A. Laaksonen

Publication List Details

Period

1994 - 2009

Number

213

Co-Authors

Sensitivity of aerosol concentrations and cloud properties to nucleation and secondary organic distribution in ECHAM5-HAM global circulation model (2009)

Makkonen, R., Asmi, A., Korhonen, H., Kokkola, H., Järvenoja, S., Räisänen, P., ...

The global aerosol-climate model ECHAM5-HAM was modified to improve the representation of new particle formation in the boundary layer. Activation-type nucleation mechanism was introduced to produce...

Sensitivity of aerosol concentrations and cloud properties to nucleation and secondary organic distribution in ECHAM5-HAM global circulation model (2009)

R. Makkonen, A. Asmi, H. Korhonen, H. Kokkola, S. Järvenoja, P. Räisänen, ...

The global aerosol-climate model ECHAM5-HAM was modified to improve the representation of new particle formation in the boundary layer. Activation-type nucleation mechanism was introduced to produce...

New particle formation from the oxidation of direct emissions of pine seedlings (2009)

L. Q. Hao, P. Yli-Pirilä, P. Tiitta, S. Romakkaniemi, P. Vaattovaara, M. K. Kajos, ...

Measurements of particle formation following the gas phase oxidation of volatile organic compounds (VOCs) emitted by Scots pine (<i>Pinus sylvestris L.</i>) seedlings are reported....

Changes in the production rate of secondary aerosol particles in central Europe in view of decreasing SO2 emissions between 1996 and 2006 (2009)

A. Hamed, W. Birmili, J. Joutsensaari, S. Mikkonen, A. Asmi, B. Wehner, ...

In anthropogenically influenced atmospheres, sulphur dioxide (SO2) is the main precursor of gaseous sulphuric acid (H2SO4), which in turn forms new aerosol particles (diameter <10 nm) through...

Size-dependent activation of aerosols into cloud droplets at a subarctic background site during the second Pallas Cloud Experiment (2nd PaCE): method development and data evaluation (2009)

T. Anttila, P. Vaattovaara, M. Komppula, H. Lihavainen, ...

In situ measurements of aerosol water uptake and activation of aerosols into cloud droplets provide information on how aerosols influence the microphysical properties of clouds. Here we present a...

Changes in the production rate of secondary aerosol particles in central Europe in view of decreasing SO<sub>2</sub> emissions between 1996 and 2006 (2009)

A. Hamed, W. Birmili, J. Joutsensaari, S. Mikkonen, A. Asmi, B. Wehner, ...

In anthropogenically influenced atmospheres, sulphur dioxide (SO<sub>2</sub>) is the main precursor of gaseous sulphuric acid (H<sub>2</sub>SO<sub>4</sub>), which...

New particle formation from the oxidation of direct emissions of pine seedlings (2009)

L. Q. Hao, P. Yli-Pirilä, P. Tiitta, S. Romakkaniemi, P. Vaattovaara, M. K. Kajos, ...

Measurements of particle formation following the gas phase oxidation of volatile organic compounds (VOCs) emitted by Scots pine (<i>Pinus sylvestris</i> L.) seedlings are reported....

Results from the CERN pilot CLOUD experiment (2009)

J. Duplissy, M. B. Enghoff, K. L. Aplin, F. Arnold, H. Aufmhoff, M. Avngaard, ...

During a 4-week run in October–November 2006, a pilot experiment was performed at the CERN Proton Synchrotron in preparation for the CLOUD<sup>1</sup> experiment, whose aim is to study...

Physicochemical properties and origin of organic groups detected in boreal forest using an aerosol mass spectrometer (2009)

T. Raatikainen, P. Vaattovaara, P. Tiitta, P. Miettinen, J. Rautiainen, M. Ehn, ...

An Aerodyne quadrupole aerosol mass spectrometer (Q-AMS) was deployed in Hyytiälä, a forested rural measurement site in southern Finland, during a 2-week measurement campaign in spring 2005. Q-AMS...

Comment on "Using multiple observationally-based constraints to estimate climate sensitivity" by J. D. Annan and J. C. Hargreaves, Geophys. Res. Lett., 33, L06704, doi:10.1029/2005GL025259, 2006 (2009)

S. V. Henriksson, E. Arjas, M. Laine, J. Tamminen, A. Laaksonen

In their paper from 2006, Annan and Hargreaves present an estimate for the uncertainty of climate sensitivity obtained by using Bayes' theorem to combine information from different sources. In this...

Sensitivity of aerosol concentrations and cloud properties to nucleation and secondary organic distribution in ECHAM5-HAM global circulation model (2008)

Makkonen, R., Asmi, A., Korhonen, H., Kokkola, H., Järvenoja, S., Räisänen, P., ...

The global aerosol-climate model ECHAM5-HAM was modified to improve the representation of new particle formation in the boundary layer. Activation-type nucleation mechanism was introduced to produce...

SO2 oxidation products other than H2SO4 as a trigger of new particle formation ? Part 1: Laboratory investigations (2008)

Berndt, T., Stratmann, F., Bräsel, S., Heintzenberg, J., Laaksonen, A., Kulmala, M.

Mechanistic investigations of atmospheric H2SO4 particle formation have been performed in a laboratory study taking either H2SO4 from a liquid reservoir or using the gas-phase reaction of OH radicals...

SO2 oxidation products other than H2SO4 as a trigger of new particle formation ? Part 2: Comparison of ambient and laboratory measurements, and atmospheric implications (2008)

Laaksonen, A., Kulmala, M., Berndt, T., Stratmann, F., Mikkonen, S., Ruuskanen, A., ...

Atmospheric new particle formation is generally thought to occur due to homogeneous or ion-induced nucleation of sulphuric acid. We compare ambient nucleation rates with laboratory data from...

The role of VOC oxidation products in continental new particle formation (2008)

Laaksonen, A., Kulmala, M., O'Dowd, C. D., Joutsensaari, J., Vaattovaara, P., Mikkonen, S., ...

Aerosol physical and chemical properties and trace gas concentrations were measured during the QUEST field campaign in March?April 2003, in Hyytiälä, Finland. Our aim was to understand the role of...

SALSA ? a Sectional Aerosol module for Large Scale Applications (2008)

Kokkola, H., Korhonen, H., Lehtinen, K. E. J., Makkonen, R., Asmi, A., Järvenoja, S., ...

The sectional aerosol module SALSA is introduced. The model has been designed to be implemented in large scale climate models, which require both accuracy and computational efficiency. We have used...

Technical note: Analytical formulae for the critical supersaturations and droplet diameters of CCN containing insoluble material (2008)

Kokkola, H., Vesterinen, M., Anttila, T., Laaksonen, A., Lehtinen, K. E. J.

In this paper, we consider the cloud drop activation of aerosol particles consisting of water soluble material and an insoluble core. Based on the Köhler theory, we derive analytical equations for...

Sensitivity of aerosol concentrations and cloud properties to nucleation and secondary organic distribution in ECHAM5-HAM global circulation model (2008)

Makkonen, R., Asmi, A., Korhonen, H., Kokkola, H., Järvenoja, S., Räisänen, P., ...

The global aerosol-climate model ECHAM5-HAM was modified to improve the representation of new particle formation in the boundary layer. Activation-type nucleation mechanism was introduced to produce...

SO2 oxidation products other than H2SO4 as a trigger of new particle formation ? Part 1: Laboratory investigations (2008)

Berndt, T., Stratmann, F., Bräsel, S., Heintzenberg, J., Laaksonen, A., Kulmala, M.

Mechanistic investigations of atmospheric H2SO4 particle formation have been performed in a laboratory study taking either H2SO4 from a liquid reservoir or using the gas-phase reaction of OH radicals...

SO2 oxidation products other than H2SO4 as a trigger of new particle formation ? Part 2: Comparison of ambient and laboratory measurements, and atmospheric implications (2008)

Laaksonen, A., Kulmala, M., Berndt, T., Stratmann, F., Mikkonen, S., Ruuskanen, A., ...

Atmospheric new particle formation is generally thought to occur due to homogeneous or ion-induced nucleation of sulphuric acid. We compare ambient nucleation rates with laboratory data from...

The role of VOC oxidation products in continental new particle formation (2008)

Laaksonen, A., Kulmala, M., O'Dowd, C. D., Joutsensaari, J., Vaattovaara, P., Mikkonen, S., ...

Aerosol physical and chemical properties and trace gas concentrations were measured during the QUEST field campaign in March?April 2003, in Hyytiälä, Finland. Our aim was to understand the role of...

SALSA ? a Sectional Aerosol module for Large Scale Applications (2008)

Kokkola, H., Korhonen, H., Lehtinen, K. E. J., Makkonen, R., Asmi, A., Järvenoja, S., ...

The sectional aerosol module SALSA is introduced. The model has been designed to be implemented in large scale climate models, which require both accuracy and computational efficiency. We have used...

Technical note: Analytical formulae for the critical supersaturations and droplet diameters of CCN containing insoluble material (2008)

Kokkola, H., Vesterinen, M., Anttila, T., Laaksonen, A., Lehtinen, K. E. J.

