the drought frequency during the last decades for Central Europe and the Mediterranean. The discrepancies between the two indices can be explained by the increasing temperature and evapotranspiration that are fundamental components of drought occurrence in Europe. The SPI12 index managed to identify the drought of August 2022 in many regions in Europe, but with less intensity than it was recorded. Conversely, SPEI12 was able to identify the intensity of the drought. [ABSTRACT FROM AUTHOR]

High temperatures during the summer months are a common feature in countries with a Mediterranean climate, such as Cyprus and Greece. However, anthropogenic climate change is responsible for the increase in the frequency, intensity and duration of extreme high temperatures in the wider Eastern Mediterranean region, especially since 1990. At the same time, future climate projections show that high temperatures and heatwaves that were observed at the beginning of the 21st century and characterized as extreme will become the norm in the coming years. This study confirms the increasing trend in maximum and minimum temperature for the last four decades in Cyprus. Bioclimatic indices provide a measure of human thermal discomfort caused by the thermal environment. In the present study, the UTCI index from the dataset ERA5-HEAT was used to estimate the heat stress of the average person under conditions of heat events. The spatial distribution of maximum monthly UTCIdaily values was carried out for the period 2004-2019. At the same time, the correlation of patient admissions to hospitals, as well as the relationship of mortality with high UTCIdaily values, was assessed. Mortality data and data from eight public hospitals located in five districts of Cyprus were analyzed as obtained from the Ministry of Health and the Cyprus Statistical Service. The data reveal that UTCIdaily values were positively associated with hospital admissions and mortality in some cases. [ABSTRACT FROM AUTHOR]

One of the main crops cultivated in Greece is the olive tree. In recent years, olives around the Mediterranean Basin and especially in Greece have been facing increasingly high temperatures and are more often exposed to water deficits, inducing severe abiotic stress, thus affecting plant physiology and productivity. Future projections point to a general increase in temperature of up to 2 °C. Precipitation is projected to decrease in northwestern Halkidiki, leading to enhanced water needs and resulting in a possible decrease in yield. The increase in temperature, especially in the winter season, seems to impact flowering buds. The small number of days with low temperatures resulting in reduced flowering during spring will decrease the quantity and quality of olives and oil. [ABSTRACT FROM AUTHOR]

Greece experienced an unusual heat wave in mid-May 2020, since it was observed earlier than the common Mediterranean heat wave period. On May 16th, the maximum air temperature at Kalamata (southern Greece) was 40 °C, and at Aydin (western Turkey) it was 41.6 °C. There was a significantly high climatological anomaly (ref: 1979-2009) relating to temperature at 850 hPa over Greece and Turkey from May 12 to May 20. The aim of this study was to evaluate how well this extreme event can be predicted at subseasonal timescales, since it is not a well-researched scientific topic by weather forecasters in the Eastern Mediterranean. Global forecasts from six meteorological centers (ECMWF, UKMO, NCEP, CMA, KMA, HMCR) and WRF simulations produced via CFS (NCEP) analyses and forecasts were examined for lead times ranging from 2 to 6 weeks ahead. The results show that skillful forecasts started 2.5 weeks before the event's onset. [ABSTRACT FROM AUTHOR]

This study examines extreme precipitation seasonality in the Mediterranean for the future period 2081-2100, based on the climate scenario SSP5-8.5. Using data from the CNRM-CM6-1-HR, the study determines the dates of extreme precipitation events using the circular statistics method. The results indicate that almost 50% of grid points experienced the first extreme event of the year between January and February during the reference period. In the future period, there will be an increase in the percentage of grid points experiencing events during the cold period, meaning that there will be a seasonal shift of extreme events to colder months mainly affecting the west and east Mediterranean. [ABSTRACT FROM AUTHOR]

Climate models are fundamental tools for assessing historical climate conditions and projecting future ones. However, the results often differ systematically from observational data. The minimization of these differences is known as bias correction. The present study aims to correct the biases between observed daily precipitation values and the respective simulated ones from a EURO-CORDEX climate model. For this purpose, powerful statistical tools--generalized additive models (GAMs)--are used. GAMs are modified to adjust the simulated rainfall with the highest accuracy, and subsequently, they are evaluated by comparison with observational data. The method was applied to two eastern Mediterranean stations (Larissa in Greece and Larnaca in Cyprus) for the period 1981 to 2005. The results from both stations reveal that GAMs offer a valuable and accurate technique for the bias adjustment of daily precipitation. [ABSTRACT FROM AUTHOR]

One of the impacts of climate change is an increase in the frequency and intensity of extreme rainfall events. This has very significant social and economic consequences for the affected areas (flooding, loss of life, destruction of infrastructure, etc.). Future trends indicate a further increase in extreme rainfall in the second half of the century, making the need for the timely and accurate forecasting of these phenomena more urgent than ever. However, despite the technological development of weather and climate models in recent years, there are still limitations in detecting the extremes, especially regarding the precipitation parameter. Extreme precipitation events show a link with temperature. The Clausius-Clapeyron (CC) equation, which relates temperature to saturation vapor pressure (es), is used to study the sensitivity of precipitation to temperature increase because it can estimate the increase in the available atmospheric water vapor with respect to temperature. Focusing on the Thessaloniki region in Greece, the aim of this paper is to investigate the applicability of the Clausius-Clapeyron relation to the scaling relationship between extreme precipitation intensity and surface air temperature. An additional attempt is also made to test the possibility of improving the underestimation that the reanalysis models exhibit in recording the extremes and in particular the ERA5 Land dataset. [ABSTRACT FROM AUTHOR]

North Atlantic plays a pivotal role in modulating the Earth's climate by absorbing, releasing, and transferring large amounts of heat all over the world. Sea level pressure (SLP), sea surface temperature (SST), and air temperature (Tair) are strongly influenced by climate change and can affect Earth's weather and climate conditions. This study aims to investigate the role of SLP, SST, and Tair in the formation of teleconnection patterns in the North Atlantic (e.g., NAO, AO). Pearson correlation and cross-correlation analysis are used to identify the relationship between the climate parameters as well as between these parameters and the teleconnection patterns. SLP over Northern Atlantic presents positive correlation with NAO and negative correlation with AO, while an above average value of NAO is likely to lead to a below average value of SST approximately 20 days later or earlier depending on the study region. Tair changes seem to occur with a day difference from NAO and AO changes. [ABSTRACT FROM AUTHOR]