25 results on '"Dietrich, Stefano"'
Search Results
2. Gamma ray storms: preliminary meteorological analysis of AGILE TGFs: Meteorology of AGILE TGF observations
- Author
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Tiberia, Alessandra, Dietrich, Stefano, Porcù, Federico, Marisaldi, Martino, Ursi, Alessandro, and Tavani, Marco
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- 2019
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3. Study of the Intense Meteorological Event Occurred in September 2022 over the Marche Region with WRF Model: Impact of Lightning Data Assimilation on Rainfall and Lightning Prediction.
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Torcasio, Rosa Claudia, Papa, Mario, Del Frate, Fabio, Dietrich, Stefano, Toffah, Felix Enyimah, and Federico, Stefano
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RAINFALL ,LIGHTNING ,METEOROLOGICAL research ,THUNDERSTORMS ,TROPICAL cyclones ,PRECIPITATION forecasting - Abstract
A destructive V-shaped thunderstorm occurred over the Marche Region, in Central Italy, on 15 September 2022. Twelve people died during the event, and damage to properties was extensive because the small Misa River flooded the area. The synoptic-scale conditions that caused this disastrous event are analysed and go back to the presence of tropical cyclone Danielle in the eastern Atlantic. The performance of the weather research and forecasting (WRF) model using lightning data assimilation (LDA) is studied in this case by comparing the forecast with the control forecast without lightning data assimilation. The forecast performance is evaluated for precipitation and lightning. The case was characterised by four intense 3-h (3 h) periods. The forecasts of these four 3-h phases are analysed in a very short-term forecast (VSF) approach, in which a 3 h data assimilation phase is followed by a 3 h forecast. A homemade 3D-Var is used for lightning data assimilation with two different configurations: ANL, in which the lightning is assimilated until the start of the forecasting period, and ANL-1H, which assimilates lightning until 1 h before the 3 h forecasting period. A sensitivity test for the number of analyses used is also discussed. Results show that LDA has a significant and positive impact on the precipitation and lightning forecast for this case. [ABSTRACT FROM AUTHOR]
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- 2023
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4. A Joint LINET and ISS-LIS View of Lightning Distribution over the Mt. Cimone Area within the GAMMA-FLASH Program.
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Tiberia, Alessandra, Arnone, Enrico, Ursi, Alessandro, Fuschino, Fabio, Virgilli, Enrico, Preziosi, Enrico, Tavani, Marco, and Dietrich, Stefano
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LIGHTNING ,NEUTRON emission ,IONIZING radiation ,THUNDERSTORMS ,RADIO measurements ,SPACE stations - Abstract
Typical features of lightning distribution in the mountain area of Mt. Cimone (2165 m a.s.l., Northern-Central Italy) have been studied through detections provided by the ground-based LIghtning NETwork data (LINET) and the Lightning Imaging Sensor (LIS) onboard the International Space Station (ISS-LIS). This study was performed within the context of the Gamma-Flash program, which includes the in situ observation of high-energy radiation (e.g., Terrestrial Gamma-ray Flashes (TGFs), gamma-ray glows) and neutron emissions from thunderstorms at the mountain-top "O. Vittori" climate observatory. LINET VLF/LF radio measurements allowed the characterization of both cloud-to-ground (CG) and intra-cloud (IC) strokes' geographical distribution and an altitude of occurrence from 2012 through 2020. The lightning distribution showed a remarkable clustering of CGs at the mountain top in contrast to a homogeneous distribution of ICs, highlighting the likely impact of orography. IC strokes peaked around 4 to 6 km altitude, in agreement with the observed typical cloud range. The joint exploitation of ISS-LIS optical observations of LINET detections extended the study to further features of flashes not seen in radio wavelengths and stands as the cross-validation of the two detection methods over such a complex orography. These results gave the quantitative indication of the expected occurrence of lightning and ionizing radiation emissions in the Mt. Cimone area and an example of mountain-driven changes in lightning occurrence. [ABSTRACT FROM AUTHOR]
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- 2022
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5. A Year-Long Total Lightning Forecast over Italy with a Dynamic Lightning Scheme and WRF.
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Federico, Stefano, Torcasio, Rosa Claudia, Lagasio, Martina, Lynn, Barry H., Puca, Silvia, and Dietrich, Stefano
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METEOROLOGICAL research ,WEATHER forecasting ,FORECASTING ,POTENTIAL energy ,MICROPHYSICS - Abstract
Lightning is an important threat to life and properties and its forecast is important for several applications. In this paper, we show the performance of the "dynamic lightning scheme" for next-day total strokes forecast. The predictions were compared against strokes recorded by a ground observational network for a forecast period spanning one year. Specifically, a total of 162 case studies were selected between 1 March 2020 and 28 February 2021, characterized by at least 3000 observed strokes over Italy. The events span a broad range of lightning intensity from about 3000 to 600,000 strokes in one day: 69 cases occurred in summer, 46 in fall, 18 in winter, and 29 in spring. The meteorological driver was the Weather Research and Forecasting (WRF) model (version 4.1) and we focused on the next-day forecast. Strokes were simulated by adding three extra variables to WRF, namely, the potential energies for positive and negative cloud to ground flashes and intracloud strokes. Each potential energy is advected by WRF, it is built by the electrification processes occurring into the cloud, and it is dissipated by lightning. Observed strokes were remapped onto the WRF model grid with a 3 km horizontal resolution for comparison with the strokes forecast. Results are discussed for the whole year and for different seasons. Moreover, statistics are presented for the land and the sea. In general, the results of this study show that lightning forecast with the dynamic lightning scheme and WRF model was successful for Italy; nevertheless, a careful inspection of forecast performance is necessary for tuning the scheme. This tuning is dependent on the season. A numerical experiment changing the microphysics scheme used in WRF shows the sensitivity of the results according to the choice of the microphysics scheme. [ABSTRACT FROM AUTHOR]
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- 2022
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6. Fulmini ed agricoltura in tempi di cambiamento climatico
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Dietrich, Stefano, Coletta, Virginia, D’Adderio, Leo Pio, Federico, Stefano, Pazienza, Luigi, and Torcasio, Rosa Claudia
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Lightning, RAMS@ISAC, Models Agriculture ,RAMS@ISAC ,Lightning ,Models Agriculture - Published
- 2019
7. The impact of lightning and radar reflectivity factor data assimilation on the very short-term rainfall forecasts of RAMS@ISAC: application to two case studies in Italy.
