Τίτλος:
From hygroscopic aerosols to cloud droplets: The HygrA-CD campaign in the Athens basin — An overview
Γλώσσες Τεκμηρίου:
Αγγλικά
Περίληψη:
The international experimental campaign Hygroscopic Aerosols to Cloud Droplets (HygrA-CD), organized in the Greater Athens Area (GAA), Greece from 15 May to 22 June 2014, aimed to study the physico-chemical properties of aerosols and their impact on the formation of clouds in the convective Planetary Boundary Layer (PBL). We found that under continental (W-NW-N) and Etesian (NE) synoptic wind flow and with a deep moist PBL (~ 2–2.5 km height), mixed hygroscopic (anthropogenic, biomass burning and marine) particles arrive over the GAA, and contribute to the formation of convective non-precipitating PBL clouds (of ~ 16–20 μm mean diameter) with vertical extent up to 500 m. Under these conditions, high updraft velocities (1–2 m s− 1) and cloud condensation nuclei (CCN) concentrations (~ 2000 cm− 3 at 1% supersaturation), generated clouds with an estimated cloud droplet number of ~ 600 cm− 3. Under Saharan wind flow conditions (S-SW) a shallow PBL (< 1–1.2 km height) develops, leading to much higher CCN concentrations (~ 3500–5000 cm− 3 at 1% supersaturation) near the ground; updraft velocities, however, were significantly lower, with an estimated maximum cloud droplet number of ~ 200 cm− 3 and without observed significant PBL cloud formation. The largest contribution to cloud droplet number variance is attributed to the updraft velocity variability, followed by variances in aerosol number concentration. © 2016 Elsevier B.V.
Συγγραφείς:
Papayannis, A.
Argyrouli, A.
Bougiatioti, A.
Remoundaki, E.
Vratolis, S.
Nenes, A.
Solomos, S.
Komppula, M.
Giannakaki, E.
Kalogiros, J.
Banks, R.
Eleftheriadis, K.
Mantas, E.
Diapouli, E.
Tzanis, C.G.
Kazadzis, S.
Binietoglou, I.
Labzovskii, L.
Vande Hey, J.
Zerefos, C.S.
Περιοδικό:
The Science of the Total Environment
Λέξεις-κλειδιά:
Aerosols; Boundary layers; Chemical properties; Coastal zones; Drops; Gallium alloys; Optical radar; Shape memory effect; Supersaturation, Athens; Cloud development; Cloud droplet number; Doppler lidars; FLEXPART; Greece; HygrA-CD; Precipitation radar; Raman LIDAR; SMPS, Precipitation (meteorology), aerosol; aerosol formation; cloud condensation nucleus; cloud droplet; convective boundary layer; Doppler lidar; Doppler radar; hygroscopicity; physicochemical property; weather forecasting; wind velocity, aerosol; airflow; Article; biomass; cloud; concentration (parameters); environmental impact; experimental study; Greece; high temperature procedures; human activities; marine environment; particle size; physical chemistry; precipitation; priority journal; velocity; wind, Athens [Attica]; Attica; Greece
DOI:
10.1016/j.scitotenv.2016.09.054
