scholarly journals Heavy rain events in the Western Mediterranean: an atmospheric pattern classification

2008 ◽  
Vol 2 (1) ◽  
pp. 61-64 ◽  
Author(s):  
C. Martínez ◽  
J. Campins ◽  
A. Jansà ◽  
A. Genovés
Keyword(s):  
Heavy Rain ◽  
Western Mediterranean ◽  
High Impact ◽  
Good Relationship ◽  
Operational Analysis ◽  
Mediterranean Regions ◽  
High Impact Weather ◽  
Components Analysis ◽  
Rain Events

Abstract. Heavy rain is one of the most important high-impact weather phenomena that occasionally affect Mediterranean areas. The aim of this study is to achieve a classification of atmospheric patterns related to heavy rain events in both French and Spanish Mediterranean regions. The classification is made on some atmospheric fields (geopotential at 1000 hPa and at 500 hPa and temperature at 850 hPa) of HIRLAM-INM-0.5° operational analysis, for heavy rain events included in the High Impact Weather MEDEX database. It covers a period of roughly 7 and a half years, from January 1997 to May 2004. A Principal Components Analysis was conducted to reduce the number of variables. After that, by means of a Cluster Analysis, the heavy rain events are classified into 8 atmospheric patterns. The results show a good relationship between regions affected by heavy rain and atmospheric patterns, in the sense that the same atmospheric patterns usually produce heavy rain in different regions, and heavy rain in different regions is usually due to specific atmospheric patterns.

scholarly journals Atmospheric patterns for heavy rain events in the Balearic Islands

2007 ◽  
Vol 12 ◽  
pp. 27-32 ◽  
Author(s):  
A. Lana ◽  
J. Campins ◽  
A. Genovés ◽  
A. Jansà
Keyword(s):  
Heavy Rainfall ◽  
Strong Relationship ◽  
Heavy Rain ◽  
Balearic Islands ◽  
Atmospheric Parameters ◽  
Mediterranean Regions ◽  
Components Analysis ◽  
Rain Events ◽  
New Variables

Abstract. The Balearic Islands, as well as other Mediterranean regions, are occasionally affected by heavy rain events, which can produce numerous damages. This study contributes to improve the understanding of the dynamical mechanisms that produce heavy rain events by means of a classification of their related atmospheric patterns. Heavy rainfall dataset for the Balearic Islands and some gridded atmospheric parameters, derived from the HIRLAM-INM-0.5° analyses, were the data used in this study. Heavy rain events were recorded at a set of pluviometric stations along the Balearics for a period of 9 years, from June 1995 to May 2004. The 1000 hPa and 500 hPa geopotential heights (hereafter φ1000 and φ500), as well as the 850 hPa temperature (T850) were the fields utilized in the classification. By means of a principal components analysis (PCA) the number of variables was reduced. The cluster analysis (CA) was then applied on those new variables and eight atmospheric patterns were finally obtained. Most of the patterns showed a strong relationship between heavy rain events and cyclones.

scholarly journals Towards a climatology of sensitivities of Mediterranean high impact weather − first approach

2006 ◽  
Vol 7 ◽  
pp. 259-267 ◽  
Author(s):  
V. Homar ◽  
A. Jansà ◽  
J. Campins ◽  
C. Ramis
Keyword(s):  
Heavy Rain ◽  
High Impact ◽  
Numerical Predictions ◽  
Special Value ◽  
Sensitivity Studies ◽  
High Impact Weather ◽  
The Mediterranean ◽  
Strong Winds ◽  
Eastern North Atlantic

