H. Vehkamäki

Homogeneous vs. heterogeneous nucleation in water-dicarboxylic acid systems (2009)

A. I. Hienola, H. Vehkamäki, I. Riipinen, M. Kulmala

Binary heterogeneous nucleation of water-succinic/glutaric/malonic/adipic acid on nanometer-sized particles is investigated within the frame of classical heterogeneous nucleation theory. Homogeneous...

Corrigendum to (2009)

I. K. Ortega, T. Kurtén, H. Vehkamäki, M. Kulmala

No abstract available.

Amines are likely to enhance neutral and ion-induced sulfuric acid-water nucleation in the atmosphere more effectively than ammonia (2008)

Kurtén, T., Loukonen, V., Vehkamäki, H., Kulmala, M.

We have studied the structure and formation thermodynamics of dimer clusters containing H2SO4 or HSO4? together with ammonia and seven different amines possibly present in the atmosphere, using the...

The role of ammonia in sulfuric acid ion induced nucleation (2008)

Ortega, I. K., Kurtén, T., Vehkamäki, H., Kulmala, M.

We have developed a new multi-step strategy for quantum chemical calculations on atmospherically relevant cluster structures that makes calculation for large clusters affordable with a good...

The role of ammonia in sulfuric acid ion induced nucleation (2008)

Ortega, I. K., Kurtén, T., Vehkamäki, H., Kulmala, M.

We have developed a new multi-step strategy for quantum chemical calculations on atmospherically relevant cluster structures that makes calculation for large clusters affordable with a good...

Amines are likely to enhance neutral and ion-induced sulfuric acid-water nucleation in the atmosphere more effectively than ammonia (2008)

Kurtén, T., Loukonen, V., Vehkamäki, H., Kulmala, M.

We have studied the structure and formation thermodynamics of dimer clusters containing H2SO4 or HSO4? together with ammonia and seven different amines possibly present in the atmosphere, using the...

The role of ammonia in sulfuric acid ion induced nucleation (2008)

Ortega, I. K., Kurtén, T., Vehkamäki, H., Kulmala, M.

We have developed a new multi-step strategy for quantum chemical calculations on atmospherically relevant cluster structures that makes calculation for large clusters affordable with a good...

The role of ammonia in sulfuric acid ion induced nucleation (2008)

Ortega, I. K., Kurtén, T., Vehkamäki, H., Kulmala, M.

We have developed a new multi-step strategy for quantum chemical calculations on atmospherically relevant cluster structures that makes calculation for large clusters affordable with a good...

The role of ammonia in sulfuric acid ion induced nucleation (2008)

I. K. Ortega, T. Kurtén, H. Vehkamäki, M. Kulmala

We have developed a new multi-step strategy for quantum chemical calculations on atmospherically relevant cluster structures that makes calculation for large clusters affordable with a good...

Amines are likely to enhance neutral and ion-induced sulfuric acid-water nucleation in the atmosphere more effectively than ammonia (2008)

T. Kurtén, V. Loukonen, H. Vehkamäki, M. Kulmala

We have studied the structure and formation thermodynamics of dimer clusters containing H₂SO₄ or...

The role of ammonia in sulfuric acid ion induced nucleation (2008)

I. K. Ortega, T. Kurtén, H. Vehkamäki, M. Kulmala

We have developed a new multi-step strategy for quantum chemical calculations on atmospherically relevant cluster structures that makes calculation for large clusters affordable with a good...

Amines are likely to enhance neutral and ion-induced sulfuric acid-water nucleation in the atmosphere more effectively than ammonia (2008)

T. Kurtén, V. Loukonen, H. Vehkamäki, M. Kulmala

We have studied the structure and formation thermodynamics of dimer clusters containing H₂SO₄ or...

Homogeneous vs. heterogeneous nucleation in water-dicarboxylic acid systems (2008)

A. I. Hienola, H. Vehkamäki, I. Riipinen, M. Kulmala

Binary heterogeneous nucleation of water-succinic/glutaric/malonic/adipic acid on nanometer-sized particles is investigated within the frame of classical heterogeneous nucleation theory. Homogeneous...

