Markku Kulmala talks with
ScienceWatch.com and answers a few questions about
this month's Fast Moving Front in the field of Environment
Article: Formation and growth rates of ultrafine
atmospheric particles: a review of
M;Vehkamaki, H;Petajda, T;Dal Maso,
M;Lauri, A;Kerminen, VM;Birmili, W;McMurry, PH
Journal: J AEROSOL SCI, 35 (2): 143-176 FEB 2004
Addresses: Univ Helsinki, Dept Phys Sci, Div Atmospher Sci,
POB 64,Gustaf Hallstrominkatu 2, FIN-00014 Helsinki,
Univ Helsinki, Dept Phys Sci, Div Atmospher Sci, FIN-00014
Finnish Meteorol Inst, FIN-00880 Helsinki, Finland.
(addresses have been truncated)
Why do you think
your paper is highly cited?
I believe that this paper is highly cited because it provides a first
comprehensive summary of observed atmospheric new particle
formation—the name given to the spontaneous formation of new
nanometer-sized particles in the atmosphere. It also gives explanations how
to obtain particle formation rates and growth rates from observations.
Does it describe a new discovery, methodology, or
synthesis of knowledge?
describes how and in which
nanoparticles are formed in the
It describes a synthesis of existing knowledge on new particle formation in
the atmosphere. The main discovery is that new particle formation is now a
Would you summarize the significance of your paper
in layman’s terms?
The paper describes how and in which conditions/environments new
nanoparticles are formed in the atmosphere. The main result is that
atmospheric nucleation is observed at various environmental conditions
practically all around the world. In other words, it is a global
How did you become involved in this research and
were any particular problems encountered along the way?
I began investigating atmospheric new particle formation in 1991. Before
that, I had studied nucleation (gas to liquid) theory.
In that time—the early 1990s—it was believed that atmospheric
nucleation was a rare phenomenon. In 1996, I started continuous
measurements to evaluate the dynamics of atmospheric aerosol particles. The
main result found so far is the formation of new aerosolparticles at nm
size and their subsequent growth to ca 80-100 nm in size.
During these studies we have also shown that new particle formation occurs
frequently. In our paper we were able to show that new particle formation
occurs all over the world. This conclusion is a new result.
Where do you see your research leading in the
Our main objective is to contribute to the reduction of scientific
uncertainties concerning global climate change issues, particularly those
related to aerosols and clouds. We aim at creating a deeper understanding
of the dynamics of aerosol particles and ion and neutral clusters in the
lower atmosphere, with the emphasis on biogenic formation mechanisms and
their linkage to biosphere-atmosphere interaction processes, biogeochemical
cycles, and trace gases. The relevance and usage of these results within
the context of global-scale modelling, and the development and utilization
of the newest measurement techniques are addressed.
Do you foresee any social or political
implications for your research?
As outlined above, the foreseen result as it pertains to the understanding
of global radiative balance and climate change is a crucial element in the
evolving political worldview of the environment.
Professor Markku Kulmala
Department of Physics
University of Helsinki