Search

Browse

• Communities
• Authors
• Year
• Titles
• Subjects

My Space

• Login

Investigation of fine particle number size distribution at Akrotiri station: Impact from urban environment and seasonal variability

Triantafyllaki Maria

Full record

---

Summary

In order to conduct this thesis, measurements of the particle number size distribution of airborne particles in the coastal suburban area of Akrotiri, Chania were carried out. The measurements were completed over a period of 100 days, for particles ranging in the size from 14.07 - 736.5 nm. Monthly variations were studied, with January having the highest concentrations of fine particles at the 31 nm size range, despite a minimal contribution to the total sampling. In the same month, due to low temperatures, higher concentrations were measured between 7:00 pm - 00:00 am and 8:00 am - 1:00 pm, indicating the significant influence of domestic heating and traffic on particle number concentration levels. During spring, the particle number concentration profile remained the same, but with lower levels of concentration. During summer, especially in July, high levels of particle concentrations were recorded between 15:00 pm - 3:00 am due to increased tourist activity and nightlife. At the same time, in comparison to weekend variations, higher number concentration was found on weekdays, especially in the size range of 60 - 70 nm. Temperature was moderately correlated to the number concentration of particles only in winter and spring, when combustion for heating purposes was still necessary. Data analysis has also showed that low-speed winds favour the accumulation of particles in the atmosphere. In January, the majority of the winds came from south-west and west-south-west directions, which links the increased fine particle concentrations with emissions from the city of Chania. Influence from the nearby domestic area of Akrotiri, the airport and the port of Souda did not strongly contribute with the particle number size distribution. Equally important was the contribution of particles arriving directly from the sea, which were carried by the north-northwest winds in the area of the station. Finally, 11 nucleation events were recognised during the sampling period with an average formation and growth rate of 0.1131 cm^(-3)×s^(-1) and 2.93 nm×h^(-1) respectively. Most of them occurred in May between 11:00 am - 2:30 pm and their presence was favored by the sea breeze.

Available Files

Services