- Author
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Federico, Stefano, Torcasio, Rosa Claudia, Avolio, Elenio, Caumont, Olivier, Montopoli, Mario, Baldini, Luca, Vulpiani, Gianfranco, and Dietrich, Stefano
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LIGHTNING ,ATMOSPHERIC sciences ,CLIMATOLOGY ,RADAR ,RAINFALL ,PRECIPITATION forecasting - Abstract
In this paper, we study the impact of lightning and radar reflectivity factor data assimilation on the precipitation VSF (very short-term forecast, 3 h in this study) for two severe weather events that occurred in Italy. The first case refers to a moderate and localized rainfall over central Italy that occurred on 16 September 2017. The second case occurred on 9 and 10 September 2017 and was very intense and caused damages in several geographical areas, especially in Livorno (Tuscany) where nine people died. The first case study was missed by several operational forecasts, including that performed by the model used in this paper, while the Livorno case was partially predicted by operational models. We use the RAMS@ISAC model (Regional Atmospheric Modelling System at Institute for Atmospheric Sciences and Climate of the Italian National Research Council), whose 3D-Var extension to the assimilation of radar reflectivity factor is shown in this paper for the first time. Results for the two cases show that the assimilation of lightning and radar reflectivity factor, especially when used together, have a significant and positive impact on the precipitation forecast. For specific time intervals, the data assimilation is of practical importance for civil protection purposes because it changes a missed forecast of intense precipitation (≥40 mm in 3 h) to a correct one. While there is an improvement of the rainfall VSF thanks to the lightning and radar reflectivity factor data assimilation, its usefulness is partially reduced by the increase in false alarms, especially when both datasets are assimilated. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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8. The impact of lightning and radar data assimilation on the performance of very short term rainfall forecast for two case studies in Italy.
- Author
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Federico, Stefano, Torcasio, Rosa Claudia, Avolio, Elenio, Caumont, Olivier, Montopoli, Mario, Baldini, Luca, Vulpiani, Gianfranco, and Dietrich, Stefano
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PRECIPITATION forecasting ,RAINFALL probabilities ,LIGHTNING - Abstract
In this paper, we study the impact of lightning and radar reflectivity factor data assimilation on the precipitation VSF (Very Short-term Forecast, 3 hours in this study) for two relevant case studies occurred over Italy. The first case refers to a moderate localised rainfall over Central Italy happened on 16 September 2017. The second case, occurred on 09 and 10 September 2017, was very intense and caused damages in several parts of Italy, while nine people died around Livorno, in Tuscany. The first case study was missed by most operational forecasts over Italy, including that performed by the model used in this paper, while the Livorno case was partially predicted by operational models. We use the RAMS@ISAC model (Regional Atmospheric Modelling System at Institute for Atmospheric Sciences and Climate of the Italian National Research Council), whose 3D-Var extension to the assimilation of RADAR reflectivity factor is shown in this paper. Results for the two cases show that the assimilation of lightning and radar reflectivity factor, especially when used together, have a significant and positive impact on the precipitation forecast. The improvement compared to the control model, not assimilating lightning and radar reflectivity factor, is systematic because occurs for all the Very Short-term Forecast (VSF, 3h) of the events considered. For specific time intervals, the data assimilation is of practical importance for Civil Protection purposes because it transforms a missed forecast of intense precipitation (>40mm/3h) in a correct forecast. While there is an improvement of the rainfall VSF thanks to the lightning and radar reflectivity factor data assimilation, its impact is reduced by the increase of the false alarms in the forecast assimilating both types of data. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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9. Observing relationships between lightning and cloud profiles by means of a satellite-borne cloud radar.
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Buiat, Martina, Porcù, Federico, and Dietrich, Stefano
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LIGHTNING ,RADAR ,DETECTORS ,REMOTE sensing ,ATMOSPHERIC electricity - Abstract
Cloud electrification and related lightning activity in thunderstorms have their origin in the charge separation and resulting distribution of charged iced particles within the cloud. So far, the ice distribution within convective clouds has been investigated mainly by means of ground-based meteorological radars. In this paper we show how the products from Cloud Profiling Radar (CPR) on board CloudSat, a polar satellite of NASA's Earth System Science Pathfinder (ESSP), can be used to obtain information from space on the vertical distribution of ice particles and ice content and relate them to the lightning activity. The analysis has been carried out, focusing on 12 convective events over Italy that crossed CloudSat overpasses during significant lightning activity. The CPR products considered here are the vertical profiles of cloud ice water content (IWC) and the effective radius (ER) of ice particles, which are compared with the number of strokes as measured by a ground lightning network (LINET). Results show a strong correlation between the number of strokes and the vertical distribution of ice particles as depicted by the 94 GHz CPR products: in particular, cloud upper and middle levels, high IWC content and relatively high ER seem to be favourable contributory causes for CG (cloud to ground) stroke occurrence. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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10. Improvement of RAMS precipitation forecast at the short-range through lightning data assimilation.