Abstract. During recent years, great interest has grown within the operational weather community on the adaptable component of observational networks. Decisions regarding where to deploy new observations of special value under threatening weather, or regarding permanent changes in observational strategies need support from sensitivity studies that determine areas where the addition of observations would optimally improve the skill of numerical predictions. Within the context of the MEDEX project (http://medex.inm.uib.es), the sensitivities of a collection of severe weather episodes in the Mediterranean have been computed using the MM5 Adjoint Modeling system. Various approaches are explored trying to summarize the results for the diversity of cases that produce high impact weather (HIW; mainly heavy rain and strong winds) in the Mediterranean region. A first attempt uses an objective classification of the trajectories of the most intense cyclone types from the ERA-40 reanalyses. Sensitivities are then computed for each group of frequent trajectories, providing a prototype sensitivity field for each of the most frequent intense cyclones in the Mediterranean. However, a large portion of HIW episodes in the Mediterranean are not linked to significantly intense cyclones within the climatology. Consequently, a subjective classification of HIW events is also performed and the sensitivity fields for an example case is shown to complete the study. Although the sensitive areas for Mediterranean HIW are not particularly confined, it is remarkable how poorly sampled areas by the regular observing networks such as North Africa and the eastern North-Atlantic are highlighted in the results.

scholarly journals High impact weather and cyclones simultaneity in Catalonia

2007 ◽  
Vol 12 ◽  
pp. 115-120 ◽  
Author(s):  
J. Campins ◽  
M. Aran ◽  
A. Genovés ◽  
A. Jansà
Keyword(s):  
Heavy Rain ◽  
Western Mediterranean ◽  
High Impact ◽  
Strong Wind ◽  
Accurate Forecast ◽  
High Impact Weather ◽  
Deep Cyclone ◽  
Almost All ◽  
Meso Scale

Abstract. The Western Mediterranean in general and Catalonia in particular are usually affected by high impact weather (HIW) events, mainly heavy rain (HR) and strong wind (SW). The improvement in the understanding and the accurate forecast of such events are major concerns for the meteorologists of the region. In the present study, HR and SW events in Catalonia are cross-referenced with an objective cyclone database for a 9-year period (from June 1995 to May 2004). Results show that in most of the HR events a cyclone is located close to Catalonia, in such a way that the feeding of a moist flow to the affected region was favoured. These cyclones can be either shallow and weak or deep and intense. A simultaneous cyclone also appears to be connected with many SW events. However, other SW events seem to be related to meso-scale circulations and, as a result, not always well captured in the cyclone database. Finally, coincident HR and SW events are analysed. In almost all of such events a deep cyclone is located in the vicinity of Catalonia.

scholarly journals Sea surface temperature and torrential rains in the Valencia region: modelling the role of recharge areas

2015 ◽  
Vol 15 (7) ◽  
pp. 1677-1693 ◽  
Author(s):  
F. Pastor ◽  
J. A. Valiente ◽  
M. J. Estrela
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Heavy Rain ◽  
Western Mediterranean ◽  
Sea Surface ◽  
Economic Losses ◽  
High Mountain ◽  
Rain Event ◽  
Air Mass ◽  
Rain Events

Abstract. Heavy rain events are frequently recorded in the Western Mediterranean causing economic losses and even human casualties. The Western Mediterranean is a deep and almost closed sea surrounded by high mountain ranges and with little exchange of water with the Atlantic ocean. A main factor in the development of torrential rains is ocean-atmosphere exchanges of heat and moisture that can potentially destabilize air masses travelling over the sea. The study of air mass trajectories previous to the rain event permits the identification of sea areas that could probably contribute to the development or intensification of rainfall. From a previous Mediterranean sea surface temperature climatology, its spatio-temporal distribution patterns have been studied showing two main distribution modes in winter and summer and transitional regimes in spring and autumn. Hence, three heavy precipitation events, for such winter and summer sea temperature regimes and for fall transition, affecting the Valencia region have been selected to study the effect of sea surface temperature in torrential rains. Simulations with perturbed sea surface temperature in different areas along the air mass path were run to compare results with unperturbed simulation. The variation of sea surface temperature in certain areas caused significant changes in model accumulated values and its spatial distribution. Therefore, the existence of areas that at a greater extent favour air-sea interaction leading to the development of torrential rainfall in the Valencia region has been shown. This methodology could be extended to the whole Mediterranean basin to look for such potential recharge areas. The identification of sea areas that contribute to the development or intensification of heavy rain events in the Mediterranean countries could be a useful prognosis and/or monitoring tool.