In this paper, we consider the cloud drop activation of aerosol particles consisting of water soluble material and an insoluble core. Based on the Köhler theory, we derive analytical equations for...

Technical note: Analytical formulae for the critical supersaturations and droplet diameters of CCN containing insoluble material (2008)

H. Kokkola, M. Vesterinen, T. Anttila, A. Laaksonen

In this paper, we consider the cloud drop activation of aerosol particles consisting of water soluble material and an insoluble core. Based on the Köhler theory, we derive analytical equations for...

SALSA ─ a Sectional Aerosol module for Large Scale Applications (2008)

H. Kokkola, H. Korhonen, R. Makkonen, A. Asmi, S. Järvenoja, ...

The sectional aerosol module SALSA is introduced. The model has been designed to be implemented in large scale climate models, which require both accuracy and computational efficiency. We have used...

The role of VOC oxidation products in continental new particle formation (2008)

A. Laaksonen, M. Kulmala, C. D. O'Dowd, J. Joutsensaari, P. Vaattovaara, S. Mikkonen, ...

Aerosol physical and chemical properties and trace gas concentrations were measured during the QUEST field campaign in March–April 2003, in Hyytiälä, Finland. Our aim was to understand the...

SO<sub>2</sub> oxidation products other than H<sub>2</sub>SO<sub>4</sub> as a trigger of new particle formation. Part 1: Laboratory investigations (2008)

T. Berndt, F. Stratmann, S. Bräsel, J. Heintzenberg, A. Laaksonen, M. Kulmala

Mechanistic investigations of atmospheric H<sub>2</sub>SO<sub>4</sub> particle formation have been performed in a laboratory study taking either...

SO<sub>2</sub> oxidation products other than H<sub>2</sub>SO<sub>4</sub> as a trigger of new particle formation. Part 2: Comparison of ambient and laboratory measurements, and atmospheric implications (2008)

A. Laaksonen, M. Kulmala, T. Berndt, F. Stratmann, S. Mikkonen, A. Ruuskanen, ...

Atmospheric new particle formation is generally thought to occur due to homogeneous or ion-induced nucleation of sulphuric acid. We compare ambient nucleation rates with laboratory data from...

SO2 oxidation products other than H2SO4 as a trigger of new particle formation. Part 1: Laboratory investigations (2008)

T. Berndt, F. Stratmann, S. Bräsel, J. Heintzenberg, A. Laaksonen, M. Kulmala

Mechanistic investigations of atmospheric H2SO4 particle formation have been performed in a laboratory study taking either H2SO4 from a liquid reservoir or using the gas-phase reaction of OH radicals...

SO2 oxidation products other than H2SO4 as a trigger of new particle formation. Part 2: Comparison of ambient and laboratory measurements, and atmospheric implications (2008)

A. Laaksonen, M. Kulmala, T. Berndt, F. Stratmann, S. Mikkonen, A. Ruuskanen, ...

Atmospheric new particle formation is generally thought to occur due to homogeneous or ion-induced nucleation of sulphuric acid. We compare ambient nucleation rates with laboratory data from...

SO<sub>2</sub> oxidation products other than H<sub>2</sub>SO<sub>4</sub> as a trigger of new particle formation – Part 2: Comparison of ambient and laboratory measurements, and atmospheric implications (2008)

A. Laaksonen, M. Kulmala, T. Berndt, F. Stratmann, S. Mikkonen, A. Ruuskanen, ...

Atmospheric new particle formation is generally thought to occur due to homogeneous or ion-induced nucleation of sulphuric acid. We compare ambient nucleation rates with laboratory data from...

SO<sub>2</sub> oxidation products other than H<sub>2</sub>SO<sub>4</sub> as a trigger of new particle formation – Part 1: Laboratory investigations (2008)

T. Berndt, F. Stratmann, S. Bräsel, J. Heintzenberg, A. Laaksonen, M. Kulmala

Mechanistic investigations of atmospheric H<sub>2</sub>SO<sub>4</sub> particle formation have been performed in a laboratory study taking either...

Sensitivity of aerosol concentrations and cloud properties to nucleation and secondary organic distribution in ECHAM5-HAM global circulation model (2008)

R. Makkonen, A. Asmi, H. Korhonen, H. Kokkola, S. Järvenoja, P. Räisänen, ...

The global aerosol-climate model ECHAM5-HAM was modified to improve the representation of new particle formation in the boundary layer. Activation-type nucleation mechanism was introduced to produce...

Size-dependent activation of aerosols into cloud droplets at a subarctic background site during the second Pallas Cloud Experiment (2nd PaCE): method development and data evaluation (2008)

T. Anttila, P. Vaattovaara, M. Komppula, H. Lihavainen, ...

In situ measurements of aerosol water uptake and activation of aerosols into cloud droplets provide information on how aerosols influence the microphysical properties of clouds. Here we present a...

SO2 oxidation products other than H2SO4 as a trigger of new particle formation – Part 2: Comparison of ambient and laboratory measurements, and atmospheric implications (2008)

A. Laaksonen, M. Kulmala, T. Berndt, F. Stratmann, S. Mikkonen, A. Ruuskanen, ...

Atmospheric new particle formation is generally thought to occur due to homogeneous or ion-induced nucleation of sulphuric acid. We compare ambient nucleation rates with laboratory data from...

SO2 oxidation products other than H2SO4 as a trigger of new particle formation – Part 1: Laboratory investigations (2008)

T. Berndt, F. Stratmann, S. Bräsel, J. Heintzenberg, A. Laaksonen, M. Kulmala

Mechanistic investigations of atmospheric H2SO4 particle formation have been performed in a laboratory study taking either H2SO4 from a liquid reservoir or using the gas-phase reaction of OH radicals...

Solvation Free Energies of Methane and Alkali Halide Ions. An Expanded Ensemble Molecular Dynamics Simulation Study (2007)

A.P. Lyubartsev, O.K. Førrisdahl, A. Laaksonen

Solvation free energy for methane, dissolved both in pure water, water/methane mixture (14 mole % methane) and in aqueous NaCl solution, is calculated using the expanded ensemble molecular dynamics...

Hygroscopic properties of ultrafine aerosol particles in the boreal forest: diurnal variation, solubility and the influence of sulfuric acid (2007)

M. Ehn, T. Petäjä, H. Aufmhoff, P. Aalto, K. Hämeri, F. Arnold, ...

The hygroscopic growth of aerosol particles present in a boreal forest was measured at a relative humidity of 88%. Simultaneously the gas phase concentration of sulfuric acid, a very hygroscopic...

Hygroscopic properties of ultrafine aerosol particles in the boreal forest: diurnal variation, solubility and the influence of sulfuric acid (2007)

Ehn, Mikael, Petäjä, T., Aufmhoff, Heinfried, Aalto, Pasi, Hämeri, K., Arnold, Frank, ...

The hygroscopic growth of aerosol particles present in a boreal forest was measured at a relative humidity of 88%. Simultaneously the gas phase concentration of sulfuric acid, a very hygroscopic...

Nucleation and growth of new particles in Po Valley, Italy (2007)

A. Hamed, J. Joutsensaari, S. Mikkonen, L. Sogacheva, M. Dal Maso, M. Kulmala, ...

Aerosol number distribution measurements are reported at San Pietro Capofiume (SPC) station (44°39' N, 11°37' E) for the time period 2002–2005. The station is located in Po...

Connections between atmospheric sulphuric acid and new particle formation during QUEST III–IV campaigns in Heidelberg and Hyytiälä (2007)

Riipinen, I., Kulmala, M., Arnold, Frank, Dal Maso, M., Birmili, W., ...

This study investigates the connections between atmospheric sulphuric acid and new particle formation during QUEST III and BACCI/QUEST IV campaigns. The campaigns have been conducted in Heidelberg...

Relation of air mass history to nucleation events in Po Valley, Italy, using back trajectories analysis (2007)

L. Sogacheva, A. Hamed, M. C. Facchini, M. Kulmala, A. Laaksonen

In this paper, we study the transport of air masses to San Pietro Capofiume (SPC) in Po Valley, Italy, by means of back trajectories analysis. Our main aim is to investigate whether air masses...

Connections between atmospheric sulphuric acid and new particle formation during QUEST III–IV campaigns in Heidelberg and Hyytiälä (2007)

I. Riipinen, M. Kulmala, F. Arnold, M. Dal Maso, W. Birmili, ...

This study investigates the connections between atmospheric sulphuric acid and new particle formation during QUEST III and BACCI/QUEST IV campaigns. The campaigns have been conducted in Heidelberg...

Technical Note: Analytical formulae for the critical supersaturations and droplet diameters of CCN containing insoluble material (2007)

Kokkola, H., Vesterinen, M., Anttila, T., Laaksonen, A., Lehtinen, K. E. J.

In this paper, we consider the cloud drop activation of aerosol particles consisting of water soluble material and an insoluble core. Based on the Köhler theory, we derive analytical equations for...

