scholarly journals <i>Brief communication</i> "Calabria daily rainfall from 1970 to 2006"

2010 ◽  
Vol 10 (4) ◽  
pp. 717-722 ◽  
Author(s):  
S. Federico ◽  
L. Pasqualoni ◽  
E. Avolio ◽  
C. Bellecci
Keyword(s):  
Large Scale ◽  
Daily Precipitation ◽  
Daily Rainfall ◽  
Mean Value ◽  
Precipitation Trend ◽  
Teleconnection Patterns ◽  
Rain Gauges ◽  
The Mediterranean ◽  
Mediterranean Oscillation ◽  
Controlled Precipitation

Abstract. This brief communication introduces a new quality-controlled precipitation database for Calabria, shows the precipitation trend for the period considered, and correlates daily rainfall with some common teleconnection patterns. The database consists of daily accumulated precipitation collected by 61 rain gauges from 1 January 1970 to 31 December 2006. The 37-year trend in yearly rainfall shows a decrease of 4.7 mm/y, with a 17% reduction in the yearly mean value. The correlation of the daily rainfall with large-scale patterns shows that the Mediterranean Oscillation Index (MOI a/c) is a useful predictor of daily precipitation over Calabria.

scholarly journals Systematic Variation in Wintertime Precipitation in East Asia by MJO-Induced Extratropical Vertical Motion

2008 ◽  
Vol 21 (4) ◽  
pp. 788-801 ◽  
Author(s):  
Jee-Hoon Jeong ◽  
Baek-Min Kim ◽  
Chang-Hoi Ho ◽  
Yeon-Hee Noh
Keyword(s):  
East Asia ◽  
Large Scale ◽  
Diabatic Heating ◽  
Daily Precipitation ◽  
Lower Troposphere ◽  
Vertical Motion ◽  
Mean Value ◽  
Asian Countries ◽  
The Indian Ocean ◽  
Omega Equation

Abstract The variations in the wintertime precipitation over East Asia and the related large-scale circulation associated with the Madden–Julian oscillation (MJO) are examined. By analyzing the observed daily precipitation for the period 1974–2000, it is found that the MJO significantly modulates the distribution of precipitation over four East Asian countries; the precipitation rate difference between wet and dry periods over East Asia, when the centers of MJO convective activities are located over the Indian Ocean and western Pacific, respectively, reaches 3–4 mm day−1, which corresponds to the climatological winter-mean value. Composite analysis with respect to the MJO suggests that the MJO–precipitation relation is mostly explained by the strong vertical motion anomalies near an entrance region of the East Asia upper-tropospheric jet and moisture supply in the lower troposphere. To elucidate different dynamic origins of the vertical motion generated by the MJO, diagnostic analysis of a generalized omega equation is adopted. It is revealed that about half of the vertical motion anomalies in East Asia are induced by the quasigeostrophic forcings by the MJO, while diabatic heating forcings explain a very small fraction, less than 10% of total anomalies.

scholarly journals Relationship between the precipitation variability in Montenegro and the Mediterranean oscillation

2014 ◽  
Vol 94 (4) ◽  
pp. 109-120 ◽  
Author(s):  
Dragan Buric ◽  
Vladan Ducic ◽  
Jovan Mihajlovic ◽  
Jelena Lukovic ◽  
Jovan Dragojlovic
Keyword(s):  
Human Factor ◽  
General Idea ◽  
Climate Indices ◽  
Intensity Increase ◽  
Negative Consequences ◽  
Teleconnection Patterns ◽  
The Mediterranean ◽  
Mediterranean Oscillation ◽  
The Relationship ◽  
The Mediterranean Basin

