Atmospheric influences and local variability of air pollution close to a motorway in an Alpine valley during winter

Schäfer, Klaus; Vergeiner, Johannes; Emeis, Stefan; Wittig, Julia; Höffmann, M.; Obleitner, Friedrich; Suppan, P.

doi:10.1127/0941-2948/2008/0294

Cited by 15 publications

(9 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It was computed using METEO-FRANCE automatic weather stations of Sallanches (541 m ASL) and Mont-Arbois (1833 m ASL). It appears that pollution episodes occur during anticyclonic conditions, which favour the development of persistent temperature inversion (dT/dz > 0), as already noted by [34][35][36]. The high levels of PM10 and the spatial variability could be explained by emissions rates and/or local dynamics.…”

Section: Context: a Steep Sided Polluted Alpine Valleymentioning

confidence: 72%

Wintertime Local Wind Dynamics from Scanning Doppler Lidar and Air Quality in the Arve River Valley

et al. 2018

View full text Add to dashboard Cite

Air quality issues are frequent in urbanized valleys, particularly in wintertime when a temperature inversion forms and the air within the valley is stably stratified over several days. In addition to pollutant sources, local winds can have a significant impact on the spatial distribution and temporal evolution of pollutant concentrations. They can be very complex and difficult to represent in numerical weather prediction models, particularly under stable conditions. Better knowledge of these local winds from observations is also a prerequisite to improving air quality prediction capability. This paper analyses local winds during the Passy-2015 field experiment that took place in a section of the Arve river valley, near Chamonix-Mont-Blanc. This location is one of the worst places in France regarding air quality. The wind analysis, which is mainly based on scanning Doppler lidar data sampling a persistent temperature inversion episode, reveals features consistent with the higher pollutant concentrations observed in this section of the valley as well as their spatial heterogeneities. In particular, an elevated down-valley jet is observed at night in the northern half of the valley, which, combined with a weak daytime up-valley wind, leads to very poor ventilation of the lowest layers. A northeast-southwest gradient in ventilation is observed on a daily-average, and is consistent with the PM10 heterogeneities observed within the valley.

show abstract

Section: Context: a Steep Sided Polluted Alpine Valleymentioning

confidence: 72%

Wintertime Local Wind Dynamics from Scanning Doppler Lidar and Air Quality in the Arve River Valley

et al. 2018

View full text Add to dashboard Cite

show abstract

“…In the same region in winter the two biggest emission sources of PM10 are road traffic with 35% and domestic burning with 25% (Umweltbundesamt 2004). The described diurnal pattern has also been observed for individual wintertime days and for other seasons (e.g., Wotawa et al 2000;Heimann et al 2007;Schäfer et al 2008). The modification of this pattern on days with HDV bans has also been documented by e.g., Beauchamp et al (2004) and Schnitzhofer et al (2008).…”

Section: Mean Diurnal Pattern Of Air Pollutionmentioning

confidence: 73%

“…The latter two show a decrease in concentrations at about 100-150 m a.g.l. The average sodar-derived mixing-layer height is about 150 m on this day (Schäfer et al 2008;their Fig. 7).…”

Section: Diurnal Pattern At the Surfacementioning

confidence: 96%

“…7.1 in Heimann et al 2007). First results are documented in Emeis et al (2007), Schäfer et al (2008), andHarnisch et al (2009). The present paper follows up on these efforts and draws a more comprehensive picture of different types of air pollution transport by analysing four selected pollution events.…”

mentioning

confidence: 88%

“…6b. Two features are outstanding: firstly, the polluted layer is much deeper than on 16 January and extends beyond the shown altitude, corresponding to a deeper sodarderived mixing-layer height of about 150-200 m (Schäfer et al 2008;their Fig. 7).…”

Section: Spatial Distribution Of Pollutantsmentioning

confidence: 98%

See 2 more Smart Citations

Air Pollution Transport in an Alpine Valley: Results From Airborne and Ground-Based Observations

Gohm

Harnisch²,

Vergeiner

et al. 2009

Boundary-Layer Meteorol

111

View full text Add to dashboard Cite

An observational dataset from a wintertime field campaign in the Inn Valley, Austria, is analysed in order to study mechanisms of air pollution transport in an Alpine valley. The results illustrate three types of mechanisms: transport by a density current, backand-forth transport by valley winds, and transport by slope winds. The first type is associated with an air mass difference along the valley. Cooler air located in the lower part of the valley behaves like a density current and produces the advection of pollutants by upvalley winds. In the second type, strong horizontal gradients in pollution concentrations exist close to ground. Multiple wind reversals result in a back-and-forth transport of pollutants by weak valley winds. In the third type, upslope winds during daytime decrease low-level pollution concentrations and cause the formation of elevated pollution layers.

show abstract

Semi‐idealized simulations of wintertime flows and pollutant transport in an Alpine valley. Part II: Passive tracer tracking

Sabatier

Largeron

Paci

et al. 2020

Quart J Royal Meteoro Soc

View full text Add to dashboard Cite

Under wintertime quiescent conditions, thermally driven circulations represent one of the only sources of tracer dispersion over mountainous terrain. Those circulations can be unequally developed at a valley scale since they strongly depend on local morphological arrangement. At the same time, very heterogeneous pollutant distribution can be observed, as for instance in a French Alpine basin located in the Arve River valley. This complex basin regularly shows large variations in pollutant concentrations with certain sectors suffering from poor wintertime air quality. On the other hand, the surrounding tributary valleys appear to be less affected, suggesting that the basin local dynamics may participate in pollutant trapping. The present study intends to classify the pollutant transport mechanisms in terms of efficiency and to identify the most dynamically vulnerable atmospheric volumes regarding pollutant accumulation. This is achieved through a set of semi‐idealized high‐resolution numerical simulations reproducing a full diurnal cycle with passive tracers released continuously at a constant rate. The model is used as a laboratory in order to quantify the influence of several processes on transport mechanism efficiency. This approach underlines the high efficiency of vertical transport by anabatic winds while horizontal transport efficiency by up‐valley wind systems remains weak, leaving the surrounding tributary valleys almost unaffected by the basin pollution during daytime. At night, the efficiency of horizontal transport by the down‐valley wind systems depends on the tracer source location within the basin. In addition, the tracers emitted within the tributary valleys do not reach the basin bottom because of thermal stratification and local morphological arrangement but rather degrade the air quality of mid‐altitude villages lying along the basin sidewalls.

show abstract

Atmospheric influences and local variability of air pollution close to a motorway in an Alpine valley during winter

Cited by 15 publications

References 0 publications

Wintertime Local Wind Dynamics from Scanning Doppler Lidar and Air Quality in the Arve River Valley

Wintertime Local Wind Dynamics from Scanning Doppler Lidar and Air Quality in the Arve River Valley

Air Pollution Transport in an Alpine Valley: Results From Airborne and Ground-Based Observations

Semi‐idealized simulations of wintertime flows and pollutant transport in an Alpine valley. Part II: Passive tracer tracking

Contact Info

Product

Resources

About