工作日、双休日和春节期间PM10中水溶性离子浓度变化特征

为了解北京冬季工作日、双休日和春节期间大气PM₁₀中水溶性离子质量浓度水平和日变化特征,2006年1月15日—2月18日在中国科学院大气物理研究所铁塔分部对大气PM10中水溶性离子状况进行了连续观测.结果表明:工作日、双休日和春节期间大气PM₁₀中主要水溶性离子均为SO₄2－,NO₃－和NH₄＋.与工作日相比,双休日中ρ（SO42－），ρ（NO₃－）和ρ（NH₄＋）平均值分别下降15%，36%和27%；春节期间三者的平均值依次下降41%, 70%和67%.工作日、双休日和春节期间ρ（Cl－）和ρ（NO₂－）日变化相似,表现为白天低,晚上高; 春节期间ρ（SO42－）和ρ（NO₃－）由于源排放的减弱，日变化较平缓，没有明显的峰值. 

Concentration Variation of Water-soluble Ions of PM10 on Workday, Weekend and Spring Festival Period

In order to comprehend concentration levels and diurnal variation of water-soluble ions of PM₁₀ on workday, weekend and the Spring Festival period in the atmosphere of Beijing, the water-soluble ions of PM₁₀ were measuredat TietaBranch of Institute of Atmospheric Physics, Chinese Academy of Sciences from 15January to 18 February, 2006.The results shows: on workday, weekend and the Spring Festival period, the most important ions of PM₁₀ are SO₄2－, NO₃－ and NH₄＋. Compared with workday, the average mass concentrations of SO₄2－, NO3－ and NH₄＋ on weekend respectively decreased by 15%, 36% and 27%. The average mass concentrations of SO₄2－, NO₃－ and NH₄＋ respectively decreased by 41%,70% and 67% on the Spring Festival period. Variations of mass concentration of Cl－ andNO₂－ are similar, shown as lower in daytime and higher at night, on workday, weekend and the Spring Festivalperiod. Due to the sources of SO₄2－ and NO₃－ decreased, the diurnal variation is gentle on the Spring Festival period.