Spatial and temporal variability of precipitation over the Mediterranean Basin based on 32-year satellite Global Precipitation Climatology Project data. Part-II: inter-annual variability and trends

2016 ◽  
Vol 36 (15) ◽  
pp. 4755-4766 ◽  
Author(s):  
Nikolaos Hatzianastassiou ◽  
Christos D. Papadimas ◽  
Christos J. Lolis ◽  
Aristides Bartzokas ◽  
Vincenzo Levizzani ◽  
...  
Keyword(s):  
Temporal Variability ◽  
Mediterranean Basin ◽  
Global Precipitation Climatology Project ◽  
Spatial And Temporal Variability ◽  
Annual Variability ◽  
Precipitation Climatology ◽  
The Mediterranean ◽  
Project Data ◽  
Global Precipitation ◽  
The Mediterranean Basin

Precipitation climatology over the Mediterranean Basin — Validation over Cyprus

2016 ◽  
Vol 169 ◽  
pp. 449-458 ◽  
Author(s):  
Adrianos Retalis ◽  
Dimitrios Katsanos ◽  
Silas Michaelides
Keyword(s):  
Mediterranean Basin ◽  
Precipitation Climatology ◽  
The Mediterranean ◽  
The Mediterranean Basin

Toward a regional-scale seasonal climate prediction system over the Mediterranean basin: evaluation and comparison of RegCM- and WRF-based dynamical downscaling approaches

2020 ◽  
Author(s):  
Lorenzo Sangelantoni ◽  
Vincenzo Mazzarella ◽  
Antonio Ricchi ◽  
Rossella Ferretti ◽  
Gianluca Redaelli
Keyword(s):  
Spatial Distribution ◽  
Mediterranean Basin ◽  
Dynamical Downscaling ◽  
Climate Prediction ◽  
Short Term ◽  
Seasonal Climate ◽  
Nested Models ◽  
Annual Variability ◽  
The Mediterranean ◽  
The Mediterranean Basin

<p>Seasonal Climate Predictions (SCPs) represent a challenging intermediate field where aspects typical of the short-term weather forecasts and long-term climate projections interact. Skillful SCPs represent an essential tool to reduce societal vulnerabilities to the inter-annual climate fluctuation through short-term (i.e., next season) climate impact mitigation measures. This is especially true over areas characterized by large climate inter-annual variability as the Mediterranean basin, which is also traditionally characterized by a poor seasonal predictability.</p><p>The primary research question of present study is to assess the capability of two dynamical downscaling approaches to improve the seasonal inter-annual variability signal coming from the global-scale driving SCP system on the Mediterranean basin.</p><p>In this work the Weather Research and Forecasting model (WRF3.9.1.1) and the Regional Climatic Model (RegCM4.1) were nested into NCEP’s operational seasonal forecast model Climate Forecast System version 2 (CFSv2) to dynamically downscale seasonal predictions over Mediterranean basin.</p><p>Using the initial and boundary conditions of an ensemble of the CFSv2 we compare the capability of the two downscaling approaches on improving the large scale CFSv2 prediction of a climatological period of 22-cold seasons (December–February) during 1982–2002.</p><p>The SCP systems (WRF- and RegCM-based) consist on a double dynamical downscaling where a height-member lagged ensemble of 3-month CFSv2 climate predictions represent the common driving fields. Both the nested models dynamically downscales CFSv2 climate prediction from the original 100 km resolution to 60 km over a domain covering the Mediterranean basin and Central Europe. The first downscaling feeds a second downscaling performed over a domain centered over Central Italy with a resolution of 12 km.</p><p>Climate variables considered are: 2 m temperature, precipitation, geopotential height at different pressure levels and mean sea level pressure. Results will be discussed by means of mean bias spatial distribution, inter-annual anomaly variability reproduction and probabilistic hit-rate of anomalous seasons, through tercile plots and reliability diagrams of the above mentioned variables.</p><p>Preliminary results, considering the RegCM, identify temperature variability reproduction benefiting from the downscaling. At the same time, precipitation shows an improved spatial distribution patterns but not improved inter-annual variability representation if compared to the driving CFSv2 reference period climate predictions.</p>

scholarly journals The regime of desert dust episodes in the Mediterranean based on contemporary satellite observations and ground measurements

2013 ◽  
Vol 13 (6) ◽  
pp. 16247-16299 ◽  
Author(s):  
A. Gkikas ◽  
N. Hatzianastassiou ◽  
N. Mihalopoulos ◽  
V. Katsoulis ◽  
S. Kazadzis ◽  
...  
Keyword(s):  
Mediterranean Basin ◽  
Western Mediterranean ◽  
Spatial And Temporal Variability ◽  
Central Mediterranean ◽  
Study Region ◽  
Desert Dust ◽  
Western Mediterranean Basin ◽  
Spatial Coverage ◽  
The Mediterranean ◽  
The Mediterranean Basin

Abstract. The regime of desert dust (DD) episodes over the broader Mediterranean basin is studied for the period 2000–2007. The novelty of this work lies in its complete spatial coverage of the region. An objective and dynamic algorithm has been set up, which uses daily measurements of various aerosol optical properties taken by different satellite databases, enabling the identification of DD episodes and their classification into strong and extreme ones. The algorithm's performance was tested against surface based (in situ) Particulate Matter (PM) and (columnar) sun-photometric AERONET measurements from stations distributed across the Mediterranean. The comparisons have shown the reasonable ability of the algorithm to detect the DD episodes taking place within the study region. The largest disagreements with PM data were found in summer and western Mediterranean, when African dust transport has a great vertical extent that cannot be satisfactorily captured by surface measurements. According to our results, DD episodes in the Mediterranean basin are quite frequent (up to 11.4 episodes/year) while there is a significant spatial and temporal variability in their frequency of occurrence and their intensity. Strong episodes occur more frequently in the western Mediterranean basin whilst extreme ones appear more frequently over central Mediterranean Sea areas. Apart from this longitudinal variation, there is a predominant latitudinal variability in both frequency and intensity, with decreasing values from south to north. A significant seasonal variation was also found for the frequency of DD episodes, with both strong and extreme episodes being more frequent during summer in the western Mediterranean basin, but during spring in its central and eastern parts. In most cases (>85%) the Mediterranean dust episodes last a bit longer than a day, although their duration can reach 6 days for strong episodes and 4 days for extreme episodes. A noticeable year by year variability was also found, especially for the frequency of the episodes. The spatial and temporal patterns of Mediterranean DD episodes can be explained based on surface pressure and precipitation spatio-temporal distribution patterns over the study region, as well as by the year by year variability of North Atlantic Oscillation (NAO). In this context, a decreasing frequency of appearance of DD episodes over the Mediterranean basin has been revealed over the period 2000–2007, especially over land surfaces, in line with decreasing NAO Index over the same period. Our findings demonstrate the reasonable ability to detect desert dust outbreaks in the Mediterranean basin from satellites.

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