Increasing compound warm spells and droughts during the growing season in the Mediterranean Basin

2020 ◽  
Author(s):  
Johannes Vogel ◽  
Eva Paton
Keyword(s):  
Mediterranean Basin ◽  
Hot Spot ◽  
Growing Season ◽  
Drought Indices ◽  
Late Winter ◽  
Daily Maximum ◽  
Standardised Precipitation Index ◽  
Compound Events ◽  
The Mediterranean ◽  
The Mediterranean Basin

<p>The Mediterranean Basin is known as a hot spot of climate change and therefore especially prone to increasing frequencies of warm spells and droughts. Investigating these events in isolation neglects their interactions, which illustrates the need to account for such compound events in a holistic manner. We analysed during which months the frequency of compound warm spells and droughts increased most over the 40-year period from 1979 – 2018. Warm spells and droughts were detected using daily maximum air temperature, precipitation and potential evaporation data from ERA 5. The two drought indices Standardised Precipitation Index (SPI) and Standardised Precipitation-Evapotranspiration Index (SPEI) were calculated.</p><p>Our results show the number of compound events increases substantially for almost the entire Mediterranean indicating that novel climatic conditions are occurring. The increases in compound events are predominantly driven by the rising number of warm spells, whereas SPI droughts remain almost constant. However, the rising temperatures lead to higher evapotranspiration, which alters the water balance in the Mediterranean. Therefore, the SPEI droughts shows significant increases in contrast to the SPI, indicating that even though the amount of precipitation does not decrease, the Mediterranean Basin is likely facing drier conditions due to increasing evapotranspiration. The highest changes in the number of compound warm spells and droughts occur in the time span from late winter to early summer. This finding is particularly relevant for Mediterranean ecosystems because this period encompasses the main growing season, and therefore ecosystem productivity and carbon sequestration might be reduced.</p>

scholarly journals Hot spot maps of forest presence in the Mediterranean basin

2016 ◽  
Vol 9 (5) ◽  
pp. 766-774 ◽  
Author(s):  
S Noce ◽  
A Collalti ◽  
R Valentini ◽  
M Santini
Keyword(s):  
Mediterranean Basin ◽  
Hot Spot ◽  
The Mediterranean ◽  
The Mediterranean Basin

scholarly journals SAETTA: high-resolution 3-D mapping of the total lightning activity in the Mediterranean Basin over Corsica, with a focus on a mesoscale convective system event

2019 ◽  
Vol 12 (11) ◽  
pp. 5765-5790 ◽  
Author(s):  
Sylvain Coquillat ◽  
Eric Defer ◽  
Pierre de Guibert ◽  
Dominique Lambert ◽  
Jean-Pierre Pinty ◽  
...  
Keyword(s):  
High Altitude ◽  
Mediterranean Basin ◽  
Hot Spot ◽  
Mesoscale Convective System ◽  
Lightning Activity ◽  
Convective System ◽  
Stratiform Region ◽  
Mesoscale Convective ◽  
The Mediterranean ◽  
The Mediterranean Basin