SALSA ? a Sectional Aerosol module for Large Scale Applications (2007)

Kokkola, H., Korhonen, H., Lehtinen, K. E. J., Makkonen, R., Asmi, A., Järvenoja, S., ...

The sectional aerosol module SALSA is introduced. The model has been designed to be implemented in large scale climate models, which require both accuracy and computational efficiency. We have used...

The effect of H2O adsorption on cloud-drop activation of insoluble particles: a theoretical framework (2007)

Sorjamaa, R., Laaksonen, A.

Cloud droplet activation of wettable insoluble compounds has been studied theoretically by assuming droplet growth to happen through multilayer adsorption. The idea is to include an adsorption...

The role of VOC oxidation products in continental new particle formation (2007)

Laaksonen, A., Kulmala, M., O'Dowd, C. D., Joutsensaari, J., Vaattovaara, P., Mikkonen, S., ...

Aerosol physical and chemical properties and trace gas concentrations were measured during the QUEST field campaign in March?April, 2003, in Hyytiälä, Finland. Our aim was to understand the role of...

The effect of H2O adsorption on cloud drop activation of insoluble particles: a theoretical framework (2007)

Sorjamaa, R., Laaksonen, A.

Cloud droplet activation of wettable insoluble compounds has been studied theoretically by assuming that droplet growth happens through multilayer adsorption. The idea is to include an adsorption...

Connections between atmospheric sulphuric acid and new particle formation during QUEST III?IV campaigns in Heidelberg and Hyytiälä (2007)

Riipinen, I., Kulmala, M., Arnold, F., Dal Maso, M., Birmili, W., ...

This study investigates the connections between atmospheric sulphuric acid and new particle formation during QUEST III and BACCI/QUEST IV campaigns. The campaigns have been conducted in Heidelberg...

Relation of air mass history to nucleation events in Po Valley, Italy, using back trajectories analysis (2007)

Sogacheva, L., Hamed, A., Facchini, M. C., Kulmala, M., Laaksonen, A.

In this paper, we study the transport of air masses to San Pietro Capofiume (SPC) in Po Valley, Italy, by means of back trajectories analysis. Our main aim is to investigate whether air masses...

Nucleation and growth of new particles in Po Valley, Italy (2007)

Hamed, A., Joutsensaari, J., Mikkonen, S., Sogacheva, L., Dal Maso, M., Kulmala, M., ...

Aerosol number distribution measurements are reported at San Pietro Capofiume (SPC) station (44°39' N, 11°37' E) for the time period 2002?2005. The station is located in Po Valley, the largest...

Hygroscopic properties of ultrafine aerosol particles in the boreal forest: diurnal variation, solubility and the influence of sulfuric acid (2007)

Ehn, M., Petäjä, T., Aufmhoff, H., Aalto, P., Hämeri, K., Arnold, F., ...

The hygroscopic growth of aerosol particles present in a boreal forest was measured at a relative humidity of 88%. Simultaneously the gas phase concentration of sulfuric acid, a very hygroscopic...

Technical Note: Analytical formulae for the critical supersaturations and droplet diameters of CCN containing insoluble material (2007)

Kokkola, H., Vesterinen, M., Anttila, T., Laaksonen, A., Lehtinen, K. E. J.

In this paper, we consider the cloud drop activation of aerosol particles consisting of water soluble material and an insoluble core. Based on the Köhler theory, we derive analytical equations for...

SALSA ? a Sectional Aerosol module for Large Scale Applications (2007)

Kokkola, H., Korhonen, H., Lehtinen, K. E. J., Makkonen, R., Asmi, A., Järvenoja, S., ...

The sectional aerosol module SALSA is introduced. The model has been designed to be implemented in large scale climate models, which require both accuracy and computational efficiency. We have used...

The effect of H2O adsorption on cloud-drop activation of insoluble particles: a theoretical framework (2007)

Sorjamaa, R., Laaksonen, A.

Cloud droplet activation of wettable insoluble compounds has been studied theoretically by assuming droplet growth to happen through multilayer adsorption. The idea is to include an adsorption...

The role of VOC oxidation products in continental new particle formation (2007)

Laaksonen, A., Kulmala, M., O'Dowd, C. D., Joutsensaari, J., Vaattovaara, P., Mikkonen, S., ...

Aerosol physical and chemical properties and trace gas concentrations were measured during the QUEST field campaign in March?April, 2003, in Hyytiälä, Finland. Our aim was to understand the role of...

The effect of H2O adsorption on cloud drop activation of insoluble particles: a theoretical framework (2007)

Sorjamaa, R., Laaksonen, A.

Cloud droplet activation of wettable insoluble compounds has been studied theoretically by assuming that droplet growth happens through multilayer adsorption. The idea is to include an adsorption...

Connections between atmospheric sulphuric acid and new particle formation during QUEST III?IV campaigns in Heidelberg and Hyytiälä (2007)

Riipinen, I., Kulmala, M., Arnold, F., Dal Maso, M., Birmili, W., ...

This study investigates the connections between atmospheric sulphuric acid and new particle formation during QUEST III and BACCI/QUEST IV campaigns. The campaigns have been conducted in Heidelberg...

Relation of air mass history to nucleation events in Po Valley, Italy, using back trajectories analysis (2007)

Sogacheva, L., Hamed, A., Facchini, M. C., Kulmala, M., Laaksonen, A.

In this paper, we study the transport of air masses to San Pietro Capofiume (SPC) in Po Valley, Italy, by means of back trajectories analysis. Our main aim is to investigate whether air masses...

Nucleation and growth of new particles in Po Valley, Italy (2007)

Hamed, A., Joutsensaari, J., Mikkonen, S., Sogacheva, L., Dal Maso, M., Kulmala, M., ...

Aerosol number distribution measurements are reported at San Pietro Capofiume (SPC) station (44°39' N, 11°37' E) for the time period 2002?2005. The station is located in Po Valley, the largest...

Hygroscopic properties of ultrafine aerosol particles in the boreal forest: diurnal variation, solubility and the influence of sulfuric acid (2007)

Ehn, M., Petäjä, T., Aufmhoff, H., Aalto, P., Hämeri, K., Arnold, F., ...

The hygroscopic growth of aerosol particles present in a boreal forest was measured at a relative humidity of 88%. Simultaneously the gas phase concentration of sulfuric acid, a very hygroscopic...

The effect of H2O adsorption on cloud drop activation of insoluble particles: a theoretical framework (2007)

R. Sorjamaa, A. Laaksonen

Cloud droplet activation of wettable insoluble compounds has been studied theoretically by assuming that droplet growth happens through multilayer adsorption. The idea is to include an adsorption...

The role of VOC oxidation products in continental new particle formation (2007)

A. Laaksonen, M. Kulmala, C. D. O'Dowd, J. Joutsensaari, P. Vaattovaara, S. Mikkonen, ...

Aerosol physical and chemical properties and trace gas concentrations were measured during the QUEST field campaign in March–April, 2003, in Hyytiälä, Finland. Our aim was to understand the...

The effect of H2O adsorption on cloud-drop activation of insoluble particles: a theoretical framework (2007)

R. Sorjamaa, A. Laaksonen

Cloud droplet activation of wettable insoluble compounds has been studied theoretically by assuming droplet growth to happen through multilayer adsorption. The idea is to include an adsorption...

SALSA – a Sectional Aerosol module for Large Scale Applications (2007)

H. Kokkola, H. Korhonen, R. Makkonen, A. Asmi, S. Järvenoja, ...

The sectional aerosol module SALSA is introduced. The model has been designed to be implemented in large scale climate models, which require both accuracy and computational efficiency. We have used...

Technical Note: Analytical formulae for the critical supersaturations and droplet diameters of CCN containing insoluble material (2007)

H. Kokkola, M. Vesterinen, T. Anttila, A. Laaksonen

In this paper, we consider the cloud drop activation of aerosol particles consisting of water soluble material and an insoluble core. Based on the Köhler theory, we derive analytical equations for...

The influence of nitric acid on the cloud processing of aerosol particles (2006)

S. Romakkaniemi, H. Kokkola, A. Laaksonen

In this paper we present simulations of the effect of nitric acid (HNO3) on cloud processing of aerosol particles. Sulfuric acid (H2SO4) production and incloud coagulation are both affected by...

Size and composition measurements of background aerosol and new particle growth in a Finnish forest during QUEST 2 using an Aerodyne Aerosol Mass Spectrometer (2006)

J. D. Allan, M. R. Alfarra, K. N. Bower, H. Coe, J. T. Jayne, D. R. Worsnop, ...

The study of the growth of nucleation-mode particles is important, as this prevents their loss through diffusion and allows them to reach sizes where they may become effective cloud condensation...

Cluster activation theory as an explanation of the linear dependence between formation rate of 3nm particles and sulphuric acid concentration (2006)

M. Kulmala, A. Laaksonen

According to atmospheric observations new particle formation seems to be a function of sulphuric acid concentration to the power from one to two. The nucleation theorem then predicts that the...

