scholarly journals Development of an empirical model for seasonal forecasting over the Mediterranean

2019 ◽  
Vol 16 ◽  
pp. 191-199
Author(s):  
Esteban Rodríguez-Guisado ◽  
Antonio Ángel Serrano-de la Torre ◽  
Eroteida Sánchez-García ◽  
Marta Domínguez-Alonso ◽  
Ernesto Rodríguez-Camino
Keyword(s):  
Empirical Model ◽  
Global Climate ◽  
Mediterranean Area ◽  
Climate Indices ◽  
Teleconnection Patterns ◽  
Sensitivity Experiments ◽  
Global Indices ◽  
Temperature And Precipitation ◽  
The Mediterranean ◽  
Smooth Transitions

Abstract. In the frame of MEDSCOPE project, which mainly aims at improving predictability on seasonal timescales over the Mediterranean area, a seasonal forecast empirical model making use of new predictors based on a collection of targeted sensitivity experiments is being developed. Here, a first version of the model is presented. This version is based on multiple linear regression, using global climate indices (mainly global teleconnection patterns and indices based on sea surface temperatures, as well as sea-ice and snow cover) as predictors. The model is implemented in a way that allows easy modifications to include new information from other predictors that will come as result of the ongoing sensitivity experiments within the project. Given the big extension of the region under study, its high complexity (both in terms of orography and land-sea distribution) and its location, different sub regions are affected by different drivers at different times. The empirical model makes use of different sets of predictors for every season and every sub region. Starting from a collection of 25 global climate indices, a few predictors are selected for every season and every sub region, checking linear correlation between predictands (temperature and precipitation) and global indices up to one year in advance and using moving averages from two to six months. Special attention has also been payed to the selection of predictors in order to guaranty smooth transitions between neighbor sub regions and consecutive seasons. The model runs a three-month forecast every month with a one-month lead time.

scholarly journals Historical Spatial and Temporal Climate Trends in Southern Ontario, Canada

2017 ◽  
Vol 56 (10) ◽  
pp. 2767-2787 ◽  
Author(s):  
Hussein Wazneh ◽  
M. Altaf Arain ◽  
Paulin Coulibaly
Keyword(s):  
Climate Models ◽  
Global Climate ◽  
Global Climate Models ◽  
Climate Indices ◽  
Total Precipitation ◽  
Southern Ontario ◽  
Temperature And Precipitation ◽  
Annual Total ◽  
Precipitation Indices ◽  
Temperature Indices

AbstractSpatial and temporal trends in historical temperature and precipitation extreme events were evaluated for southern Ontario, Canada. A number of climate indices were computed using observed and regional and global climate datasets for the area of study over the 1951–2013 period. A decrease in the frequency of cold temperature extremes and an increase in the frequency of warm temperature extremes was observed in the region. Overall, the numbers of extremely cold days decreased and hot nights increased. Nighttime warming was greater than daytime warming. The annual total precipitation and the frequency of extreme precipitation also increased. Spatially, for the precipitation indices, no significant trends were observed for annual total precipitation and extremely wet days in the southwest and the central part of Ontario. For temperature indices, cool days and warm night have significant trends in more than 90% of the study area. In general, the spatial variability of precipitation indices is much higher than that of temperature indices. In terms of comparisons between observed and simulated data, results showed large differences for both temperature and precipitation indices. For this region, the regional climate model was able to reproduce historical observed trends in climate indices very well as compared with global climate models. The statistical bias-correction method generally improved the ability of the global climate models to accurately simulate observed trends in climate indices.

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.

scholarly journals Sources of predictability over the Mediterranean at seasonal time-scale: building up an empirical forecasting model

2021 ◽  
Author(s):  
Esteban Rodríguez-Guisado ◽  
Ernesto Rodríguez-Camino
Keyword(s):  
Time Series ◽  
Global Climate ◽  
Supplementary Information ◽  
Climate Indices ◽  
Least Squares Regression ◽  
Dynamical Models ◽  
Flexible Tool ◽  
Probabilistic Forecasts ◽  
The Mediterranean ◽  
The Impact

