Characterization of the atmospheric boundary layer from radiosonde observations along eastern end of monsoon trough of India

Chandra, Saket; Dwivedi, Arun K.; Kumar, Manoj

doi:10.1007/s12040-014-0458-4

Cited by 12 publications

(11 citation statements)

References 12 publications

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“…There is no rainfall reported at the site during January 2017 (Fig. 2c), and the average BLH is 1398 m. These high values of BLH during January month are characteristics of eastern Indian region with clear skies and no convective activity [6]. For May 2017, the average wind speeds are relatively high (~ 1.5-2.0 m s −1 ), and the wind directions are south-easterly (Fig.…”

Section: Variation Of Meteorological Parametersmentioning

confidence: 93%

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Evaluating the variability, transport and periodicity of particulate matter over smart city Bhubaneswar, a tropical coastal station of eastern India

et al. 2019

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Air pollution has become a matter of concern over Indian mega-cities. In the present study, we analyse the variation of particulate matter (PM) (PM 10 and PM 2.5) over Bhubaneswar (20.18°N, 85.50°E, 45 above MSL), which is a coastal Indian station, and the state capital of Odisha. Variation of meteorological parameters (i.e. air temperature, humidity, wind speed, and wind direction) over the station shows low winds originating and transported mainly from land areas during post-monsoon and winter, and from the Bay of Bengal during pre-monsoon and monsoon seasons. The site, in general, has evident diurnal variations of meteorological parameters and PM, other than monsoon season. In addition to surface observations at the site, 48-h back trajectory calculation by HYSPLIT model and the study employs potential source contribution function analysis for precise identification of the transported pollution areas for different seasons.

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Section: Variation Of Meteorological Parametersmentioning

confidence: 93%

“…6d). However, on the smaller side of the range (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16), the localisation of periodicity is more evident at 97-193 h (05-08 July), and 577-673 h (24-28 July). When we analysed the periodicity associated with PM 2.5 ( Fig.…”

Section: Continuous Wavelet Transform (Cwt) Analysismentioning

confidence: 99%

Evaluating the variability, transport and periodicity of particulate matter over smart city Bhubaneswar, a tropical coastal station of eastern India

et al. 2019

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“…Observational and theoretical evidence suggests there are significant gradients of different meteorological variables in the lower troposphere due to the transition between the ABL and the free atmosphere, allowing the use of vertical profiles of atmospheric variables to infer the ABL height (Chandra et al . ). The vertical structure of the aerosol concentration, virtual potential temperature ( θ v ), wind speed and relative humidity are some of the most commonly used profiles for indirect ABL height estimates.…”

Section: Methodsmentioning

confidence: 97%

“…; Chandra et al . ). The Rib , for a specific z level, is computed as

R i b false(z false) = \frac{g}{θ_{s}} \frac{θ false(z false) - θ_{s}}{u {false(z false)}^{2} + v {false(z false)}^{2}} z,

where θ s is the potential temperature for a reference level near the surface, θ ( z ) is the potential temperature, and u ( z ) and v ( z ) are the zonal and meridional wind components.…”

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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“…Various definitions and methods could result in a wide range of estimates (Eresmaa et al 2012;Lotteraner and Piringer 2016). Among the most widely used methods are the gradient method using radiosondes (Seidel et al 2010;Lee et al 2014), the minimum gradient method, maximum variance using ceilometer profiles (Hayden et al 1997;Stachlewska et al 2012), and the bulk Richardson number method (Stull 1988;Chandra et al 2014;Zhang et al 2014). In this study we use the ABL height estimates obtained by Herrera-Mejía and Hoyos (2019) using a Richardson number-based multisensor methodology.…”

Section: ) Atmospheric Profiles Thermodynamic Stability Indices Anmentioning

confidence: 99%

An Investigation of the Precipitation Net Effect on the Particulate Matter Concentration in a Narrow Valley: Role of Lower-Troposphere Stability

Roldán-Henao

Hoyos

Herrera

et al. 2020

Journal of Applied Meteorology and Climatology

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Precipitation modulates the pollutant concentration in the atmosphere directly and indirectly through different mechanisms. Wet deposition, including in-cloud scavenging and below-cloud scavenging, is one of the main drivers of particulate matter removal from the atmosphere. Our focus is to assess the net effect of precipitation on the pollutant concentration using observations, a nonparametric conditional analysis, and the signed overlapping coefficient complement index. The study considers not only the direct near-surface aerosol below-cloud scavenging, but also the indirect effect associated with the induced lower-troposphere stability limiting the vertical dispersion, leading to a pollutant concentration increase. We consider the precipitation effects on fine and coarse particulate matter concentration. Probability density functions of the pollutant concentration during precipitation events and under dry conditions are analyzed for every hour of the day. The net effect of precipitation on the fine and coarse particulate matter concentration is strongly dependent on the atmospheric stability. During the nighttime and before midmorning, the atmosphere is stable; a precipitation event during this time induces below-cloud scavenging, reducing the concentration of particulate matter in the atmosphere. During the afternoon, unstable atmospheric conditions are predominant, and aerosols disperse vertically; a precipitation event during this period stabilizes the atmosphere, generating early stabilization that, together with the continued anthropogenic emissions during the day, leads to near-surface pollutant accumulation, offsetting the washout effect of the precipitation.

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Characterization of the atmospheric boundary layer from radiosonde observations along eastern end of monsoon trough of India

Cited by 12 publications

References 12 publications

Evaluating the variability, transport and periodicity of particulate matter over smart city Bhubaneswar, a tropical coastal station of eastern India

Evaluating the variability, transport and periodicity of particulate matter over smart city Bhubaneswar, a tropical coastal station of eastern India

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

An Investigation of the Precipitation Net Effect on the Particulate Matter Concentration in a Narrow Valley: Role of Lower-Troposphere Stability

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