Chemical composition and droplet size distribution of cloud at the summit of Mount Tai, China
نویسندگان
چکیده
The chemical composition of 39 cloud samples and droplet size distributions in 24 cloud events were investigated at the summit of Mt. Tai from July to October 2014. Inorganic ions, organic acids, metals, HCHO, H2O2, sulfur(IV), organic carbon, and elemental carbon as well as pH and electrical conductivity were analyzed. The acidity of the cloud water significantly decreased from a reported value of pH 3.86 during 2007–2008 (Guo et al., 2012) to pH 5.87 in the present study. The concentrations of nitrate and ammonium were both increased since 2007–2008, but the overcompensation of ammonium led to an increase in the mean pH value. The microphysical properties showed that cloud droplets were smaller than 26.0 μm and most were in the range of 6.0–9.0 μm at Mt. Tai. The maximum droplet number concentration (Nd) was associated with a droplet size of 7.0 μm. High liquid water content (LWC) values could facilitate the formation of larger cloud droplets and broadened the droplet size distribution. Cloud droplets exhibited a strong interaction with atmospheric aerosols. Higher PM2.5 levels resulted in higher concentrations of water-soluble ions and smaller sizes with increased numbers of cloud droplets. The lower pH values were likely to occur at higher PM2.5 concentrations. Clouds were an important sink for soluble materials in the atmosphere. The dilution effect of cloud water should be considered when estimating concentrations of soluble components in the cloud phase.
منابع مشابه
Characterization of cloud water chemistry at Mount Tai, China: Seasonal variation, anthropogenic impact, and cloud processing
To investigate cloud chemistry in the fast developing region of north China, five intensive observation campaigns were performed at the summit of Mount Tai (Mt. Tai) during 2007e2008. A total of 482 cloud water samples were collected using single-stage and two-stage cloud collectors. Inorganic ions, organic acids and species associated with S(IV) oxidation in cloud water were analyzed. The resu...
متن کاملThe measurement of droplet size distribution of water-oil emulsion through NMR method
The effects of water/oil volume ratio, type and concentration of demulsifier, water salinity and mixing speed on the average water droplets size in water-oil emulsion are evaluated at different times through NMR measurements.The type and concentration of demulsifier have the greatest effects on the average droplet size with 38% and 31.5%, respectively. The water/oil volume ratio, water salinity...
متن کاملInfluence of Salinity, Surfactants and Power of Ultrasonic Homogenizer on Droplet Size Distribution of Crude Oil/Water Emulsions
متن کامل
The Role of Entrainment and Mixing in Altering the Relationship Between Aerosol Concentration and Cloud Drop Number Concentration
Two basic methods have been used to relate the change in droplet number concentration to aerosol number concentration. The first method uses empirically derived relationships based on either observed aerosol number concentrations and droplet concentrations or observed aerosol sulfate or droplet mass concentrations and droplet number concentrations. This method was followed by Jones et al. (1994...
متن کاملThe effect of local sources on particle size and chemical composition and their role in aerosol–cloud interactions at Puijo measurement station
Interactions between aerosols and liquid water clouds were studied during autumns 2010–2011 at a semiurban measurement station on Puijo tower in Kuopio, Finland. Cloud interstitial and total aerosol size distributions, particle chemical composition and hygroscopicity and cloud droplet size distribution were measured, with a focus on comparing clean air masses with those affected by local source...
متن کامل