- Author
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Federico, Stefano, Petracca, Marco, Panegrossi, Giulia, and Dietrich, Stefano
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METEOROLOGICAL precipitation ,LIGHTNING ,CONVECTION (Meteorology) ,ATMOSPHERIC water vapor ,ATMOSPHERIC models - Abstract
This study shows the application of a total lightning data assimilation technique to the RAMS (Regional Atmospheric Modeling System) forecast. The method, which can be used at high horizontal resolution, helps to initiate convection whenever flashes are observed by adding water vapour to the model grid column. The water vapour is added as a function of the flash rate, local temperature, and graupel mixing ratio. The methodology is set up to improve the short-term (3 h) precipitation forecast and can be used in real-time forecasting applications. However, results are also presented for the daily precipitation for comparison with other studies. The methodology is applied to 20 cases that occurred in fall 2012, which were characterized by widespread convection and lightning activity. For these cases a detailed dataset of hourly precipitation containing thousands of rain gauges over Italy, which is the target area of this study, is available through the HyMeX (HYdrological cycle in the Mediterranean Experiment) initiative. This dataset gives the unique opportunity to verify the precipitation forecast at the short range (3 h) and over a wide area (Italy). Results for the 27 October case study show how the methodology works and its positive impact on the 3 h precipitation forecast. In particular, the model represents better convection over the sea using the lightning data assimilation and, when convection is advected over the land, the precipitation forecast improves over the land. It is also shown that the precise location of convection by lightning data assimilation improves the precipitation forecast at fine scales (meso-β). The application of the methodology to 20 cases gives a statistically robust evaluation of the impact of the total lightning data assimilation on the model performance. Results show an improvement of all statistical scores, with the exception of the bias. The probability of detection (POD) increases by 3-5% for the 3 h forecast and by more than 5% for daily precipitation, depending on the precipitation threshold considered. Score differences between simulations with or without data assimilation are significant at 95% level for most scores and thresholds considered, showing the positive and statistically robust impact of the lightning data assimilation on the precipitation forecast. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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- View/download PDF
11. Improvement of RAMS precipitation forecast at the short range through lightning data assimilation.
- Author
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Federico, Stefano, Petracca, Marco, Panegrossi, Giulia, and Dietrich, Stefano
- Subjects
WATER vapor ,LIGHTNING ,METEOROLOGICAL precipitation - Abstract
This study shows the application of a total lightning data assimilation technique to the RAMS (Regional Atmospheric Modeling System) forecast. The method, which can be used at high horizontal resolution, helps to initiate convection whenever flashes are observed by adding water vapour to the model grid column. The water vapour is added as a function of the flash rate, local temperature and graupel mixing ratio. The methodology is set-up to improve the short-term (3 h) precipitation forecast and can be used in real-time forecasting applications. However, results are also presented for the daily precipitation for comparison with other studies. The methodology is applied to twenty cases occurred in fall 2012, that were characterized by widespread convection and lightning activity. For these cases a detailed dataset of hourly precipitation containing thousands of raingauges over Italy, which is the target of this study, is available through the HyMeX (HYdrological cycle in the Mediterranean Experiment) initiative. This dataset gives the unique opportunity to verify the precipitation forecast at the short range (3 h) and over a wide area (Italy). Results for the 27 October case study show how the methodology works and its positive impact on the 3 h precipitation forecast. In particular, the model represents better the convection over the sea using the lightning data assimilation and, when convection is advected over the land, the precipitation forecast improves over the land. It is also shown that the precise location of the convection by lightning data assimilation, improves the precipitation forecast at fine scales (meso-Б). The application of the methodology to twenty cases gives a statistically robust evaluation of the impact of the total lightning data assimilation on the model performance. Results show an improvement of all statistical scores, with the exception of the Bias. The Probability of Detection (POD) increases by 3-5 % for the 3 h forecast and by more than 5 % for daily precipitation, depending on the precipitation threshold considered. Score differences between simulations with or without data assimilation are significant at 95 % level for most scores and thresholds considered, showing the positive and statistically robust impact of the lightning data assimilation on the precipitation forecast. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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12. Impact of Radar Reflectivity and Lightning Data Assimilation on the Rainfall Forecast and Predictability of a Summer Convective Thunderstorm in Southern Italy.
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Federico, Stefano, Torcasio, Rosa Claudia, Puca, Silvia, Vulpiani, Gianfranco, Comellas Prat, Albert, Dietrich, Stefano, and Avolio, Elenio
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THUNDERSTORMS ,RADAR ,LIGHTNING ,PRECIPITATION forecasting ,FORECASTING ,SUMMER - Abstract
Heavy and localized summer events are very hard to predict and, at the same time, potentially dangerous for people and properties. This paper focuses on an event occurred on 15 July 2020 in Palermo, the largest city of Sicily, causing about 120 mm of rainfall in 3 h. The aim is to investigate the event predictability and a potential way to improve the precipitation forecast. To reach this aim, lightning (LDA) and radar reflectivity data assimilation (RDA) was applied. LDA was able to trigger deep convection over Palermo, with high precision, whereas the RDA had a key role in the prediction of the amount of rainfall. The simultaneous assimilation of both data sources gave the best results. An alert for a moderate–intense forecast could have been issued one hour and a half before the storm developed over the city, even if predicting only half of the total rainfall. A satisfactory prediction of the amount of rainfall could have been issued at 14:30 UTC, when precipitation was already affecting the city. Although the study is centered on a single event, it highlights the need for rapidly updated forecast cycles with data assimilation at the local scale, for a better prediction of similar events. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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13. A Comprehensive Study on the Improved Radio-Frequency Magnetic Field Measurement for the Initial Upward Leader of a Negative Rocket-Triggered Lightning Flash.