Abstract. Deployed on the mountainous island of Corsica for thunderstorm monitoring purposes in the Mediterranean Basin, SAETTA is a network of 12 LMA (Lightning Mapping Array, designed by New Mexico Tech, USA) stations that allows the 3-D mapping of very high-frequency (VHF) radiation emitted by cloud discharges in the 60–66 MHz band. It works at high temporal (∼40 ns in each 80 µs time window) and spatial (tens of meters at best) resolution within a range of about 350 km. Originally deployed in May 2014, SAETTA was commissioned during the summer and autumn seasons and has now been permanently operational since April 2016 until at least the end of 2020. We first evaluate the performances of SAETTA through the radial, azimuthal, and altitude errors of VHF source localization with the theoretical model of Thomas et al. (2004). We also compute on a 240 km × 240 km domain the minimum altitude at which a VHF source can be detected by at least six stations by taking into account the masking effect of the relief. We then report the 3-year observations on the same domain in terms of number of lightning days per square kilometer (i.e., total number of days during which lightning has been detected in a given 1 km square pixel) and in terms of lightning days integrated across the domain. The lightning activity is first maximum in June because of daytime convection driven by solar energy input, but concentrates on a specific hot spot in July just above the intersection of the three main valleys. This hot spot is probably due to the low-level convergence of moist air fluxes from sea breezes channeled by the three valleys. Lightning activity increases again in September due to numerous small thunderstorms above the sea and to some high-precipitation events. Finally we report lightning observations of unusual high-altitude discharges associated with the mesoscale convective system of 8 June 2015. Most of them are small discharges on top of an intense convective core during convective surges. They are considered in the flash classification of Thomas et al. (2003) to be small–isolated and short–isolated flashes. The other high-altitude discharges, much less numerous, are long-range flashes that develop through the stratiform region and suddenly undergo upward propagations towards an uppermost thin layer of charge. This latter observation is apparently consistent with the recent conceptual model of Dye and Bansemer (2019) that explains such an upper-level layer of charge in the stratiform region by the development of a non-riming ice collisional charging in a mesoscale updraft.

scholarly journals Reusing Grey Water to Lower Temperatures in the Mediterranean Basin Cities

Earth ◽  
2022 ◽  
Vol 3 (1) ◽  
pp. 72-75
Author(s):  
Giuseppe Maggiotto
Keyword(s):  
Climate Change ◽  
Soil Moisture ◽  
Moisture Content ◽  
Air Temperature ◽  
Mediterranean Basin ◽  
Soil Moisture Content ◽  
Hot Spot ◽  
Grey Water ◽  
The Mediterranean ◽  
The Mediterranean Basin

The Mediterranean region is a hot spot for climate change, and cities of this area will be exposed to both increasing temperatures and decreasing precipitations. Green Infrastructures (GIs) can lower urban temperatures through evapotranspiration with an adequate soil moisture content. Grey water reuse can both guarantee the right soil moisture content and reduce freshwater exploitation. In order to test the effectiveness of soil moisture on reducing air temperature, two modelling simulations ran with the microclimate CFD-based model ENVI-met 4.0. The chosen day was a registered heat wave (7 July 2019) in Lecce, a city of south Italy, which was selected as case study for the Mediterranean area. The results demonstrated the effectiveness of soil moisture on evapotranspiration in reducing air temperature. From a circular economy perspective, the supply of grey water for urban GIs represents a strategic adaptation strategy to the expected effects of climate change on the Mediterranean basin.

Impact of compound events (heatwaves and ozone episodes) on mortality over the Mediterranean basin under climate change scenarios

2021 ◽  
Author(s):  
Patricia Tarín-Carrasco ◽  
Laura Palacios-Peña ◽  
Juan P. Montávez ◽  
Pedro Jiménez-Guerrero
Keyword(s):  
Climate Change ◽  
Heat Wave ◽  
Tropospheric Ozone ◽  
Mediterranean Basin ◽  
Future Climate Change ◽  
Economic Damage ◽  
Climate Change Scenarios ◽  
Compound Events ◽  
The Mediterranean ◽  
The Mediterranean Basin

