Paolo Di Girolamo - Academia.edu (original) (raw)

Papers by Paolo Di Girolamo

HAL (Le Centre pour la Communication Scientifique Directe), 2020

Epj Web of Conferences, 2018

Research

Measuring the characteristics of seawater constituent is in great demand for studies of marine ec... more Measuring the characteristics of seawater constituent is in great demand for studies of marine ecosystems and biogeochemistry. However, existing techniques based on remote sensing or in situ samplings present various tradeoffs with regard to the diversity, synchronism, temporal-spatial resolution, and depth-resolved capacity of their data products. Here, we demonstrate a novel oceanic triple-field-of-view (FOV) high-spectral-resolution lidar (HSRL) with an iterative retrieval approach. This technique provides, for the first time, comprehensive, continuous, and vertical measurements of seawater absorption coefficient, scattering coefficient, and slope of particle size distribution, which are validated by simulations and field experiments. Furthermore, it depicts valuable application potentials in the accuracy improvement of seawater classification and the continuous estimation of depth-resolved particulate organic carbon export. The triple-FOV HSRL with high performance could greatly...

Within the frame of the project CONCERNING (COmpact RamaN lidar for Atmospheric CO2 and ThERmodyN... more Within the frame of the project CONCERNING (COmpact RamaN lidar for Atmospheric CO2 and ThERmodyNamic ProfilING), we investigated the feasibility and the limits of a ground-based Raman lidar system dedicated to the measurement of CO2 profiles. The performance of the lidar system was evaluated through a set of numerical simulations. The possibility of exploiting both CO2 Raman lines of the ν1:2ν2 resonance was explored. An accurate quantification of the contribution of the Raman O2 lines on the signal and other (e.g., aerosol, absorbing gases) disturbance sources was carried out. The signal integration over the vertical and over time required to reach a useful signal to noise ratio both in day-time and night-time needed for a quantitative analysis of carbon dioxide sources and sinks was evaluated. The above objectives were obtained developing an instrument simulator software consisting of a radiative transfer model able to simulate, in a spectrally resolved manner, all laser light in...

CALIGOLA (Cloud Aerosol Lidar for Global Scale Observations of the Ocean-Land-Atmosphere System) ... more CALIGOLA (Cloud Aerosol Lidar for Global Scale Observations of the Ocean-Land-Atmosphere System) is a mission funded by the Italian Space Agency (ASI), aimed at the development of a space-borne Raman Lidar. A Phase A study to assess the technological feasibility of the laser source and receiver system is currently underway at the Leonardo S.p.A., while scientific studies in support of the mission are conducted by the University of Basilicata. Scientific and technical studies are furthermore supported by other Italian institutions (CNR-ISMAR, CNR-IMAA), with NASA also having expressed an interest in contributing to the mission .Mission objectives include the observation of the Earth atmosphere, surface (ocean and land). Among the atmospheric objectives, the characterization of the global scale distribution of natural and anthropogenic aerosols, their radiative properties and interactions with clouds, and the measurements of ocean color, suspended particulate matter and marine chlorop...

A network of water vapor Raman lidars WaLiNeas (Lidar Network Assimilation) for improving heavy ... more A network of water vapor Raman lidars WaLiNeas (Lidar Network Assimilation) for improving heavy precipitation forecasting in the Mediterranean Sea has been designed among with the aim of providing water vapor measurements with high spatial-temporal resolution and accuracy, in order to be assimilated into AROME mesoscale models using a four-dimensional ensemble-variational approach with 15-min updates. The CONCERNIG Lidar from University of Basilicata and a Wind Lidar form CNR–IMAA are co-located in the University of Toulone between October 2022 and January 2023 in order to reach the campaign objective. For this scope a of vertical profiles of latent heat flux were obtained as a Covariance matrices from vertical wind component (w') and mixing ratio (q') are estimated as a retrieval of a Wind Lidar and Raman Lidar UV respectively.In this way, a time series of vertical wind profiles from the selected case (31 Oct to 03 Nov) are computed. with temporal resolution Δt = 15 min ...

