155 research outputs found
Mt. Etna aerosol optical thickness from MIVIS images
This work focuses on the evaluation of Aerosol Optical Thickness (AOT) in Mt. Etna volcano area starting from
the analysis of MIVIS VIS images. MIVIS images and ancillary data (atmospheric profiles, photometric measurements,
atmospheric infrared radiances, surface temperatures, ground reflectances, SO2 abundances) were collected
during the «Sicily ’97» campaign. Data elaboration was performed with extensive use of 6S radiative transfer model,
determining optical thickness with an inversion algorithm that uses atmospheric vertical profile, ground reflectance
data and radiance measured by the first MIVIS spectrometer (channels 1-20; range 0.44-0.82 n). Ground
reflectance is the most problematic parameter for the algorithm. In order to have a low and ‘uniform’ surface reflectance,
only pixels located at an altitude between 2000-3000 m a.s.l. were analysed. At this altitude,AOT is very
low during non-eruptive periods: at Torre del Filosofo (2920 m a.s.l.) on June 16th 1997, during one MIVIS flight,
AOT at 0.55 n was 0.19. The uncertainty about ground reflectance produces significant errors on volcanic background
AOT, and in some cases the error is up to 100%. The developed algorithm worked well on volcanic plume,
allowing us to determine the plume related pixels’AOT. High plume AOT values minimize the problems deriving
from reflectance uncertainty. Plume optical thickness shows values included in a range from 0.5 to 1.0. The plume
AOT map of Mt. Etna volcano, derived from a MIVIS image of June 16th 1997, is presented
Impact of vehicular emissions in an urban area of the Po valley by microscale simulation with the GRAL dispersion model
This work sets out the test of the GRAL model (Graz Lagrangian Model, vs.18.1) in the urban area of Modena (Po valley, Northern Italy). The simulation domain sizes 2 000 x 3 000 m2 and it features 'microscale' cells of 4 x 4 m2. The simulation focuses on an intersection featured by large traffic flows next to a school and a regulatory air quality monitoring station classified as an urban traffic site. The model is a lagrangian particle dispersion model and it takes into account the presence of buildings as obstacles and generating microscale wind fields accordingly, making this class of model suitable for investigating spatial pattern of atmospheric pollution in urban areas where local accumulation might occur. The simulation investigates traffic emissions of nitrogen oxides (NOx) over the period October 29 to November 10, 2016, when direct measurements of traffic flow were collected by four one-channel doppler radar traffic counters. These counters provided continuous estimate of vehicle length, speed and number. These latter data were combined with available traffic flows at rush hour by PTV VISUM mobility software and the fleet composition of the municipality to estimate the total NOx emissions by vehicular traffic over the roads included in the simulation domain. NOx simulated concentrations showed a moderate correlation with the NOx observations at the nearby monitoring site. To have a better insight on the potential and the limitations of the GRAL model, its results will be compared with the output of the lagrangian particle dispersion model PMSS over the same area
Continuous photometric observations at ENEA base in Lampedusa to estimate precipitable water
Water vapour is a variable component of the atmosphere both in space and time. It is one of the most important
components because of its effects in many fi elds: Meteorology, Climatology, Remote Sensing, Energy-Budget,
Hydrology, etc. This work compares radiometric (sun photometer) readings, Global Positioning System (GPS)
data and a meteorological model forecasted data. The aim is to understand if GPS measurements may help
Numerical Weather Prediction (NWP) models. It is well known that GPS measurements are affected by the
so-called tropospheric delay. Part of it, the so-called wet delay is related mainly to the amount of water vapour
along the path of the GPS signal through the troposphere. Precise knowledge of the abundance of water vapour,
in space and time, is important for NWP model because water vapour is the predecessor of precipitation. Despite
the high variability of water vapour compared to other meteorological fi elds, like pressure and wind, water vapour
observations are scarce, so that additional measurements of water vapour are expected to benefi t meteorology.
A new sun photometer, which is part of the AERONET (AErosol and RObotic NETwork) program, has been
installed at the ENEA (Ente per le Nuove tecnologie, l'Energia e l'Ambiente) base of Lampedusa Island. The
sun photometer is quite close (less then 4 km) to an ASI (Agenzia Spaziale Italiana) GPS permanent receiver.
