The usefulness of the Global Navigation Satellite Systems (GNSS) in the analysis of precipitation events

Bonafoni, Stefania; Biondi, Riccardo

doi:10.1016/j.atmosres.2015.07.011

Cited by 26 publications

(10 citation statements)

References 39 publications

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“…Longterm ZTD time series derived from the European permanent network (EPN) have been analyzed (Pacione et al 2013), and experimental studies on the use of GNSS data for the tomographic reconstruction of the refractivity field have been conducted (Notarpietro et al 2011). GNSS-derived water vapor has been compared to other water vapor products (Basili et al 2001;Boccolari et al 2002;Ciotti et al 2003;Cheng et al 2012;Bonafoni and Biondi 2016). Finally, within the last decade, a few studies on the use of GNSS products for both regional-and local-scale meteorological events have been carried out (Faccani et al 2005;Tammaro et al 2016;Ferrando 2017).…”

Section: Introductionmentioning

confidence: 99%

Detection of water vapor time variations associated with heavy rain in northern Italy by geodetic and low-cost GNSS receivers

Barindelli

Realini²,

Venuti

et al. 2018

Earth Planets Space

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GNSS atmospheric water vapor monitoringis not yet routinely performed in Italy, particularly at the regional scale. However, in order to support the activities of regional environmental protection agencies, there is a widespread need to improve forecasting of heavy rainfall events. Localized convective rain forecasts are often misplaced in space and/ or time, causing inefficiencies in risk mitigation activities. Water vapor information can be used to improve these forecasts. In collaboration with the environmental protection agencies of the Lombardy and Piedmont regions in northern Italy, we have collected and processed GNSS and weather station datasets for two heavy rain events: one which was spatially widespread, and another which was limited to few square kilometers. The time variations in water vapor derived from a regional GNSS network with inter-station distances on the order of 50 km were analyzed, and the relationship between the time variations and the evolution of the rain events was evaluated. Results showed a signature associated with the passage of the widespread rain front over each GNSS station within the area of interest. There was a peak in the precipitable water vapor value when the heavier precipitation area surrounded the station, followed by a steep decrease (5-10 mm in about 1 h) as the rainclouds moved past the station. The smaller-scale event, a convective storm a few kilometers in extent, was not detected by the regional GNSS network, but strong fluctuations in water vapor were detected by a low-cost station located near the area of interest.

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Section: Introductionmentioning

confidence: 99%

Detection of water vapor time variations associated with heavy rain in northern Italy by geodetic and low-cost GNSS receivers

Barindelli

Realini²,

Venuti

et al. 2018

Earth Planets Space

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“…Second, given that the observed RO refractivity is higher than the weather model, the reliability of operational RO retrievals using the weather analyses temperatures is lower. Our ability to analyze the moist thermodynamics of precipitation from either weather model, as done in most of the available literature, or standard RO retrievals (e.g., Biondi et al, ; Biondi et al, ; Bonafoni & Biondi, ; Vergados et al, ) is lower and therefore one benefits from model‐independent validation. Those situations where weather models and RO differ are where RO soundings are most useful to identify and correct errors in the weather prediction models.…”

Section: Data and Approachmentioning

confidence: 99%

Signatures of Heavy Precipitation on the Thermodynamics of Clouds Seen From Satellite: Changes Observed in Temperature Lapse Rates and Missed by Weather Analyses

