scholarly journals Estimating surface visibility at Hong Kong from ground-based LIDAR, sun photometer and operational MODIS products

2013 ◽  
Vol 63 (9) ◽  
pp. 1098-1110 ◽  
Author(s):  
Muhammad I. Shahzad ◽  
Janet E. Nichol ◽  
Jun Wang ◽  
James R. Campbell ◽  
Pak W. Chan
2009 ◽  
Vol 3 (1) ◽  
pp. 131-137 ◽  
Author(s):  
P.W. Chan

The performance and application of AOD products from the Moderate Resolution Imaging Spectroradiometer (MODIS) are studied by comparing with the AOD derived from the ground-based Doppler LIDAR inside the Hong Kong International Airport (HKIA). The backscattered power data of the LIDAR are used to determine the extinction coefficient profile, from which the AOD is calculated. The AOD determined from the LIDAR is found to have good quality by comparing with the AOD measurements from a hand-held sun photometer at HKIA over a period of three months, and as such it is used to study the quality of AOD estimated from MODIS. The 1-km resolution AOD product from MODIS is found to have better correlation with the LIDAR AOD in comparison to the 10-km resolution product. Moreover, since AOD is a column-integrated quantity, its application to the monitoring of the surface visibility changes should be made with caution during the presence of elevated layers of higher aerosol concentrations. Examples of the effects of such elevated aerosol layers are studied.


Author(s):  
K. L. Chan ◽  
K. Qin

In this study, we present a quantitative estimation of the impacts of biomass burning emissions from different source regions to the local air quality in Hong Kong in 2014 using global chemistry transport model simulations, sun photometer measurements, satellite observations and local monitoring network data. This study focuses on two major biomass burning pollutants, black carbon aerosols and carbon monoxide (CO). The model simulations of atmospheric black carbon and CO show excellent agreement with sun photometer aerosol optical depth (AOD) measurements, satellite CO columns observations and local monitoring stations data. From the model simulation results, we estimated that biomass burning contributes 12 % of total black carbon and 16 % of atmospheric CO in Hong Kong on annual average. South East Asia shows the largest influence to the black carbon and CO levels in Hong Kong, accounts for 11 % of the total atmospheric black carbon and 8 % of CO. Biomass burning in North East Asia and Africa also show significant impacts to Hong Kong. Elevated levels of atmospheric black carbon aerosols and CO were observed during springtime (March and April) which is mainly due to the enhancement of biomass burning contributions. Black carbon and CO originating from biomass burning sources are estimated to contribute 40 % of atmospheric black carbon and 28 % of CO in Hong Kong during March 2014. An investigation focusing on the biomass burning pollution episode during springtime suggests the intensified biomass burning activities in the Indochinese Peninsula are the major sources of black carbon and CO in Hong Kong during the time.


2018 ◽  
Vol 176 ◽  
pp. 08014
Author(s):  
Dandocsi Alexandru ◽  
Sapartoc Georgiana ◽  
Preda Liliana ◽  
Stan Cristina ◽  
Radu Cristian

One year records of AErosolROboticNEtwork (AERONET) sun photometer measurements were analyzed to investigate the seasonal and daily variations of columnar aerosol optical depth. Some irregularities of this time series are associated with aerosol intrusions. The aerosol layers indicated by these irregularities are identified and characterized using the extensive optical data from coincident CALIPSO satellite observations and ground based LIDAR.


2017 ◽  
Vol 122 (7) ◽  
pp. 3929-3943 ◽  
Author(s):  
Tianning Su ◽  
Jing Li ◽  
Chengcai Li ◽  
Pengzhan Xiang ◽  
Alexis Kai-Hon Lau ◽  
...  

1998 ◽  
Vol 13 (11-s4) ◽  
pp. S289-S293 ◽  
Author(s):  
SSY WONG ◽  
WC YAM ◽  
PHM LEUNG ◽  
PCY WOO ◽  
KY YUEN

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