scholarly journals Sea surface temperature and torrential rains in the Valencia region: modelling the role of recharge areas

2015 ◽  
Vol 3 (2) ◽  
pp. 1357-1396 ◽  
Author(s):  
F. Pastor ◽  
J. A. Valiente ◽  
M. J. Estrela
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Heavy Rain ◽  
Western Mediterranean ◽  
Sea Surface ◽  
Economic Losses ◽  
High Mountain ◽  
Rain Event ◽  
Air Mass ◽  
Rain Events

Abstract. Heavy rain events are frequently recorded in the Western Mediterranean causing economic losses and even human casualties. The Western Mediterranean is a deep and almost closed sea surrounded by high mountain ranges and with little exchange of water with the Atlantic ocean. A main factor in the development of torrential rains are ocean-atmosphere exchanges of heat and moisture that can potentially destabilize air masses travelling over the sea. The study of air mass trajectories previous to the rain event permits the identification of sea areas that could probably contribute to the development or intensification of rainfall. From a previous Mediterranean sea surface temperature climatology, its spatio-temporal distribution patterns have been studied showing two main distribution modes in winter and summer and transitional regimes in spring and autumn. Hence, three heavy precipitation events, for such winter and summer sea temperature regimes and for fall transition, affecting the Valencia region have been selected to study the effect of sea surface temperature in torrential rains. Simulations with perturbed sea surface temperature in different areas along the air mass path were run to compare results with unperturbed simulation. The variation of sea surface temperature in certain areas caused significant changes in model accumulated values and its spatial distribution. Therefore, the existence of recharge areas where air–sea interaction favors the development of torrential rainfall in Valencia region has been shown. This methodology could be extended to the whole Mediterranean basin to look for such potential recharge areas. The identification of sea areas that contribute to the development or intensification of heavy rain events in the Mediterranean countries could be a useful prognosis and/or monitoring tool.

scholarly journals An optimized ensemble sensitivity climatology of Mediterranean intense cyclones

2010 ◽  
Vol 10 (12) ◽  
pp. 2441-2450 ◽  
Author(s):  
L. Garcies ◽  
V. Homar
Keyword(s):  
Mediterranean Basin ◽  
Western Europe ◽  
Western Mediterranean ◽  
High Impact ◽  
North African ◽  
New Classification ◽  
New Approach ◽  
Western Mediterranean Basin ◽  
Analysis Technique

Abstract. A new approach was recently proposed to compute climatological statistical sensitivities. It was applied on an already available classification of Mediterranean intense cyclones. However, those sensitivity results are questionable due to the limited homogeneity of some cyclone classes, which severely hampers the application of the statistical sensitivity analysis technique. In this study, a new classification of Mediterranean intense cyclones is built with the aim of improving the reliability of the final climatological sensitivity results. In addition to implementing a regional classification and a subsequent division according to the preceding conditions that lead to cyclone formation, a cluster pruning is applied to maximize the homogeneity of the classes. The increased cluster homogeneity and the higher significance of the obtained sensitivity estimates are quantified. Furthermore, the improved representativeness of the sensitivity fields derived after cluster pruning is tested and compared to previous results by means of numerical experiments. Eventually, summary sensitivity fields highlight the European Atlantic coasts, central and western Europe, the central and western Mediterranean basin and north african lands as sensitive regions for the evolution of these Mediterranean high-impact systems. Although some outstanding improvements are confirmed in this study, a further verification experiments are needed to objectively verify the sensitivity results and build solid confidence on the method.

scholarly journals Atmospheric Water Monitoring by Using Ground-Based GPS during Heavy Rains Produced by TPV and SWV

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Guoping Li ◽  
Jia Deng
Keyword(s):  
Tibetan Plateau ◽  
Precipitable Water ◽  
Heavy Rain ◽  
The Tibetan Plateau ◽  
Chengdu Plain ◽  
Gps Network ◽  
High Impact Weather ◽  
Tibetan Plateau Vortex ◽  
Rain Events ◽  
Short Term Forecasting

