The OPERA experiment: on the way to the direct observation of νμ→ντ\nu_\mu \to \nu_\tau oscillation

OPERA (\emph{O}scillation \emph{P}roject with \emph{E}mulsion t\emph{R}acking \emph{A}pparatus) is a long-baseline neutrino experiment, designed to provide the first direct proof of $\nu_\mu \to \nu_\tau$ oscillation in the atmospheric sector using the \emph{C}ERN \emph{N}eutrinos to \emph{G}ran \emph{S}asso (CNGS) $\nu_\mu$ beam. The detector, consisting of a modular target made of lead - nuclear emulsion units complemented by electronic trackers and muon spectrometers, has been conceived to select $\rm{\nu_\tau}$ charged current interactions, among all neutrino flavour events, through the observation of the outcoming tau leptons and subsequent decays. In this paper, the detector, the event analysis chain and the preliminary results from the first OPERA physics run are reported.Comment: To be published in the proceedings of DPF-2009, Detroit, MI, July 2009, eConf C09072

Observation ofνμ→ ντoscillations in the CNGS beam with the OPERA experiment

The OPERA long-baseline neutrino experiment was exposed to the CNGS νμ beam from 2008 to 2012, collecting 19505 interactions in the target. The evidence for oscillated ντ appearance, based on the observation of three ντ candidate events, has been previously reported. A fourth candidate event has been recently found in an extended data sample, corresponding to about 89% of the final statistics. The absence of a signal from νμ → ντ oscillations is currently excluded at 4.2σ. The status of the analysis is described in detail with special emphasis on the procedures applied for the selection of signal candidate events and the assessment of efficiencies and background. The fourth ντ candidate event is presented and the significance of the observation is discussed

Observation of νμ → ντ oscillations in the CNGS beam with the OPERA experiment

The OPERA long-baseline neutrino experiment was exposed to the CNGS ν μ beam from 2008 to 2012, collecting 19505 interactions in the target. The evidence for oscillated ν τ appearance, based on the observation of three ν τ candidate events, has been previously reported. A fourth candidate event has been recently found in an extended data sample, corresponding to about 89% of the final statistics. The absence of a signal from ν μ → ν τ oscillations is currently excluded at 4.2 σ . The status of the analysis is described in detail with special emphasis on the procedures applied for the selection of signal candidate events and the assessment of efficiencies and background. The fourth ν τ candidate event is presented and the significance of the observation is discussed

Spatio-temporal constraints for emissivity and surface temperature retrieval: Preliminary results and comparisons for SEVIRI and IASI observation

Infrared instrumentation on geostationary satellites is now rapidly approaching the spectral quality and accuracy of modern sensors flying on polar platforms. Currently, the core of EUMETSAT geostationary meteorological programme is the Meteosat Second Generation (MSG). However, EUMETSAT is preparing for the Meteosat Third Generation (MTG). The capability of geostationary satellites to resolve the diurnal cycle and hence to provide time-resolved sequences or times series of observations is a source of information which could suitably constrain the derivation of geophysical parameters. Nowadays, also because of lack of time continuity, when dealing with observations from polar platforms, the problem of deriving geophysical parameters is normally solved by considering each single observation as independent of past and future events. For historical reason, the same approach is currently pursued with geostationary observations, which are still being dealt with as they were with polar observations. In this study we show some preliminary results on emissivity and surface temperature retrieval for SEVIRI observations, using the Kalman filter methodology (KF) and compare the retrievals with those obtained using IASI observations co-localized with SEVIRI ones using the times accumulation approach (Optimal Estimation OE). The Sahara desert was chosen as target area, and both SEVIRI and IASI data (infrared radiances and cloud mask) were acquired. The time period considered is that of July 2010 (the whole month). ECMWF analyses for the same date and target area have also been acquired, which comprise Ts, T(p), O(p), Q(p) for the canonical hours 0:00, 6:00, 12:00 and 18:00. Moreover, for the purpose of developing a suitable background for emissivity, the Global Infrared Land Surface Emissivity database developed at CIMSS, University of Wisconsin, derived by MODIS observations was used and was available from the year 2003 till 2011. Concerning the performance of the two methodologies, the retrieval of skin temperature is almost equivalent. The agreement between OE and KF is fairly good if compared with ECMWF analysis for sea surface, while for land surface, OE and KF agree fairly well with ECMWF during the night, but at midday ECMWF shows a cold bias of 10 K and more. For emissivity the comparison with the UW/BFEMIS database for the same date and location is fairly good for both methods

Technical note: Functional sliced inverse regression to infer temperature, water vapour and ozone from IASI data.

