A southeastern Mediterranean PV streamer and its role in December 2001 case with torrential rains in Israel

A precipitation event of unprecedented intensity took place over northern part of Israel during 4 December 2001–5 December 2001. The case was associated with formation of a Cyprus Low cyclone over the Asia Minor. In the current study the synoptic developments over the eastern part of the Mediterranean region are simulated with the MM5 nonhydrostatic model and analyzed based on dynamic tropopause patterns calculated from the simulation results. According to the results, a powerful potential vorticity (PV) streamer system played a major role in the process over the southeastern Mediterranean region. The PV streamer created conditions for seclusion of moist air masses from the equatorial East Africa and Atlantics during the cyclone development. Condensation of the moisture, associated with the latent heat release processes have contributed to the intense thunderstorm activity and heavy precipitation of the event

The surface climatology of the eastern Mediterranean region obtained in a three-member ensemble climate change simulation experiment

International audienceTwo configurations of RegCM3 regional climate model (RCM) have been used to downscale results of two atmosphere-ocean global climate model (AOGCM) simulations of the current (1961?1990) and future climates (2071?2100) over the eastern Mediterranean (EM) region. The RCM domain covering the EM region from northern Africa to central part of Asia Minor with grid spacing of 50 km was used. Three sets of RCM simulations were completed. Results of the RCM experiment support earlier projections of a temperature (annual precipitation) increase (decrease) to the end of 21st century over the EM. The roles of several major factors in controlling uncertainty of the climate change estimates are evaluated. The main uncertainty factors appear to be associated with possible inadequacies in RCM description of the EM-climate-controlling developments over remotely located areas as well as those in the simulations of the global climate and its trends by the AOGCMs

Структурні зміни мікроциркуляторного русла дванадцятипалої кишки при обтураційному холестазі

The aim of the work: to study morphologically the features of vascular remodeling of the microcirculatory bed of the duodenum at prolonged obstructive cholestasis. Materials and Methods. Features of vascular remodeling of the microcirculatory bed of the duodenum at prolonged obstructive cholestasis were investigated morphologically. Оbstructive cholestasis was modeled by the ligation of the common bile duct. The microcirculatory bed of the duodenum was examined by the method of V. V. Kupriyanov after 3, 7, 14 and 28 days of simulated obstructive cholestasis. Results and Discussion. Studies have shown that obstructive cholestasis leads to marked remodeling of the microcirculatory bed of the duodenum. In the early stages of the simulated pathology, there is a spasm of the arterial vessels of the hemomicrocirculatory bed and expansion of the capillary venules and venules, increasing their density. At 14 and 28 days, obstructive cholestasis is complicated by the enlargement of the lymphatic and venous vessels of the microcirculatory bed, the decrease in the number of hemocapillaries, hypoxia, dystrophic, necrobiotic, infiltrative and sclerotic processes in the duodenal wall.Цель работы: морфологически изучить особенности ремоделирования сосудов микроциркуляторного русла двенадцятиперстной кишки при длительном обтурационном холестазе. Материалы и методы. Морфологически исследованы особенности ремоделирования сосудов микроциркуляторного русла двенадцатиперстной кишки при длительном обтурационном холестазе, который моделировали перевязкой общего желчного протока. Микроциркуляторное русло двенадцатиперстной кишки исследовалось методом В. В. Куприянова через 3, 7, 14 и 28 суток смоделированного обтурационного холестаза. Результаты исследований и их обсуждение. Проведенными исследованиями установлено, что обтурационный холестаз приводит к выраженному ремоделированию микроциркуляторного русла двенадцатиперстной кишки. На ранних стадиях смоделированной патологии возникает спазм приносящих сосудов гемомикроциркуляторного русла и расширения закапиллярних венул и венул, увеличение их плотности. На 14 и 28 суток обтурационный холестаз осложняется расширением лимфатических и венозных сосудов микроциркуляторного русла, уменьшением количества гемокапилляров, гипоксией, дистрофическими, некробиотическими, инфильтративными и склеротическими процессами в стенке двенадцатиперстной кишки.Мета роботи: морфологічно вивчити особливості ремоделювання судин мікроциркуляторного русла дванадцятипалої кишки при тривалому обтураційному холестазі. Матеріали і методи. Морфологічно досліджено особливості ремоделювання судин мікроциркуляторного русла дванадцятипалої кишки при тривалому обтураційному холестазі, який моделювали перев’язкою загальної жовчної протоки. Мікроциркуляторне русло дванадцятипалої кишки досліджувалося за методом В. В. Купріянова через 3, 7, 14 та 28 діб змодельованого обтураційного холестазу. Результати досліджень та їх обговорення. Проведеними дослідженнями встановлено, що обтураційний холестаз призводить до вираженого ремоделювання мікроциркуляторного русла дванадцятипалої кишки. На ранніх стадіях змодельованої патології виникає спазм приносних судин гемомікроциркуляторного русла та розширення закапілярних венул та венул, збільшення їх щільності. На 14 та 28 доби обтураційний холестаз ускладнюється розширенням лімфатичних та венозних судин мікроциркуляторного русла, зменшенням кількості гемокапілярів, гіпоксією, дистрофічними, некробіотичними, інфільтративними та склеротичними процесами у стінці дванадцятипалої кишки