<p>The Mediterranean Basin is nowadays considered as one of the most vulnerable areas worldwide to extreme climate/weather events, especially those related to photochemical pollution (tropospheric ozone) and extreme temperatures (e.g. heatwaves). Heatwaves and air pollution have a high impact on society, both from a health and an economical perspective, leading to increases on heat stroke hospital admissions and mortality. For this reason, heatwaves and their associated ozone pollution have to be taken into account for dwellers welfare.</p><p>In addition, in recent years, it has become increasingly clear that climatic or meteorological impacts often result from the compounding nature of several variables and/or events, even if they are not extreme when analysed independently. Such compound events can lead to socio-economic damage exceeding that expected if the individual hazards were to occur separately. For instance, compound events of heat wave and stagnation display higher temperature than stagnation events or heat wave events alone, so the formation of secondary pollutants like tropospheric ozone is enhanced relative to individual events.</p><p>Under this umbrella, this study assesses compound climate events using high-resolution regional chemistry/climate simulations, with the aim of characterizing and quantifying the influence of temperature/pollution compound events on mortality over Europe, with a special focus on the Mediterranean Basin. Model data from the REPAIR and ACEX projects (obtained from simulations with the on-line chemistry/coupled WRF-Chem model) is used in order to check the changes in mortality under both present-observed and future-forced conditions. The results presented in this contribution quantify the important increase in mortality causes associated to cerebrovascular diseases (CEV) and other pathologies during those compound events (especially under future climate change scenarios) with respect to episodes led by single drivers. This increase in mortality is more evident in northern countries in relative terms; and in southern European countries in absolute mortality incidence, since the concurrent presence of heatwaves and high levels of tropospheric ozone will have a higher frequency in future scenarios over the Mediterranean basin.</p>

scholarly journals A Warming Mediterranean: 38 Years of Increasing Sea Surface Temperature

2020 ◽  
Vol 12 (17) ◽  
pp. 2687 ◽  
Author(s):  
Francisco Pastor ◽  
Jose Antonio Valiente ◽  
Samiro Khodayar
Keyword(s):  
Time Series ◽  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Mediterranean Basin ◽  
Extreme Values ◽  
Hot Spot ◽  
Warming Trend ◽  
Sea Surface ◽  
The Mediterranean ◽  
The Mediterranean Basin

The Mediterranean basin has been classified as a hot-spot for climate change. The Mediterranean Sea plays a fundamental regulatory role in the regional climate. We have analyzed the largest available and complete time series (1982–2019) of blended sea surface temperature (SST) data to study its seasonal cycle and look for a possible warming trend in the basin. From the analysis of the Mediterranean mean SST time series, a new temporal seasonal division is derived that differs from the one used in atmospheric climatology. Then, the SST time series were decomposed into their seasonal and trend components, and a consistent warming trend of 0.035 °C/year was obtained. The nature of this trend has been investigated, indicating a higher warming trend for both maximum and high/summer SST values than for the winter/colder ones. This reinforces the consistency of the SST increase since it is not only based on the presence of extreme values, but on a homogeneous basin global increase of high SST records as well. Although warming is found throughout the Mediterranean basin, the spatial variability found leads to the division of the basin into three distinct subareas regarding warming.

scholarly journals SAETTA: high resolution 3D mapping of the total lightning activity in the Mediterranean basin over Corsica, with a focus on a MCS event

2019 ◽  
Author(s):  
Sylvain Coquillat ◽  
Eric Defer ◽  
Pierre de Guibert ◽  
Dominique Lambert ◽  
Jean-Pierre Pinty ◽  
...  
Keyword(s):  
High Altitude ◽  
Mediterranean Basin ◽  
Hot Spot ◽  
Mesoscale Convective System ◽  
Lightning Activity ◽  
Convective System ◽  
Sea Breezes ◽  
Stratiform Region ◽  
The Mediterranean ◽  
The Mediterranean Basin