et al. 2018

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Analyses of the thermodynamics of precipitating clouds are mostly based on localized in situ campaigns or, more globally, weather analyses and reanalyses. This work presents a comparison of weather analyses to satellite observations and a radiometeorological method that shows how precipitating layers inside clouds coincide with weather analyses underestimates of the amount of water vapor. The thermodynamic information from inside precipitating clouds is extracted using observed radio occultation (RO) refractivity profiles without requiring weather analysis input, thus reducing analysis-induced biases. The radiometeorological method is described by first identifying the differences between adiabatically dry, mixing-ratio conserving, and saturated pseudoadiabatic refractivity profiles. These reference profiles are then compared to observed RO refractivity profiles within precipitating and nonprecipitating clouds to infer changes in their height-dependent thermodynamic states and in stability to convection. Precipitation is found to start below layers close to pseudoadiabatic and precipitation layers coincide with changes into conditional stability against convection. A statistical comparison between observed profiles and the gradients predicted for a saturated pseudoadiabatic profile is made and finds that on the global average, precipitation separates clouds from the Clausius-Clapeyron law and profiles are close to a saturated pseudoadiabat. The results (a) help constrain the physical processes associated to precipitation inside clouds and (b) validate the potential of graphical RO techniques to analyze observations without ancillary temperature data from weather analyses. Plain Language SummaryPredicting how precipitation responds to changes in atmospheric thermal profiles remains a challenge identified by the Intergovernmental Panel on Climate Change. Solving this challenge requires comparing models with the observed thermodynamics of precipitating clouds. Only radio occultation (RO) can constraint globally the thermodynamics inside clouds with high vertical resolution. Infrared and microwave can measure the thermodynamics outside and only partially clouds, and radar instruments that measure inside clouds do not provide thermodynamic information.This paper develops a method to use RO for distinguishing the thermodynamics inside precipitating versus nonprecipitating clouds. The identification of rain is made using coincidences of RO soundings with Tropical Rainfall Measuring Mission and CloudSat observations. Using the method, we show that globally, (1) the European Center for Medium-Range Weather Forecast ERA Interim reanalysis and the Global Forecast System weather analysis have a global bias in precipitating clouds caused by misrepresentation of the thermodynamics inside clouds; (2) the nature of the bias is associated to a misrepresentation of the lapse rates by the analyses; (3) there are changes in stability to moist convection associated to the height where precipitation originates, and (4) the transition ...

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“…However, the corresponding terrestrial stations are only located over land and are not evenly distributed. Recent works have analyzed the complementarity potential of GPS RO and GB GNSS due to their global and permanent measurements but different specific characteristics and some of these studies have compared their outcomes (e.g., Bonafoni and Biondi, 2016;Kuleshov et al, 2016).…”

Section: Accepted M Manuscriptmentioning

confidence: 99%

Comparison between GNSS ground-based and GPS radio occultation precipitable water observations over ocean-dominated regions

Fonseca

Alexander

Torre

et al. 2018

Atmospheric Research

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Precipitable water (PW) inferred from GPS (Global Positioning System) radio occultation (RO) and ground-based (GB) Global Navigation Satellite System (GNSS) observations are compared between years 2007 and 2014. As previous studies were mainly performed over continental areas we now focus over oceandominated geographical areas. Our analysis is done in order to find out how the reliability level of RO results over oceanic areas compares to land. As RO soundings usually miss some information close to the ground, we also assess different methods to complete the lacking data. We found 47 terrestrial stations that lie in islands small and far away from continental areas where the weather might be governed by the sea conditions. From comparisons of almost 5000 collocated samples, PW from RO and GB exhibit a global mean difference around 1 mm, root-mean-square deviation about 5 mm and a correlation above 0.9. The 2007-2014 timeseries and the monthly mean RO and GB PW were also I Manuscript prepared under grants CONICET PIP 11220120100034 and ANPCYT PICT 2013-1097. P. Alexander, A. de la Torre, R. Hierro and P. Llamedo are members of CONICET. GPS RO water vapor pressure observations were downloaded from cdaac-ftp.cosmic.ucar.edu, GB GNSS PW data from rda.ucar.edu/datasets/ds721.1 and NCEP and ECMWF reanalyses respectively from www.esrl.noaa.gov/psd/data/gridded and apps.ecmwf.int/datasets.

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The usefulness of the Global Navigation Satellite Systems (GNSS) in the analysis of precipitation events

Cited by 26 publications

References 39 publications

Detection of water vapor time variations associated with heavy rain in northern Italy by geodetic and low-cost GNSS receivers

Detection of water vapor time variations associated with heavy rain in northern Italy by geodetic and low-cost GNSS receivers

Signatures of Heavy Precipitation on the Thermodynamics of Clouds Seen From Satellite: Changes Observed in Temperature Lapse Rates and Missed by Weather Analyses

Comparison between GNSS ground-based and GPS radio occultation precipitable water observations over ocean-dominated regions

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