This study investigates the influence of atmospheric circulation in the Mediterranean region on the precipitation in Montenegro. Nine precipitation parameters have been used in the analysis and the relationship has been investigated by the Mediterranean and West Mediterranean Oscillation change index (MO and WeMO). According to a 60 - year observed period (1951-2010), the research results show that nothing characteristic happens with seasonal and annual precipitation sums because the trend is mainly insignificant. However, precipitation extremes are getting more extreme, which corresponds with a general idea of global warming. Negative consequences of daily intensity increase and frequency of precipitation days above fixed and percentile thresholds have been recorded recently in the form of torrents, floods, intensive erosive processes, etc., but it should be pointed out that human factor is partly a cause of such events. The estimate of the influence of teleconnection patterns primarily related to the Mediterranean Basin has shown that their variability affects the observed precipitation parameters on the territory of Montenegro regarding both seasonal and annual sums and frequency and intensity of extreme events shown by climate indices.

A sub-regional approach for the analysis of atmospheric teleconnection influence on precipitation in Calabria (southern Italy)

2020 ◽  
Author(s):  
Giulio Nils Caroletti ◽  
Roberto Coscarelli ◽  
Tommaso Caloiero
Keyword(s):  
Climate Change ◽  
Large Scale ◽  
Monthly Precipitation ◽  
The South ◽  
The North ◽  
Eastern Zone ◽  
Teleconnection Indices ◽  
Western Zone ◽  
The Mediterranean ◽  
Mediterranean Oscillation

&lt;p&gt;Due to the importance of precipitation as a climatic and meteorological variable, it is paramount to detect the relationships between teleconnections and precipitation at different temporal and spatial scale. In fact, large-scale systems can i) influence precipitation directly, ii) establish a favourable environment to deep moist convection, and thus extreme precipitation, but also iii) help triggering dry conditions and drought.&lt;/p&gt;&lt;p&gt;In this study, developed within the INDECIS EU project, the teleconnection influence on precipitation in the Calabria region has been evaluated over the 1981-2010 time period, by means of a database of 79 rain gauge stations and seven teleconnections indices. Calabria, the southernmost region of peninsular Italy, was chosen as a valuable test bed mainly because it is located in the centre of the Mediterranean region, which constitutes a hot spot for climate change. Moreover, Calabria has a high-density, long-time network of precipitation gauges, recently validated and homogenized.&lt;/p&gt;&lt;p&gt;Statistical relationships between teleconnection indices and precipitation are often developed through well-known correlation analyses techniques, e.g. Pearson, Spearman and Kendall, where a teleconnection index is compared to cumulated precipitation values. In this study, three types of correlation analysis were performed: i) seasonal indices vs seasonal cumulated precipitation; ii) three-month indices vs monthly cumulated precipitation; iii) monthly indices vs monthly cumulated precipitation. These analyses have been performed in five Rainfall Zones (RZs) of the study area, characterised by different climatic conditions: the North-Eastern Zone (I1), the Central-Eastern Zone (I2) and the South-Eastern Zone (I3) on the Ionian side of Calabria and the North-Western Zone (T1) and the South-Western Zone (T2) on the Tyrrhenian part.&lt;/p&gt;&lt;p&gt;Results showed that the Mediterranean Oscillation and the North Atlantic Oscillation are the most important large-scale contributors to the precipitation regime of Calabria. Moreover, seasonal Eastern Atlantic pattern influenced seasonal precipitation in the RZs I1 and T1; three-monthly East Atlantic/Western Russian pattern influenced monthly precipitation in the RZs I2 and T1; three-monthly Western Mediterranean Oscillation influenced monthly precipitation in the RZs I3 and T1; while three-monthly El Nino-Southern Oscillation influenced monthly precipitation in the RZ T2.&lt;/p&gt;&lt;p&gt;Investigating changes in the response of local precipitation and teleconnections throughout the 1951-2010 and 1951-1980 time periods, a change in precipitation response to teleconnection patterns emerged, i.e., in the impact that the Mediterranean Oscillation has on the East coast precipitation (RZs I1-I3), a possible result of natural variation or climate change. In addition, these results have been compared to those obtained with the classical correlation analyses between teleconnection indices and single-station precipitation.&lt;/p&gt;&lt;p&gt;The approach developed for this study is a general method that, in principle, can be reproduced for any variable for any region and for every teleconnection.&lt;/p&gt;&lt;p&gt;Acknowledgments:&lt;/p&gt;&lt;p&gt;The Project INDECIS is part of ERA4CS, an ERA-NET initiated by JPI Climate, and funded by FORMAS (SE), DLR (DE), BMWFW (AT), IFD (DK), MINECO (ES), ANR (FR) with co-funding by the European Union (Grant 690462).&lt;/p&gt;

