ARPA-E

About: ARPA-E is a government organization based out in Washington D.C., District of Columbia, United States. It is known for research contribution in the topics: Population & Climate change. The organization has 1161 authors who have published 1267 publications receiving 30049 citations. The organization is also known as: Advanced Research Projects Agency - Energy.

Aerosol optical characteristics in the urban area of Rome, Italy, and their impacton the UV index

Abstract: . The aerosol optical characteristics in the urban area of Rome were retrieved over a period of 7 years from March to September 2010–2016. The impact of aerosol single scattering albedo (SSA), optical depth (AOD), estimated at 400 nm, and Angstrom exponent on the ultraviolet (UV) index has been analyzed. Aerosol optical properties are provided by a PREDE-POM sun-sky radiometer of the ESR/SKYNET network and the UV index values were retrieved by a Brewer spectrophotometer both located in Rome. Chemical characterization of urban PM10 (particulate matter 10 micrometers or less in diameter) samples, collected during the URBan Sustainability Related to Observed and Monitored Aerosol (URBS ROMA) intensive filed campaign held in summer 2011 in the same site, was performed. PM macro-components were grouped in order to evaluate the contribution of the main macro-sources (SOIL, SEA, SECONDARY INORGANIC, ORGANICS and TRAFFIC) and the analysis of the modulation of their concentration was found to strongly affects the absorption capability of the atmosphere over Rome. The surface forcing efficiency, provided by the decreasing trend of UV index with AOD, which is the primary parameter affecting the surface irradiance, was found very significant, probably masking the dependence of UV index on SSA and Angstrom exponents. Moreover it was found greater for larger particles and with a more pronounced slope at the smaller solar zenith angle. In Rome large particles are generally less absorbing since related to the presence of SOIL and SEA components in the atmosphere. The former contribution was found much higher in summer months because of the numerous episodes of Saharan dust transport.

Experimental Horizontal Wavenumber Spectra and Implications for Full Field Processing

Abstract: Acoustic pressure levels were recorded from a multifrequency source towed at mid-depth on three legs, both towards and away from a 24-element vertical hydrophone array. Horizontal wavenumber spectra were estimated using a synthetic aperture Hankel transform technique. Plots of modal amplitude as a function of depth and wavenumber reveal details of the propagation which are not readily apparent in plots of transmission loss. Two compressional speed profiles beneath the ocean bottom were derived for different legs from the modal wavenumbers at 50 Hz. Comparisons between the experimental data and SAFARI modelling using these profiles give excellent agreement both in amplitude and phase. KRAKEN and IFD/PE modelling using profiles based on nearby borehole data also give excellent agreement. Some aspects of the modal plots can be explained by lateral variability along with a double-ducted sound channel in the sediment below a depth of 75 meters. The multifrequency experimental acoustic data, measured sound speed profiles, and derived geoacoustic bottom profiles were used with variable success in matched field processing to obtain source localization. The high quality of this experimental data set makes it particularly useful for the testing of full field inversion techniques.

Monitoring of Posidonia oceanica meadows in the Sicilian coasts under the Water Framework Directive (WFD)

Abstract: The present paper aims to assess for the first time the ecological status of the Sicilian water bodies using the PREI (Posidonia oceanica Rapid Easy Index) method according to the Water Framework Directive (WFD, 2000/60/EC) requirements. The PREI is based on five metrics: shoot density, shoot leaf surface area, E/L ratio, depth of lower limit, and type of this lower limit. Monitoring of the 29 P. oceanica meadows allowed to classify the 20 WBs of Sicilian coasts in the first two levels of status: 10 as “high” and 10 as “good” with the PREI values ranged between 0,551 and 1.

Reforecast of the November 1994 flood in Piedmont using ERA5 and COSMO model: an operational point of view

Abstract: The scope of this work is to assess the progresses made in the warning alert system of Piedmont since the 1994 flood. We used the COSMO model at high horizontal resolution forced by ERA5 re-forecast to simulate the November 1994 event, performing also a simple sensitivity test regarding the parameterization of convection. We compared the results with the original forecast and with the available observations, in order to understand how the emission of the alert would have been affected using the current operational system.

Mediterranean river biomonitoring in Central Italy: Diatom biodiversity and characterization of communities

Abstract: In compliance with the European and Italian regulations, the Environmental Protection Agency of Umbria Region (ARPA Umbria) defined specific river monitoring programs and networks based on river type definition, human pressures and risk analysis The Umbria Region lies in Central Italy and it can be split into three hydro-ecoregions belonging to the Mediterranean area Data on diatom community composition were collected in five different Mediterranean macrotypes (M1-M5) throughout the diatom-based river monitoring network that is composed by 52 sampling stations in 36 watercourses The main aim of this study was to characterise and to analyse diatom diversity across the different regional river macrotypes Specifically, we investigated if: i) there were differences in species diversity (species richness and Shannon Index) among macrotypes; ii) there was difference in three water quality indexes (ICMi, IPS, and TI) among sites; and iii) there was a relationship between the observed ICMi, IPS and TI value and the diatom diversity Two-hundred diatom species and varieties were identified, and the number of species per sampling station ranged from a minimum of 10 to a maximum of 38 species The most frequent and abundant species were Amphora pediculus , Achnanthidium minutissimum, Navicula cryptotenella , Nitzschia dissipata , and each macrotype showed some peculiar species The ecological status evaluation based on Intercalibration Common Metric Index (ICMi) classified 69% of the water bodies in high or good class Significant differences in diversity and ICMi value among stream macrotypes were found, with M4 (small and medium mountain) and M5 (small, lowland, temporary) typologies showing the lowest species richness, and with M5 showing the lowest Shannon Index Conversely, M2 (small and medium lowland) and M5 showed the highest ICMi value Lastly, significant correlations between Shannon Index and the ICMi, IPS and TI indexes were found