Abstract. Deployed in the mountainous island of Corsica for thunderstorm monitoring purpose in the Mediterranean Basin, SAETTA is a network of 12 LMA stations (Lightning Mapping Array, designed by New Mexico Tech, USA) that allows the 3-D mapping of VHF radiations emitted by cloud discharges in the 60–66 MHz band. It works at high temporal (80 µs) and spatial (tens of meters at best) resolutions within a range of about 350 km. Originally deployed in May 2014, SAETTA was commissioned during the summer and fall seasons and is now permanently operational since April 2016 until at least the end of 2020. We first evaluate the performances of SAETTA through the radial, azimuthal, and altitude errors of VHF sources localization with the theoretical model of Thomas et al. (2004). We also compute on a 240 km × 240 km domain the minimum altitude at which a VHF source can be detected by at least 6 stations by taking into account the mask effect of the relief. We then report the 3-year observations on the same domain in terms of number of lightning days per square kilometer and in terms of lightning days integrated on the whole domain. The lightning activity is first maximum in June because of daytime convection driven by solar energy input, but concentrates on a specific hot spot in July just above the crossroad of the three main valleys. This hot spot is probably due to the low-level convergence of moist air fluxes from sea breezes channeled by the three valleys. Lighting activity increases again in September due to numerous small thunderstorms above the sea and to some high precipitating events. Finally we report lightning observations of unusual high altitude discharges associated with the mesoscale convective system of June 8, 2015. Most of them are small discharges on top of an intense convective core during convective surges. They are considered in the flash classification of Thomas et al. (2003) as small-isolated and short-isolated flashes. The other high altitude discharges, much less numerous, are long range flashes that develop through the stratiform region and suddenly undergo upward propagations towards an uppermost thin layer of charge. This observation supports the recent conceptual model of Dye and Bansemer (2019) that explains such upper level layer of charge in the stratiform region by the development of a non-riming ice collisional charging in a mesoscale updraft.

The Polycladida (Platyhelminthes) of the Canary Islands. New genus, species and records

Zootaxa ◽  
2017 ◽  
Vol 4312 (1) ◽  
pp. 38 ◽  
Author(s):  
DANIEL CUADRADO ◽  
LEOPOLDO MORO ◽  
CAROLINA NOREÑA
Keyword(s):  
Canary Islands ◽  
Mediterranean Basin ◽  
Morphological Study ◽  
New Genus ◽  
New Records ◽  
Hot Spot ◽  
New Genus And Species ◽  
The Mediterranean ◽  
Available Information ◽  
The Mediterranean Basin

The main focus of this study is the biodiversity of the order Polycladida in the Canary Islands, archipelago belonging to Macaronesia and to the Mediterranean basin hot spot region. Polycladida is a cosmopolitan order with some species distributed worldwide; but it also is comprised of endemic species. Here, 19 polyclad species are revised and determined, ten of which were previously recorded for the Canary Islands (De Vera et al. 2009). A new genus and species Multisepta fengari n. gen., n. sp., of the suborder Acotylea and five new species belonging to the suborder Cotylea including Anonymus ruber n. sp., Enchiridium magec n. sp., Eurylepta guayota n. sp., Acanthozoon aranfaibo n. sp. and Pseudoceros mororum n. sp., are presented and described. In addition, two well-known species, Pseudobiceros wirtzi (Madeira and Cape Verde) and Pericelis cata (Caribbean coasts), are new records for the Canary Islands and for the hot spot region of the Mediterranean basin. Using all available information, including from the morphological study presented here, a key for the species for the Canary Islands has been generated. 

scholarly journals An Assessment of Stratospheric Intrusions in Italian Mountain Regions Using STEFLUX

Atmosphere ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 413 ◽  
Author(s):  
Paolo Cristofanelli ◽  
Piero Di Carlo ◽  
Eleonora Aruffo ◽  
Francesco Apadula ◽  
Mariantonia Bencardino ◽  
...  
Keyword(s):  
Mediterranean Basin ◽  
Hot Spot ◽  
Alpine Region ◽  
Northern Apennines ◽  
High Mountain ◽  
Mountain Regions ◽  
Near Surface ◽  
Stratospheric Intrusion ◽  
The Mediterranean ◽  
The Mediterranean Basin

