One-year observation of urban mixed layer characteristics at Tsukuba, Japan using a micro pulse lidar

Chen, Weibiao; Kuze, Hiroaki; Uchiyama, Akihiro; Suzuki, Y.; Takeuchi, Nobuo

doi:10.1016/s1352-2310(01)00181-9

Cited by 48 publications

(33 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Values are also comparable to those found by Granados-Muñoz et al (2012) at a site in southern Spain. They are larger than those reported by Chen et al (2001) for a city in Japan which is probably due to the more moist climate and thus a lower surface sensible heat flux. As one could expect, they are lower than those found by Korhonen et al (2014) in South Africa at a lower latitude in a drier climate.…”

Section: Mixing-layer Characteristicscontrasting

confidence: 70%

Mixing-layer height retrieval with ceilometer and Doppler lidar: from case studies to long-term assessment

Hirsikko²,

et al. 2014

View full text Add to dashboard Cite

Abstract. Aerosol signatures observed by ceilometers are frequently used to derive mixing-layer height (MLH) which is an essential variable for air quality modelling. However, Doppler wind lidar measurements of vertical velocity can provide a more direct estimation of MLH via simple thresholding. A case study reveals difficulties in the aerosol-based MLH retrieval during transition times when the mixing layer builds up in the morning and when turbulence decays in the afternoon. The difficulties can be explained by the fact that the aerosol distribution is related to the history of the mixing process and aerosol characteristics are modified by humidification. The results of the case study are generalized by evaluating one year of joint measurements by a Vaisala CT25K and a HALO Photonics Streamline wind lidar. On average the aerosol-based retrieval gives higher MLH than the wind lidar with an overestimation of MLH by about 300 m (600 m) in the morning (late afternoon). Also, the daily aerosol-based maximum MLH is larger and occurs later during the day and the average morning growth rates are smaller than those derived from the vertical wind. In fair weather conditions classified by less than 4 octa cloud cover the mean diurnal cycle of cloud base height corresponds well to the mixing-layer height showing potential for a simplified MLH estimation.

show abstract

Section: Mixing-layer Characteristicscontrasting

confidence: 70%

Mixing-layer height retrieval with ceilometer and Doppler lidar: from case studies to long-term assessment

Hirsikko²,

et al. 2014

View full text Add to dashboard Cite

show abstract

“…It is considered that the potential temperature nearly remains steady within the boundary layer and the top of the boundary layer is marked by a sudden change in the lapse rate. We have evaluated the boundary layer height using the second derivative approach where in the minimum point of the 9-point smoothed second derivative profile with 30-m resolution is considered as the top of the boundary layer (Chen et al 2001;Niranjan et al 2006). Mean diurnal variation in the boundary-layer height as derived from MPL observations over VSP during winter and summer are shown in Fig.…”

Section: Altitudinal Distribution Of Aerosol Abundance As Observed Usmentioning

confidence: 99%

Diurnal variations in the aerosol physical, optical and altitude distributional characteristics over three locations in eastern India: Implications to black carbon radiative forcing

Kandula¹,

Vakacherla²,

Bade³

et al. 2017

Terr. Atmos. Ocean. Sci.

View full text Add to dashboard Cite

A qualitative assessment on the effect of boundary layer dynamics in the estimation of clear sky black carbon (BC) radiative forcing has been made considering the debate on the lower bound and possible uncertainties in the aerosol radiative forcing estimation. Comprehensive measurements made on aerosol optical and physical properties, near surface BC mass concentrations and Lidar derived aerosol back scatter intensity profiles at three selected locations in India (Visakhapatnam, Kharagpur, and Kolkata) are utilized for this purpose. Sensitivity analysis carried out to estimate the errors in short wave (SW) BC forcing computation indicated that nonincorporation of diurnal changes in the boundary layer depth into the models may lead to over estimation of diurnally averaged (as the study is limited to short wave radiative forcing, diurnally averaged forcing refers to day-time averaged) BC forcing. The relative errors may vary between 7 to 70% depending on the season and the location changes in boundary layer depth day-time behaviour. The results reported in the present study, though specific to the study locations, clearly indicate that a more systematic approach is needed to investigate the sensitivity of aerosol radiative forcing to various atmospheric parameters and processes within the boundary layer, particularly at stations characterised by strong anthropogenic influence and large diurnal temperature variability that affect the boundary layer depth.

show abstract

“…Micro Pulse Lidar (MPL) systems were used to measure aerosol properties during the Indian Ocean Experiment (IN-DOEX) 1999 field phase (Welton et al, 2000. Chen et al (2001) observed seasonal changes of the mixing layer height in Japan by using the MPL. He et al (2008) analysed aerosol vertical distribution in the lower troposphere by examining the aerosol extinction profiles derived from MPL measurements in Hong Kong.…”

Section: Introductionmentioning

confidence: 99%

Quantifying the relationship between PM<sub>2.5</sub> concentration, visibility and planetary boundary layer height for long-lasting haze and fog–haze mixed events in Beijing

Luan

Guo

et al. 2018

Atmos. Chem. Phys.