Technical Note: The heterogeneous Zeldovich factor (2007)

H. Vehkamäki, A. Määttänen, A. Lauri, I. Napari, M. Kulmala

In this technical note we present the exact form of the Zeldovich factor for heterogeneous nucleation on spherical pre-existing particles. We study the error caused by planar pre-existing surface...

Estimating the NH3:H2SO4 ratio of nucleating clusters in atmospheric conditions using quantum chemical methods (2007)

T. Kurtén, L. Torpo, M. R. Sundberg, H. Vehkamäki, M. Kulmala

We study the ammonia addition reactions of H2SO4·NH3 molecular clusters containing up to four ammonia and two sulfuric acid molecules using the ab initio method RI-MP2 (Resolution of Identity...

Estimating the NH3:H2SO4ratio of nucleating clusters in atmospheric conditions using quantum chemical methods (2007)

Kurtén, T., Torpo, L., Sundberg, M. R., Vehkamäki, H., Kulmala, M.

We study the ammonia addition reactions of H2SO4·NH3 molecular clusters containing up to four ammonia and two sulfuric acid molecules using the ab initio method RI-MP2 (Resolution of Identity 2nd...

Estimating the NH3:H2SO4 ratio of nucleating clusters in atmospheric conditions using quantum chemical methods (2007)

Kurtén, T., Torpo, L., Sundberg, M. R., Vehkamäki, H., Kulmala, M.

We study the ammonia addition reactions of H2SO4·NH3 molecular clusters containing up to four ammonia and two sulfuric acid molecules using the ab initio method RI-MP2 (Resolution of Identity 2nd...

Technical Note: The heterogeneous Zeldovich factor (2007)

Vehkamäki, H., Määttänen, A., Lauri, A., Napari, I., Kulmala, M.

In this technical note we present the exact form of the Zeldovich factor for heterogeneous nucleation on spherical pre-existing particles. We study the error caused by planar pre-existing surface...

Estimating the NH3:H2SO4ratio of nucleating clusters in atmospheric conditions using quantum chemical methods (2007)

Kurtén, T., Torpo, L., Sundberg, M. R., Vehkamäki, H., Kulmala, M.

We study the ammonia addition reactions of H2SO4·NH3 molecular clusters containing up to four ammonia and two sulfuric acid molecules using the ab initio method RI-MP2 (Resolution of Identity 2nd...

Estimating the NH3:H2SO4 ratio of nucleating clusters in atmospheric conditions using quantum chemical methods (2007)

Kurtén, T., Torpo, L., Sundberg, M. R., Vehkamäki, H., Kulmala, M.

We study the ammonia addition reactions of H2SO4·NH3 molecular clusters containing up to four ammonia and two sulfuric acid molecules using the ab initio method RI-MP2 (Resolution of Identity 2nd...

Technical Note: The heterogeneous Zeldovich factor (2007)

Vehkamäki, H., Määttänen, A., Lauri, A., Napari, I., Kulmala, M.

In this technical note we present the exact form of the Zeldovich factor for heterogeneous nucleation on spherical pre-existing particles. We study the error caused by planar pre-existing surface...

Estimating the NH3:H2SO4ratio of nucleating clusters in atmospheric conditions using quantum chemical methods (2007)

T. Kurtén, L. Torpo, M. R. Sundberg, H. Vehkamäki, M. Kulmala

We study the ammonia addition reactions of H2SO4·NH3 molecular clusters containing up to four ammonia and two sulfuric acid molecules using the ab initio method RI-MP2 (Resolution of Identity...

Changes in background aerosol composition in Finland during polluted and clean periods studied by TEM/EDX individual particle analysis (2006)

J. V. Niemi, S. Saarikoski, H. Tervahattu, T. Mäkelä, R. Hillamo, H. Vehkamäki, ...

Aerosol samples were collected at a rural background site in southern Finland in May 2004 during pollution episode (PM1~16 µg m−3, backward air mass trajectories from south-east),...

