Search results for "mediterranean"
showing 10 items of 3196 documents
Charybdis glaucophylla (Asparagaceae), a new species from Sardinia
2012
Charybdis glaucophylla (Asparagaceae), a new species from Sardinia, is described and illustrated. It is a diploid species with 2n = 20 chromosomes growing along the rocky coast, sandy dunes and mountain top in the south-western part of the island. Within the genus, this species results taxonomically well isolated and differentiated due to relevant morphological and phenological features, such as the leaves wide and short, very rigid and glaucous-pruinose, as well as the very late foliation (winter). It shows only some relationships with C. pancration for the whitish bulb tunics and the diploid chromosome complement, and with C. maura and C. aphylla due to the glaucous leaves.
Ultrahigh energy neutrinos in the Mediterranean: Detecting ντ and νμ with a km3 telescope
2007
23 pages, 13 figures.-- PACS nrs.: 95.85.Ry, 95.55.Vj, 13.15.+g.-- ISI Article Identifier: 000245928000025.-- ArXiv pre-print available at: http://arxiv.org/abs/astro-ph/0609241
Analysis of the aerosol radiative forcing over a Mediterranean urban coastal site
2014
Abstract The aerosol radiative forcing for the period 2003–2011 has been analyzed in Burjassot, Spain, an urban coastal site on the western Mediterranean, using measurements of global solar irradiance and aerosol properties, as well as simulated data. The aerosol radiative forcing was calculated at 5 minute intervals, and then integrated over 24 h to obtain daily mean values for 200 complete days under cloud-free skies. The monthly mean values of the aerosol radiative forcing showed a clear variation during the year, associated to the annual variability of the aerosol optical depth at 500 nm, ranging from − 6 to − 29 Wm− 2 at the surface, and from − 1.5 to − 3.9 Wm− 2 at the top of the atmo…
The ASHRAE clear sky model. An evaluation in the Mediterranean Zone
1988
Abstract The ASHRAE clear sky model in the version proposed by G. L. Powell is here applied to a yearly set of data for Palermo with small scale time intervals. The model is shown to yield computed values generally higher than the measured ones. New values for the atmospheric extinction coefficient are derived and proposed for the application to the Mediterranean atmosphere. A successful verification is performed using hourly data of Genoa, a location belonging to the same meteoclimatic area.
Cambios en la frecuencia de los Regímenes de Tiempo sobre la región Euro-Atlántica y Mediterránea y su relación con las temperaturas anómalas sobre e…
2014
An exercise has been carried out to assess to what extent the Euro-Atlantic Weather Regimes (WR), described from the ERA-interim Reanalysis in the summer season, projects onto a pool of AGCMAMIP simulations in which sea surface temperatures (SST) are prescribed from observations. Although the model simulations present some biases in the spatial structure and seasonality of WRs, exhibiting also less variability, they are able to capture main WR over the region in summer season: +Middle East –Middle East, +NAO, -NAO. WR paradigm is used to quantify changes in the atmosphere under warmer/colder than normal conditions over the Mediterranean Sea. To address this problem, firstly, changes in the …
High-speed intensified video recordings of sprites and elves over the western Mediterranean Sea during winter thunderstorms
2010
We report the first intensified high‐speed video images of elves, sprites, and halos observed in Europe. All the events corresponded to winter season thunderstorms over the Mediterranean Sea. The observations comprise many elves generated by both cloud‐to‐ground lightning current polarities. In 8 of the 14 sprite observations we observed an elve previous to the sprite. In three cases we observed also an elve quickly followed by a halo and a sprite. In several observations we observed lightning light before the mesospheric transient luminous event. We present a case where the lightning from cloud tops was visible during the entire event. Thanks to the high‐speed videos and their resolution a…
Performances of GPM satellite precipitation over the two major Mediterranean islands
2018
Reliable and accurate precipitation measurement or estimation is crucial for disaster monitoring and water resource management. However, obtaining accurate high-resolution precipitation fields is still a challenging task for scientists and practitioners, especially in the poorer region of the world. Nowadays the scientific community expects significant improvements in precipitation monitoring by the continuous technological evolution of satellite-rainfall estimate systems which are able to produce data with global coverage and thus can provide low-cost information even in scarcely populated areas or places where for economic reasons ground measures are missing. The most recent satellite mis…
Climate signals in carbon and oxygen isotope ratios of Pinus cembra tree‐ring cellulose from the Călimani Mountains, Romania
2020
Abstract We analyze annually resolved tree-ring stable carbon (I´13C) and oxygen (I´18O) isotopic chronologies from Swiss stone pine (Pinus cembra L.) in Romania. The chronologies cover the period between 1876 and 2012 and integrate data from four individual trees from the Calimani Mts in the eastern Carpathians where climatic records are scarce and starts only from 1961. Calibration trials show that the I´13C values correlate with local April-May relative humidity and with regional to larger scale (European) summer precipitation. I´18O correlates significantly with local relative humidity, cloud cover, maximum temperature, as well as European scale drought conditions. In all cases, the cli…
Air parcel trajectory analysis of stable isotopes in water vapor in the eastern Mediterranean
2008
[1] With the help of a Lagrangian moisture source diagnostic, linkages between stable isotope measurements in water vapor in Rehovot (Israel), with typical sampling times of 8 hours, and the meteorological conditions in the evaporation regions are established. These linkages can be formulated in quantitative terms, and are also quantitatively comparable with other data from isotope measurements over the ocean and with simple theoretical calculations. On the one hand, a strong negative correlation (r = −0.82) between relative humidity with respect to sea surface temperature in the source regions and measured deuterium excess (d) is found, corroborating results from isotope global circulation…
A complex case study of down to the surface intrusions of persistent stratospheric air over the Eastern Mediterranean
2006
Abstract In this study, we present a complex case study of concurrent stratosphere-to-troposphere transport (STT) events down to the surface of a low topography region in Northern Greece, which occurred in spring 2000. Two surface stations at Livadi (850 m asl) and Thessaloniki (20 m asl) were influenced by intrusions of stratospheric air masses that persisted for a time period from 7 to 10 days within the troposphere before reaching the stations. Before reaching the surface stations in Greece, the air masses crossed the tropopause in different synoptic systems over Eastern Europe, N. America and the N. Atlantic. This is the first study, to our knowledge, that presents a down to the surface…