View full text Add to dashboard Cite

Abstract. Air quality and visibility are strongly influenced by aerosol loading, which is driven by meteorological conditions. The quantification of their relationships is critical to understanding the physical and chemical processes and forecasting of the polluted events. We investigated and quantified the relationship between PM 2.5 (particulate matter with aerodynamic diameter is 2.5 µm and less) mass concentration, visibility and planetary boundary layer (PBL) height in this study based on the data obtained from four long-lasting haze events and seven fog-haze mixed events from January 2014 to March 2015 in Beijing. The statistical results show that there was a negative exponential function between the visibility and the PM 2.5 mass concentration for both haze and fog-haze mixed events (with the same R 2 of 0.80). However, the fog-haze events caused a more obvious decrease of visibility than that for haze events due to the formation of fog droplets that could induce higher light extinction. The PM 2.5 concentration had an inversely linear correlation with PBL height for haze events and a negative exponential correlation for fog-haze mixed events, indicating that the PM 2.5 concentration is more sensitive to PBL height in fog-haze mixed events. The visibility had positively linear correlation with the PBL height with an R 2 of 0.35 in haze events and positive exponential correlation with an R 2 of 0.56 in foghaze mixed events. We also investigated the physical mechanism responsible for these relationships between visibility, PM 2.5 concentration and PBL height through typical haze and fog-haze mixed event and found that a double inversion layer formed in both typical events and played critical roles in maintaining and enhancing the long-lasting polluted events. The variations of the double inversion layers were closely associated with the processes of long-wave radiation cooling in the nighttime and short-wave solar radiation reduction in the daytime. The upper-level stable inversion layer was formed by the persistent warm and humid southwestern airflow, while the low-level inversion layer was initially produced by the surface long-wave radiation cooling in the nighttime and maintained by the reduction of surface solar radiation in the daytime. The obvious descending process of the upper-level inversion layer induced by the radiation process could be responsible for the enhancement of the lowlevel inversion layer and the lowering PBL height, as well as high aerosol loading for these polluted events. The reduction of surface solar radiation in the daytime could be around 35 % for the haze event and 94 % for the fog-haze mixed event. Therefore, the formation and subsequent descending processes of the upper-level inversion layer should be an important factor in maintaining and strengthening the longlasting severe polluted events, which has not been revealed in previous publications. The interactions and feedbacks between PM 2.5 concentration and PBL height linked by radiation process caused a more significant an...

show abstract

One-year observation of urban mixed layer characteristics at Tsukuba, Japan using a micro pulse lidar

Cited by 48 publications

References 13 publications

Mixing-layer height retrieval with ceilometer and Doppler lidar: from case studies to long-term assessment

Mixing-layer height retrieval with ceilometer and Doppler lidar: from case studies to long-term assessment

Diurnal variations in the aerosol physical, optical and altitude distributional characteristics over three locations in eastern India: Implications to black carbon radiative forcing

Quantifying the relationship between PM<sub>2.5</sub> concentration, visibility and planetary boundary layer height for long-lasting haze and fog–haze mixed events in Beijing

Contact Info

Product

Resources

About

One-year observation of urban mixed layer characteristics at Tsukuba, Japan using a micro pulse lidar

Cited by 48 publications

References 13 publications

Mixing-layer height retrieval with ceilometer and Doppler lidar: from case studies to long-term assessment

Mixing-layer height retrieval with ceilometer and Doppler lidar: from case studies to long-term assessment

Diurnal variations in the aerosol physical, optical and altitude distributional characteristics over three locations in eastern India: Implications to black carbon radiative forcing

Quantifying the relationship between PM&lt;sub&gt;2.5&lt;/sub&gt; concentration, visibility and planetary boundary layer height for long-lasting haze and fog–haze mixed events in Beijing

Contact Info

Product

Resources

About

Quantifying the relationship between PM<sub>2.5</sub> concentration, visibility and planetary boundary layer height for long-lasting haze and fog–haze mixed events in Beijing