The effect of physical and chemical aerosol properties on warm cloud droplet activation (2006)

G. McFiggans, P. Artaxo, U. Baltensperger, H. Coe, M. C. Facchini, G. Feingold, ...

The effects of atmospheric aerosol on climate forcing may be very substantial but are quantified poorly at present; in particular, the effects of aerosols on cloud radiative properties, or the...

Atmospheric sulphuric acid and aerosol formation: implications from atmospheric measurements for nucleation and early growth mechanisms (2006)

M. Kulmala, M. Dal Maso, T. Petäjä, I. Riipinen, ...

We have investigated the formation and early growth of atmospheric secondary aerosol particles building on atmospheric measurements. The measurements were part of the QUEST 2 campaign which took...

The composition of nucleation and Aitken modes particles during coastal nucleation events: evidence for marine secondary organic contribution (2006)

P. Vaattovaara, P. E. Huttunen, Y. J. Yoon, J. Joutsensaari, C. D. O'Dowd, ...

Newly-formed nanometer-sized particles have been observed at coastal and marine environments world wide. Organic species have so far not been detected in those newly-formed nucleation mode particles....

Using discriminant analysis as a nucleation event classification method (2006)

S. Mikkonen, A. Hamed, J. Joutsensaari, M. C. Facchini, A. Laaksonen

More than three years of measurements of aerosol size-distribution and different gas and meteorological parameters made in Po Valley, Italy were analysed for this study to examine which of the...

Atmospheric sulfuric acid and aerosol formation: implications from atmospheric measurements for nucleation and early growth mechanisms. (2006)

Sihto, L.H., Kulmala, M., Kerminen, V.M., Dal Maso, M., Petäjä, T., Riipinen, I., ...

We have investigated the formation and early growth of atmospheric secondary aerosol particles building on atmospheric measurements. The measurements were part of the QUEST 2 campaign which took...

Relation of air mass history to nucleation events in Po Valley, Italy, using back trajectories analysis (2006)

Sogacheva, L., Hamed, A., Facchini, M. C., Kulmala, M., Laaksonen, A.

In this paper, we study the transport of air mass to San Pietro Capofiume (SPC) in Po Valley, Italy, by means of back trajectory analysis. Our main aim is to investigate whether air masses originate...

Connections between atmospheric sulphuric acid and new particle formation during QUEST III?IV campaigns in Heidelberg and Hyytiälä (2006)

Riipinen, I., Kulmala, M., Arnold, F., Dal Maso, M., Birmili, W., ...

This study investigates the connections between atmospheric sulphuric acid and new particle formation during QUEST III and BACCI/QUEST IV campaigns. The campaigns have been conducted in Heidelberg...

Hygroscopic properties of ultrafine aerosol particles in the boreal forest: diurnal variation, solubility and the influence of sulfuric acid (2006)

Ehn, M., Petäjä, T., Aufmhoff, H., Aalto, P., Hämeri, K., Arnold, F., ...

Freshly formed atmospheric aerosol particles are neither large enough to efficiently scatter incoming solar radiation nor able to act as cloud condensation nuclei. As the particles grow larger, their...

Nucleation and growth of new particles in Po Valley, Italy (2006)

Hamed, A., Joutsensaari, J., Mikkonen, S., Sogacheva, L., Dal Maso, M., Kulmala, M., ...

Aerosol number distribution measurements are reported at San Pietro Capofiume (SPC) station (44°39' N, 11°37' E) for the time period 2002?2005. The station is located in Po Valley, the largest...

Using discriminant analysis as a nucleation event classification method (2006)

Mikkonen, S., Lehtinen, K. E. J., Hamed, A., Joutsensaari, J., Facchini, M. C., Laaksonen, A.

More than three years of measurements of aerosol size-distribution and different gas and meteorological parameters made in Po Valley, Italy were analysed for this study to examine which of the...

Atmospheric sulphuric acid and aerosol formation: implications from atmospheric measurements for nucleation and early growth mechanisms (2006)

Kulmala, M., Dal Maso, M., Petäjä, T., Riipinen, I., ...

We have investigated the formation and early growth of atmospheric secondary aerosol particles building on atmospheric measurements. The measurements were part of the QUEST 2 campaign which took...

The composition of nucleation and Aitken modes particles during coastal nucleation events: evidence for marine secondary organic contribution (2006)

Vaattovaara, P., Huttunen, P. E., Yoon, Y. J., Joutsensaari, J., Lehtinen, K. E. J., O'Dowd, C. D., ...

Newly-formed nanometer-sized particles have been observed at coastal and marine environments worldwide. Interestingly, organic species have so far not been detected in those newly-formed nucleation...

On the hygroscopic growth of ammoniated sulfate particles of non-stoichiometric composition (2006)

Kokkola, H., Joutsensaari, J., Hyppönen, N., Lehtinen, K. E. J., Laaksonen, A.

The hygroscopic growth of ammoniated sulfate particles was studied by measurements and model calculations for particles with varying ammonium-to-sulfate ratio. In the measurements, the...

Using discriminant analysis as a nucleation event classification method (2006)

Mikkonen, S., Lehtinen, K. E. J., Hamed, A., Joutsensaari, J., Facchini, M. C., Laaksonen, A.

More than three years of measurements of aerosol size-distribution and different gas and meteorological parameters made in Po Valley, Italy were analysed for this study to examine which of the...

The composition of nucleation and Aitken modes particles during coastal nucleation events: evidence for marine secondary organic contribution (2006)

Vaattovaara, P., Huttunen, P. E., Yoon, Y. J., Joutsensaari, J., Lehtinen, K. E. J., O'Dowd, C. D., ...

Newly-formed nanometer-sized particles have been observed at coastal and marine environments world wide. Organic species have so far not been detected in those newly-formed nucleation mode particles....

Atmospheric sulphuric acid and aerosol formation: implications from atmospheric measurements for nucleation and early growth mechanisms (2006)

Kulmala, M., Dal Maso, M., Petäjä, T., Riipinen, I., ...

We have investigated the formation and early growth of atmospheric secondary aerosol particles building on atmospheric measurements. The measurements were part of the QUEST 2 campaign which took...

The effect of physical and chemical aerosol properties on warm cloud droplet activation (2006)

Mcfiggans, G., Artaxo, P., Baltensperger, U., Coe, H., Facchini, M. C., Feingold, G., ...

The effects of atmospheric aerosol on climate forcing may be very substantial but are quantified poorly at present; in particular, the effects of aerosols on cloud radiative properties, or the...

The influence of nitric acid on the cloud processing of aerosol particles (2006)

Romakkaniemi, S., Kokkola, H., Lehtinen, K. E. J., Laaksonen, A.

In this paper we present simulations of the effect of nitric acid (HNO3) on cloud processing of aerosol particles. Sulfuric acid (H2SO4) production and incloud coagulation are both affected by...

Cluster activation theory as an explanation of the linear dependence between formation rate of 3nm particles and sulphuric acid concentration (2006)

Kulmala, M., Lehtinen, K. E. J., Laaksonen, A.

According to atmospheric observations new particle formation seems to be a function of sulphuric acid concentration to the power from one to two. The nucleation theorem then predicts that the...

Size and composition measurements of background aerosol and new particle growth in a Finnish forest during QUEST 2 using an Aerodyne Aerosol Mass Spectrometer (2006)

Allan, J. D., Alfarra, M. R., Bower, K. N., Coe, H., Jayne, J. T., Worsnop, D. R., ...

The study of the growth of nucleation-mode particles is important, as this prevents their loss through diffusion and allows them to reach sizes where they may become effective cloud condensation...

Relation of air mass history to nucleation events in Po Valley, Italy, using back trajectories analysis (2006)

Sogacheva, L., Hamed, A., Facchini, M. C., Kulmala, M., Laaksonen, A.

In this paper, we study the transport of air mass to San Pietro Capofiume (SPC) in Po Valley, Italy, by means of back trajectory analysis. Our main aim is to investigate whether air masses originate...

Connections between atmospheric sulphuric acid and new particle formation during QUEST III?IV campaigns in Heidelberg and Hyytiälä (2006)

Riipinen, I., Kulmala, M., Arnold, F., Dal Maso, M., Birmili, W., ...

This study investigates the connections between atmospheric sulphuric acid and new particle formation during QUEST III and BACCI/QUEST IV campaigns. The campaigns have been conducted in Heidelberg...

Hygroscopic properties of ultrafine aerosol particles in the boreal forest: diurnal variation, solubility and the influence of sulfuric acid (2006)

Ehn, M., Petäjä, T., Aufmhoff, H., Aalto, P., Hämeri, K., Arnold, F., ...

Freshly formed atmospheric aerosol particles are neither large enough to efficiently scatter incoming solar radiation nor able to act as cloud condensation nuclei. As the particles grow larger, their...

Nucleation and growth of new particles in Po Valley, Italy (2006)

Hamed, A., Joutsensaari, J., Mikkonen, S., Sogacheva, L., Dal Maso, M., Kulmala, M., ...

Aerosol number distribution measurements are reported at San Pietro Capofiume (SPC) station (44°39' N, 11°37' E) for the time period 2002?2005. The station is located in Po Valley, the largest...