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Shi, Tao, Lu, Gaopeng, Fan, Yanfeng, Li, Xiao, Zhang, Yang, and Dietrich, Stefano
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MAGNETIC field measurements ,LIGHTNING ,MAGNETIC sensors ,MAGNETIC fields ,SPECTRUM analysis - Abstract
The spectrum analysis of the lightning current in the experiment campaign of 2019 reveals that the lightning current waveform contains rich medium-frequency (MF) radiation signals in the initial stage. However, there is a lack of resolution for MF signals by using conventional magnetic sensors. The bandwidth of radio-frequency magnetic field measurement is improved by extending to 20 kHz–1.2 MHz in the Guangdong Comprehensive Observation Experiment on Lightning Discharge (GCOELD). During the previously noticed "quiet period" that can only maintain the upward propagation with relatively small-scale breakdown, magnetic pulses of quiet period (MPQPs) are discerned more clearly than the previous experiment in GCOELD. Aided by the improvement of a magnetic sensor, this paper captures richer magnetic field signals radiated from the weak discharge of the precursory phage than previous experiments in GCOELD. The analysis shows that both aborted UPLs and UPLs are caused by weak discharge pulses called initial precursor pulses (IPPs), which are very similar to the amplitude of the streamer discharge obtained in the laboratory. In summary, the signals detected by an improved magnetic sensor will provide an important reference for exploring the pulse characteristics of the whole discharge process and formation mechanism of the UPL in the initial stage of triggered lightning. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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14. Enhancement of Cloud-to-Ground Lightning Activity Caused by the Urban Effect: A Case Study in the Beijing Metropolitan Area.
- Author
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Wang, Yongping, Lu, Gaopeng, Shi, Tao, Ma, Ming, Zhu, Baoyou, Liu, Dongxia, Peng, Changzhi, Wang, Yu, and Dietrich, Stefano
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THUNDERSTORMS ,METROPOLITAN areas ,URBAN growth ,LIGHTNING ,CENTRAL business districts - Abstract
To investigate the possible impact of urban development on lightning activity, an eight-year (2010–2017) cloud-to-ground (CG) lightning dataset provided by the National-Wide Lightning Detection Network in China was analyzed to characterize the CG lightning activity in the metropolitan area of Beijing. There is a high CG flash density area over the downtown of Beijing, but different from previous studies, the downwind area of Beijing is not significantly enhanced. Compared with the upwind area, the CG flash density in the downtown area was enhanced by about 50%. Negative CG flashes mainly occurred in the downtown and industrial area, while positive CG flashes were distributed evenly. The percentage of positive CG flashes with I
peak ≥ 75 kA is more than six times that of the corresponding negative CG flashes in the Beijing area. The enhancement of lightning activity varies with season and time. About 98% of CG flashes occurred from May to September, and the peak of CG diurnal variation is from 1900 to 2100 local time. Based on the analysis of thunderstorm types in Beijing, it is considered that the abnormal lightning activity is mainly responsible for an enhancement of the discharge number in frontal systems rather than the increase of the number of local thunderstorms. In addition, there is a non-linear relationship between pollutant concentrations and CG flash number, which indicates that there are other critical factors affecting the production of lightning. [ABSTRACT FROM AUTHOR]- Published
- 2021
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15. Time Evolution of Storms Producing Terrestrial Gamma-Ray Flashes Using ERA5 Reanalysis Data, GPS, Lightning and Geostationary Satellite Observations.
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Tiberia, Alessandra, Mascitelli, Alessandra, D'Adderio, Leo Pio, Federico, Stefano, Marisaldi, Martino, Porcù, Federico, Realini, Eugenio, Gatti, Andrea, Ursi, Alessandro, Fuschino, Fabio, Tavani, Marco, Dietrich, Stefano, and Van Diedenhoven, Bastiaan
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GEOSTATIONARY satellites ,PRECIPITABLE water ,THUNDERSTORMS ,LIGHTNING ,GAMMA rays ,POSITION sensors ,WEATHER ,ARTIFICIAL satellites - Abstract
In this article, we report the first investigation over time of the atmospheric conditions around terrestrial gamma-ray flash (TGF) occurrences, using GPS sensors in combination with geostationary satellite observations and ERA5 reanalysis data. The goal is to understand which characteristics are favorable to the development of these events and to investigate if any precursor signals can be expected. A total of 9 TGFs, occurring at a distance lower than 45 km from a GPS sensor, were analyzed and two of them are shown here as an example analysis. Moreover, the lightning activity, collected by the World Wide Lightning Location Network (WWLLN), was used in order to identify any links and correlations with TGF occurrence and precipitable water vapor (PWV) trends. The combined use of GPS and the stroke rate trends identified, for all cases, a recurring pattern in which an increase in PWV is observed on a timescale of about two hours before the TGF occurrence that can be placed within the lightning peak. The temporal relation between the PWV trend and TGF occurrence is strictly related to the position of GPS sensors in relation to TGF coordinates. The life cycle of these storms observed by geostationary sensors described TGF-producing clouds as intense with a wide range of extensions and, in all cases, the TGF is located at the edge of the convective cell. Furthermore, the satellite data provide an added value in associating the GPS water vapor trend to the convective cell generating the TGF. The investigation with ERA5 reanalysis data showed that TGFs mainly occur in convective environments with unexceptional values with respect to the monthly average value of parameters measured at the same location. Moreover, the analysis showed the strong potential of the use of GPS data for the troposphere characterization in areas with complex territorial morphologies. This study provides indications on the dynamics of con-vective systems linked to TGFs and will certainly help refine our understanding of their production, as well as highlighting a potential approach through the use of GPS data to explore the lightning activity trend and TGF occurrences. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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16. Impact of Lightning Data Assimilation on the Short-Term Precipitation Forecast over the Central Mediterranean Sea.