scholarly journals Influence of Daily Rainfall Characteristics on Regional Summertime Precipitation over the Southwestern United States

2009 ◽  
Vol 10 (5) ◽  
pp. 1218-1230 ◽  
Author(s):  
Bruce T. Anderson ◽  
Jingyun Wang ◽  
Suchi Gopal ◽  
Guido Salvucci
Keyword(s):  
United States ◽  
Large Scale ◽  
Daily Precipitation ◽  
Daily Rainfall ◽  
Southwestern United States ◽  
Regional Variability ◽  
Rainfall Frequency ◽  
Circulation Patterns ◽  
Precipitation Characteristics ◽  
Precipitation Anomalies

Abstract The regional variability in the summertime precipitation over the southwestern United States is studied using stochastic chain-dependent models generated from 70 yr of station-based daily precipitation observations. To begin, the spatiotemporal structure of the summertime seasonal mean precipitation over the southwestern United States is analyzed using two independent spatial cluster techniques. Four optimal clusters are identified, and their structures are robust across the techniques used. Next, regional chain-dependent models—comprising a previously dependent occurrence chain, an empirical rainfall coverage distribution, and an empirical rainfall amount distribution—are constructed over each subregime and are integrated to simulate the regional daily precipitation evolution across the summer season. Results indicate that generally less than 50% of the observed interannual variance of seasonal precipitation in a given region lies outside the regional chain-dependent models’ stochastic envelope of variability; this observed variance, which is not captured by the stochastic model, is sometimes referred to as the “potentially predictable” variance. In addition, only a small fraction of observed years (between 10% and 20% over a given subregime) contain seasonal mean precipitation anomalies that contribute to this potentially predictable variance. Further results indicate that year-to-year variations in daily rainfall coverage are the largest contributors to potentially predictable seasonal mean rainfall anomalies in most regions, whereas variations in daily rainfall frequency contribute the least. A brief analysis for one region highlights how the identification of years with potentially predictable precipitation characteristics can be used to better understand large-scale circulation patterns that modulate the underlying daily rainfall processes responsible for year-to-year variations in regional rainfall.

scholarly journals Statistical-Observational Analysis of Skillful Oceanic Predictors of Heavy Daily Precipitation Events in the Sahel

Atmosphere ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 584
Author(s):  
Moussa Diakhaté ◽  
Roberto Suárez-Moreno ◽  
Iñigo Gómara ◽  
Elsa Mohino
Keyword(s):  
Mediterranean Sea ◽  
Daily Precipitation ◽  
Southern Oscillation ◽  
Rainfall Variability ◽  
Daily Rainfall ◽  
Forecast Model ◽  
Temporal Prediction ◽  
Forecasting System ◽  
The Mediterranean ◽  
Precipitation Events

