Найдено научных статей и публикаций: 1, для научной тематики: Condensation particle counter
1.
Nand L Sharma, Jagdish C Kuniyal, Mahavir Singh, Priyanka Sharma, Kesar Chand, Ajay Kumar Negi, Manum Sharma and Harinder Kumar Thakur
- Journal of Earth system science , 2010
The concentration of ultrafine aerosol particles of aitken and nucleation mode having size in the range of
1–20 nm was monitored with water-based Condensation Particle Counter. The monitoring was carried out
from midnight-to-midnight in every alternate day on a fortnightly basis to represent summer,...
The concentration of ultrafine aerosol particles of aitken and nucleation mode having size in the range of
1–20 nm was monitored with water-based Condensation Particle Counter. The monitoring was carried out
from midnight-to-midnight in every alternate day on a fortnightly basis to represent summer, monsoon
and winter (autumn) seasons of 2008 at Mohal (1154 m amsl) and Kothi (2530 m amsl) in Kullu-Manali
area of the northwestern Himalayan region of India. The results indicate that diurnal pattern has faint
bimodal structure with two peaks, one in morning and the other in evening at both the sites but it is not as
distinct as found in plains. There is rather a constant particle density pattern of large magnitude consistent
with vehicular movement from morning till evening. The monthly 24 h average particle density gradually
picks up from January, increases rapidly in summer months and then decreases in monsoon season
at Mohal but at Kothi it keeps on rising from April to October with a slight more increase in September.
The particle density is more in summer than in monsoon season at Mohal, a trend opposite to plains. It
may be due to the development of warm thermal layer on valley floor while a cold layer develops along
snowy hilltops in winter leading to convection of fine particle up the slopes of valley during daytime. At
Kothi, the trend is same as it is in continental plains but opposite to Mohal. The relatively more value
of particle density in September and October at both the sites may be due to month long International
Kullu Dussehra fair in the valley. The vehicular survey conducted agrees well with entire study period
averaged diurnal variations and monthly 24 h averaged value of fine particle density. The average value
of ultrafine particle density at each hour of a day for entire study period is 20369±1230 Ncm−3 and
14389±1464 Ncm−3 at Mohal and Kothi sites, respectively. The comparison with earlier results shows
a significant increase indicating impact of vehicular onslaught on pure air of this hilly region.
