Origin of aerosol particles in the mid-latitude and subtropical upper troposphere and lowermost stratosphere from cluster analysis of CARIBIC data
The origin of aerosol particles in the upper troposphere and lowermost stratosphere over the Eurasian continent was investigated by applying cluster analysis methods to in situ measured data. Number concentrations of submicrometer aerosol particles and trace gas mixing ratios derived by the CARIBIC...
| Main Authors: | , , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2009-11-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | http://www.atmos-chem-phys.net/9/8413/2009/acp-9-8413-2009.pdf |
| _version_ | 1819088874122510336 |
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| author | H. Ziereis A. Zahn A. Wiedensohler P. F. J. van Velthoven D. Sprung F. Slemr T. Schuck H. Schlager J. Heintzenberg C. A. M. Brenninkmeijer M. Hermann M. Köppe |
| author_facet | H. Ziereis A. Zahn A. Wiedensohler P. F. J. van Velthoven D. Sprung F. Slemr T. Schuck H. Schlager J. Heintzenberg C. A. M. Brenninkmeijer M. Hermann M. Köppe |
| author_sort | H. Ziereis |
| collection | DOAJ |
| description | The origin of aerosol particles in the upper troposphere and lowermost stratosphere over the Eurasian continent was investigated by applying cluster analysis methods to in situ measured data. Number concentrations of submicrometer aerosol particles and trace gas mixing ratios derived by the CARIBIC (Civil Aircraft for Regular Investigation of the Atmosphere Based on an Instrument Container) measurement system on flights between Germany and South-East Asia were used for this analysis. Four cluster analysis methods were applied to a test data set and their capability of separating the data points into scientifically reasonable clusters was assessed. The best method was applied to seasonal data subsets for summer and winter resulting in five cluster or air mass types: stratosphere, tropopause, free troposphere, high clouds, and boundary layer influenced. Other source clusters, like aircraft emissions could not be resolved in the present data set with the used methods. While the cluster separation works satisfactory well for the summer data, in winter interpretation is more difficult, which is attributed to either different vertical transport pathways or different chemical lifetimes in both seasons. The geographical distribution of the clusters together with histograms for nucleation and Aitken mode particles within each cluster are presented. Aitken mode particle number concentrations show a clear vertical gradient with the lowest values in the lowermost stratosphere (750–2820 particles/cm<sup>3</sup> STP, minimum of the two 25% – and maximum of the two 75%-percentiles of both seasons) and the highest values for the boundary-layer-influenced air (4290–22 760 particles/cm<sup>3</sup> STP). Nucleation mode particles are also highest in the boundary-layer-influenced air (1260–29 500 particles/cm<sup>3</sup> STP), but are lowest in the free troposphere (0–450 particles/cm<sup>3</sup> STP). The given submicrometer particle number concentrations represent the first large-scale seasonal data sets for the upper troposphere and lowermost stratosphere over the Eurasian continent. |
| first_indexed | 2024-12-21T21:58:58Z |
| format | Article |
| id | doaj.art-f6c6fe9ce57a417b9ff571bd2cf4816c |
| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-12-21T21:58:58Z |
| publishDate | 2009-11-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-f6c6fe9ce57a417b9ff571bd2cf4816c2022-12-21T18:48:54ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242009-11-0192184138430Origin of aerosol particles in the mid-latitude and subtropical upper troposphere and lowermost stratosphere from cluster analysis of CARIBIC dataH. ZiereisA. ZahnA. WiedensohlerP. F. J. van VelthovenD. SprungF. SlemrT. SchuckH. SchlagerJ. HeintzenbergC. A. M. BrenninkmeijerM. HermannM. KöppeThe origin of aerosol particles in the upper troposphere and lowermost stratosphere over the Eurasian continent was investigated by applying cluster analysis methods to in situ measured data. Number concentrations of submicrometer aerosol particles and trace gas mixing ratios derived by the CARIBIC (Civil Aircraft for Regular Investigation of the Atmosphere Based on an Instrument Container) measurement system on flights between Germany and South-East Asia were used for this analysis. Four cluster analysis methods were applied to a test data set and their capability of separating the data points into scientifically reasonable clusters was assessed. The best method was applied to seasonal data subsets for summer and winter resulting in five cluster or air mass types: stratosphere, tropopause, free troposphere, high clouds, and boundary layer influenced. Other source clusters, like aircraft emissions could not be resolved in the present data set with the used methods. While the cluster separation works satisfactory well for the summer data, in winter interpretation is more difficult, which is attributed to either different vertical transport pathways or different chemical lifetimes in both seasons. The geographical distribution of the clusters together with histograms for nucleation and Aitken mode particles within each cluster are presented. Aitken mode particle number concentrations show a clear vertical gradient with the lowest values in the lowermost stratosphere (750–2820 particles/cm<sup>3</sup> STP, minimum of the two 25% – and maximum of the two 75%-percentiles of both seasons) and the highest values for the boundary-layer-influenced air (4290–22 760 particles/cm<sup>3</sup> STP). Nucleation mode particles are also highest in the boundary-layer-influenced air (1260–29 500 particles/cm<sup>3</sup> STP), but are lowest in the free troposphere (0–450 particles/cm<sup>3</sup> STP). The given submicrometer particle number concentrations represent the first large-scale seasonal data sets for the upper troposphere and lowermost stratosphere over the Eurasian continent.http://www.atmos-chem-phys.net/9/8413/2009/acp-9-8413-2009.pdf |
| spellingShingle | H. Ziereis A. Zahn A. Wiedensohler P. F. J. van Velthoven D. Sprung F. Slemr T. Schuck H. Schlager J. Heintzenberg C. A. M. Brenninkmeijer M. Hermann M. Köppe Origin of aerosol particles in the mid-latitude and subtropical upper troposphere and lowermost stratosphere from cluster analysis of CARIBIC data Atmospheric Chemistry and Physics |
| title | Origin of aerosol particles in the mid-latitude and subtropical upper troposphere and lowermost stratosphere from cluster analysis of CARIBIC data |
| title_full | Origin of aerosol particles in the mid-latitude and subtropical upper troposphere and lowermost stratosphere from cluster analysis of CARIBIC data |
| title_fullStr | Origin of aerosol particles in the mid-latitude and subtropical upper troposphere and lowermost stratosphere from cluster analysis of CARIBIC data |
| title_full_unstemmed | Origin of aerosol particles in the mid-latitude and subtropical upper troposphere and lowermost stratosphere from cluster analysis of CARIBIC data |
| title_short | Origin of aerosol particles in the mid-latitude and subtropical upper troposphere and lowermost stratosphere from cluster analysis of CARIBIC data |
| title_sort | origin of aerosol particles in the mid latitude and subtropical upper troposphere and lowermost stratosphere from cluster analysis of caribic data |
| url | http://www.atmos-chem-phys.net/9/8413/2009/acp-9-8413-2009.pdf |
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