A long record (summer period of the year 2000) of sun photometric measurements is available for the station at
Lampedusa. We found that the GPS and sun photometric data are better correlated (std. dev. about 10 mm for the
wet delay) than are the GPS measurements with the NWP model predictions. This is an indication that GPS delay
data may contain information useful for weather prediction
Spectral emissivity and temperature maps of the Solfatara crater from DAIS hyperspectral images
Quantitative maps of surface temperature and spectral emissivity have been retrieved on the
Solfatara crater at Pozzuoli (Naples) from remote sensing hyperspectral data. The present study
relies on thermal infrared images collected on July 27, 1997 by the DAIS hyperspectral sensor,
owned by the German aerospace center (DLR). The Emissivity Spectrum Normalization method
was used to make temperature and emissivity estimates. Raw data were previously transformed in
radiance and corrected for the atmospheric contributes using the MODTRAN radiative transfer code
and the sensor response functions. During the DAIS flight a radiosonde was launched to collect the
atmospheric profiles of pressure, temperature and humidity used as input to the code. Retrieved
temperature values are in good agreement with temperature measures performed in situ during the
campaign. The spectral emissivity map was used to classify the image in different geomineralogical
units with the Spectral Angle Mapper method. Areas of geologic interest were
previously selected using a mask obtained from an NDVI image calculated with two channels of the
visible (red) and the near infrared respectively
GPS Zenith Total Delays and precipitable water in comparison with special meteorological observations in Verona (Italy) during MAP-SOP
Continuous meteorological examination of the Pre-Alpine zones in Northern Italy (Po Valley) is important for determination of atmospheric water cycles connected kith floods and rainfalls. During a special meteorological observing period (MAP-SOP). radiosounding and other measurements were made in the site of Verona (Italy), This paper deals with Zenith Total Delay (ZTD) and Precipitable Water (PW) comparisons obtained by GPS, radiosounding and other meteorological measurements. PW and ZTD from ground-based GPS data in comparison with classical techniques (e.g.. WVR, radiosounding,) from recent literature present an accurate tool for use in meteorology applications (e.g., assimilation in Numerical Weather Prediction (NWP) models oil short-range precipitation forecasts). Comparison of such ZTD for MAP-SOP showed a standard deviation of 16.1 mm and PW comparison showed a standard deviation of 2.7 mm, confirming the accuracy of GPS measurements for meteorology applications. In addition, PW data and its time variation are also matched with time series of meteorological situations. Those results indicate that changes in PW values could be connected to changes in air masses, i.e. to passages of both cold and warm fronts. There is also a correlation between precipitation. forthcoming increase and the following decrease of PW. A good agreement between oscillation of PW and precipitation and strong cyclonic activities is found
GPS Zenith Total Delays and Precipitable Water in comparison with special meteorological observations in Verona (Italy)during MAP-SOP
Continuous meteorological examination of the Pre-Alpine zones in Northern Italy (Po Valley)is important for determination of atmospheric water cycles connected with floods and rainfalls.During a special meteorological observing period (MAP-SOP),radiosounding and other measurements were made in the site of Verona (Italy). This paper deals with Zenith Total Delay (ZTD)and Precipitable Water (PW)comparisons obtained by GPS, radiosounding and other meteorological measurements.PW and ZTD from ground-based GPS data in comparisonwith classical techniques (e.g.,WVR,radiosounding)from recent literature present an accurate tool for use in meteorology applications (e.g.,assimilation in Numerical Weather Prediction (NWP)models on short-range precipitation forecasts).Comparison of such ZTD for MAP-SOP showed a standard deviation of 16.1 mm and PW comparison showed a standard deviation of 2.7 mm,confirming the accuracy of GPS measurements for meteorology applications.In addition,PW data and its time variation are also matched with time series of meteorological situations.Those results indicate that changes in PW values could be connected to changes in air masses,i.e.to passages of both cold and warm fronts.There is also a correlation between precipitation, forthcoming increase and the following decrease of PW.A good agreement between oscillation of PW and precipitation and strong cyclonic activities is found
Volcanic Risk System (SRV): ASI Pilot Project to Support The Monitoring of Volcanic Risk In Italy by Means of EO Data
The ASI-SRV(Sistema Rischio Vulcanico) project
started at the beginning of the 2007 is funded by the Italian
Space Agency (ASI) in the frame of the National Space Plan
2003-2005 under the Earth Observations section for natural
risks management. Coordinated by the Istituto Nazionale di
Geofisica e Vulcanologia (INGV), which is responsible at national
level for the volcanic monitoring, the project has as main
objective to develop a pre-operative system based on EO data
and ground measurements integration to support the volcanic
risk monitoring of the Italian Civil Protection Department. The
project philosophy is to implement specific modules which allow
to process, store and visualize through Web GIS tools EO derived
parameters considering three activity phases: 1) knowledge and
prevention; 2) crisis; 3) post crisis. In order to combine
effectively the EO data and the ground networks measurements
the system will implement a multi-parametric analysis tool,
which represents and unique tool to analyze contemporaneously
a large data set of data in “near real time”. The SRV project will
be tested his operational capabilities on three Italian Volcanoes:
Etna,Vesuvio and Campi Flegrei.I.N.G.V. - O.V. SEZIONE DI NAPOLI
I.R.E.A. - C.N.R.
