Filomena Romano

EAQUATE: An International Experiment For Hyperspectral Atmospheric Sounding Validation

The international experiment called the European Aqua Thermodynamic Experiment (EAQUATE) was held in September 2004 in Italy and the United Kingdom to validate Aqua satellite Atmospheric Infrared Sounder (AIRS) radiance measurements and derived products with certain groundbased and airborne systems useful for validating hyperspectral satellite sounding observations. A range of flights over land and marine surfaces were conducted to coincide with overpasses of the AIRS instrument on the Earth Observing System Aqua platform. Direct radiance evaluation of AIRS using National Polar-Orbiting Operational Environmental Satellite System (NPOESS) Airborne Sounder Testbed-Interferometer (NAST-I) and the Scanning High-Resolution Infrared Sounder has shown excellent agreement. Comparisons of level-2 retrievals of temperature and water vapor from AIRS and NAST-I validated against high-quality lidar and dropsonde data show that the 1-K/l-km and 10%/1-km requirements for temperature and water vapor (respectively) are ge...

An Advanced Model for the Estimation of the Surface Solar Irradiance Under All Atmospheric Conditions Using MSG/SEVIRI Data

A new advanced model for estimation of surface solar irradiance from satellite (AMESIS), designed to estimate with better accuracy the incident solar radiation at the surface from the spinning enhanced visible and infrared imager (SEVIRI) satellite measurements, has been developed. The new generations of sensors such as SEVIRI payload on board the geostationary meteosat second generation gives an opportunity to improve the solar irradiance estimation at surface with accuracy as well as the high spatial and time resolution for a large geographical area according to the needs of solar energy applications. The model developed takes into account the effect of aerosol, the overcast and partially cloudy coverage, and provides irradiance solar maps every 15 min both for monitoring purposes and for monthly, annual averages of surface solar irradiance. Cloud and aerosol microphysical parameters are retrieved by using VIS and IR SEVIRI channels, while surface solar irradiance is retrieved through the high-resolution broadband visible channel. Comparisons with the Global Atmosphere Watch station ground-based measurements of incoming solar radiation agree with the values retrieved with AMESIS model. The results show a very good correlation of about 0.99, a root mean square and a bias ranging, respectively, between 1 and 2.7 J/cm2 and -0.6 and 0.4 J/cm2 depending on the station.

Inverting for geophysical parameters from IMG radiances

Radiances observed by the Interferometric Monitor for Greenhouse gases sounder have been used to retrieve temperature, water vapor, and ozone profiles. It is shown that the sounder allows one to simultaneously retrieve stable solutions for temperature and water vapor. Once water vapor and temperature have been retrieved, ozone profile may be estimated on the same fine vertical mesh as water vapor and temperature. Comparison among calculated and observed radiances shows good agreement in several parts of the thermal band which is sensed by the sounder. A slight discrepancy is observed in the wing region of the 720-cm/sup -1/ CO/sub 2/ Q-branch, whereas the most severe form of disagreement is seen in the 6.7-/spl mu/m vibrational H/sub 2/O absorption band. Nevertheless, suitable spectral ranges may be identified which yield accurate and stable inversions for temperature, water vapor, and ozone.

Cloud detection over sea surface by use of autocorrelation functions of upwelling infrared spectra in the 800–900-cm -1 window region

A new algorithm for cloud detection over sea surface has been developed that makes use of autocorrelation and cross correlation between a real spectrum and either a synthetic or a laboratory spectrum. The scheme is intended for high-spectral-resolution satelliteborne infrared sensors that will measure the Earths entire emission spectrum rather than the upwelling radiance in a few channels. A new index is defined with which one can determine quantitatively the degree of homogeneity of two spectra in the 800-900-cm(-1) (11.11-12.5 mum) window region. The index makes use of only the observed spectrum along with a reference synthetic spectrum and, therefore, may form the basis for an operational stand-alone cloud-detection algorithm for next-generation high-spectral-resolution infrared sensors. Application both to synthetic spectra obtained in simulation and to sea-surface real spectra recorded through the interferometric monitor for greenhouse gases is considered.