A retrieval algorithm that uses a statistical strategy based on dimension reduction is proposed. The methodology and details of the implementation of the new algorithm are presented and discussed. The algorithm has been applied to high resolution spectra measured by the Infrared Atmospheric Sounding Interferometer instrument to retrieve atmospheric profiles of temperature, water vapour and ozone. The performance of the inversion strategy has been assessed by comparing the retrieved profiles to the ones obtained by co-locating in space and time profiles from the European Centre for Medium-Range Weather Forecasts analysi

Experimental Setup and Measuring System to Study SolitaryWave Interaction with Rigid Emergent Vegetation

The aim of this study is to present a peculiar experimental setup, designed to investigate the interaction between solitary waves and rigid emergent vegetation. Flow rate changes due to the opening and closing of a software-controlled electro-valve generate a solitary wave. The complexity of the problem required the combined use of different measurement systems of water level and velocity. Preliminary results of the experimental investigation, which allow us to point out the effect of the vegetation on the propagation of a solitary wave and the effectiveness of the measuring system, are also presented. In particular, water level and velocity field changes due to the interaction of the wave with rigid vegetation are investigated in detail

Kalman filter physical retrieval of surface emissivity and temperature from geostationary infrared radiances

The high temporal resolution of data acquisition by geostationary satellites and their capability to resolve the diurnal cycle allows for the retrieval of a valuable source of information about geophysical parameters. In this paper, we implement a Kalman filter approach to applying tempo-ral constraints on the retrieval of surface emissivity and temperature from radiance measurements made from geostationary platforms. Although we consider a case study in which we apply a strictly temporal constraint alone, the methodology will be presented in its general four-dimensional, i.e., space-time, setting. The case study we consider is the retrieval of emissivity and surface temperature from SEVIRI (Spinning Enhanced Visible and Infrared Imager) observations over a target area encompassing the Iberian Peninsula and northwestern Africa. The retrievals are then compared with in situ data and other similar satellite products. Our findings show that the Kalman filter strategy can simultaneously retrieve surface emissivity and temperature with an accuracy of ± 0.005 and ±0.2 K, respectively

Quasi-geostrophic jet-like flow with obstructions

Jet-like flows are ubiquitous in the atmosphere and oceans, and thus a thorough investigation of their behaviour in rotating systems is fundamental. Nevertheless, how they are affected by vegetation or, generally speaking, by obstructions is a crucial aspect which has been poorly investigated up to now. The aim of the present paper is to propose an analytical model developed for jet-like flows in the presence of both obstructions and the Coriolis force. In this investigation the jet-like flow is assumed homogeneous, turbulent and quasi-geostrophic, and with the same density as the surrounding fluid. Laws of momentum deficit, length scales, velocity scales and jet centreline are analytically deduced. These analytical solutions are compared with some experimental data obtained using the Coriolis rotating platform at LEGI-Grenoble (France), showing a good agreemen

Legionella detection in water networks as per iso 11731:2017: Can different filter pore sizes and direct placement on culture media influence laboratory results?

Determination of Legionella concentrations in water networks is useful for predicting legionellosis risks. The standard culture technique using concentration with membranes filters is the most commonly used method for environmental surveillance of Legionella. The aim of this study was to verify whether filtration with different filter pore sizes (0.2 and 0.45 \ub5m) according to (ISO) 11731:2017, followed by directly placing them on culture media, can influence Legionella detection. Three laboratories participated in an experimental study that tested a known suspension of Legionella pneumophila (Lpn) serogroup 1 (ATCC 33152) (approximate final cell density of 15 CFU/mL). E. coli (ATCC 11775) and Pseudomonas aeruginosa (ATCC 25668) were included as control tests. The average (95% CI) percentage of recovery of Lpn was 65% using 0.45-\ub5m filters and 15% using 0.2-\ub5m filters (p < 0.0001). For control tests, the average (95% CI) percentage of recovery was higher with 0.45 vs. 0.2 \ub5m filters: 97% vs. 64% for Escherichia coli (p < 0.00001) and 105% vs. 97% (p = 0.0244) for P. aeruginosa. Our results showed that the 0.45-\ub5m filters provided the greatest detection of Legionella. Because the current national guidelines leave the choice of membrane porosity to the operator, experimental studies are important for directing operators towards a conscious choice to standardize Legionella environmental surveillance methods