- Author
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Torcasio, Rosa Claudia, Federico, Stefano, Comellas Prat, Albert, Panegrossi, Giulia, D'Adderio, Leo Pio, Dietrich, Stefano, and Katsanos, Dimitrios
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PRECIPITATION forecasting ,METEOROLOGICAL research ,LIGHTNING ,WEATHER forecasting ,RAIN gauges ,FALSE alarms ,PRECIPITATION gauges - Abstract
Lightning data assimilation (LDA) is a powerful tool to improve the weather forecast of convective events and has been widely applied with this purpose in the past two decades. Most of these applications refer to events hitting coastal and land areas, where people live. However, a weather forecast over the sea has many important practical applications, and this paper focuses on the impact of LDA on the precipitation forecast over the central Mediterranean Sea around Italy. The 3 h rapid update cycle (RUC) configuration of the weather research and forecasting (WRF) model) has been used to simulate the whole month of November 2019. Two sets of forecasts have been considered: CTRL, without lightning data assimilation, and LIGHT, which assimilates data from the LIghtning detection NETwork (LINET). The 3 h precipitation forecast has been compared with observations of the Integrated Multi-satellitE Retrievals for Global Precipitation Mission (GPM) (IMERG) dataset and with rain gauge observations recorded in six small Italian islands. The comparison of CTRL and LIGHT precipitation forecasts with the IMERG dataset shows a positive impact of LDA. The correlation between predicted and observed precipitation improves over wide areas of the Ionian and Adriatic Seas when LDA is applied. Specifically, the correlation coefficient for the whole domain increases from 0.59 to 0.67, and the anomaly correlation (AC) improves by 5% over land and by 8% over the sea when lightning is assimilated. The impact of LDA on the 3 h precipitation forecast over six small islands is also positive. LDA improves the forecast by both decreasing the false alarms and increasing the hits of the precipitation forecast, although with variability among the islands. The case study of 12 November 2019 (time interval 00–03 UTC) has been used to show how important the impact of LDA can be in practice. In particular, the shifting of the main precipitation pattern from land to the sea caused by LDA gives a much better representation of the precipitation field observed by the IMERG precipitation product. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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17. Application of Lightning Data Assimilation for the 10 October 2018 Case Study over Sardinia.
- Author
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Torcasio, Rosa Claudia, Federico, Stefano, Puca, Silvia, Vulpiani, Gianfranco, Comellas Prat, Albert, and Dietrich, Stefano
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ATMOSPHERIC models ,LIGHTNING ,NUMERICAL weather forecasting ,CASE studies ,FALSE alarms ,FORECASTING - Abstract
On 10 October 2018 an intense storm, characterized by heavy rainfall, hit the Sardinia island, reaching a peak of 452 mm of rain measured in 24 h. Among others, two particularly intense phases were registered between 3 and 6 UTC (Universal Coordinated Time), and between 18 and 24 UTC. The forecast of this case study is challenging because the precipitation was heavy and localized. In particular, the meteorological model used in this paper, provides a good prediction only for the second period over the eastern part of the Sardinia island. In this work, we study the impact of lightning data assimilation and horizontal grid resolution on the Very Short-term Forecast (VSF, 3 and 1 h) for this challenging case, using the RAMS@ISAC meteorological model. The comparison between the 3 h VSF control run and the simulations with lightning data assimilation shows the considerable improvement given by lightning data assimilation, especially for the precipitation that occurred in the eastern part of the island. Reducing the VSF range to 1 h, resulted in higher model performance with a good precipitation prediction over eastern and south-central Sardinia. In addition, the comparison between simulated and observed reflectivity shows an important improvement of simulations with lightning data assimilation compared to the control forecast. However, simulations assimilating lightning overestimated the precipitation in the last part of the day. The increasing of the horizontal resolution to 2 km grid spacing reduces the false alarms and improves the model performance. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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18. A Combined IR-GPS Satellite Analysis for Potential Applications in Detecting and Predicting Lightning Activity.
- Author
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D'Adderio, Leo Pio, Pazienza, Luigi, Mascitelli, Alessandra, Tiberia, Alessandra, and Dietrich, Stefano
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LIGHTNING ,PRECIPITABLE water ,ATMOSPHERIC water vapor measurement ,GLOBAL Positioning System ,ORBIT determination ,BRIGHTNESS temperature ,RECEIVING antennas - Abstract
Continuous estimates of the vertical integrated precipitable water vapor content from the tropospheric delay of the signal received by the antennas of the global positioning system (GPS) are used in this paper, in conjunction with the measurements of the Meteosat Second Generation (MSG) spinning enhanced visible and infrared imager (SEVIRI) radiometer and with the lightning activity, collected here by the ground-based lightning detection network (LINET), in order to identify links and recurrent patterns useful for improving nowcasting applications. The analysis of a couple of events is shown here as an example of more general behavior. Clear signs appear before the peak of lightning activity on a timescale from 2 to 3 h. In particular, the lightning activity is generally preceded by a period in which the difference between SEVIRI brightness temperature (TB) at channel 5 and channel 6 (i.e., ∆TB) presents quite constant values around 0 K. This trend is accompanied by an increase in precipitable water vapor (PWV) values, reaching a maximum in conjunction with the major flash activity. The results shown in this paper evidence good potentials of using radiometer and GPS measurements together for predicting the abrupt intensification of lightning activity in nowcasting systems. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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19. Multi-Variable Classification Approach for the Detection of Lightning Activity Using a Low-Cost and Portable X Band Radar.
