Low-level jets and their implications on air pollution: A review

Abstract

Low-level jets (LLJ) are a common phenomenon in the atmospheric boundary layer and have been reported worldwide. Additionally, they have considerable relevance in a series of fields. This review aimed to document their implications on air quality, specifically particulate matter, mineral dust, and ozone in recent literature focus on i) generalizing long-range advection of pollutants by the low-level jets; ii) analysing vertical transport due to low-level jets-enhanced turbulence mixing and the corresponding mechanisms for different pollutants; and iii) introducing the performance of state-of-the-art numerical models. Finally, we suggest that high-resolution spatiotemporal observations of the pollutants and turbulence must be conducted, and current parameterization schemes should be improved to better represent the low-level jets and nocturnal boundary layer structures for reproducing the complicated interactions between the low-level jets and pollutants.

A case study analysis of the impact of a new free tropospheric turbulence scheme on the dispersion of an atmospheric tracer

“…It is clear from our results that the inclusion of the free tropospheric VT parametrization has incorporated turbulent mixing that has hitherto not been represented within the dispersion model; that is, that associated with LLJs. In their review article, Wei et al (2023) suggest that LLJs are a common feature and they discuss the implications this may have on the dispersion of gases and particulates. Wei et al (2023) indicate that LLJs have at least two effects on air concentrations: (a) decreases due to long‐range advection of pollutants above the LLJ (Banta et al, 1998; Corsmeier et al, 1997; Klein et al, 2019; Martins et al, 2018) and (b) increases below the LLJ due to downward momentum brought about by the enhanced vertical wind shear (Fiedler et al, 2013; Karipot et al, 2006; Kulkarni et al, 2016; Schepanski et al, 2009).…”

“…In their review article, Wei et al (2023) suggest that LLJs are a common feature and they discuss the implications this may have on the dispersion of gases and particulates. Wei et al (2023) indicate that LLJs have at least two effects on air concentrations: (a) decreases due to long‐range advection of pollutants above the LLJ (Banta et al, 1998; Corsmeier et al, 1997; Klein et al, 2019; Martins et al, 2018) and (b) increases below the LLJ due to downward momentum brought about by the enhanced vertical wind shear (Fiedler et al, 2013; Karipot et al, 2006; Kulkarni et al, 2016; Schepanski et al, 2009). Our results are consistent with the first of these effects.…”

“…Pollutants such as ozone, with a tropospheric reservoir, may well be mixed downwards towards the surface by the enhanced turbulence associated with LLJs (Corsmeier et al, 1997; Klein et al, 2019). Wei et al (2023) conclude their review with the recommendation that current turbulence parametrizations should be improved to capture and represent the interaction between LLJs and the boundary layer and its effects on the dispersion of atmospheric gases and particulates.…”

“…We focus on LLJs in this article, as they are most likely to influence near‐surface air concentrations and long‐range transport of pollutants; for example, ozone, mineral dust, and particulates (Wei et al, 2023). There are several types of LLJ.…”

Evaluating air quality and criteria pollutants prediction disparities by data mining along a stretch of urban-rural agglomeration includes coal-mine belts and thermal power plants

“…Rapid increase in air pollution is the result of urbanization, industrialization and emission activities from other sectors (Choudhary et al, 2022b;. Time to time advanced technologies is used to combat air pollution like as now a days low level jets are common and used worldwide to enhance the air quality (Wei et al, 2023). To understand the impact of air pollutants and their prediction, researchers have been studying the criteria for air pollutants, namely, Particulate Matter (PM), Ozone (O 3 ), Carbon Monoxide (CO), Nitrogen Dioxide (NO 2 ), and Sulphur Dioxide (SO 2 ) (Choudhary et al, 2020;Pratap et al, 2020;Zhu et al, 2023).…”