Ground-based multi-axis differential optical absorption spectroscopy(MAX-DOAS)observations were operated from 02 to 21 December 2018 in Leshan,southwest China,to measure HONO,NO_(2) and aerosol extinction vertical dis...Ground-based multi-axis differential optical absorption spectroscopy(MAX-DOAS)observations were operated from 02 to 21 December 2018 in Leshan,southwest China,to measure HONO,NO_(2) and aerosol extinction vertical distributions,and these were the first MAX-DOAS measurement results in Sichuan Basin.During the measurement period,characteristic ranges for surface concentration were found to be 0.26-4.58 km^(−1) and averaged at 0.93 km^(−1) for aerosol extinction,0.49 to 35.2 ppb and averaged at 4.57 ppb for NO_(2) and 0.03 to 7.38 ppb and averaged at 1.05 ppb for HONO.Moreover,vertical profiles of aerosol,NO_(2) and HONO were retrieved from MAX-DOAS measurements using the Heidelberg Profile(HEIPRO)algorithm.By analysing the vertical gradients of pollutants and meteorological information,we found that aerosol and HONO are strongly localised,while NO_(2) is mainly transmitted from the north direction(city center direction).Nitrogen oxides such as HONO and NO_(2) are important for the production of hydroxyl radical(OH)and oxidative capacity in the troposphere.In this study,the averaged value of OH production rate from HONO is about 0.63 ppb/hr and maximum value of ratio between OH production from HONO and from(HONO+O_(3))is>93%before12:00 in Leshan.In addition,combustion emission contributes to 26%for the source of HONO in Leshan,and we found that more NO_(2) being converted to HONO under the conditions with high aerosol extinction coefficient and high relative humidity is also a dominant factor for the secondary produce of HONO.展开更多
基金supported by grants from the National Key Research and Development Program of China(Nos.,2018YFC0213104,2018YFC0213201,2016YFC0203302 and 2017YFC0210002)the Anhui Science and Technology Major Project(No.18030801111)+4 种基金the National Natural Science Foun-dation of China(Nos.41722501,91544212,51778596,41575021 and 41977184)the Strategic Priority Research Program of the Chinese Academy of Sciences(Nos.XDA23020301)the National Key Project for Causes and Control of Heavy Air Pollution(Nos.DQGG0102-03 and DQGG0205)the National High-Resolution Earth Observation Project of China(Nos.05-Y30B01-9001-19/20-3)the Civil Aerospace Technology Advance Research Project,No.Y7K00100KJ.
文摘Ground-based multi-axis differential optical absorption spectroscopy(MAX-DOAS)observations were operated from 02 to 21 December 2018 in Leshan,southwest China,to measure HONO,NO_(2) and aerosol extinction vertical distributions,and these were the first MAX-DOAS measurement results in Sichuan Basin.During the measurement period,characteristic ranges for surface concentration were found to be 0.26-4.58 km^(−1) and averaged at 0.93 km^(−1) for aerosol extinction,0.49 to 35.2 ppb and averaged at 4.57 ppb for NO_(2) and 0.03 to 7.38 ppb and averaged at 1.05 ppb for HONO.Moreover,vertical profiles of aerosol,NO_(2) and HONO were retrieved from MAX-DOAS measurements using the Heidelberg Profile(HEIPRO)algorithm.By analysing the vertical gradients of pollutants and meteorological information,we found that aerosol and HONO are strongly localised,while NO_(2) is mainly transmitted from the north direction(city center direction).Nitrogen oxides such as HONO and NO_(2) are important for the production of hydroxyl radical(OH)and oxidative capacity in the troposphere.In this study,the averaged value of OH production rate from HONO is about 0.63 ppb/hr and maximum value of ratio between OH production from HONO and from(HONO+O_(3))is>93%before12:00 in Leshan.In addition,combustion emission contributes to 26%for the source of HONO in Leshan,and we found that more NO_(2) being converted to HONO under the conditions with high aerosol extinction coefficient and high relative humidity is also a dominant factor for the secondary produce of HONO.