<p>Although most operational seasonal forecasting systems are based on dynamical models, empirical forecasting systems, built on statistical relationships between present and future at seasonal time horizons conditions of the climate system, provide a feasible and realistic alternative and a source of supplementary information. Here, a new empirical model based on partial least squares regression is presented. Originally designed as a flexible tool, the model can be run with many configurations including different predictands, resolutions, leads and aggregation times. To be able of producing forecast for any selected configuration, the model automatically selects predictors from an initial pool, containing global climate indices and specific predictors for the Mediterranean region unveiled in the frame of the MEDSCOPE project. Additionally, the model explores spatial fields, generating time series based on spatial averages of areas well correlated with the predictand. These time series are added to the initial pool of candidate predictors.  We present here results from a configuration producing probabilistic forecasts of seasonal (3 month averages) temperature and precipitation, their verification and comparison against a selection of state-of-the-art seasonal forecast systems based on dynamical models in a hindcast period (1994-2015). The model is able to produce spatially coherent anomaly patterns, and reach levels of skill comparable to those based on dynamical models. As predictors can be easily removed or incorporated, the model can provide information on the impact of a particular predictor on skill, so it can be used to help in the search and understanding of new sources of predictability. Evaluation of soil moisture impact on summer temperature predictability is shown as an example</p>

scholarly journals Endemic Freshwater Fish Range Shifts Related to Global Climate Changes: A Long-Term Study Provides Some Observational Evidence for the Mediterranean Area

Water ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2349 ◽  
Author(s):  
Carosi ◽  
Padula ◽  
Ghetti ◽  
Lorenzoni
Keyword(s):  
Climate Changes ◽  
Global Climate ◽  
Mediterranean Area ◽  
Freshwater Fishes ◽  
Environmental Data ◽  
Dispersal Ability ◽  
Global Climate Changes ◽  
Long Term Study ◽  
River Fragmentation ◽  
The Mediterranean

Climate changes will lead to a worsening of the ecological conditions, in terms of hydrological instability and rising water temperatures, of the Mediterranean rivers. Freshwater fishes inhabiting this area can be threatened in the near future by accelerating drought and decreased ecological connectivity. The main aim of the research was to analyze changes in the distribution of the endemic freshwater fishes Padogobius nigricans, Squalius lucumonis and Telestes muticellus in the Tiber River basin (Italy), within a proven period of climate warming, in terms of increasing water temperature and droughts. A multivariate analysis was conducted using fish and environmental data collected in 117 sites over the years 1990–2017. For the three species, population abundance, age structure and body condition were analyzed. Detectability, occupancy, local extinction and colonization processes were also examined. We showed that S. lucumonis and T. muticellus have shifted their distributions upstream, likely in order to reach their thermal optimum. Padogobius nigricans did not move upstream significantly, since the species is characterized by limited vagility and thus a low dispersal capability in a context of high river fragmentation. In the study area, elevation and river barriers seem to play a key role in extirpation and colonization processes; for S. lucumonis and T. muticellus the extinction probability decreased with increasing altitude, while for P. nigricans the colonization probability decreased with an increasing degree of river fragmentation. These results highlight how species-specific dispersal ability can lead to varying adaptability to climate change.

scholarly journals Interannual Variability of GPS Heights and Environmental Parameters over Europe and the Mediterranean Area

2021 ◽  
Vol 13 (8) ◽  
pp. 1554
Author(s):  
Letizia Elia ◽  
Susanna Zerbini ◽  
Fabio Raicich
Keyword(s):  
Time Series ◽  
Interannual Variability ◽  
Environmental Parameters ◽  
Mediterranean Area ◽  
Space Time ◽  
The Arctic ◽  
Climate Indices ◽  
Geological Processes ◽  
Second Mode ◽  
The Mediterranean

