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Dipartimento di Fisica, Universita` di Bologna, Bologna, Italy
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- PublicationOpen AccessEffective Solar Indices for Ionospheric Modeling: A Review and a Proposal for a Real-Time Regional IRI(2018-01)
; ; ; ; ; ; ; The first part of this paper reviews methods using effective solar indices to update a background ionospheric model focusing on those employing the Kriging method to perform the spatial interpolation. Then, it proposes a method to update the International Reference Ionosphere (IRI) model through the assimilation of data collected by a European ionosonde network. The method, called International Reference Ionosphere UPdate (IRI UP), that can potentially operate in real time, is mathematically described and validated for the period 9–25 March 2015 (a time window including the well-known St. Patrick storm occurred on 17 March), using IRI and IRI Real Time Assimilative Model (IRTAM) models as the reference. It relies on foF2 and M(3000)F2 ionospheric characteristics, recorded routinely by a network of 12 European ionosonde stations, which are used to calculate for each station effective values of IRI indices IG12 and R12 (identified as IG12eff and R12eff ); then, starting from this discrete dataset of values, two-dimensional (2D) maps of IG12eff and R12eff are generated through the universal Kriging method. Five variogram models are proposed and tested statistically to select the best performer for each effective index. Then, computed maps of IG12eff and R12eff are used in the IRI model to synthesize updated values of foF2 and hmF2. To evaluate the ability of the proposed method to reproduce rapid local changes that are common under disturbed conditions, quality metrics are calculated for two test stations whose measurements were not assimilated in IRI UP, Fairford (51.7°N, 1.5°W) and San Vito (40.6°N, 17.8°E), for IRI, IRI UP, and IRTAM models. The proposed method turns out to be very effective under highly disturbed conditions, with significant improvements of the foF2 representation and noticeable improvements of the hmF2 one. Important improvements have been verified also for quiet and moderately disturbed conditions. A visual analysis of foF2 and hmF2 maps highlights the ability of the IRI UP method to catch small-scale changes occurring under disturbed conditions which are not seen by IRI.172 142 - PublicationRestrictedRetrieval of foreign-broadened water vapor continuum coefficients from emitted spectral radiance in the H2O rotational band from 240 to 590 cm −1(2008-09-29)
; ; ; ; ; ; ; ; ; ; ; ; ;Serio, C.; Dip. Ingegeneria e Fisica dell’Ambiente, Università della Basilicata, Potenza, Italy ;Masiello, G.; Dip. Ingegeneria e Fisica dell’Ambiente, Università della Basilicata, Potenza, Italy ;Esposito, F.; Dip. Ingegeneria e Fisica dell’Ambiente, Università della Basilicata, Potenza, Italy ;Di Girolamo, P.; Dip. Ingegeneria e Fisica dell’Ambiente, Università della Basilicata, Potenza, Italy ;Di Iorio, T.; Dip. Fisica, Università di Roma ”La Sapienza”, Roma, Italy ;Palchetti, L.; Istituto di Fisica Applicata ”Nello Carrara”, IFAC-CNR, Firenze, Italy ;Bianchini, G.; Istituto di Fisica Applicata ”Nello Carrara”, IFAC-CNR, Firenze, Italy ;Muscari, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Pavese, G.; Istituto di Metodologie per l’Analisi Ambientale, IMAA-CNR, Potenza, Italy ;Rizzi, R.; Dip. Fisica, Università di Bologna, Bologna, Italy ;Carli, B.; Istituto di Fisica Applicata ”Nello Carrara”, IFAC-CNR, Firenze, Italy ;Cuomo, V.; Istituto di Metodologie per l’Analisi Ambientale, IMAA-CNR, Potenza, Italy; ; ; ; ; ; ; ; ; ; ; The paper presents a novel methodology to retrieve the foreign-broadened water vapor continuum absorption coefficients in the spectral range 240 to 590 cm−1 and is