In this paper, the sea surface temperature (SST) based statistical seasonal forecast model (S4CAST) is utilized to examine the spatial and temporal prediction skill of Sahel heavy and extreme daily precipitation events. As in previous studies, S4CAST points out the Mediterranean Sea and El Niño Southern Oscillation (ENSO) as the main drivers of Sahel heavy/extreme daily rainfall variability at interannual timescales (period 1982–2015). Overall, the Mediterranean Sea emerges as a seasonal short-term predictor of heavy daily rainfall (1 month in advance), while ENSO returns a longer forecast window (up to 3 months in advance). Regarding the spatial skill, the response of heavy daily rainfall to the Mediterranean SST forcing is significant over a widespread area of the Sahel. Contrastingly, with the ENSO forcing, the response is only significant over the southernmost Sahel area. These differences can be attributed to the distinct physical mechanisms mediating the analyzed SST-rainfall teleconnections. This paper provides fundamental elements to develop an operational statistical-seasonal forecasting system of Sahel heavy and extreme daily precipitation events.

scholarly journals Climatic Indices over the Mediterranean Sea: A Review

2020 ◽  
Vol 10 (17) ◽  
pp. 5790
Author(s):  
Francisco Criado-Aldeanueva ◽  
Javier Soto-Navarro
Keyword(s):  
Mediterranean Sea ◽  
Large Scale ◽  
Thermohaline Circulation ◽  
Point Of View ◽  
East Atlantic ◽  
Physical Point ◽  
Climatic Indices ◽  
The North ◽  
The Mediterranean ◽  
Mediterranean Oscillation

The Mediterranean Sea, strategically situated across a dynamic frontier line that separates two regions with different climates (Europe and North Africa), has been the focus of attention of many studies dealing with its thermohaline circulation, deep water formation processes or heat and freshwater budgets. Large-scale atmospheric forcing has been found to play an important role in these topics and attention has been renewed in climatic indices that can be used as a proxy for atmospheric variability. Among them, the North Atlantic oscillation, the East Atlantic or the East Atlantic–West Russia patterns have been widely addressed but much less attention has been devoted to a Mediterranean mode, the Mediterranean oscillation. This overview summarizes the recent advances that have been achieved in the understanding of these climatic indices and their influence on the functioning of the Mediterranean from a physical point of view. The important role of the Mediterranean oscillation is emphasized and the most relevant aspects of the other indices are revisited and discussed.

scholarly journals The Mediterranean Oscillation Teleconnection Index: Station-Based versus Principal Component Paradigms

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Francisco Criado-Aldeanueva ◽  
F. Javier Soto-Navarro
Keyword(s):  
Mediterranean Sea ◽  
Large Scale ◽  
Principal Component ◽  
Poor Correlation ◽  
Atmospheric Forcing ◽  
Sea Level Pressure ◽  
Levantine Basin ◽  
The Mediterranean ◽  
The Difference ◽  
Mediterranean Oscillation

Two different paradigms of the Mediterranean Oscillation (MO) teleconnection index have been compared in this work: station-based definitions obtained by the difference of some climate variable between two selected points in the eastern and western basins (i.e., Algiers and Cairo, Gibraltar and Israel, Marseille and Jerusalem, or south France and Levantine basin) and the principal component (PC) approach in which the index is obtained as the time series of the first mode of normalised sea level pressure anomalies across the extended Mediterranean region. Interannual to interdecadal precipitation (P), evaporation (E),E-P, and net heat flux have been correlated with the different MO indices to compare their relative importance in the long-term variability of heat and freshwater budgets over the Mediterranean Sea. On an annual basis, the PC paradigm is the most effective tool to assess the effect of the large-scale atmospheric forcing in the Mediterranean Sea because the station-based indices exhibit a very poor correlation with all climatic variables and only influence a reduced fraction of the basin. In winter, the station-based indices highly improve their ability to represent the atmospheric forcing and results are fairly independent of the paradigm used.

scholarly journals Isotopic composition of daily precipitation along southern foothills of the Himalayas: impact of marine and continental sources of atmospheric moisture

2017 ◽  
Author(s):  
Ghulam Jeelani ◽  
Rajendrakumar D. Deshpande ◽  
Michal Galkowski ◽  
Kazimierz Rozanski
Keyword(s):  
Isotopic Composition ◽  
Large Scale ◽  
Daily Precipitation ◽  
Isotope Composition ◽  
Daily Rainfall ◽  
Himalayan Region ◽  
Water Evaporation ◽  
Atmospheric Moisture ◽  
Air Masses ◽  
Continental Origin