Vertical deformations of the Earth’s surface result from a host of geophysical and geological processes. Identification and assessment of the induced signals is key to addressing outstanding scientific questions, such as those related to the role played by the changing climate on height variations. This study, focused on the European and Mediterranean area, analyzed the GPS height time series of 114 well-distributed stations with the aim of identifying spatially coherent signals likely related to variations of environmental parameters, such as atmospheric surface pressure (SP) and terrestrial water storage (TWS). Linear trends and seasonality were removed from all the time series before applying the principal component analysis (PCA) to identify the main patterns of the space/time interannual variability. Coherent height variations on timescales of about 5 and 10 years were identified by the first and second mode, respectively. They were explained by invoking loading of the crust. Single-value decomposition (SVD) was used to study the coupled interannual space/time variability between the variable pairs GPS height–SP and GPS height–TWS. A decadal timescale was identified that related height and TWS variations. Features common to the height series and to those of a few climate indices—namely, the Arctic Oscillation (AO), the North Atlantic Oscillation (NAO), the East Atlantic (EA), and the multivariate El Niño Southern Oscillation (ENSO) index (MEI)—were also investigated. We found significant correlations only with the MEI. The first height PCA mode of variability, showing a nearly 5-year fluctuation, was anticorrelated (−0.23) with MEI. The second mode, characterized by a decadal fluctuation, was well correlated (+0.58) with MEI; the spatial distribution of the correlation revealed, for Europe and the Mediterranean area, height decrease till 2015, followed by increase, while Scandinavian and Baltic countries showed the opposite behavior.

scholarly journals Assessment of climate services prototypes on seasonal water management for the Mediterranean regions 

2021 ◽  
Author(s):  
Gildas Dayon ◽  
Francois Besson ◽  
Christian Viel ◽  
Jean-Michel Soubeyroux ◽  
Pierre Etchevers
Keyword(s):  
Water Resource Management ◽  
Mediterranean Area ◽  
Hydrologic Model ◽  
Po River ◽  
Climate Services ◽  
Temperature And Precipitation ◽  
Operational Application ◽  
Mediterranean Regions ◽  
The Mediterranean ◽  
Input Variables

<p>In the framework of the MEDSCOPE project, Météo-France has initiated the development of new prototypes for seasonal water resource management in the Mediterranean region, addressing different scientific and technical challenges essential for a future operationalization of the services . In order to have a replicable result on the Mediterranean area, we decided first to consider the three large watersheds onof the Rhone river in France, the Ebro river in Spain and the Po river in Italy.</p><p>Our first challenge was to use a new hydrologic model SURFEX-CTRIP, covering the whole Mediterranean area. Another point was to perfect and evaluate a new downscaling tool named ADAMONT permitting to debiase all seasonal forecast input variables needed for hydrology applications and not only (temperature and, precipitation and 5 other surface meteorological parameters). We decided also to assess the new UERRA hydrological analyse available on these three countries. Lthe last challenge was to identify local end users facing with decision making process at seasonal scale for water resources management and develop decision help products adapted to their needs.</p><p>The evaluation of these prototypes, carried out over the period 2019-2020 using the MF Syst 6 and then Syst 7 seasonal forecasting model, has highlighted a significant potential in a future operational application but also difficulties to be overcome.</p><p>The communication will present the main results of this work and discuss the lessons to be learnet from this experience</p><p> </p>

Spatial Distribution of Pre-Warm Front Rainfall in the Mediterranean Area

1988 ◽  
Vol 19 (1) ◽  
pp. 53-64 ◽  
Author(s):  
C. Corradini ◽  
F. Melone
Keyword(s):  
Mediterranean Area ◽  
Compact Structure ◽  
Large Variability ◽  
Air Mass ◽  
Orographic Effects ◽  
Warm Front ◽  
Average Rainfall ◽  
Convective Motions ◽  
Rainfall Type ◽  
The Mediterranean

Evidence is given of the distribution of pre-warm front rainfall at the meso-γ scale, together with a discussion of the main mechanisms producing this variability. An inland region in the Mediterranean area is considered. The selected rainfall type is commonly considered the most regular inasmuch as it is usually unaffected by extended convective motions. Despite this, within a storm a large variability in space was observed. For 90% of measurements, the typical deviations from the area-average total depth ranged from - 40 to 60 % and the storm ensemble-average rainfall rate over an hilly zone was 60 % greater than that in a contiguous low-land zone generally placed upwind. This variability is largely explained in terms of forced uplift of air mass over an envelope type orography. For a few storms smaller orographic effects were found in locations influenced by an orography with higher slopes and elevations. This feature is ascribed to the compact structure of these mountains which probably determines a deflection of air mass in the boundary layer. The importance of this type of analysis in the hydrological practice is also emphasized.

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