the first estimation of the continuum coefficient at wave numbers smaller than 400 cm−1 under atmospheric conditions. The derivation has been accomplished by processing a suitable set of atmospheric emitted spectral radiance observations obtained during the March 2007 Alps campaign of the ECOWAR project (Earth COoling by WAter vapor Radiation). It is shown that, in the range 450 to 600 cm−1, our findings are in good agreement with the widely used Mlawer, Tobin-Clough, Kneizys-Davies (MT_CKD) continuum. Below 450 cm−1 however the MT_CKD model overestimates the magnitude of the continuum coefficient.320 27 - PublicationOpen AccessCorrection to: Effective Solar Indices for Ionospheric Modeling: A Review and a Proposal for a Real-Time Regional IRI(2018-01)
; ; ; ; ; ; ; Correction to: Surv Geophys https://doi.org/10.1007/s10712-017-9438-y158 100 - PublicationOpen AccessModeling the Lower Part of the Topside Ionospheric Vertical Electron Density Profile Over the European Region by Means of Swarm Satellites Data and IRI UP MethodAn empirical method to model the lower part of the ionospheric topside region from the F2 layer peak height to about 500–600 km of altitude over the European region is proposed. The method is based on electron density values recorded from December 2013 to June 2016 by Swarm satellites and on foF2 and hmF2 values provided by IRI UP (International Reference Ionosphere UPdate), which is a method developed to update the IRI model relying on the assimilation of foF2 and M(3000)F2 data routinely recorded by a network of European ionosonde stations. Topside effective scale heights are calculated by fitting some definite analytical functions (α-Chapman, β-Chapman, Epstein, and exponential) through the values recorded by Swarm and the ones output by IRI UP, with the assumption that the effective scale height is constant in the altitude range considered. Calculated effective scale heights are then modeled as a function of foF2 and hmF2, in order to be operationally applicable to both ionosonde measurements and ionospheric models, like IRI. The method produces two-dimensional grids of the median effective scale height binned as a function of foF2 and hmF2, for each of the considered topside profiles. A statistical comparison with Constellation Observing System for Meteorology, Ionosphere, and Climate/FORMOsa SATellite-3 collected Radio Occultation profiles is carried out to assess the validity of the proposed method and to investigate which of the considered topside profiles is the best one. The α-Chapman topside function displays the best performance compared to the others and also when compared to the NeQuick topside option of IRI.
124 56 - PublicationOpen AccessOn the Development of a Method for Updating an Empirical Climatological Ionospheric Model by Means of Assimilated vTEC Measurements From a GNSS Receiver Network(2019-06)
; ; ; ; ; ; ; In this paper, a procedure for updating the International Reference Ionosphere (IRI) model by means of assimilated vertical total electron content (vTEC) measurements from a Global Navigational Satellite Systems (GNSS) receiver network is presented. This procedure stands as an additional implementation of the IRI UPdate (IRI UP) method, which is based on the assimilation of ionosonde derived F2 layer ionospheric characteristics. According to this, a mathematical procedure for obtaining foF2 and M(3000)F2 values from vTEC measurements is here proposed. Mathematical relationships between F2 layer characteristics and vTEC values have been derived using South African colocated ionosonde and GNSS stations. The same procedure can, however, be applied successfully in each region where such data are available. The goodness of the proposed IRI UP method, based on assimilated vTEC values, has been tested for several quiet and disturbed days in 2017 and 2018. IRI UP