Using discriminant analysis as a nucleation event classification method (2006)

Mikkonen, S., Lehtinen, K. E. J., Hamed, A., Joutsensaari, J., Facchini, M. C., Laaksonen, A.

More than three years of measurements of aerosol size-distribution and different gas and meteorological parameters made in Po Valley, Italy were analysed for this study to examine which of the...

Atmospheric sulphuric acid and aerosol formation: implications from atmospheric measurements for nucleation and early growth mechanisms (2006)

Kulmala, M., Dal Maso, M., Petäjä, T., Riipinen, I., ...

We have investigated the formation and early growth of atmospheric secondary aerosol particles building on atmospheric measurements. The measurements were part of the QUEST 2 campaign which took...

The composition of nucleation and Aitken modes particles during coastal nucleation events: evidence for marine secondary organic contribution (2006)

Vaattovaara, P., Huttunen, P. E., Yoon, Y. J., Joutsensaari, J., Lehtinen, K. E. J., O'Dowd, C. D., ...

Newly-formed nanometer-sized particles have been observed at coastal and marine environments worldwide. Interestingly, organic species have so far not been detected in those newly-formed nucleation...

On the hygroscopic growth of ammoniated sulfate particles of non-stoichiometric composition (2006)

Kokkola, H., Joutsensaari, J., Hyppönen, N., Lehtinen, K. E. J., Laaksonen, A.

The hygroscopic growth of ammoniated sulfate particles was studied by measurements and model calculations for particles with varying ammonium-to-sulfate ratio. In the measurements, the...

Using discriminant analysis as a nucleation event classification method (2006)

Mikkonen, S., Lehtinen, K. E. J., Hamed, A., Joutsensaari, J., Facchini, M. C., Laaksonen, A.

More than three years of measurements of aerosol size-distribution and different gas and meteorological parameters made in Po Valley, Italy were analysed for this study to examine which of the...

The composition of nucleation and Aitken modes particles during coastal nucleation events: evidence for marine secondary organic contribution (2006)

Vaattovaara, P., Huttunen, P. E., Yoon, Y. J., Joutsensaari, J., Lehtinen, K. E. J., O'Dowd, C. D., ...

Newly-formed nanometer-sized particles have been observed at coastal and marine environments world wide. Organic species have so far not been detected in those newly-formed nucleation mode particles....

Atmospheric sulphuric acid and aerosol formation: implications from atmospheric measurements for nucleation and early growth mechanisms (2006)

Kulmala, M., Dal Maso, M., Petäjä, T., Riipinen, I., ...

We have investigated the formation and early growth of atmospheric secondary aerosol particles building on atmospheric measurements. The measurements were part of the QUEST 2 campaign which took...

The effect of physical and chemical aerosol properties on warm cloud droplet activation (2006)

Mcfiggans, G., Artaxo, P., Baltensperger, U., Coe, H., Facchini, M. C., Feingold, G., ...

The effects of atmospheric aerosol on climate forcing may be very substantial but are quantified poorly at present; in particular, the effects of aerosols on cloud radiative properties, or the...

The influence of nitric acid on the cloud processing of aerosol particles (2006)

Romakkaniemi, S., Kokkola, H., Lehtinen, K. E. J., Laaksonen, A.

In this paper we present simulations of the effect of nitric acid (HNO3) on cloud processing of aerosol particles. Sulfuric acid (H2SO4) production and incloud coagulation are both affected by...

Cluster activation theory as an explanation of the linear dependence between formation rate of 3nm particles and sulphuric acid concentration (2006)

Kulmala, M., Lehtinen, K. E. J., Laaksonen, A.

According to atmospheric observations new particle formation seems to be a function of sulphuric acid concentration to the power from one to two. The nucleation theorem then predicts that the...

Size and composition measurements of background aerosol and new particle growth in a Finnish forest during QUEST 2 using an Aerodyne Aerosol Mass Spectrometer (2006)

Allan, J. D., Alfarra, M. R., Bower, K. N., Coe, H., Jayne, J. T., Worsnop, D. R., ...

The study of the growth of nucleation-mode particles is important, as this prevents their loss through diffusion and allows them to reach sizes where they may become effective cloud condensation...

On the hygroscopic growth of ammoniated sulfate particles of non-stoichiometric composition (2006)

H. Kokkola, J. Joutsensaari, N. Hyppönen, A. Laaksonen

The hygroscopic growth of ammoniated sulfate particles was studied by measurements and model calculations for particles with varying ammonium-to-sulfate ratio. In the measurements, the...

Atmospheric sulphuric acid and aerosol formation: implications from atmospheric measurements for nucleation and early growth mechanisms (2006)

M. Kulmala, M. Dal Maso, T. Petäjä, I. Riipinen, ...

We have investigated the formation and early growth of atmospheric secondary aerosol particles building on atmospheric measurements. The measurements were part of the QUEST 2 campaign which took...

Relation of air mass history to nucleation events in Po Valley, Italy, using back trajectories analysis (2006)

L. Sogacheva, A. Hamed, M. C. Facchini, M. Kulmala, A. Laaksonen

In this paper, we study the transport of air mass to San Pietro Capofiume (SPC) in Po Valley, Italy, by means of back trajectory analysis. Our main aim is to investigate whether air masses originate...

Nanoparticle formation by ozonolysis of inducible plant volatiles (2005)

J. Joutsensaari, M. Loivamäki, T. Vuorinen, P. Miettinen, J. K. Holopainen, ...

We present the first laboratory experiments of aerosol formation from oxidation of volatile organic species emitted by living plants, a process which for half a century has been known to take place...

Application of several activity coefficient models to water-organic-electrolyte aerosols of atmospheric interest (2005)

T. Raatikainen, A. Laaksonen

In this work, existing and modified activity coefficient models are examined in order to assess their capabilities to describe the properties of aqueous solution droplets relevant in the atmosphere....

A method for detecting the presence of organic fraction in nucleation mode sized particles (2005)

P. Vaattovaara, M. Räsänen, T. Kühn, J. Joutsensaari, A. Laaksonen

New particle formation and growth has a very important role in many climate processes. However, the overall knowlegde of the chemical composition of atmospheric nucleation mode (particle diameter, d

Commentary on cloud modelling and the mass accommodation coefficient of water (2005)

A. Laaksonen, T. Vesala, M. Kulmala, P. M. Winkler, P. E. Wagner

The mass accommodation coefficient of water is a quantity for which different experimental techniques have yielded conflicting values in the range 0.04-1. From the viewpoint of cloud modelling, this...

Effects of SO2 oxidation on ambient aerosol growth in water and ethanol vapours (2005)

T. Petäjä, K. Hämeri, P. Vaattovaara, J. Joutsensaari, W. Junkermann, ...

Hygroscopicity (i.e. water vapour affinity) of atmospheric aerosol particles is one of the key factors in defining their impacts on climate. Condensation of sulphuric acid onto less hygroscopic...

Parameterization of the nitric acid effect on CCN activation (2005)

S. Romakkaniemi, H. Kokkola, A. Laaksonen

In this paper we present a parameterization of the nitric acid effect on cloud droplet formation. The new parameterization is intended to be used in large scale models in order to obtain regional and...

Why formation rate of 3 nm particles depends linearly on sulphuric acid concentration? (2005)

Kulmala, M., Lehtinen, K. E. J., Laaksonen, A.

According to atmospheric observations new particle formation seems to be a function of sulphuric acid concentration to the power from one to two. The nucleation theorem then predicts that the...

The influence of nitric acid on the cloud processing of aerosol particles (2005)

Romakkaniemi, S., Kokkola, H., Lehtinen, K. E. J., Laaksonen, A.

In this paper we present simulations of the effect of nitric acid (HNO3) on cloud processing of aerosol particles. Sulfuric acid (H2SO4) production and incloud coagulation are both affected by...

Size and composition measurements of background aerosol and new particle growth in a Finnish forest during QUEST 2 using an Aerodyne Aerosol Mass Spectrometer (2005)

Allan, J. D., Alfarra, M. R., Bower, K. N., Coe, H., Jayne, J. T., Worsnop, D. R., ...

The study of the growth of nucleation-mode particles is important, as this prevents their loss through diffusion and allows them to reach sizes where they may become effective cloud condensation...

The effect of physical and chemical aerosol properties on warm cloud droplet activation (2005)

Mcfiggans, G., Artaxo, P., Baltensperger, U., Coe, H., Facchini, M. C., Feingold, G., ...

The effects of atmospheric aerosol on climate forcing may be very substantial but are quantified poorly at present; in particular, the effects of aerosols on cloud radiative properties, or the...

Application of several activity coefficient models to water-organic-electrolyte aerosols of atmospheric interest (2005)

Raatikainen, T., Laaksonen, A.

In this work, existing and modified activity coefficient models are examined in order to assess their capabilities to describe the properties of aqueous solution droplets relevant in the atmosphere....

A method for detecting the presence of organic fraction in nucleation mode sized particles (2005)

Vaattovaara, P., Räsänen, M., Kühn, T., Joutsensaari, J., Laaksonen, A.