Changes in background aerosol composition in Finland during polluted and clean periods studied by TEM/EDX individual particle analysis (2006)

Niemi, J. V., Saarikoski, S., Tervahattu, H., Mäkelä, T., Hillamo, R., Vehkamäki, H., ...

Aerosol samples were collected at a rural background site in southern Finland in May 2004. The elemental composition, morphology and mixing state of individual aerosol particles in three size...

Changes in background aerosol composition in Finland during polluted and clean periods studied by TEM/EDX individual particle analysis (2006)

Niemi, J. V., Saarikoski, S., Tervahattu, H., Mäkelä, T., Hillamo, R., Vehkamäki, H., ...

Aerosol samples were collected at a rural background site in southern Finland in May 2004 during pollution episode (PM1~16 µg m?3, backward air mass trajectories from south-east), intermediate...

Changes in background aerosol composition in Finland during polluted and clean periods studied by TEM/EDX individual particle analysis (2006)

Niemi, J. V., Saarikoski, S., Tervahattu, H., Mäkelä, T., Hillamo, R., Vehkamäki, H., ...

Aerosol samples were collected at a rural background site in southern Finland in May 2004. The elemental composition, morphology and mixing state of individual aerosol particles in three size...

Changes in background aerosol composition in Finland during polluted and clean periods studied by TEM/EDX individual particle analysis (2006)

Niemi, J. V., Saarikoski, S., Tervahattu, H., Mäkelä, T., Hillamo, R., Vehkamäki, H., ...

Aerosol samples were collected at a rural background site in southern Finland in May 2004 during pollution episode (PM1~16 µg m?3, backward air mass trajectories from south-east), intermediate...

Characterization of aerosol particle episodes in Finland caused by wildfires in Eastern Europe (2005)

J. V. Niemi, H. Tervahattu, H. Vehkamäki, J. Martikainen, L. Laakso, M. Kulmala, ...

We studied the sources, compositions and size distributions of aerosol particles during long-range transport (LRT) PM2.5 episodes which occurred on 12–15 August, 26–28 August and...

Characterization of aerosol particle episodes in Finland caused by wildfires in Eastern Europe (2005)

Niemi, J. V., Tervahattu, H., Vehkamäki, H., Martikainen, J., Laakso, L., Kulmala, M., ...

We studied the sources, compositions and size distributions of aerosol particles during long-range transport (LRT) PM2.5 episodes occurred on 12?15 August, 26?28 August and 5?6 September 2002 in...

Characterization of aerosol particle episodes in Finland caused by wildfires in Eastern Europe (2005)

Niemi, J. V., Tervahattu, H., Vehkamäki, H., Martikainen, J., Laakso, L., Kulmala, M., ...

We studied the sources, compositions and size distributions of aerosol particles during long-range transport (LRT) PM2.5 episodes which occurred on 12?15 August, 26?28 August and 5?6 September 2002...

Characterization of aerosol particle episodes in Finland caused by wildfires in Eastern Europe (2005)

Niemi, J. V., Tervahattu, H., Vehkamäki, H., Martikainen, J., Laakso, L., Kulmala, M., ...

We studied the sources, compositions and size distributions of aerosol particles during long-range transport (LRT) PM2.5 episodes occurred on 12?15 August, 26?28 August and 5?6 September 2002 in...

Characterization of aerosol particle episodes in Finland caused by wildfires in Eastern Europe (2005)

Niemi, J. V., Tervahattu, H., Vehkamäki, H., Martikainen, J., Laakso, L., Kulmala, M., ...

We studied the sources, compositions and size distributions of aerosol particles during long-range transport (LRT) PM2.5 episodes which occurred on 12?15 August, 26?28 August and 5?6 September 2002...