Analysis of Catania Flash Flood Case Study by Using Combined Microwave and Infrared Technique

AbstractIn this paper, the analysis of an extreme convective event atypical for the winter season, which occurred on 21 February 2013 on the east coast of Sicily and caused a flash flood over Catania, is presented. In just 1 h, more than 50 mm of precipitation was recorded, but it was not forecast by numerical weather prediction (NWP) models and, consequently, no severe weather warnings were sent to the population. The case study proposed is first examined with respect to the synoptic situation and then analyzed by means of two algorithms based on satellite observations: the Cloud Mask Coupling of Statistical and Physical Methods (MACSP) and the Precipitation Evolving Technique (PET), developed at the National Research Council of Italy. Both of the algorithms show their ability in the near-real-time monitoring of convective cell formation and their rapid evolution. As quantitative precipitation forecasts by NWP could fail, especially for atypical convective events like in Catania, tools like MACSP and PET...

Downstream Services for Rice Crop Monitoring in Europe: From Regional to Local Scale

The ERMES agromonitoring system for rice cultivations integrates EO data at different resolutions, crop models, and user-provided in situ data in a unified system, which drives two operational downstream services for rice monitoring. The first is aimed at providing information concerning the behavior of the current season at regional/rice district scale, while the second is dedicated to provide farmers with field-scale data useful to support more efficient and environmentally friendly crop practices. In this contribution, we describe the main characteristics of the system, in terms of overall architecture, technological solutions adopted, characteristics of the developed products, and functionalities provided to end users. Peculiarities of the system reside in its ability to cope with the needs of different stakeholders within a common platform, and in a tight integration between EO data processing and information retrieval, crop modeling, in situ data collection, and information dissemination. The ERMES system has been operationally tested in three European rice-producing countries (Italy, Spain, and Greece) during growing seasons 2015 and 2016, providing a great amount of near-real-time information concerning rice crops. Highlights of significant results are provided, with particular focus on real-world applications of ERMES products and services. Although developed with focus on European rice cultivations, solutions implemented in the ERMES system can be, and are already being, adapted to other crops and/or areas of the world, thus making it a valuable testing bed for the development of advanced, integrated agricultural monitoring systems.

Vertical and horizontal aerosol spectral extinction at a rural location in southern Italy

The vertical extinction of the aerosol has been measured with a multiwavelength sunphotometer at a rural location in southern Italy. All measurements were performed during a period with relatively stable weather condition, thus it could be expected to have measured always the same air mass at least within each day. The direct solar radiation was recorded at wavelengths between 400 and 1100 nm with a resolution of 0.5 nm. Calibration of the instrument was performed by means of a Langley plot at an elevation of approximately 3000 m. From these measurements, vertical optical depths have been derived for a series of days in June 1993. The spectral extinction coefficient of the atmospheric aerosol at the same location has been measured by means of a telephotometer. The radiance of a target at a distance of 12 km was measured at nine wavelengths in the visible. Thus the extinction coefficient of the aerosol contained within a conical volume of about 450,000 m 3 and a length of 12 km has been measured. The daily variation usually followed the same pattern : a decrease in extinction coefficient in the morning and in the early afternoon and an increase toward the evening. This variation correlated well with the change in humidity, so that it can be assumed that the aerosol particles have decreased their size due to evaporation of water in the morning and uptake of water in the evening. The regular daily pattern of the horizontal aerosol extinction coefficient normally was not followed by the vertical aerosol optical density, but on the other hand, changes in vertical extinction have occurred on some days, which had no effect on the horizontal extinction. Vertical extinction measurements were inverted to obtain aerosol size distributions. Inversions were obtained by the Twomey-Phillips method and they confirm the presence of a hygroscopic aerosol as suggested directly by the variation of the extinction coefficients against the relative humidity. The aerosol undergoes very clear processes of growth which are well correlated with the behavior of the humidity. Overall, the type of aerosol we have measured could be classified as rural aerosol. This kind of aerosol is typical of the boundary layer of clean continental area and is composed prevalently by water-soluble substances and in minor abundance by dustlike aerosol.