New particle formation and growth has a very important role in many climate processes. However, the overall knowlegde of the chemical composition of atmospheric nucleation mode (particle diameter, d

Nanoparticle formation by ozonolysis of inducible plant volatiles (2005)

Joutsensaari, J., Loivamäki, M., Vuorinen, T., Miettinen, P., Holopainen, J. K., ...

We present the first laboratory experiments of aerosol formation from oxidation of volatile organic species emitted by living plants, a process which for half a century has been known to take place...

A method for detecting the presence of organic fraction in nucleation mode sized particles (2005)

Vaattovaara, P., Räsänen, M., Kühn, T., Joutsensaari, J., Laaksonen, A.

New particle formation and growth has a very important role in many climate processes. However, the overall knowlegde of the chemical composition of atmospheric nucleation mode (particle diameter, d

Application of several activity coefficient models to water-organic-electrolyte aerosols of atmospheric interest (2005)

Raatikainen, T., Laaksonen, A.

In this work, existing and modified activity coefficient models are examined in order to assess their capabilities to describe the properties of aqueous solution droplets relevant in the atmosphere....

Nanoparticle formation by ozonolysis of inducible plant volatiles (2005)

Joutsensaari, J., Loivamäki, M., Vuorinen, T., Miettinen, P., Holopainen, J. K., ...

We present the first laboratory experiments of aerosol formation from oxidation of volatile organic species emitted by living plants, a process which for half a century has been known to take place...

Parameterization of the nitric acid effect on CCN activation (2005)

Romakkaniemi, S., Kokkola, H., Laaksonen, A.

In this paper we present a parameterization of the nitric acid effect on cloud droplet formation. The new parameterization is intended to be used in large scale models in order to obtain regional and...

Effects of SO2 oxidation on ambient aerosol growth in water and ethanol vapours (2005)

Petäjä, T., Hämeri, K., Vaattovaara, P., Joutsensaari, J., Junkermann, W., ...

Hygroscopicity (i.e. water vapour affinity) of atmospheric aerosol particles is one of the key factors in defining their impacts on climate. Condensation of sulphuric acid onto less hygroscopic...

Commentary on cloud modelling and the mass accommodation coefficient of water (2005)

Laaksonen, A., Vesala, T., Kulmala, M., Winkler, P. M., Wagner, P. E.

The mass accommodation coefficient of water is a quantity for which different experimental techniques have yielded conflicting values in the range 0.04-1. From the viewpoint of cloud modelling, this...

Why formation rate of 3 nm particles depends linearly on sulphuric acid concentration? (2005)

Kulmala, M., Lehtinen, K. E. J., Laaksonen, A.

According to atmospheric observations new particle formation seems to be a function of sulphuric acid concentration to the power from one to two. The nucleation theorem then predicts that the...

The influence of nitric acid on the cloud processing of aerosol particles (2005)

Romakkaniemi, S., Kokkola, H., Lehtinen, K. E. J., Laaksonen, A.

In this paper we present simulations of the effect of nitric acid (HNO3) on cloud processing of aerosol particles. Sulfuric acid (H2SO4) production and incloud coagulation are both affected by...

Size and composition measurements of background aerosol and new particle growth in a Finnish forest during QUEST 2 using an Aerodyne Aerosol Mass Spectrometer (2005)

Allan, J. D., Alfarra, M. R., Bower, K. N., Coe, H., Jayne, J. T., Worsnop, D. R., ...

The study of the growth of nucleation-mode particles is important, as this prevents their loss through diffusion and allows them to reach sizes where they may become effective cloud condensation...

The effect of physical and chemical aerosol properties on warm cloud droplet activation (2005)

Mcfiggans, G., Artaxo, P., Baltensperger, U., Coe, H., Facchini, M. C., Feingold, G., ...

The effects of atmospheric aerosol on climate forcing may be very substantial but are quantified poorly at present; in particular, the effects of aerosols on cloud radiative properties, or the...

Application of several activity coefficient models to water-organic-electrolyte aerosols of atmospheric interest (2005)

Raatikainen, T., Laaksonen, A.

In this work, existing and modified activity coefficient models are examined in order to assess their capabilities to describe the properties of aqueous solution droplets relevant in the atmosphere....

A method for detecting the presence of organic fraction in nucleation mode sized particles (2005)

Vaattovaara, P., Räsänen, M., Kühn, T., Joutsensaari, J., Laaksonen, A.

New particle formation and growth has a very important role in many climate processes. However, the overall knowlegde of the chemical composition of atmospheric nucleation mode (particle diameter, d

Nanoparticle formation by ozonolysis of inducible plant volatiles (2005)

Joutsensaari, J., Loivamäki, M., Vuorinen, T., Miettinen, P., Holopainen, J. K., ...

We present the first laboratory experiments of aerosol formation from oxidation of volatile organic species emitted by living plants, a process which for half a century has been known to take place...

A method for detecting the presence of organic fraction in nucleation mode sized particles (2005)

Vaattovaara, P., Räsänen, M., Kühn, T., Joutsensaari, J., Laaksonen, A.

New particle formation and growth has a very important role in many climate processes. However, the overall knowlegde of the chemical composition of atmospheric nucleation mode (particle diameter, d

Application of several activity coefficient models to water-organic-electrolyte aerosols of atmospheric interest (2005)

Raatikainen, T., Laaksonen, A.

In this work, existing and modified activity coefficient models are examined in order to assess their capabilities to describe the properties of aqueous solution droplets relevant in the atmosphere....

Nanoparticle formation by ozonolysis of inducible plant volatiles (2005)

Joutsensaari, J., Loivamäki, M., Vuorinen, T., Miettinen, P., Holopainen, J. K., ...

We present the first laboratory experiments of aerosol formation from oxidation of volatile organic species emitted by living plants, a process which for half a century has been known to take place...

Parameterization of the nitric acid effect on CCN activation (2005)

Romakkaniemi, S., Kokkola, H., Laaksonen, A.

In this paper we present a parameterization of the nitric acid effect on cloud droplet formation. The new parameterization is intended to be used in large scale models in order to obtain regional and...

Effects of SO2 oxidation on ambient aerosol growth in water and ethanol vapours (2005)

Petäjä, T., Hämeri, K., Vaattovaara, P., Joutsensaari, J., Junkermann, W., ...

Hygroscopicity (i.e. water vapour affinity) of atmospheric aerosol particles is one of the key factors in defining their impacts on climate. Condensation of sulphuric acid onto less hygroscopic...

Commentary on cloud modelling and the mass accommodation coefficient of water (2005)

Laaksonen, A., Vesala, T., Kulmala, M., Winkler, P. M., Wagner, P. E.

The mass accommodation coefficient of water is a quantity for which different experimental techniques have yielded conflicting values in the range 0.04-1. From the viewpoint of cloud modelling, this...

Nanoparticle formation by ozonolysis of inducible plant volatiles (2005)

J. Joutsensaari, M. Loivamäki, T. Vuorinen, P. Miettinen, J. K. Holopainen, ...

We present the first laboratory experiments of aerosol formation from oxidation of volatile organic species emitted by living plants, a process which for half a century has been known to take place...

A method for detecting the presence of organic fraction in nucleation mode sized particles (2005)

P. Vaattovaara, M. Räsänen, T. Kühn, J. Joutsensaari, A. Laaksonen

New particle formation and growth has a very important role in many climate processes. However, the overall knowlegde of the chemical composition of atmospheric nucleation mode (particle diameter,...

Application of several activity coefficient models to water-organic-electrolyte aerosols of atmospheric interest (2005)

T. Raatikainen, A. Laaksonen

In this work, existing and modified activity coefficient models are examined in order to assess their capabilities to describe the properties of aqueous solution droplets relevant in the atmosphere....

Why formation rate of 3 nm particles depends linearly on sulphuric acid concentration? (2005)

M. Kulmala, A. Laaksonen

According to atmospheric observations new particle formation seems to be a function of sulphuric acid concentration to the power from one to two. The nucleation theorem then predicts that the...

Modelling the formation of organic particles in the atmosphere (2004)

T. Anttila, M. Kulmala, A. Laaksonen, C. D. O'Dowd

Particle formation resulting from activation of inorganic stable clusters by a supersaturated organic vapour was investigated using a numerical model. The applied aerosol dynamic model included a...

The role of surfactants in Köhler theory reconsidered (2004)

R. Sorjamaa, B. Svenningsson, T. Raatikainen, S. Henning, M. Bilde, A. Laaksonen

Atmospheric aerosol particles typically consist of inorganic salts and organic material. The inorganic compounds as well as their hygroscopic properties are well defined, but the effect of organic...

Growth of upper tropospheric aerosols due to uptake of HNO3 (2004)

S. Romakkaniemi, H. Kokkola, A. Petzold, A. Laaksonen

The effect of nitric acid on the equilibrium size distributions of upper tropospheric aerosols is calculated as a function of relative humidity. It is shown that HNO3 concentrations above a few...

