A Case of African Dust Transport over Athens Captured by a Ceilometer

Kambezidis, H. D.; Παλιατσός, Α. Γ.; Kappos, Nikos; Kasselouri, B.

doi:10.1007/978-3-642-29172-2_141

Cited by 3 publications

(2 citation statements)

References 14 publications

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“…; Münkel and Roininen, ; Kambezidis et al . ). Measured profiles from three Vaisala CL51 ceilometers, installed at different locations inside the valley (Figure ), are used to estimate ABL heights.…”

Section: Methodsmentioning

confidence: 97%

Characterization of the atmospheric boundary layer in a narrow tropical valley using remote‐sensing and radiosonde observations and the WRF model: the Aburrá Valley case‐study

Herrera

Hoyos

2019

Quart J Royal Meteoro Soc

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The spatiotemporal evolution of the atmospheric boundary layer (ABL), in a narrow, highly complex terrain located in the Colombian Andes, is studied using radiosondes and remote-sensing equipment. Different techniques are implemented to automatically estimate the ABL height using ceilometer backscattering profiles and a combination of a radar wind profiler and microwave radiometer retrievals. The large aerosol load from anthropogenic emissions within the valley allows the use of ceilometer-based ABL height detection methods, especially under stable atmospheric conditions. However, convective atmospheres favour aerosol dispersion, increasing the uncertainty associated with the estimation of the convective boundary layer using ceilometers. In contrast, the multisensor technique is more robust, performing better in stable and unstable conditions. All ceilometer-based methods and the multisensor scheme capture the observed ABL height diurnal cycle. The main difference among ABL height retrievals occurs in the afternoon and during the night when Richardson number estimates tend to detect the top-down contraction of the residual layer, while ceilometer-based estimates detect the sudden bottom-up onset of the nocturnal stable layer. The results also show that intra-annual and annual variations of cloudiness strongly condition the ABL expansion, leading to a modulation of the ABL height diurnal cycle. The amount of aerosol particles near the surface is influenced by the evolution of the ABL, modifying the available control volume for the pollutants to interact and disperse. The evolution of ABL over the slopes and at the valley floor differs as a result of the local thickening associated with upslope winds. Weather Research and Forecasting model simulations, from a climatological point of view, skilfully simulate the observed ABL height for both the diurnal and annual cycles; the model skill is higher over the valley floor than over the slopes. K E Y W O R D S atmospheric boundary layer; complex terrain; tropical narrow valley; remote sensing; ABL automatic retrieval methods; ABL model simulations; ABL diurnal cycle; ABL annual cycleThis is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.

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Section: Methodsmentioning

confidence: 97%

Characterization of the atmospheric boundary layer in a narrow tropical valley using remote‐sensing and radiosonde observations and the WRF model: the Aburrá Valley case‐study

Herrera

Hoyos

2019

Quart J Royal Meteoro Soc

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“…Ceilometers provide information regarding the laser-pulse energy that is backscattered by clouds and other atmospheric components, including PM, expressed as the backscattering attenuated coefficient ( β ) (Emeis et al 2009; Münkel and Roininen 2010; Kambezidis et al 2013)s. Lidars and ceilometers have been widely used to detect sand to characterize aerosols in the atmosphere (Muenkel et al 2004; Morille et al 2007; Wiegner et al 2014), including PM from fireworks plumes (Calhoun et al 2004; van der Kamp et al 2008; Han et al 2014). For example, van der Kamp et al (2008) show evidence of an elevated aerosol plume using ceilometer retrievals, corresponding to a pyrotechnic competition in Vancouver, Canada.…”

Section: Region Of Study and Datamentioning

confidence: 99%

Effects of fireworks on particulate matter concentration in a narrow valley: the case of the Medellín metropolitan area

Hoyos

Herrera

Roldán-Henao

et al. 2019

Environ Monit Assess

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The extensive use of fireworks generates large amounts of pollutants, deteriorating air quality and potentially causing adverse health impacts. In Medellín and its metropolitan area, although fireworks are banned during December, their use is widespread during the Christmas season, particularly during the midnight of November 30 (La Alborada) and New Year’s Eve (NYE). It is therefore essential to assess the effects of these celebrations on air quality in the region. Air-quality data from the official monitoring network and a low-cost particulate matter (PM) citizen science project, backscattering intensity (BI) retrievals from a ceilometer network, potential temperature from a microwave radiometer, and information from a radar wind profiler provide an excellent platform to study the spatio-temporal distribution of contaminants resulting from the La Alborada and NYE celebrations. Substantial increases in PM2.5 and PM10 mass concentrations due to La Alborada and NYE, ranging in some cases from 50 to 100 μgm−3, are observed in the Aburrá Valley and particularly in the densely populated communes of Medellín, with most concentration changes corresponding to ultrafine and fine particles. The PM increments resulting from fireworks show almost no increase in the net amount of black carbon in the atmosphere. Ceilometer BI profiles show a substantial change immediately after the La Alborada and NYE midnights, confined to the atmospheric boundary layer (ABL). Strong thermal inversions lead to fairly homogeneous increments in BI within the ABL, lasting until the onset of the convective boundary layer. In contrast, weak thermal inversions lead to rapid dispersion of aerosols, allowing them to episodically escape above the ABL.

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Impact of a Saharan dust intrusion over southern Spain on DNI estimation with sky cameras

Alonso-Montesinos

Barbero

Polo

et al. 2017

Atmospheric Environment

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A Case of African Dust Transport over Athens Captured by a Ceilometer

Cited by 3 publications

References 14 publications

Characterization of the atmospheric boundary layer in a narrow tropical valley using remote‐sensing and radiosonde observations and the WRF model: the Aburrá Valley case‐study

Characterization of the atmospheric boundary layer in a narrow tropical valley using remote‐sensing and radiosonde observations and the WRF model: the Aburrá Valley case‐study

Effects of fireworks on particulate matter concentration in a narrow valley: the case of the Medellín metropolitan area

Impact of a Saharan dust intrusion over southern Spain on DNI estimation with sky cameras

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