- Author
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Capozzi, Vincenzo, Montopoli, Mario, Mazzarella, Vincenzo, Marra, Anna Cinzia, Roberto, Nicoletta, Panegrossi, Giulia, Dietrich, Stefano, and Budillon, Giorgio
- Subjects
RADAR meteorology ,LIGHTNING ,CONVECTIVE clouds ,FALSE alarms ,REFLECTANCE - Abstract
This work proposes a multi-parameter method for the detection of cloud-to-ground stroke rate (SR
CG ) associated to convective cells, based on the measurements of a low-cost single-polarization X-band weather radar. To train and test our procedure, we built up a multi-year dataset, collecting 1575 radar reflectivity volumes that were acquired in the pilot study area of Naples metropolitan environment matched with the LIghtning NETwork (LINET) strokes and meteorological in-situ data. Three radar-based variables are extracted simultaneously for each rain cell and properly merged together, using "ad hoc" classification methods, to produce an estimation of the expected lightning activity for each rain cell. These variables, proxies of mixed-phase particles and ice amount into a convective cell, are combined into a single label to cluster the SRCG into two categories: SRCG = 0 (no production of strokes) or SRCG > 0 (stroke production), respectively. Overall, the main results are comparable with those that were obtained from more advanced radar systems, showing a Critical Success Index of 0.53, an Equitable Threat Score of 0.34, a Frequency Bias Index of 1.00, a Heidke Skill Score of 0.42, a Hanssen-Kuiper Skill Score of 0.42, and an area under the curve of probability of detection as a function of false alarm rate (usually referred as ROC curve) equal to 0.78. The developed technique, although with some limitations, outperforms those based on the use of single stroke proxy parameters. [ABSTRACT FROM AUTHOR]- Published
- 2018
- Full Text
- View/download PDF
20. Improving the lightning forecast with the WRF model and lightning data assimilation: Results of a two-seasons numerical experiment over Italy.
- Author
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Federico, Stefano, Torcasio, Rosa Claudia, Popova, Jana, Sokol, Zbyněk, Pop, Lukáš, Lagasio, Martina, Lynn, Barry H., Puca, Silvia, and Dietrich, Stefano
- Subjects
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LIGHTNING , *METEOROLOGICAL research , *WEATHER forecasting , *FORECASTING , *WATER vapor , *PRECIPITATION forecasting - Abstract
We show, for the first time over Italy and over part of the central Mediterranean Basin, the impact of lightning data assimilation (LDA) on the strokes forecast for a long period. We use the Weather Research and Forecasting (WRF) model coupled with the Dynamic Lightning Scheme (DLS) at convection allowing horizontal resolution (3 km). We carried out a two-seasons experiment (summer 2020 and fall 2021) providing the forecast of lightning and precipitation for the next 6 h (nowcasting), considering two sub-periods (0-3 h and 3-6 h) for verification. The LDA is done through a nudging scheme that increases the water vapor mass in the mixed-phase region based on observed flash density rates and simulated graupel mixing ratio. No changes are made to the model run if spurious convection is predicted or no flashes are observed. LDA can trigger convection missed by the control forecast, without LDA, and/or can redistribute the strokes predicted to be more consistent with observations. LDA has a positive impact on strokes forecast, improving correct forecasts and reducing false alarms. This improvement is however confined to the first three-hours of forecast with negligible to negative impact for longer time ranges, in line with other studies. The improvement pattern is different in summer and fall, depending on the convection development. The analysis of the Fraction Skill Score shows the usefulness of the forecast for practical purposes, considering the current areas used by the Civil Protection Department to issue meteorological alerts for intense convective events over Italy. Finally, it is shown that the forecast at the short-range (0−3 h) using LDA can improve the strokes forecast issued on the previous day, not using LDA, and the methodology of this paper can be applied to issue warnings and alerts as the storm is approaching. A brief examination of rainfall forecast shows positive impact of LDA at the short-range (0-3 h), with neutral impact for longer time ranges. The different impact of LDA on the strokes and precipitation forecasts is also highlighted. • Lightning data assimilation improves the lightning and precipitation forecast for the first three-hours in summer and fall. • The pattern of improvement is different in summer and fall. • The very short-term forecast refines the previous day forecast as the storm is approaching. [ABSTRACT FROM AUTHOR]
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- 2024
- Full Text
- View/download PDF
21. A 13-year long strokes statistical analysis over the Central Mediterranean area.
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Petracca, Marco, Federico, Stefano, Roberto, Nicoletta, Puca, Silvia, D'Adderio, Leo Pio, Torcasio, Rosa Claudia, and Dietrich, Stefano
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STATISTICS , *INFLUENCE of altitude , *ATMOSPHERIC models , *AUTUMN , *LIGHTNING - Abstract
This paper presents the first detailed analysis of cloud-to-ground (CG) and intra-cloud (IC) strokes characteristics from the Lightning Detection Network (LINET) over Italy and the Central Mediterranean area, a lightning active area in south Europe. We study the strokes over a 13-year period from 2010 to 2022, aiming to understand how it varies with different temporal scales (hourly, monthly, seasonally, and yearly), surface types (sea and land), and ground levels (0–100 m ; 100–200 m ; 200–400 m ; 400–800 m ; 800–1200 m ; 1200–2000 m and above 2000 m). We found that the stroke's maximum activity was observed in August; specifically, July has the maximum activity over the land with a maximum diurnal peak in the afternoon, while in September, the convection shifts over the sea with a secondary daily maximum in the morning. The largest current intensities are observed in January, over sea and during nighttime. Moreover we found that stroke current intensities, polarity and IC height emissions are influenced by ground altitude level. Our paper provides new insights into the spatio-temporal patterns and characteristics of lightning over Italy and the Central Mediterranean area, which can be useful for improving weather forecasting, climate modeling, risk assessment, and damage mitigation strategies in this area. • Orography has strong impact on lightning density, polarity, intensity and discharge height. • Vigorous convection develops over the land in summer and over the sea in autumn. • Overall stroke density reaches its peak in August. • Atmospheric instability decreases the breakdown threshold increasing weaker strokes. [ABSTRACT FROM AUTHOR]