Abstract. The flow of the Himalayan rivers, a key source of fresh water to more than a billion people primarily depends upon the strength, behaviour and duration of Indian Summer Monsoon (ISM) and Western Disturbances (WD), two contrasting circulation regimes of the regional atmosphere. Analysis of 2H and 18O isotope composition of daily precipitation collected along the southern foothills of the Himalayas combined with extensive backward trajectory modelling was used to gain deeper insight into the mechanisms controlling isotopic composition of precipitation and the origin of atmospheric moisture and precipitation during ISM and WD periods. Daily precipitation samples have been collected during the period September 2008 – December 2011 at six stations, extending from Srinagar in the west (Kashmir state) to Dibrugarh in the east (Assam state). In total, 548 daily precipitation samples have been collected and analysed for their stable isotope composition. It is suggested that gradual reduction in 2H and 18O content of precipitation in the studied region, progressing from δ18O values close to zero down to ca. −10 ‰ in the course of ISM evolution, stems from regional, large-scale recycling of moisture-driven monsoonal circulation. Superimposed on this general trend are short-term fluctuations of the isotopic composition of rainfall, having their roots in the local effects such as enhanced convective activity and associated higher degree of rainout of moist air masses (local amount effect), cyclonic storms or impact of isotopically heavy moisture of continental origin. Seasonal footprint maps constructed for three stations representing western, central and eastern portion of the Himalayan region indicate that influence of monsoonal circulation reaches western edges of the Himalayan region. While characteristic imprint of monsoon air masses (increase of monthly rainfall amount) can be completely absent in the western Himalaya, the onset of ISM period in this region is still clearly visible in the isotopic composition of daily precipitation. Characteristic feature of daily precipitation collected during WD period is a gradual increase of 2H and 18O content, reaching positive δ2H and δ18O values towards the end of this period. This trend can be explained by growing importance of moisture of continental origin as a source of daily precipitation. High d-excess values of daily rainfall recorded at the monitoring stations (38 cases in total, range from 20.6 to 44.0 ‰) are attributed to moisture of continental origin released into the atmosphere during evaporation of surface water bodies and/or soil water evaporation.

scholarly journals The INTENSE project: using observations and models to understand the past, present and future of sub-daily rainfall extremes

2018 ◽  
Vol 15 ◽  
pp. 117-126 ◽  
Author(s):  
Stephen Blenkinsop ◽  
Hayley J. Fowler ◽  
Renaud Barbero ◽  
Steven C. Chan ◽  
Selma B. Guerreiro ◽  
...  
Keyword(s):  
Short Duration ◽  
Large Scale ◽  
Daily Rainfall ◽  
Future Climate Change ◽  
Climate Modelling ◽  
Global Challenge ◽  
Rain Gauges ◽  
The Us ◽  
Rainfall Extremes

Abstract. Historical in situ sub-daily rainfall observations are essential for the understanding of short-duration rainfall extremes but records are typically not readily accessible and data are often subject to errors and inhomogeneities. Furthermore, these events are poorly quantified in projections of future climate change making adaptation to the risk of flash flooding problematic. Consequently, knowledge of the processes contributing to intense, short-duration rainfall is less complete compared with those on daily timescales. The INTENSE project is addressing this global challenge by undertaking a data collection initiative that is coupled with advances in high-resolution climate modelling to better understand key processes and likely future change. The project has so far acquired data from over 23 000 rain gauges for its global sub-daily rainfall dataset (GSDR) and has provided evidence of an intensification of hourly extremes over the US. Studies of these observations, combined with model simulations, will continue to advance our understanding of the role of local-scale thermodynamics and large-scale atmospheric circulation in the generation of these events and how these might change in the future.

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