Overview of the field measurement campaign in Hyytiälä, August 2001 in the framework of the EU project OSOA (2004)

M. Boy, T. Petäjä, M. Dal Maso, Ü. Rannik, J. Rinne, P. Aalto, ...

As part of the OSOA (Origin and formation of Secondary Organic Aerosols) project, two intensive field campaigns were conducted in Melpitz, Germany and Hyytiälä, Finland. This paper gives an...

Parameterization of the nitric acid effect on CCN activation (2004)

Romakkaniemi, S., Kokkola, H., Laaksonen, A.

In this paper we present a parameterization of the nitric acid effect on cloud droplet formation. The new parameterization is intended to be used in large scale models in order to obtain regional and...

Effects of SO2 oxidation on ambient aerosol growth in water and ethanol vapours (2004)

Petäjä, T., Hämeri, K., Vaattovaara, P., Joutsensaari, J., Junkermann, W., ...

Hygroscopicity (i.e. water vapour affinity) of atmospheric aerosol particles is one of the key factors in defining their impacts on climate. Condensation of sulphuric acid onto less hygroscopic...

On cloud modelling and the mass accommodation coefficient of water (2004)

Laaksonen, A., Vesala, T., Kulmala, M., Winkler, P. M., Wagner, P. E.

The mass accommodation coefficient of water is a quantity for which different experimental techniques have yielded conflicting values in the range 0.04?1. From the viewpoint of cloud modelling, this...

The role of surfactants in Köhler theory reconsidered (2004)

Sorjamaa, R., Raatikainen, T., Laaksonen, A.

Atmospheric aerosol particles typically consist of inorganic salts and organic material. The inorganic compounds as well as their hygroscopic properties are well defined, but the effect of organic...

Growth of upper tropospheric aerosols due to uptake of HNO3 (2004)

Romakkaniemi, S., Kokkola, H., Petzold, A., Laaksonen, A.

The effect of nitric acid on the equilibrium size distributions of upper tropospheric aerosols is calculated as a function of relative humidity. It is shown that HNO3 concentrations above a few...

The role of surfactants in Köhler theory reconsidered (2004)

Sorjamaa, R., Svenningsson, B., Raatikainen, T., Henning, S., Bilde, M., Laaksonen, A.

Atmospheric aerosol particles typically consist of inorganic salts and organic material. The inorganic compounds as well as their hygroscopic properties are well defined, but the effect of organic...

Modelling the formation of organic particles in the atmosphere (2004)

Anttila, T., Kulmala, M., Laaksonen, A., O'Dowd, C. D.

Particle formation resulting from activation of inorganic stable clusters by a supersaturated organic vapour was investigated using a numerical model. The applied aerosol dynamic model included a...

Overview of the field measurement campaign in Hyytiälä, August 2001 in the framework of the EU project OSOA (2004)

Boy, M., Petäjä, T., Dal Maso, M., Rannik, Ü., Rinne, J., Aalto, P., ...

As part of the OSOA (Origin and formation of Secondary Organic Aerosols) project, two intensive field campaigns were conducted in Melpitz, Germany and Hyytiälä, Finland. This paper gives an...

Growth of upper tropospheric aerosols due to uptake of HNO3 (2004)

Romakkaniemi, S., Kokkola, H., Petzold, A., Laaksonen, A.

The effect of nitric acid on the equilibrium size distributions of upper tropospheric aerosols is calculated as a function of relative humidity. It is shown that HNO3 concentrations above a few...

Parameterization of the nitric acid effect on CCN activation (2004)

Romakkaniemi, S., Kokkola, H., Laaksonen, A.

In this paper we present a parameterization of the nitric acid effect on cloud droplet formation. The new parameterization is intended to be used in large scale models in order to obtain regional and...

Effects of SO2 oxidation on ambient aerosol growth in water and ethanol vapours (2004)

Petäjä, T., Hämeri, K., Vaattovaara, P., Joutsensaari, J., Junkermann, W., ...

Hygroscopicity (i.e. water vapour affinity) of atmospheric aerosol particles is one of the key factors in defining their impacts on climate. Condensation of sulphuric acid onto less hygroscopic...

On cloud modelling and the mass accommodation coefficient of water (2004)

Laaksonen, A., Vesala, T., Kulmala, M., Winkler, P. M., Wagner, P. E.

The mass accommodation coefficient of water is a quantity for which different experimental techniques have yielded conflicting values in the range 0.04?1. From the viewpoint of cloud modelling, this...

The role of surfactants in Köhler theory reconsidered (2004)

Sorjamaa, R., Raatikainen, T., Laaksonen, A.

Atmospheric aerosol particles typically consist of inorganic salts and organic material. The inorganic compounds as well as their hygroscopic properties are well defined, but the effect of organic...

Growth of upper tropospheric aerosols due to uptake of HNO3 (2004)

Romakkaniemi, S., Kokkola, H., Petzold, A., Laaksonen, A.

The effect of nitric acid on the equilibrium size distributions of upper tropospheric aerosols is calculated as a function of relative humidity. It is shown that HNO3 concentrations above a few...

The role of surfactants in Köhler theory reconsidered (2004)

Sorjamaa, R., Svenningsson, B., Raatikainen, T., Henning, S., Bilde, M., Laaksonen, A.

Atmospheric aerosol particles typically consist of inorganic salts and organic material. The inorganic compounds as well as their hygroscopic properties are well defined, but the effect of organic...

Modelling the formation of organic particles in the atmosphere (2004)

Anttila, T., Kulmala, M., Laaksonen, A., O'Dowd, C. D.

Particle formation resulting from activation of inorganic stable clusters by a supersaturated organic vapour was investigated using a numerical model. The applied aerosol dynamic model included a...

Overview of the field measurement campaign in Hyytiälä, August 2001 in the framework of the EU project OSOA (2004)

Boy, M., Petäjä, T., Dal Maso, M., Rannik, Ü., Rinne, J., Aalto, P., ...

As part of the OSOA (Origin and formation of Secondary Organic Aerosols) project, two intensive field campaigns were conducted in Melpitz, Germany and Hyytiälä, Finland. This paper gives an...

Growth of upper tropospheric aerosols due to uptake of HNO3 (2004)

Romakkaniemi, S., Kokkola, H., Petzold, A., Laaksonen, A.

The effect of nitric acid on the equilibrium size distributions of upper tropospheric aerosols is calculated as a function of relative humidity. It is shown that HNO3 concentrations above a few...

Growth of upper tropospheric aerosols due to uptake of HNO3 (2004)

S. Romakkaniemi, H. Kokkola, A. Petzold, A. Laaksonen

The effect of nitric acid on the equilibrium size distributions of upper tropospheric aerosols is calculated as a function of relative humidity. It is shown that HNO3 concentrations above a few...

The role of surfactants in Köhler theory reconsidered (2004)

R. Sorjamaa, T. Raatikainen, A. Laaksonen

Atmospheric aerosol particles typically consist of inorganic salts and organic material. The inorganic compounds as well as their hygroscopic properties are well defined, but the effect of organic...

On cloud modelling and the mass accommodation coefficient of water (2004)

A. Laaksonen, T. Vesala, M. Kulmala, P. M. Winkler, P. E. Wagner

The mass accommodation coefficient of water is a quantity for which different experimental techniques have yielded conflicting values in the range 0.04–1. From the viewpoint of cloud modelling,...

Effects of SO2 oxidation on ambient aerosol growth in water and ethanol vapours (2004)

T. Petäjä, K. Hämeri, P. Vaattovaara, J. Joutsensaari, W. Junkermann, ...

Hygroscopicity (i.e. water vapour affinity) of atmospheric aerosol particles is one of the key factors in defining their impacts on climate. Condensation of sulphuric acid onto less hygroscopic...

Parameterization of the nitric acid effect on CCN activation (2004)

S. Romakkaniemi, H. Kokkola, A. Laaksonen

In this paper we present a parameterization of the nitric acid effect on cloud droplet formation. The new parameterization is intended to be used in large scale models in order to obtain regional and...

On coarse-graining by the Inverse Monte Carlo method: Dissipative Particle Dynamics simulations made to a precise tool in soft matter modeling (2003)

Lyubartsev, A. P., Karttunen, M., Vattulainen, I., Laaksonen, A.

We present a promising coarse-graining strategy for linking micro- and mesoscales of soft matter systems. The approach is based on effective pairwise interaction potentials obtained from detailed...

Köhler theory for a polydisperse droplet population in the presence of a soluble trace gas, and an application to stratospheric STS droplet growth (2003)

H. Kokkola, S. Romakkaniemi, A. Laaksonen

We consider the equilibrium behavior of a polydisperse aqueous droplet population as a function of relative humidity (RH) when a soluble trace gas, such as nitric acid, is present in the system. The...

On the formation of radiation fogs under heavily polluted conditions (2003)

H. Kokkola, S. Romakkaniemi, A. Laaksonen

We have studied the effect of gaseous pollutants on fog droplet growth in heavily polluted air using a model that describes time-dependent sulfate production in the liquid phase and thermodynamical...

Modelling the formation of organic particles in the atmosphere (2003)

Anttila, T., Kulmala, M., Laaksonen, A., O'Dowd, C.