A Technique for Classifying Uncertain MOD35/MYD35 Pixels Through Meteosat Second Generation-Spinning Enhanced Visible and Infrared Imager Observations

This paper describes a technique that uses the information gathered from the geostationary instrumentation [Meteosat Second Generation (MSG)-Spinning Enhanced Visible and Infrared Imager (SEVIRI)] to investigate the pixels detected as ¿uncertain¿ by the operational Moderate Resolution Imaging Spectroradiometer (MODIS) cloud-mask algorithm. This technique analyzes the uncertain MODIS areas by using a time series of MSG-SEVIRI images taken at infrared (IR) and visible (VIS) wavelengths. In order to classify the uncertain pixels related to the granules acquired during the daytime and completely included in the high-resolution visible (HRV) image, the spectral and textural features derived from a time series of HRV images are used as inputs in a K-nearest neighbor (K-NN) classifier. For the areas not included in the HRV image and for those acquired during nighttime, the input parameters are determined from a time series of IR/VIS and IR images, respectively. The K-NN classifier detected 52.0%, 48.7%, and 37.0% of the MOD35/MYD35 uncertain pixels analyzed over land and 54.5%, 45.4%, and 49.7% of those analyzed over sea as cloud free, when using HRV, IR, and IR/VIS features as inputs, respectively. Percentages of 39.8%, 31.8%, and 37.3% of the pixels analyzed over land and 40.7%, 47.4%, and 38.0% of those analyzed over sea were classified as cloudy when using HRV, IR, and IR/VIS features as inputs, respectively. The remaining uncertain pixels were classified as low confidence cloudy or cloud free by the K-NN classifier. A set of comparisons was made with cloud-profiling radar/cloud-aerosol lidar with orthogonal polarization 2B-Geometrical Profiling-Lidar product results.

Pollino Project Action D: a multiscale approach in the space-time domain to environmental risk monitoring

Physical parameters related to Earth surface and atmosphere show different behaviors when observed at different space-time scales by using both remote sensing or traditional ground based techniques. The main aim of this project was to investigate the information content degradation which results moving from the use of observations obtained by direct-punctual (ground-based), higher spectral/spatial resolution (airborne sensors), higher time-resolution, low cost and low spatial resolution (satellites), in the context of the activities related to natural and environmental risks monitoring in protected natural areas. Several observational techniques have been contemporary used during two fields campaigns in the Pollino National Park (Southern Italy): a) from ground by direct measurements of near surface parameters (from - 70cm of depth up to 200cm of height) as well as by radiosonde and radiometric measurements of surface and atmospheric parameters; b) using hyperspectral (MIVIS) and photographic aerial observations; c) from LANDSAT-TM, NOAAA/AVHRR and ADEOS/AVIRIS satellite sounders. Campaign data have been integrated on a GIS (including high resolution cartographic layers) and long term evolutionary trends (up to 20 years) also considered after the analysis of available historical, LANDSAT and NOAA, satellite records. This paper will present the main achievements of the project with special emphasis on the trade-off between expected performances and economical sustainability of different environmental monitoring strategies in an operational context.

In place merging of satellite based atmospheric water vapour measurements

Abstract Atmospheric water vapour plays a key role in the climatology of the Earth. It has traditionally been measured using radiosondes for reasons of instrumental simplicity but these offer limited opportunities for spatial and continuous measurements of dynamic water vapour changes over large areas of the Earths atmosphere. Efforts have recently turned to using satellite remote sensing instruments with different spectral and spatial capabilities to derive measurements of total water vapour content in atmospheric columns or simply precipitable water. The merging of remote sensing data with different spectral and spatial capabilities can result in large biases when independent measurements are not nested correctly to produce the final product. Consequently, such merging of data must take into account the intrinsic time dynamics of measured parameters. In this paper, the impact of atmospheric water vapour dynamics on the merging of satellite-based retrieval of precipitable water estimates is investigated...