The time series of precipitable water (PW) in 30 min intervals has been determined through experimentation and operational application of a ground-based global positioning system (GPS) network in Chengdu Plain, which is used for precise and reliable meteorological research. This study is the first to apply PW to the southwest vortex (SWV) and heavy rain events by using the data from an intensive SWV experiment conducted in summer 2010. The PW derived from the local ground-based GPS network was used in the monitoring and analysis of heavy rain caused by the SWV and the Tibetan Plateau vortex (TPV). Results indicate that an increase in GPS precipitable water (GPS-PW) occurs prior to the development of the TPV and SWV; rainfall occurs mainly during high levels of GPS-PW. The evolution features of GPS-PW in rainfall process caused by different weather systems over the Tibetan Plateau (TP) also differ. These results indicate the reference values for operational applications of GPS-PW data in short-term forecasting and nowcasting of high-impact weather in addition to further investigation of heavy rain caused by the TPV, SWV, and other severe weather systems over the TP.

“Stay with me. Talk to me”: reader interaction strategies in modern poetry

2020 ◽  
Vol 7 (2) ◽  
pp. 419-436
Author(s):  
Olga Igorevna Severskaya
Keyword(s):  
Discourse Analysis ◽  
High Impact ◽  
Modern Poetry ◽  
Self Presentation ◽  
Communication Plan ◽  
Communicative Strategies ◽  
The World ◽  
Poetic Text ◽  
Communicative Context

The article is devoted to the consideration of a poetic text as a communicative phenomenon with a high impact potential. The author defines the features of poetic communication, which is both mass and interpersonal, and its main goal, which is the poet’s desire to communicate author’s vision of the world and thereby change the picture of the reader’s world, achieving empathy from it. Based on the understanding of the speech strategy as a cognitive communication plan, a program for generating and perceiving speech, the author talks about the fundamental reversibility of text-generating and interpretative strategies and offers own classification of strategies and tactics that are most often used in modern poetry. In this classification, the main communicative strategies of self-presentation and rapprochement with the reader are associated with auxiliary discursive strategies of actualizing, dramatizing and dialogizing the text and programming interpretations by tactics for highlighting objects and situations using sound “gestures”, pointing to the referent, framing, directly introducing the reader into the communicative context, attracting the recipient’s attention through appeals and pragmatic instructions, interrogation, and some others. Particular attention is paid to the multimodality of interactions and its specific manifestations in poetic discourse. The study is based on the material of Russian poetry of the 1980- 2000s using the methods of intent and discourse analysis.

scholarly journals Comparison of Radar-Based Hail Detection Using Single- and Dual-Polarization

2019 ◽  
Vol 11 (12) ◽  
pp. 1436 ◽  
Author(s):  
Skripniková ◽  
Řezáčová
Keyword(s):  
Comparative Analysis ◽  
Heavy Rain ◽  
Radar Data ◽  
Severe Weather ◽  
Detection Methods ◽  
Polarimetric Radar ◽  
Dual Polarization ◽  
Rain Events ◽  
Single Polarization ◽  
Strong Agreement

The comparative analysis of radar-based hail detection methods presented here, uses C-band polarimetric radar data from Czech territory for 5 stormy days in May and June 2016. The 27 hail events were selected from hail reports of the European Severe Weather Database (ESWD) along with 21 heavy rain events. The hail detection results compared in this study were obtained using a criterion, which is based on single-polarization radar data and a technique, which uses dual-polarization radar data. Both techniques successfully detected large hail events in a similar way and showed a strong agreement. The hail detection, as applied to heavy rain events, indicated a weak enhancement of the number of false detected hail pixels via the dual-polarization hydrometeor classification. We also examined the performance of hail size detection from radar data using both single- and dual-polarization methods. Both the methods recognized events with large hail but could not select the reported events with maximum hail size (diameter above 4 cm).

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