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Atmospheric response to the 20 March 2015 solar eclipse along the whole aerosol column by lidar measurements
摘要： Lidar measurements at 355, 532, and 1064 nm have been performed at Lecce (40.3°N, 18.1°E), in south-eastern Italy, to investigate for the first time the impact of the 20 March 2015 solar eclipse on both the planetary boundary layer (PBL) height and the aerosol optical and microphysical properties along the whole aerosol column. The partial solar eclipse lasted from 08:30 up to 10:47 UTC and reached the full phase at 09:37 UTC. The maximum percentage obscuration of the solar disk was 43.6%. The eclipse cooling effect was responsible at the full phase time (tF) for the downward solar irradiance decrease at the top of the atmosphere, at the surface, and within the atmosphere of 429.2 ± 0.6, 373 ± 25, and 56 ± 26 W m-2, respectively. The turbulent kinetic energy, the potential temperature flux, the sensible heat flux, the variance of air temperature, and the vertical wind speed at the surface revealed that the turbulence activity reached the maximum weakening at the time tF. The standard deviation (SD) technique has been applied to both the lidar range corrected signals (RCS) at 1064 nm and the linear volume depolarization ratio (δV) profiles at 355 nm to determine the time evolution of the shallow PBL height and the aloft aerosol layers. The SD technique applied to RCS and δV profiles revealed similar results within experimental uncertainties. The PBL height, which was equal to 380 ± 40 m above ground level (AGL) at the eclipse full phase (09:37 UTC), decreased up to 220 ± 20 m at 09:45 UTC because of the eclipse cooling effect, and then increased up to 320 ± 30 m at 10:17 UTC. The determined PBL height time evolution was in good agreement with the ones of the main turbulence parameters at the surface after tF. The vertical profiles of the aerosol backscatter coefficient (β), the δV at 355 nm, and the extinction-related ?ngstr?m exponent (?), calculated at the 355-1064 nm wavelength pair revealed a marked decrease of β, δV, and ? at the eclipse full phase, within the aloft aerosol layers. The abrupt β, δV, and ? decrease due to the aerosol concentration and type changes has mainly been associated with the decrease of the fine-mode particle contribution.
关键词： solar irradiance,Solar eclipse,lidar measurements,atmospheric aerosols,turbulence parameters,planetary boundary layer
更新于2025-09-23 15:21:01
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[IEEE 2018 IEEE PES/IAS PowerAfrica - Cape Town, South Africa (2018.6.28-2018.6.29)] 2018 IEEE PES/IAS PowerAfrica - Impact of Solar Eclipse on Utility Grid Operations
摘要： Solar eclipse is viewed as a volatile meteorological condition in electric power grids with Photovoltaics (PV) penetration. The impact of the U.S. August 21, 2017 solar eclipse on control center operations associated with a large PV plant has been investigated and compared with normal day operations. The utility-scale PV plant simulated using a real-time digital simulator and receiving real-time weather data measurements from the weather monitoring station at Clemson University, South Carolina has been studied. The open challenge utilities are facing nowadays with increasing penetration of PV in the grid has been illustrated. The insights of this study can be used by utilities for planning and operational studies.
关键词： solar eclipse,automatic generation control,real-time grid operations,Area control error,photovoltaics
更新于2025-09-09 09:28:46
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[Institution of Engineering and Technology 12th European Conference on Antennas and Propagation (EuCAP 2018) - London, UK (9-13 April 2018)] 12th European Conference on Antennas and Propagation (EuCAP 2018) - Analysis of Ionospheric GPS TEC Measurements During Total Solar Eclipse over American Region on August 21, 2017
摘要： Solar eclipse provides a unique opportunity to investigate the ionospheric response to the change in the solar flux emission towards the Earth. The variability of the ionospheric total electron content (TEC) in response to the total solar eclipse of August 21, 2017 has been studied by the analysis of dual frequency Global Positioning System (GPS) data from the University NAVSTAR Consortium (UNAVCO) established at North Carolina, USA (P779), and from the Rede Brasileira de Monitoramento Contínuo (RBMC) Amapá (APS1) station. The path of the solar obscuration passed through the North American region, also affecting the northern part of Brazil. The magnitudes of the ionospheric TEC from both monitoring stations during the eclipse are compared with those from the days immediately preceding and following it. This comparison will highlight the effects from the eclipse on the ionospheric electron density variations observed by the stations that are located over its path.
关键词： measurements,Ionosphere,Global Positioning System,solar eclipse,propagation
更新于2025-09-04 15:30:14