E.S.A.
A.S.I.PublishedNapoli1.10. TTC - Telerilevamentoope
Volcanic Risk System (SRV): ASI Pilot Project to Support The Monitoring of Volcanic Risk In Italy by Means of EO Data
The ASI-SRV(Sistema Rischio Vulcanico) project
started at the beginning of the 2007 is funded by the Italian
Space Agency (ASI) in the frame of the National Space Plan
2003-2005 under the Earth Observations section for natural
risks management. Coordinated by the Istituto Nazionale di
Geofisica e Vulcanologia (INGV), which is responsible at national
level for the volcanic monitoring, the project has as main
objective to develop a pre-operative system based on EO data
and ground measurements integration to support the volcanic
risk monitoring of the Italian Civil Protection Department. The
project philosophy is to implement specific modules which allow
to process, store and visualize through Web GIS tools EO derived
parameters considering three activity phases: 1) knowledge and
prevention; 2) crisis; 3) post crisis. In order to combine
effectively the EO data and the ground networks measurements
the system will implement a multi-parametric analysis tool,
which represents and unique tool to analyze contemporaneously
a large data set of data in “near real time”. The SRV project will
be tested his operational capabilities on three Italian Volcanoes:
Etna,Vesuvio and Campi Flegrei
Volcanic Risk System (SRV): ASI Pilot Project to Support The Monitoring of Volcanic Risk In Italy by Means of EO Data
The ASI-SRV(Sistema Rischio Vulcanico) project
started at the beginning of the 2007 is funded by the Italian
Space Agency (ASI) in the frame of the National Space Plan
2003-2005 under the Earth Observations section for natural
risks management. Coordinated by the Istituto Nazionale di
Geofisica e Vulcanologia (INGV), which is responsible at national
level for the volcanic monitoring, the project has as main
objective to develop a pre-operative system based on EO data
and ground measurements integration to support the volcanic
risk monitoring of the Italian Civil Protection Department. The
project philosophy is to implement specific modules which allow
to process, store and visualize through Web GIS tools EO derived
parameters considering three activity phases: 1) knowledge and
prevention; 2) crisis; 3) post crisis. In order to combine
effectively the EO data and the ground networks measurements
the system will implement a multi-parametric analysis tool,
which represents and unique tool to analyze contemporaneously
a large data set of data in “near real time”. The SRV project will
be tested his operational capabilities on three Italian Volcanoes:
Etna,Vesuvio and Campi Flegrei
Outdoor artificial light at night and risk of early-onset dementia: A case-control study in the Modena population, Northern Italy
Background
Dementia is a neurological syndrome characterized by severe cognitive impairment with functional impact on everyday life. It can be classified as young onset dementia (EOD) in case of symptom onset before 65, and late onset dementia (LOD). The purpose of this study is to assess the risk of dementia due to light pollution, and specifically outdoor artificial light at night (LAN).
Methods
Using a case-control design, we enrolled dementia patients newly-diagnosed in the province of Modena in the period 2017–2019 and a referent population from their caregivers. We geo-referenced the address of residence on the date of recruitment, provided it was stable for the previous five years. We assessed LAN exposure through 2015 nighttime luminance satellite images from the Visible Infrared Imaging Radiometer Suite (VIIRS). Using a logistic regression model adjusted for age, sex, and education, we calculated the risk of dementia associated with increasing LAN exposure, namely using <10 nW/cm2/sr as reference and considering ≥10-<40 nW/cm2/sr intermediate and ≥40 nW/cm2/sr high exposure, respectively We also implemented non-linear assessment using a spline regression model.
Results
We recruited 58 EOD cases, 34 LOD cases and 54 controls. Average LAN exposure levels overlapped for EOD cases and controls, while LOD cases showed higher levels. Compared with the lowest exposure, the risk of EOD associated with LAN was higher in the intermediate exposure (OR = 1.36, 95% CI 0.54–3.39), but not in the high exposure category (OR = 1.04, 95% CI 0.32–3.34). In contrast, the risk of LOD was positively associated with LAN exposure, with ORs of 2.58 (95% CI 0.26–25.97) and 3.50 (95% CI 0.32–38.87) in the intermediate and high exposure categories, respectively. The spline regression analysis showed substantial lack of association between LAN and EOD, while almost linear although highly imprecise association emerged for LOD.
Conclusions
Although the precision of the estimates was affected by the limited sample size and the study design did not allow us to exclude the presence of residual confounding, these results suggest a possible role of LAN in the etiology of dementia, particularly of its late-onset form
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