Journal of Geophysical Research: Atmospheres

International Symposium on Tropospheric Profiling, 2006

&lt;p&gt;The Atmospheric Thermodynamic LidAr in Space (ATLAS) is a mission concep... more &lt;p&gt;The Atmospheric Thermodynamic LidAr in Space (ATLAS) is a mission concept proposed to the European Space Agency in the frame of &amp;#8220;Earth Explorer-11 Mission Ideas&amp;#8221; Call by a team of researchers, with the aim to develop the first Raman Lidar in space capable to measure simultaneously atmospheric temperature and water vapour mixing ratio profiles with high temporal and spatial resolutions. Accurate measurements of these profiles are essential to understand water and energy cycles, as well as the prediction of extreme events, that nowadays still show huge deficiencies on all temporal and spatial scales (1). Such measurements would have a revolutionary impact on our understanding of the Earth system and would close the gap in our observational capabilities from the surface to the lower troposphere.&lt;/p&gt;&lt;p&gt;The specifications of the different lidar sub-system, as well as the expected capability to provide measurements with high temporal and spatial resolution in the low and middle troposphere, have already been established with an analytical simulation model (2,3). These simulations considered different atmospheric models and conditions to estimate the statistical uncertainty on water vapour and temperature measurements. New studies have been now performed to estimate the performances along several dawn-dusk orbits. An end-to-end simulator has been developed and used to estimate the statistical and systematic uncertainties. The input data, comprehensive of thermodynamic and optical parameters, have been extracted from the GEOS-5 Nature Run and have been chosen to perform simulations with different solar zenith angles and therefore different background contributions. The model includes information on cloud fraction and optical thickness, so it was also possible to consider the performances in cloudy conditions. The simulations show promising results, both in clear and cloudy conditions and with different background contributions. A comprehensive study of the assessed performances will be presented at the conference.&lt;/p&gt;&lt;p&gt;The simulated measurements obtained from the simulator will be also used as input observations in the Weather Research and Forecasting model (WRF). The aim is to estimate the impact of global measurements from a space-borne Raman Lidar in terms of skill-scores, obtained by the comparison of the weather forecast output with and without the assimilation of the simulated lidar data.&lt;/p&gt;&lt;p&gt;1 - Wulfmeyer, Hardesty, Turner, Behrendt, Cadeddu, Di Girolamo, et al. A review of the remote sensing of lower tropospheric thermodynamic profiles and its indispensable role for the understanding and the simulation of water and energy cycles. Reviews of Geophysics. 2015; 53(3):819&amp;#8211;95.&lt;/p&gt;&lt;p&gt;2 - Di Girolamo, Behrendt, Wulfmeyer. Space-borne profiling of atmospheric thermodynamic variables with Raman lidar: performance simulations. Opt Express,OE. 2 aprile 2018; 26(7):8125&amp;#8211;61.&lt;/p&gt;&lt;p&gt;3 - Di Girolamo, Behrendt, Wulfmeyer. Spaceborne profiling of atmospheric temperature and particle extinction with pure rotational Raman lidar and of relative humidity in combination with differential absorption lidar: performance simulations. Appl Opt, AO. 10 aprile 2006; 45(11):2474&amp;#8211;94.&lt;/p&gt;

&lt;p&gt;The height of the planetary boundary layer is strongly influenced by the... more &lt;p&gt;The height of the planetary boundary layer is strongly influenced by the surface of the earth since it is directly in contact with it. In this study &amp;#160;we want to discuss the correlation between global warming and PBL variation. This is addressed using both the boundary layer height and other thermodynamic indices.&amp;#160;In this study we want to highlight how the variation in the height of the PBL, together with other thermodynamic indices, represent an indication of climate change. PBL variations are therefore analyzed both in the daytime and in the night case, by means of radiosonding profiles from the Global Integrated Archive (IGRA) at the mid-latitudes in the range [30 &amp;#176;; 50 &amp;#176;] N. Data from the European Center for Medium-Range Weather Forecasting (ECMWF) and all the GRUAN station in the same latitude belt station GCOS Upper-Air Network (GRUAN) are used as a comparison dataset for atmospheric parameter uncertainties.&amp;#160;&lt;/p&gt;&lt;p&gt;The study reports a statistical analysis over 40 years, in order to have an evolution of thermodynamic variables both on monthly,&amp;#160; seasonal averages and also&amp;#160; annual. In general, a good agreement is found for the nighttime data compared between IGRA and ERA5, while during the day, the boundary layer height estimates in Europe with ERA5 are characterized by lower spatial homogeneity than those obtained with IGRA.&lt;/p&gt;&lt;p&gt;Finally, the comparison between the Lindenberg data as processed at high-resolution by GRUAN and as provided to IGRA at a lower resolution, shows the significant impact of using high-resolution data in the determination of the boundary layer height. [1,2]&lt;/p&gt;&lt;p&gt;[1] Madonna, F., Summa, D., Di Girolamo, P., Marra, F., Wang, Y., Rosoldi, M. Assessment of Trends and Uncertainties in the Atmospheric Boundary Layer Height Estimated Using Radiosounding Observations over Europe. Atmosphere 2021, 12, 301. https://doi.org/10.3390/atmos12030301&lt;/p&gt;&lt;p&gt;[2] Vivone G., D&amp;#8217;Amico G., Summa D., Lolli S., Amodeo A., Bortoli D., and Pappalardo G. Atmospheric boundary layer height estimation from aerosol lidar: a new approach based on morphological image processing techniques. Atmos. Chem. Phys., 21, 4249&amp;#8211;4265, 2021,https://doi.org/10.5194/acp-21-4249-2021&lt;/p&gt;

EPJ Web of Conferences, 2020

This extended abstract reports measurements that were carried out by the Raman lidar system BASIL... more This extended abstract reports measurements that were carried out by the Raman lidar system BASIL in the frame of the Hydrological Cycle in the Mediterranean Experiment – Special Observation Period 1 (HyMeX-SOP1). A specific case study was selected revealing the presence of variable aerosol properties at different altitudes. Specifically, Raman lidar measurements on 02 October 2012 reveal the presence of two distinct aerosol layers, a lower one extending up to ~3 km and an upper one extending from 3.5 km to 4.7 km. Aerosol and size microphysical properties are determined from multi-wavelength measurements of particle backscattering and extinction profiles based on the application of a retrieval scheme which employs Tikhonov’s inversion with regularization. Inversion results suggest a size distribution with the presence, in both the lower and upper aerosol layer, of two particle modes (a fine mode, with a radius of ~0.2 μm, and a coarse mode, with radii in the range 2-4 μm), volume c...