A modelling study investigating the formation of organic particles from inorganic, thermodynamically stable clusters was carried out. A recently-developed theory, the so-called nano-Köhler theory,...

Overview of the field measurement campaign in Hyytiälä, August 2001 in the framework of the EU project OSOA (2003)

Boy, M., Petäja, T., Dal Maso, M., Rannik, Ü., Rinne, J., Aalto, P., ...

As one part of the OSOA (Origin and formation of Secondary Organic Aerosols) project, two intensive field campaigns were conducted in Melpitz, Germany and Hyytiälä, Finland. This paper gives an...

Köhler theory for a polydisperse droplet population in the presence of a soluble trace gas, and an application to stratospheric STS droplet growth (2003)

Kokkola, H., Romakkaniemi, S., Laaksonen, A.

We consider the equilibrium behavior of a polydisperse aqueous droplet population as a function of relative humidity (RH) when a soluble trace gas, such as nitric acid, is present in the system. The...

On the formation of radiation fogs under heavily polluted conditions (2003)

Kokkola, H., Romakkaniemi, S., Laaksonen, A.

We have studied the effect of gaseous pollutants on fog droplet growth in heavily polluted air using a model that describes time-dependent sulfate production in the liquid phase and thermodynamical...

Köhler theory for a polydisperse droplet population in the presence of a soluble trace gas, and an application to stratospheric STS droplet growth (2003)

Kokkola, H., Romakkaniemi, S., Laaksonen, A.

We consider the equilibrium behavior of a polydisperse aqueous droplet population as a function of relative humidity (RH) when a soluble trace gas, such as nitric acid, is present in the system. The...

On the formation of radiation fogs under heavily polluted conditions (2003)

Kokkola, H., Romakkaniemi, S., Laaksonen, A.

We have studied the effect of gaseous pollutants on fog droplet growth in heavily polluted air using a model that describes time-dependent sulfate production in the liquid phase and thermodynamical...

Modelling the formation of organic particles in the atmosphere (2003)

Anttila, T., Kulmala, M., Laaksonen, A., O'Dowd, C.

A modelling study investigating the formation of organic particles from inorganic, thermodynamically stable clusters was carried out. A recently-developed theory, the so-called nano-Köhler theory,...

Overview of the field measurement campaign in Hyytiälä, August 2001 in the framework of the EU project OSOA (2003)

Boy, M., Petäja, T., Dal Maso, M., Rannik, Ü., Rinne, J., Aalto, P., ...

As one part of the OSOA (Origin and formation of Secondary Organic Aerosols) project, two intensive field campaigns were conducted in Melpitz, Germany and Hyytiälä, Finland. This paper gives an...

Köhler theory for a polydisperse droplet population in the presence of a soluble trace gas, and an application to stratospheric STS droplet growth (2003)

Kokkola, H., Romakkaniemi, S., Laaksonen, A.

We consider the equilibrium behavior of a polydisperse aqueous droplet population as a function of relative humidity (RH) when a soluble trace gas, such as nitric acid, is present in the system. The...

On the formation of radiation fogs under heavily polluted conditions (2003)

Kokkola, H., Romakkaniemi, S., Laaksonen, A.

We have studied the effect of gaseous pollutants on fog droplet growth in heavily polluted air using a model that describes time-dependent sulfate production in the liquid phase and thermodynamical...

Köhler theory for a polydisperse droplet population in the presence of a soluble trace gas, and an application to stratospheric STS droplet growth (2003)

Kokkola, H., Romakkaniemi, S., Laaksonen, A.

We consider the equilibrium behavior of a polydisperse aqueous droplet population as a function of relative humidity (RH) when a soluble trace gas, such as nitric acid, is present in the system. The...

On the formation of radiation fogs under heavily polluted conditions (2003)

Kokkola, H., Romakkaniemi, S., Laaksonen, A.

We have studied the effect of gaseous pollutants on fog droplet growth in heavily polluted air using a model that describes time-dependent sulfate production in the liquid phase and thermodynamical...

The study of finely divided aqueous systems as a clue to understanding the formation mechanisms of polar stratospheric clouds:  1.  HNO3/H2O and H2SO4/H2O systems. (2003)

Bogdan, A., Kulmala, M., MacKenzie, A. Robert, Laaksonen, A., Molina, M. J., Avramenko, A.

The study of nanometer-scale aqueous systems (finely divided aqueous systems (FDAS)) can be achieved using the absorption of vapors on fumed silica (SiO2) powder. Being a product of flame synthesis...

Köhler theory for a polydisperse droplet population in the presence of a soluble trace gas, and an application to stratospheric STS droplet growth (2003)

H. Kokkola, S. Romakkaniemi, A. Laaksonen

We consider the equilibrium behavior of a polydisperse aqueous droplet population as a function of relative humidity (RH) when a soluble trace gas, such as nitric acid, is present in the system. The...

Overview of the field measurement campaign in Hyytiälä, August 2001 in the framework of the EU project OSOA (2003)

M. Boy, T. Petäja, M. Dal Maso, Ü. Rannik, J. Rinne, P. Aalto, ...

As one part of the OSOA (Origin and formation of Secondary Organic Aerosols) project, two intensive field campaigns were conducted in Melpitz, Germany and Hyytiälä, Finland. This paper gives an...

An improved parameterization for sulfuric acid-water nucleation rates for tropospheric and stratospheric conditions (2002)

Vehkamaki,H., Kulmala,M., Napari,I., Lehtinen,K. E. J., Timmreck,C., Noppel,M., ...

In this paper we present parameterized equations for calculation of sulfuric acid-water critical nucleus compositions, critical cluster radii and homogeneous nucleation rates for tropospheric and...

An improved parameterization for sulfuric acid-water nucleation rates for tropospheric and stratospheric conditions (2002)

Vehkamaki, H., Kulmala, M., Napari, I., Lehtinen, K. E. J., Timmreck, C., Noppel, M., ...

In this paper we present parameterized equations for calculation of sulfuric acid-water critical nucleus compositions, critical cluster radii and homogeneous nucleation rates for tropospheric and...

A novel tandem differential mobility analyzer with organic vapor treatment of aerosol particles (2001)

J. Joutsensaari, P. Vaattovaara, M. Vesterinen, K. Hämeri, A. Laaksonen

A novel method to characterize the organic composition of aerosol particles has been developed. The method is based on organic vapor interaction with aerosol particles and it has been named an...

Overview of the international project on biogenic aerosol formation in the boreal forest (BIOFOR) (2001)

Kulmala, M., Hameri, K., Aalto, P.P., Makela, J.M., Pirjola, L., Nilsson, E.D., ...

Aerosol formation and subsequent particle growth in ambient air have been frequently observed at a boreal forest site (SMEAR II station) in Southern Finland. The EU funded project BIOFOR (Biogenic...

A novel tandem differential mobility analyzer with organic vapor treatment of aerosol particles (2001)

Joutsensaari, J., Vaattovaara, P., Hämeri, K., Laaksonen, A.

A novel method to characterize the organic composition of aerosol particles has been developed. The method is based on organic vapor interaction with aerosol particles and it has been named an...

A novel tandem differential mobility analyzer with organic vapor treatment of aerosol particles (2001)

Joutsensaari, J., Vaattovaara, P., Vesterinen, M., Hämeri, K., Laaksonen, A.

A novel method to characterize the organic composition of aerosol particles has been developed. The method is based on organic vapor interaction with aerosol particles and it has been named an...

A novel tandem differential mobility analyzer with organic vapor treatment of aerosol particles (2001)

Joutsensaari, J., Vaattovaara, P., Hämeri, K., Laaksonen, A.

A novel method to characterize the organic composition of aerosol particles has been developed. The method is based on organic vapor interaction with aerosol particles and it has been named an...

A novel tandem differential mobility analyzer with organic vapor treatment of aerosol particles (2001)

Joutsensaari, J., Vaattovaara, P., Vesterinen, M., Hämeri, K., Laaksonen, A.

A novel method to characterize the organic composition of aerosol particles has been developed. The method is based on organic vapor interaction with aerosol particles and it has been named an...

A novel tandem differential mobility analyzer with organic vapor treatment of aerosol particles (2001)

J. Joutsensaari, P. Vaattovaara, K. Hämeri, A. Laaksonen

A novel method to characterize the organic composition of aerosol particles has been developed. The method is based on organic vapor interaction with aerosol particles and it has been named an...

Ternary nucleation of H2SO4, NH3 and H2O (2000)

Kulmala, M., Korhonen, P., Laaksonen, A., Viisanen, Y., McGraw, R., Seinfeld, J. H.

A classical theory of the ternary homogeneous nucleation of sulfuric acid—ammonia—water is presented. For NH3 mixing ratios exceeding 1 ppt, the presence of ammonia enhances the binary (sulfuric...

Calculations of Solvation Free Energies By Expanded Ensemble Method. (1996)

A.P. Lyubartsev, O.K. Førrisdahl, A. Laaksonen

The expanded ensemble method [J.Chem.Phys, 96,1776 (1992)] is applied to calculate solvation free energies for methane disolved in water at infinite dilution and at finite concentration and for...