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- 2024
- Full Text
- View/download PDF
22. Analysis of TGF-associated thunderstorms with the Meteosat geostationary satellites.
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Ursi, Alessandro, Marisaldi, Martino, Dietrich, Stefano, Tavani, Marco, Porcù, Federico, and Tiberia, Alessandra
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GEOSTATIONARY satellites , *THUNDERSTORMS , *LOW temperatures , *STRATOCUMULUS clouds , *LIGHTNING , *STATISTICS - Abstract
We analyzed a sample of 278 TGFs detected by the RHESSI, AGILE, and Fermi satellites between 2003 and 2015, occurring within the 60°W and 60°E longitude range. Each of these events has an associated lightning sferic occurring within ±500 µs, detected by the World Wide Lightning Location Network (WWLLN), that provides the best geographic localization of the source thunderstorm (<20 km). We performed a systematic analysis of the 278 TGF-associated storms, by exploiting data acquired by the Spinning Enhanced Visible and Infrared Imager (SEVIRI) instrument, onboard the Meteosat Second Generation (MSG) geostationary satellites (i.e., Meteosat-8/9/10, or MSG-1/2/3). For each storm, we analyzed several meteorological parameters, such as the cloud top temperature, the cloud extension, the cloud top altitude, the convective level, and the lightning flash rate, provided by the WWLLN. Furthermore, we studied those quantities at the time that TGFs occurred (taken into account the MSG time resolution), and their evolution within a time interval of ±100 min about the TGF time.The TGF-associated thunderstorms turn out to follow the typical behavior of tropical thunderstorms, peaking in the afternoons and over continental regions. The study of the meteorological parameters shows that these systems exhibit a wide range of values, mostly involving storms with lowest cloud top temperatures (<-75°C), highest top heights (>15 km), and large top extensions (> 35,000 km2), confirming what already found in other studies; morevoer, the study of the time evolution shows that TGFs tend to take place during the peak of the cooling phase, when the top temperature reaches its lowest value and the lightning flash rate is at its maximum. In order to investigate whether thunderstorms found producing TGFs show peculiar characteristics, with respect to typical thunderstorms, we carried out a cross-check with random storms occurring in the same geographic region, and performed a statistical analysis to establish whether differences are present between the two populations. [ABSTRACT FROM AUTHOR]
- Published
- 2019
23. Climatology of Transient Luminous Events and Lightning Observed Above Europe and the Mediterranean Sea
- Author
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Martin Füllekrug, Carl‑Fredrik Enell, Veronika Barta, Ferruccio Zanotti, Diego Valeri, Yoav Yair, Thomas Farges, Serge Soula, Martin Popek, Olivier Chanrion, Marco Prevedelli, Antti Mäkelä, Anna Odzimek, József Bór, Marco Ridolfi, Przemyslaw Zoladek, Enrico Arnone, Antti Kero, Keren Mezuman, Torsten Neubert, Oscar van der Velde, Stefano Dietrich, Roberto Labanti, Universitat Politècnica de Catalunya. Departament d'Enginyeria Elèctrica, Universitat Politècnica de Catalunya. LRG - Lightning Research Group, Consiglio Nazionale delle Ricerche [Bologna] (CNR), Research Centre for Astronomy and Earth Sciences [Budapest], Hungarian Academy of Sciences (MTA), National Space Institute [Lyngby] (DTU Space), Technical University of Denmark [Lyngby] (DTU), EISCAT Scientific Association [Sweden], Département Analyse Surveillance Environnement (DASE), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Department of Electronics and Electrical Engineering [Bath], University of Bath [Bath], University of Oulu, Italian Meteor and TLE Network (IMTN), Bologna, Italy, Finnish Meteorological Institute (FMI), Department of Earth and Environmental Sciences [New York], Columbia University [New York], Institute of Geophysics [Warsaw], Polska Akademia Nauk = Polish Academy of Sciences (PAN), Czech Academy of Sciences [Prague] (CAS), University of Bologna, Istituto Nazionale di Ottica [Firenze] (INO-CNR), Consiglio Nazionale delle Ricerche (CNR), Laboratoire d'aérologie (LAERO), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome], Universitat Politècnica de Catalunya [Barcelona] (UPC), Interdisciplinary Center [Israël] (IDC), Interdisciplinary Center, Space Research Centre, Polish Academy of Sciences (PAS), ul. Bartycka 18A, 00-716 Warsaw, Funding: European Commission H2020 (Grant No. H2020-MSCA-ITN-2016 no. 722337), European Project: 0722337(2007), Arnone, Enrico, Bór, József, Chanrion, Olivier, Barta, Veronika, Dietrich, Stefano, Enell, Carl-Fredrik, Farges, Thoma, Füllekrug, Martin, Kero, Antti, Labanti, Roberto, Mäkelä, Antti, Mezuman, Keren, Odzimek, Anna, Popek, Martin, Prevedelli, Marco, Ridolfi, Marco, Soula, Serge, Valeri, Diego, van der Velde, Oscar, Yair, Yoav, Zanotti, Ferruccio, Zoladek, Przemyslaw, Neubert, Torsten, Danmarks Tekniske Universitet = Technical University of Denmark (DTU), University of Bologna/Università di Bologna, National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), and Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome] (UNIROMA)
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Transient luminous event ,010504 meteorology & atmospheric sciences ,010502 geochemistry & geophysics ,01 natural sciences ,Lightning ,Mediterranean sea ,Europe Climatology ,Geochemistry and Petrology ,14. Life underwater ,0105 earth and related environmental sciences ,[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph] ,Climatology ,Enginyeria elèctrica [Àrees temàtiques de la UPC] ,Transient luminous events ,Thunderstorms ,Ground-based observations ,Europe ,Geophysics ,13. Climate action ,Thunderstorms, Lightning, Transient luminous events, Ground-based observations, Europe, Climatology ,Thunderstorm ,Environmental science ,Seasonal cycle ,Llamps - Abstract