The Mediterranean basin is considered a global hot-spot region for climate change and air quality, especially concerning summer-time ozone (O3). Previous investigations indicated that the Mediterranean basin is a preferred region for stratosphere-to-troposphere exchange (STE) and deep stratospheric intrusion (SI) events. The Lagrangian tool STEFLUX, based on a STE climatology that uses the ERA Interim data, was hereby used to diagnose the occurrence of deep SI events in four mountain regions over the Italian peninsula, spanning from the Alpine region to the southern Apennines. By using near-surface O3 and relative humidity (RH) observations at three high-mountain observatories, we investigated the performance of STEFLUX in detecting deep SI events. Both experimental and STEFLUX detections agreed in describing the seasonal cycle of SI occurrence. Moreover, STEFLUX showed skills in detecting “long-lasting” SI events, especially in the Alps and in the northern Apennines. By using STEFLUX, we found positive tendencies in the SI occurrence during 1979–2017. However, in contrast to similar studies carried out in the Alpine region, the negative long-term (1996–2016) trend of O3 in the northern Apennines did not appear to be related to the SI’s variability.

Italian network of four permanent observatories: implementation of background data selection (BaDSfit) and 5-year analysis of the atmospheric CO2 mixing ratio.

2020 ◽  
Author(s):  
Pamela Trisolino ◽  
Alcide di Sarra ◽  
Damiano Sferlazzo ◽  
Salvatore Piacentino ◽  
Francesco Monteleone ◽  
...  
Keyword(s):  
Radiative Forcing ◽  
Mediterranean Basin ◽  
Large Scale ◽  
Hot Spot ◽  
Regional Scale ◽  
Data Selection ◽  
Background Data ◽  
The Mediterranean ◽  
The Mediterranean Basin

<p>The Mediterranean basin is considered a global hot-spot region for climate change and air-quality. CO<sub>2</sub> is the single most-important anthropogenic greenhouse gas (GHG) in the atmosphere, accounting approximatively for ∼63% of the anthropogenic radiative forcing by long-lived GHG. According to Le Quérée et al. (2018), the increasing of the atmospheric CO<sub>2</sub> mixing ratios in the global atmosphere is driven by fossil fuel and cement production.<br>In order to reduce GHG emissions and taking into account the needs for economy and society development, schemes of regulation and emission trading have been adopted at international, national, and city levels. The implementation of these regulation, to achieve the goal successfully, needs scientific evidence and information provided on consistent datasets. In the last year, efforts are dedicated to set up harmonized reference networks at difference scales (WMO/GAW, AGAGE, ICOS).<br>In this work, we analysed a set of continuous long-term measurements of CO<sub>2</sub> carried out at 4 atmospheric observatories in Italy belonging to the WMO/GAW network and spanning from the Alpine region to central Mediterranean Sea: Plateau Rosa (western Italian Alps, 3480 m a.s.l.), Mt. Cimone (northern Apennines, 2165 m a.s.l.), Capo Granitola (southern Sicily coastline) and Lampedusa Island. Mt. Cimone is also a “class-2” ICOS station, while Plateau Rosa and Lampedusa are in the labelling process. Starting time of GHG observations range from 1979 for Mt. Cimone to 2015 for Capo Granitola. Due to their different locations and ecosystems, they provide useful hints to investigate CO<sub>2</sub> variability on different latitudinal and altitudinal ranges in the Mediterranean basin and to study of natural and anthropogenic-related processes able to affect the observed variability.<br>The study addresses primarily differences in daily and seasonal cycles at the different sites, and implemented a procedure to identify background conditions called BaDSfit (Background Data Selection for Italian stations; Trisolino et al., submitted). This methodology was originally used at Plateau Rosa station (Apadula, 2019) and it is based on the Mauna Loa data selection method (Tans and Thoning, 2008). BaDSfit consist of three steps and an optimization of the procedure was carried out with a sensitivity study.  Marked differences among the daily cycles at the various sites exist. The effect of the data selection on the seasonal and diurnal cycle and long-term evolution is investigated. The BaDSfit lead to a more coherent diurnal and seasonal evolution of the different datasets, is able to identify background condition and allows the separation of local/regional scale from large scale phenomena in the CO<sub>2</sub> time series.</p>

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