TY - JOUR

T1 - The influence of solar x-ray flares on sar meteorology: The determination of the wet component of the tropospheric phase delay and precipitable water vapor

AU - Nina, Aleksandra

AU - Radović, Jelena

AU - Nico, Giovanni

AU - Popović, Luka

AU - Radovanović, Milan

AU - Biagi, Pier Francesco

AU - Vinković, Dejan

PY - 2021/7/1

Y1 - 2021/7/1

N2 - In this work, we study the impact of high-energy radiation induced by solar X-ray flares on the determination of the temporal change in precipitable water vapor (∆PWV) as estimated using the synthetic aperture radar (SAR) meteorology technique. As recent research shows, this radiation can significantly affect the ionospheric D-region and induces errors in the estimation of the total electron content (TEC) by the applied models. Consequently, these errors are reflected in the determination of the phase delay and in many different types of measurements and models, including calculations of meteorological parameters based on SAR observations. The goal of this study is to quantify the impact of solar X-ray flares on the estimation of ∆PWV and provide an estimate of errors induced if the vertical total electron content (VTEC) is obtained by single layer models (SLM) or multiple layer models (MLM) (these models do not include ionosphere properties below the altitude of 90 km as input parameters and cannot provide information about local disturbances in the D-region). The performed analysis is based on a known procedure for the determination of the D-region electron density (and, consequently, the vertical total electron content in the D-region (VTECD)) using ionospheric observations of very low frequency (VLF) radio waves. The main result indicates that if the D-region, perturbed by medium-sized and intense X-ray flares, is not modeled, errors occur in the determination of ∆PWV. This study emphasizes the need for improved MLMs for the estimation of the TEC, including observational data at D-region altitudes during medium-sized and intense X-ray flare events.

AB - In this work, we study the impact of high-energy radiation induced by solar X-ray flares on the determination of the temporal change in precipitable water vapor (∆PWV) as estimated using the synthetic aperture radar (SAR) meteorology technique. As recent research shows, this radiation can significantly affect the ionospheric D-region and induces errors in the estimation of the total electron content (TEC) by the applied models. Consequently, these errors are reflected in the determination of the phase delay and in many different types of measurements and models, including calculations of meteorological parameters based on SAR observations. The goal of this study is to quantify the impact of solar X-ray flares on the estimation of ∆PWV and provide an estimate of errors induced if the vertical total electron content (VTEC) is obtained by single layer models (SLM) or multiple layer models (MLM) (these models do not include ionosphere properties below the altitude of 90 km as input parameters and cannot provide information about local disturbances in the D-region). The performed analysis is based on a known procedure for the determination of the D-region electron density (and, consequently, the vertical total electron content in the D-region (VTECD)) using ionospheric observations of very low frequency (VLF) radio waves. The main result indicates that if the D-region, perturbed by medium-sized and intense X-ray flares, is not modeled, errors occur in the determination of ∆PWV. This study emphasizes the need for improved MLMs for the estimation of the TEC, including observational data at D-region altitudes during medium-sized and intense X-ray flare events.

KW - Ionospheric D-region

KW - Modeling

KW - Phase delay

KW - Precipitable water vapor

KW - Remote sensing

KW - SAR meteorology

KW - Solar X-ray flare

KW - VLF/LF signals

UR - http://www.scopus.com/inward/record.url?scp=85110154710&partnerID=8YFLogxK

U2 - 10.3390/rs13132609

DO - 10.3390/rs13132609

M3 - Article

AN - SCOPUS:85110154710

VL - 13

JO - Remote Sensing

JF - Remote Sensing

SN - 2072-4292

IS - 13

M1 - 2609

ER -