Characterization of aerosol particle episodes in Finland caused by wildfires in Eastern Europe (2005)

J. V. Niemi, H. Tervahattu, H. Vehkamäki, J. Martikainen, L. Laakso, M. Kulmala, ...

We studied the sources, compositions and size distributions of aerosol particles during long-range transport (LRT) PM_2.5 episodes occurred on 12–15 August, 26–28...

Characterization of aerosol particle episodes in Finland caused by wildfires in Eastern Europe (2005)

Niemi, J. V., Tervahattu, H., Vehkamäki, H., Martikainen, J., Laakso, L., Kulmala, M., ...

We studied the sources, compositions and size distributions of aerosol particles during long-range transport (LRT) PM2.5 episodes which occurred on 12–15 August, 26– 28 August and 5–6 September...

Fatty acids on continental sulfate aerosol particles (2005)

Tervahattu, H., Juhanoja, J., Vaida, V., Tuck, A. F., Niemi, J. V., Kupiainen, K., ...

Published 2005 American Geophysical Union. Reproduced by permission of American Geophysical Union.

Atmospheric particle formation events at Värriö measurement station in Finnish Lapland 1998-2002 (2004)

H. Vehkamäki, M. Dal Maso, T. Hussein, R. Flanagan, A. Hyvärinen, J. Lauros, ...

During the calendar years 1998-2002, 147 clear 8nm diameter particle formation events have been identified at the SMEAR I station in Värriö, northern Finland. The events have been...

Atmospheric particle formation events at Värriö measurement station in Finnish Lapland 1998?2002 (2004)

Vehkamäki, H., Dal Maso, M., Hussein, T., Flanagan, R., Hyvärinen, A., Lauros, J., ...

We have identified 147 clear 8 nm diameter particle formation events at the SMEAR I station in Värriö, northern Finland during calendar years 1998?2002. The events have been classified in detail...

Atmospheric particle formation events at Värriö measurement station in Finnish Lapland 1998-2002 (2004)

Vehkamäki, H., Dal Maso, M., Hussein, T., Flanagan, R., Hyvärinen, A., Lauros, J., ...

During the calendar years 1998-2002, 147 clear 8nm diameter particle formation events have been identified at the SMEAR I station in Värriö, northern Finland. The events have been classified in...

Atmospheric particle formation events at Värriö measurement station in Finnish Lapland 1998?2002 (2004)

Vehkamäki, H., Dal Maso, M., Hussein, T., Flanagan, R., Hyvärinen, A., Lauros, J., ...

We have identified 147 clear 8 nm diameter particle formation events at the SMEAR I station in Värriö, northern Finland during calendar years 1998?2002. The events have been classified in detail...

Atmospheric particle formation events at Värriö measurement station in Finnish Lapland 1998-2002 (2004)

Vehkamäki, H., Dal Maso, M., Hussein, T., Flanagan, R., Hyvärinen, A., Lauros, J., ...

During the calendar years 1998-2002, 147 clear 8nm diameter particle formation events have been identified at the SMEAR I station in Värriö, northern Finland. The events have been classified in...

Atmospheric particle formation events at Värriö measurement station in Finnish Lapland 1998–2002 (2004)

H. Vehkamäki, M. Dal Maso, T. Hussein, R. Flanagan, A. Hyvärinen, J. Lauros, ...

We have identified 147 clear 8 nm diameter particle formation events at the SMEAR I station in Värriö, northern Finland during calendar years 1998–2002. The events have been...

Characterization and source identification of a fine particle episode in Finland (2004)

Niemi, J.V., Tervahattu, H., Vehkamäki, H., Kulmala, M., Koskentalo, T., Sillanpää, M., ...

http://www.elsevier.com/locate/issn/13522310

Characterization and source identification of a fine particle episode in Finland (2004)

Niemi, J. V., Tervahattu, H., Vehkamäki, H., Kulmala, M., Koskentalo, T., Sillanpää, M., ...

A strong long-range transported (LRT) fine particle (PM2.5) episode occurred from March 17–22, 2002 over large areas of Finland. Most of the LRT particle mass was in the submicrometre size...