Technical note: Boundary layer height determination from lidar for improving air pollution episode modeling: development of new algorithm and evaluation

Abstract. Predicting air pollution events in the low atmosphere over megacities requires a thorough understanding of the tropospheric dynamics and chemical processes, involving, notably, continuous and accurate determination of the boundary layer height (BLH). Through intensive observations experimented over Beijing (China) and an exhaustive evaluation of existing algorithms applied to the BLH determination, persistent critical limitations are noticed, in particular during polluted episodes. Basically, under weak thermal convection with high aerosol loading, none of the retrieval algorithms is able to fully capture the diurnal cycle of the BLH due to insufficient vertical mixing of pollutants in the boundary layer associated with the impact of gravity waves on the tropospheric structure. Consequently, a new approach based on gravity wave theory (the cubic root gradient method: CRGM) is developed to overcome such weakness and accurately reproduce the fluctuations of the BLH under various atmospheric pollution conditions. Comprehensive evaluation of CRGM highlights its high performance in determining BLH from lidar. In comparison with the existing retrieval algorithms, CRGM potentially reduces related computational uncertainties and errors from BLH determination (strong increase of correlation coefficient from 0.44 to 0.91 and significant decreases of the root mean square error from 643 to 142 m). Such a newly developed technique is undoubtedly expected to contribute to improving the accuracy of air quality modeling and forecasting systems.

[1]  Gerhard Peters,et al.  Remote sensing of turbulent ozone fluxes and the ozone budget in the convective boundary layer with DIAL and Radar-RASS : A case study , 1996 .

[2]  W. Gong,et al.  Statistical characteristics of atmospheric gravity wave in the mesopause region observed with a sodium lidar at Beijing, China , 2013 .

[3]  Albert Ansmann,et al.  Continuous monitoring of the boundary-layer top with lidar , 2008 .

[4]  Edwin W. Eloranta,et al.  Convective boundary layer mean depths and cloud geometrical properties obtained from volume imaging lidar data , 1995 .

[5]  M. Sicarda,et al.  Mixed layer depth determination in the Barcelona coastal area from regular lidar measurements : methods , results and limitations , 2005 .

[6]  E. Dewan,et al.  Saturation and the “universal” spectrum for vertical profiles of horizontal scalar winds in the atmosphere , 1986 .

[7]  Raymond M. Hoff,et al.  The Detection of Mixed Layer Depth and Entrainment Zone Thickness from Lidar Backscatter Profiles , 1999 .

[8]  Pierre H. Flamant,et al.  Internal gravity waves convectively forced in the atmospheric residual layer during the morning transition , 2011 .

[9]  Delong Zhao,et al.  Evolution of planetary boundary layer under different weather conditions, and its impact on aerosol concentrations , 2013 .

[10]  M. Alexander,et al.  Gravity wave dynamics and effects in the middle atmosphere , 2003 .

[11]  Jacques Pelon,et al.  Study of the moist Convective Boundary Layer structure by backscattering lidar , 1994 .

[12]  N. Soulakellis,et al.  A Comparison Between Modelled and Measured Mixing-Layer Height Over Munich , 2009 .

[13]  Teruyuki Nakajima,et al.  Observation of dust and anthropogenic aerosol plumes in the Northwest Pacific with a two‐wavelength polarization lidar on board the research vessel Mirai , 2002 .

[14]  Raymond M. Hoff,et al.  The vertical chemical and meteorological structure of the boundary layer in the Lower Fraser Valley during Pacific '93 , 1997 .

[15]  J. M. Baldasano,et al.  Mixed-Layer Depth Determination in the Barcelona Coastal Area From Regular Lidar Measurements: Methods, Results and Limitations , 2006 .

[16]  R. Stull.  An Introduction to Boundary Layer Meteorology , 1988 .

[17]  Zifa Wang,et al.  Evaluation of the effect of air pollution control during the Beijing 2008 Olympic Games using Lidar data , 2010 .

[18]  M. Stettler,et al.  On the relation between haze layer and air mass aerosol at an urban location — case studies , 1996 .

[19]  S. H. Melfi,et al.  Lidar observations of vertically organized convection in the planetary boundary layer over the ocean , 1985 .

[20]  Z. Wang.  Interactive comment on “Lidar measurement of planetary boundary layer height and comparison with microwave profiling radiometer observation” by Z. Wang et al , 2012 .

[21]  Stefan Emeis,et al.  Multiple atmospheric layering and mixing-layer height in the Inn valley observed by remote sensing , 2007 .

[22]  Spyros N. Pandis,et al.  Response of Inorganic PM to Precursor Concentrations , 1998 .

[23]  C. Flamant,et al.  LIDAR DETERMINATION OF THE ENTRAINMENT ZONE THICKNESS AT THE TOP OF THE UNSTABLE MARINE ATMOSPHERIC BOUNDARY LAYER , 1997 .

[24]  Donald H. Lenschow,et al.  An Objective Method for Deriving Atmospheric Structure from Airborne Lidar Observations , 2000 .

[25]  Andrea Lammert,et al.  Determination of the Atmospheric Boundary Layer Height from Radiosonde and Lidar Backscatter , 2006 .

[26]  C. Gardner.  Testing theories of atmospheric gravity wave saturation and dissipation , 1996 .

[27]  Ting Yang,et al.  Investigation of the sources and evolution processes of severe haze pollution in Beijing in January 2013 , 2014 .

[28]  William P. Hooper,et al.  Lidar Measurements of Wind in the Planetary Boundary Layer: The Method, Accuracy and Results from Joint Measurements with Radiosonde and Kytoon. , 1986 .

[29]  Laboratory Simulation Of Vertical Plume Dispersion Within A Convective Boundary Layer , 2001 .

[30]  Nobuo Sugimoto,et al.  Evolution of a lidar network for tropospheric aerosol detection in East Asia , 2016 .

[31]  R. Boers,et al.  Cold air outbreak during MASEX: Lidar observations and boundary-layer model test , 1987 .

[32]  Jing Li,et al.  An intercomparison of long‐term planetary boundary layer heights retrieved from CALIPSO, ground‐based lidar, and radiosonde measurements over Hong Kong , 2017 .

[33]  F. G. Fernald.  Analysis of atmospheric lidar observations: some comments. , 1984, Applied optics.

[34]  Zhanqing Li,et al.  Detection, variations and intercomparison of the planetary boundary layer depth from radiosonde, lidar and infrared spectrometer , 2013 .

[35]  C. Chan,et al.  Air pollution in mega cities in China , 2008 .

[36]  Hans Peter Schmid,et al.  Meteorological Research Needs for Improved Air Quality Forecasting Report of the 11th Prospectus Development Team of the U.S. Weather Research Program , 2004 .

[37]  Volker Wulfmeyer,et al.  Elastic-backscatter-lidar-based characterization of the convective boundary layer and investigation of related statistics , 2010 .

[38]  Jie Chen,et al.  Observational and modeling studies of urban atmospheric boundary-layer height and its evolution mechanisms , 2006 .

[39]  S. Madronich,et al.  Characterizations of chemical oxidants in Mexico City: A regional chemical dynamical model (WRF-Chem) study , 2007 .

[40]  Petra Seibert,et al.  Review and intercomparison of operational methods for the determination of the mixing height , 2000 .