EPJ Web of Conferences, 2020

In November 2012, the University of BASILicata Raman Lidar system (BASIL) was approved to enter t... more In November 2012, the University of BASILicata Raman Lidar system (BASIL) was approved to enter the International Network for the Detection of Atmospheric Composition Change (NDACC). Since then measurements were routinely carried out on a once per week basis. This paper illustrates specific measurement examples from this effort, with a dedicated focus on temperature and water vapour measurements, with the ultimate goal to provide a characterization of the system performance. Case studies illustrated in this paper demonstrate the ability of BASIL to perform measurements of the temperature profile up to 50 km and of the water vapour mixing ratio profile up to 15 km, based on an integration time of 2 hours and a vertical resolution of 150 m, with measurement bias not exceeding 0.1 K and 0.1 g kg−1, respectively. Raman lidar measurements are compared with measurements from additional instruments, such as radiosondings and satellite sensors (IASI and AIRS), and with model re-analyses dat...

EPJ Web of Conferences, 2016

Journal of Quantitative Spectroscopy and Radiative Transfer, 2014

ABSTRACT This paper analyses high spectral resolution downwelling radiance measurements in the fa... more ABSTRACT This paper analyses high spectral resolution downwelling radiance measurements in the far infrared in presence of cirrus clouds taken by the REFIR-PAD interferometer, deployed at 3500 m above sea level at the Testa Grigia station (Italy), during the Earth COoling by WAter vapouR emission (ECOWAR) campaign. Atmospheric state and cloud geometry are characterised by the co-located millimeter-wave spectrometer GBMS and by radiosonde profile data, an interferometer (I-BEST) and a Raman lidar system deployed at a nearby location (Cervinia). Cloud optical depth and effective diameter are retrieved from REFIR-PAD data using a limited number of channels in the 820–960 cm−1 interval. The retrieved cloud parameters are the input data for simulations covering the 250–1100 cm−1 band in order to test our ability to reproduce the REFIR-PAD spectra in presence of ice clouds. Inverse and forward simulations are based on the same radiative transfer code. A priori information concerning cloud ice vertical distribution is used to better constrain the simulation scheme and an analysis of the degree of approximation of the phase function within the radiative transfer codes is performed to define the accuracy of computations. Simulation-data residuals over the REFIR-PAD spectral interval show an excellent agreement in the window region, but values larger than total measurement uncertainties in the far infrared. Possible causes are investigated. It is shown that the uncertainties related to the water vapour and temperature profiles are of the same order as the sensitivity to the a priori assumption on particle habits for an up-looking configuration. In case of a down-looking configuration, errors due to possible incorrect description of the water vapour profile would be drastically reduced.

Journal of Geophysical Research, 2011

The Radiation Explorer in the Far InfraRed-Prototype for Applications and Development (REFIR-PAD)... more The Radiation Explorer in the Far InfraRed-Prototype for Applications and Development (REFIR-PAD) spectroradiometer was operated from the Testa Grigia Italian-Alps station in March 2007 during the Earth Cooling by Water Vapour Radiation (ECOWAR) measurement campaign, obtaining downwelling radiance spectra in the 100–1100 cm−1 range, under clear-sky conditions and in the presence of cirrus clouds. The analysis of these measurements has proven that the instrument is capable of determining precipitable water vapor with a total uncertainty of 5–7% by using the far-infrared rotational band of water. The measurement is unaffected by the presence of cirri, whose optical depth can be instead retrieved as an additional parameter. Information on the vertical profiles of water vapor volume mixing ratio and temperature can also be retrieved for three altitude levels. The ability to measure the water vapor column with a simple, uncooled instrument, capable of operating continuously and with a time resolution of about 10 min, makes REFIR-PAD a very valuable instrument for meteorological and climatological studies for the characterization of the water vapor distribution.

EGU General Assembly Conference Abstracts, Apr 1, 2019

Atmospheric Research, 2009

Atmospheric Chemistry and Physics, 2012

HAL (Le Centre pour la Communication Scientifique Directe), 2020

Epj Web of Conferences, 2018

Research

Journal of Geophysical Research: Atmospheres

International Symposium on Tropospheric Profiling, 2006

EPJ Web of Conferences, 2020

EPJ Web of Conferences, 2016

Journal of Quantitative Spectroscopy and Radiative Transfer, 2014

Journal of Geophysical Research, 2011

EGU General Assembly Conference Abstracts, Apr 1, 2019

Atmospheric Research, 2009

Atmospheric Chemistry and Physics, 2012