Eötvös-napi előadás

[Szommer Peter]

				M E G H Í V Ó

	az Eötvös Loránd Tudományegyetem Természettudományi Kara,
		az MTA Környezeti Kémiai Munkabizottsága és
			a Magyar Aeroszol Társaság



			    szakmai előadói ülésére
az ELTE tiszteletbeli doktor és professzor címének adományozása alkalmából, 
				    melyet


				MARKKU  KULMALA,
			a Helsinki Egyetem professzora tart

Atmospheric aerosolparticles: from molecular clustering to global climate
				    címmel.

Hely: Pázmány Péter sétány 1/A, földszint 0.81 (Ortvay terem)
Kezdési idő: 2012. május 10. 15 óra


Az előadás kivonata:

Atmospheric aerosol particles affect the quality of our life in many different 
ways. First of all, they influence the Earth's radiation balance directly by 
scattering and absorbing solar radiation, and indirectly by acting as cloud 
condensation nuclei (CCN). The interaction between atmospheric aerosols and 
climate system is the dominant uncertainty in predicting the radiative forcing 
and future climate. Secondly, aerosol particles deteriorate both human health 
and visibility in urban areas. The interactions between air quality and 
climate are largely unknown, although some links have been identified. Thirdly,
 aerosol particles modify the intensity and distribution of radiation that 
reaches the earth surface, having direct influences on the terrestrial carbon 
sink. Better understanding and quantifying of the above aerosol effects in 
the atmosphere requires detailed information on how different sources (such 
as atmospheric nucleation) and atmospheric transformation processes modify 
the properties of atmospheric particles and the concentrations of trace gases.

Formation and growth of aerosol particles have been observed all around the 
world, and its contribution to total aerosol concentration is dominating 
(50-90%) and to CCN production is significant (30-50%). The detailed 
understanding of the initial process requires knowledge on the concentrations 
of neutral and charged clusters, on their chemical composition and on the 
gas phase precursor data. We have shown that the atmospheric nucleation 
occurs in size around 1.5 nm (mobility diameter). Already in 2000, we 
predicted theoretically the existence of thermodynamically stable atmospheric 
clusters, and nowadays there is growing number of observations of sub 3 nm 
and even sub 2 nm clusters. Recently, we have been able to perform the size 
segregated measurements of concentration and dynamics of atmospheric clusters 
down to 0.9 nm.