In this study, an updated and extended climatology of cyclonic tracks affecting the eastern Mediterranean region is presented, in order to better understand the Mediterranean climate and its changes. This climatology includes intermonthly variations, classification of tracks according to their origin domain, dynamic and kinematic characteristics, and trend analysis. The dataset used is the 1962–2001, 2.5° × 2.5°, 40-yr European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERA-40). The identification and tracking of the cyclones was performed with the aid of the Melbourne University algorithm. It was verified that considerable intermonthly variations of track density occur in the eastern Mediterranean, consistent with previous studies for the entire Mediterranean, while further interesting new features have been revealed. The classification of the tracks according to their origin domain reveals that the vast majority originate within the examined area itself, mainly in the Cyprus area and the southeastern Aegean Sea, while the tracks that originate elsewhere most frequently enter from the west. Deeper cyclones follow the southwest track originating from the area between Algeria and the Atlas Mountains. A greater size characterizes the westerly tracks (southwest, northwest, and west), while the northwest tracks propagate faster over the study area. A negative trend of the track frequency was found on an annual basis that can be mostly attributed to the winter months, being associated with variations in the baroclinicity. This negative trend is more prominent for the westerly and northeasterly tracks, as well as for those originating in the northern part of the examined area.

An objective climatology of explosive cyclones is performed over a 40-year period

Abstract:In this study, an attempt is made to investigate possible teleconnection patterns of atmospheric circulation, centered over eastern Mediterranean (EM) with the aid of gridded NCEP/NCAR daily values of geopotential heights for the period 1958-2003. For this purpose, two approaches have been used: correlation analysis and rotated principal component analysis (PCA) on a seasonal and monthly basis. A teleconnection pattern between the EM and northeastern Atlantic was identified at 500 and 300 hPa in winter, which will be referred to as the Eastern Mediterranean Pattern (EMP), appearing as an independent mode of the upper circulation. The pattern also exists in autumn but is substantially weakened with its dipole centers being shifted eastwards. Significant monthly variations were found in the location, strength and structure of the pattern. The employment of a standardized index demonstrated that the negative phase of the EMP prevails throughout the year with the maximum frequency at wintertime.

Abstract. Current trends in the Mediterranean climate, and more specifically in Greece, indicate longer and more intense summer droughts that even extend out of season. In connection to this, the frequency of forest fire occurrence and intensity is on the rise. In the present study, the Canadian Fire Weather Index (FWI) is used in order to investigate the relationship between fire risk and meteorological conditions in Greece. FWI is a meteorologically based index designed in Canada and used worldwide, including the Mediterranean Basin, to estimate fire danger in a generalised fuel type based solely on weather observations. Here, an evaluation of the index is initially performed for the Greek territory using fire observations that cover a 15 yr period. Three critical fire risk threshold values are established for the area of Greece based on daily mean meteorological data: FWI = 15, FWI = 30 and FWI = 45, increasing from the northwest to the southeast. Subsequently, a regional climate model is employed providing input for the FWI system to investigate the impacts of climate change on fire risk for two future time periods, 2021-2050 and 2071-2100, under the A1B emissions scenario. Days with critical fire risk are expected to increase by as many as 50 days per year by the end of the century.

Abstract. A large number of intense cyclones occur every year in the Mediterranean basin, one of the climate change hotspots. Producing a broad range of severe socio-economic and environmental impacts in such a densely populated region, Mediterranean cyclones call for coordinated and interdisciplinary research efforts. This article aims at supporting these efforts by reviewing the status of knowledge in the broad field of Mediterranean cyclones. First, we focus on the climatology of Mediterranean cyclone tracks, their relationship to large-scale atmospheric circulation and their future trends. Second, we discuss the dynamics and atmospheric processes that govern the genesis and development of Mediterranean cyclones. Then, we present the different subtypes of Mediterranean cyclones, devoting special attention to medicanes, i.e. cyclones with tropical characteristics and subjects of numerous recent studies. In a subsequent section, we review the state of the art in forecasting cyclones and relevant high-impact weather, and we discuss in detail the challenges and recent efforts to increase their forecast skill. Finally, we discuss the main impacts produced by cyclones, namely heavy precipitation, windstorms, dust transport, storm surges and sea wave extremes. In the last section of this review article, we thoroughly outline the future directions of research that would advance the broader field of Mediterranean cyclones.

The objective of this study is to investigate the impact of the eastern Mediterranean teleconnection pattern (EMP) on the present and future climate of the eastern Mediterranean during winter. For the present climate, daily precipitation and maximum and minimum surface temperature station data are employed for the period of 1958–2003. For the future climate, datasets of the same parameters are derived from the Hadley Centre Regional Climatic Model (HadRM3P) for the period of 2070–2100, using two Intergovernmental Panel on Climate Change (IPCC) emission scenarios for the evolvement of the future atmospheric concentrations of greenhouse gases. The investigation of the impact was based on the regularized canonical correlation analysis (RCCA), while qualitative estimations were performed for each phase of the pattern. It was found that the pattern indeed affects the mean winter patterns of temperature, precipitation, and their extreme events with inverse impacts between the two phases. More specifically, a positive phase of EMP is associated with a decrease in temperatures and an increase in precipitation, while the opposite occurs during the negative phase of EMP. In the future, the present impact according to each phase persists and intensifies in most of the cases. However, results are quite different between the two scenarios, because of the different estimated future shift of the EMP poles.

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Abstract. Recent and future changes in temperature and precipitation climate extremes are estimated using the Hadley Centre PRECIS ("Providing REgional Climates for Impacts Studies") climate model for the eastern Mediterranean and Middle East region. The area of interest is considered vulnerable to extreme climate events as there is evidence for a temperature rise while precipitation tends to decline, suggesting likely effects on vital socioeconomic sectors in the region. Observations have been obtained for the recent period ) and used to evaluate the model output. The spatial distribution of recent temporal trends in temperature indicates strong increasing in minimum temperature over the eastern Balkan Peninsula, Turkey and the Arabian Peninsula. The rate of warming reaches 0.4-0.5 • C decade −1 in a large part of the domain, while warming is expected to be strongest in summer (0.6-0.7 • C decade −1 ) in the eastern Balkans and western Turkey. The trends in annual and summer maximum temperature are estimated at approximately 0.5 and 0.6 • C decade −1 respectively. Recent estimates do not indicate statistically significant trends in precipitation except for individual sub-regions. Results indicate a future warming trend for the study area over the last 30 years of the 21st century. Trends are estimated to be positive and statistically significant in nearly the entire region. The annual trend patterns for both minimum and maximum temperature show warming rates of approximately 0.4-0.6 • C decade −1 , with pronounced warming over the Middle Eastern countries. Summer temperatures reveal a gradual warming (0.5-0.9 • C decade −1 ) over much of the region. The model projects drying trends by 5-30 % in annual precipitation towards the end of the 21st century, with the number of wet days decreasing at the rate of 10-30 days year −1 , while heavy precipitation is likely to decrease in the high-elevation areas by 15 days year −1 .