International audience; In 1999, the first sprites were observed above European thunderstorms using sensitive cameras. Since then, Eurosprite campaigns have been conducted to observe sprites and other transient luminous events (TLEs), expanding into a network covering large parts of Europe and coastal areas. In 2009 through 2013, the number of optical observations of TLEs reached a peak of 2000 per year. Because of this unprecedented number of European observations, it was possible to construct a climatology of 8394 TLEs observed above 1018 thunderstorm systems and study for the first time their distribution and seasonal cycle above Europe and parts of the Mediterranean Sea. The number of TLEs per thunderstorm was found to follow a power law, with less than 10 TLEs for 801 thunderstorms and up to 195 TLEs above the most prolific one. The majority of TLEs were classified as sprites, 641 elves, 280 halos, 70 upward lightning, 2 blue jets and 1 gigantic jet. The climatology shows intense TLE activity during summer over continental areas and in late autumn over coastal areas and sea. The two seasons peak, respectively, in August and November, separated by March and April with almost no TLEs, and a relative minimum around September. The observed TLE activity, i.e. mostly sprites, is shown to be largely consistent with lightning activity, with a 1/1000 of observed TLE-to-lightning ratio in regions with most observations. The overall behaviour is consistent among individual years, making the observed seasonal cycle a robust general feature of TLE activity above Europe
- Published
- 2020
24. Lightning data assimilation in the WRF-ARW model for short-term rainfall forecasts of three severe storm cases in Italy.
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Comellas Prat, Albert, Federico, Stefano, Torcasio, Rosa Claudia, Fierro, Alex O., and Dietrich, Stefano
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RAIN gauges , *SEVERE storms , *LIGHTNING , *RAINFALL , *PRECIPITATION forecasting , *FORECASTING - Abstract
This study analyses the impact of total lightning data assimilation on cloud-resolving short-term (3 and 6 h) precipitation forecasts of three heavy rainfall events that occurred recently in Italy by providing an evaluation of forecast skill using statistical scores for 3-hourly thresholds against observational data from a dense rain gauge network. The experiments are performed with two initial and boundary conditions datasets as a sensitivity test. The three rainfall events have been chosen to better represent the convective regime spectrum: from a short-lived and localised thunderstorm to a long-lived and widespread event, along with a case that had elements of both. This analysis illustrates the ability of the lightning data assimilation (LDA) to notably improve the short-term rainfall forecasts with respect to control simulations without LDA. The assimilation of lightning enhances the representation of convection in the model and translates into a better spatiotemporal positioning of the storm systems. The results of the statistical scores reveal that simulations with LDA always improve the probability of detection, particularly for rainfall thresholds exceeding 40 mm/3 h. The false alarm ratio also improves but appears to be more sensitive to the model initial and boundary conditions. Overall, these results show a systematic advantage of the LDA with a 3-h forecast range over 6-h. • A lightning data assimilation scheme for WRF is tested for three severe storm cases. • 3 and 6 h short-term cloud-resolving precipitation forecasts are analyzed against rain gauges. • Assimilating lightning significantly improves rainfall forecasts compared to controls. • Statistical analysis shows data assimilation improves probability of detection especially for high thresholds. • Employing this scheme at 3-h forecast ranges systematically outperform those at 6-h. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
25. Ground-based climatology of lightning and transient luminous events above Europe.
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Arnone, Enrico, Bòr, Jòzsef, Chanrion, Olivier, Barta, Veronika, Dietrich, Stefano, Enell, Carl-Fredrik, Farges, Thomas, Fullekrug, Martin, Kero, Antti, Labanti, Roberto, Makela, Antti, Mezuman, Keren, Odzimek, Anna, Popek, Martin, Ridolfi, Marco, Soula, Serge, van der Velde, Oscar, Yair, Yoav, and Neubert, Torsten
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CLIMATOLOGY , *LIGHTNING , *SPACE stations , *SEASONAL distribution of insects - Abstract
Over the past years, ground-based optical observations of transient luminous events (TLEs) have been taken by the Eurosprite network and partners, covering large areas over Europe and parts of the Mediterranean Sea. In particular, a coordinated effort in 2009 through 2013 led to producing the first climatology of more than 8000 TLEs observed above about 1000 thunderstorm systems, and study for the first time their distribution and seasonal variations in these areas. Consistently, lightning were recorded from the World Wide Lightning Location Network (WWLLN) allowing a direct comparison to TLEs. The climatology shows that TLE activity in Europe is intense during summer over continental areas, and in late autumn over coastal areas and sea. The two seasons peak respectively in August and November, whereas almost no TLEs are recorded in March and April. The observed TLE activity, which is composed mostly by sprites, is shown to be consistent with the seasonal distribution of lightning activity. The consistency among individual years makes the observed seasonal cycle a robust general feature of TLE activity above Europe. Because of the inhomogeneous spatial distribution of the adopted ground-based observing systems, observations were treated in terms of anomalies about the yearly mean. Key areas where the observations have a homogeneous coverage and were continued in the following years are identified and discussed. These areas may be used to normalize the overall distribution and for intercomparing with space-based observations from the Atmosphere-Space Interactions Monitor (ASIM) flying on the International Space Station, and to future lightning observations from the Meteosat Third Generation Lightning Imager. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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