Tropical tele-connections to the Mediterranean climate and weather

Some strong natural fluctuations of climate in the Eastern Mediterranean (EM) region are shown to be connected to the major tropical systems. Potential relations between EM rainfall extremes to tropical systems, e.g. El Niño, Indian Monsoon and hurricanes, are demonstrated. For a specific event, high resolution modelling of the severe flood on 3-5 December 2001 in Israel suggests a relation to hurricane Olga. In order to understand the factors governing the EM climate variability in the summer season, the relationship between extreme summer temperatures and the Indian Monsoon was examined. Other tropical factors like the Red-Sea Trough system and the Saharan dust are also likely to contribute to the EM climate variability

The role of the export of tropical moisture into midlatitudes for extreme precipitation events in the Mediterranean region

Abstract The aims of the study are twofold: firstly, to investigate the role of the export of humid tropical air in the formation of cool season heavy precipitating events (HPEs) in the Mediterranean region (MR); and secondly, to examine the possible linkage between the export of humid tropical air and the multiyear trend in extreme precipitation in the region. For this purpose, we analyze the spatial distributions of a number of key atmospheric variables with a reanalysis data for more than 50 intense HPEs for the MR. The results of this evaluation for both individual and composite events suggest that the HPEs are associated with atmospheric rivers (ARs). The MR HPEs are being characterized by the poleward export of humid air of tropical origin into the midlatitude MR from the Atlantic Ocean and Arabian Sea. These export events appear to be associated with the effects of hurricanes or intense cyclones in the North Atlantic. It was also found that the linear trend (for 1979-2013) of the frequency of humid days (days with precipitable water greater than 20 kg m −2 ) is consistent with recent changes in the character of precipitation over the MR and southern Europe

Discussing the role of tropical and subtropical moisture sources in cold season extreme precipitation events in the Mediterranean region from a climate change perspective

This paper presents a review of a large number of research studies performed during the last few decades that focused on the investigation of cold season extreme precipitation events (EPEs) in the Mediterranean region (MR). The publications demonstrate the important role of anomalously intense transports of moist air from the tropical and subtropical Atlantic in the occurrence of EPEs in the MR. EPEs in the MR are directly or indirectly connected to narrow bands with a high concentration of moisture in the lower troposphere, i.e., atmospheric rivers, along which a large amount of moisture is transported from the tropics to midlatitudes. Whereas in a significant fraction of the EPEs in the western MR moisture is transported to the MR from the tropical Atlantic, EPEs in the central, and especially the eastern, MR are more often associated with intense tropical moisture transports over North Africa and the Red Sea. The moist air for the EPEs in the latter part of the MR also mainly originates from the tropical Atlantic and Indian oceans, and in many cases it serves as a temporary moisture reservoir for future development. The paper is supplemented by the results of a test for a possible connection between declining Arctic sea ice and the climatology of intense precipitation in the eastern MR. Based on the results of the evaluation supporting those from the earlier climate change analyses and modeling studies, it is concluded that a further anthropogenic global warming may lead a greater risk of higher rainfall totals and therefore larger winter floods in western and central parts of the MR as a consequence of stronger and more numerous Atlantic atmospheric rivers, possibly accompanied by a decline in the number of EPEs in the eastern part of the MR

Relations between variability in the Mediterranean region and mid-latitude variability

In order to meet the requirements of emerging demanding services, network resource management functionality that is decentralized, flexible and adaptive to traffic and network dynamics is of paramount importance. In this paper we describe the main mechanisms of DACoRM, a new intra-domain adaptive resource management approach for IP networks. Based on path diversity provided by multi-topology routing, our approach controls the distribution of traffic load in the network in an adaptive manner through periodical re-configurations that uses real-time monitoring information. The re-configuration actions performed are decided in a coordinated fashion between a set of source nodes that form an in-network overlay. We evaluate the overall performance of our approach using realistic network topologies. Results show that near-optimal network performance in terms of resource utilization can be achieved in scalable manner