The aerosol size distribution and cloud condensation nuclei (CCN) number concentration were measured using a wide-range particle spectrometer (WPS) and a cloud condensation nuclei counter (CCNC) on Mt. Tian from 31 July to 9 September, 2019. Combined with meteorological data, distribution characteristics of aerosol size and CCN and their influencing factors were analyzed. The results indicated that the mean aerosol number concentration was 5475.6 ± 5636.5 cm-3. The mean CCN concentrations were 183.7 ± 114.5 cm-3, 729.8 ± 376.1 cm-3, 1630.5 ± 980.5 cm-3, 2162.5 ± 1345.3 cm-3, and 2575.7 ± 1632.9 cm-3 at supersaturation levels of 0.1%, 0.2%, 0.4%, 0.6%, and 0.8%, respectively. The aerosol number size distribution is unimodal, and the dominant particle size is 30-60 nm. Affected by the height of the boundary layer and the valley wind, the diurnal variation in aerosol number concentration shows a unimodal distribution with a peak at 17:00, and the CCN number concentration showed a bimodal distribution with peaks at 18:00 and 21:00. The particle size distribution and supersaturation have a major impact on the activation of the aerosol into CCN. At 0.1% supersaturation (S), the 300-500 nm particles are most likely to activate to CCN. Particles of 100-300 nm are most easily activated at 0.2% (S), while particles of 60-80 nm are most likely activated at high supersaturation (≥0.4%). The concentrations of aerosol and CCN are higher in the northerly wind. Ambient relative humidity (RH) has little relationship with the aerosol activation under high supersaturation. According to N = CSk fitting the CCN spectrum, C = 3297 and k = 0.90 on Mt. Tian, characteristic of the clean continental type.
CITATION STYLE
Liu, A., Wang, H., Li, Y., Yin, Y., Li, B., Chen, K., … Dai, M. (2020). Distribution characteristics of aerosol size and CCN during the summer on Mt. Tian and their influencing factors. Atmosphere, 11(9). https://doi.org/10.3390/ATMOS11090912
Mendeley helps you to discover research relevant for your work.