exhibits better performances than IRI for foF2, for most of the analyzed cases. Slight improvements are achieved in modeling hmF2 only for very disturbed periods in 2017. Due to the very good coverage of the terrestrial surface that GNSS receivers have achieved in recent years, we suggest that the method proposed here can be a good implementation of the IRI model for Space Weather nowcasting purposes, at least for foF2.194 20 - PublicationRestrictedSpectrally resolved observations of atmospheric emitted radiance in the H2O rotation band(2008-02)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;Bhawar, R.; Dipartimento di Ingegeneria e Fisica dell’Ambiente, Universita` della Basilicata, Potenza, Italy ;Bianchini, G.; Istituto di Fisica Applicata Nello Carrara, CNR, Sesto Fiorentino, Italy ;Bozzo, A.; Dipartimento di Fisica, Universita` di Bologna, Bologna, Italy ;Cacciani, M.; Dipartimento di Fisica, Universita di Roma La Sapienza, Roma, Italy ;Calvello, M. R.; Dipartimento di Ingegeneria e Fisica dell’Ambiente, Universita` della Basilicata, Potenza, Italy ;Carlotti, M.; Dipartimento di Chimica Fisica ed Inorganica, Universita` di Bologna, Bologna, Italy ;Castagnoli, F.; Istituto di Fisica Applicata Nello Carrara, CNR, Sesto Fiorentino, Italy ;Cuomo, V.; Istituto di Metodologie per l’Analisi Ambientale, CNR, Tito Scalo, Italy ;Di Girolamo, P.; Dipartimento di Ingegeneria e Fisica dell’Ambiente, Universita` della Basilicata, Potenza, Italy ;Di Iorio, T.; Dipartimento di Fisica, Universita di Roma La Sapienza, Roma, Italy ;Di Liberto, L.; Dipartimento di Fisica, Universita di Roma La Sapienza, Roma, Italy ;di Sarra, A.; Dipartimento di Fisica, Universita di Roma La Sapienza, Roma, Italy ;Esposito, F.; Dipartimento di Ingegeneria e Fisica dell’Ambiente, Universita` della Basilicata, Potenza, Italy ;Fiocco, G.; Dipartimento di Fisica, Universita di Roma La Sapienza, Roma, Italy ;Fuà, D.; Dipartimento di Fisica, Universita di Roma La Sapienza, Roma, Italy ;Grieco, G.; Dipartimento di Ingegeneria e Fisica dell’Ambiente, Universita` della Basilicata, Potenza, Italy ;Maestri, T.; Dipartimento di Fisica, Universita` di Bologna, Bologna, Italy ;Masiello, G.; Dipartimento di Ingegeneria e Fisica dell’Ambiente, Universita` della Basilicata, Potenza, Italy ;Muscari, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Palchetti, L.; Istituto di Fisica Applicata Nello Carrara, CNR, Sesto Fiorentino, Italy ;Papandrea, E.; Dipartimento di Chimica Fisica ed Inorganica, Universita` di Bologna, Bologna, Italy ;Pavese, G.; Istituto di Metodologie per l’Analisi Ambientale, CNR, Tito Scalo, Italy ;Restieri, R.; Dipartimento di Ingegeneria e Fisica dell’Ambiente, Universita` della Basilicata, Potenza, Italy ;Rizzi, R.; Dipartimento di Fisica, Universita` di Bologna, Bologna, Italy ;Romano, F.; Istituto di Metodologie per l’Analisi Ambientale, CNR, Tito Scalo, Italy ;Serio, C.; Dipartimento di Ingegeneria e Fisica dell’Ambiente, Universita` della Basilicata, Potenza, Italy ;Summa, D.; Dipartimento di Ingegeneria e Fisica dell’Ambiente, Universita` della Basilicata, Potenza, Italy ;Todini, G.; Dipartimento di Fisica, Universita` di Bologna, Bologna, Italy ;Tosi, E.; Dipartimento di Fisica, Universita` di Bologna, Bologna, Italy; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; This paper presents the project Earth Cooling by Water Vapor Radiation, an observational programme, which aims at developing a database of spectrally resolved far infrared observations, in atmospheric dry conditions, in order to validate radiative transfer models and test the quality of water vapor continuum and line parameters. The project provides the very first set of far-infrared spectral downwelling radiance measurements, in dry atmospheric conditions, which are complemented with Raman Lidar-derived temperature and water vapor profiles.261 32