Oxalic acid as a heterogeneous ice nucleus in the upper troposphere and its indirect aerosol effect
| Autor: | Zobrist, Bernhard, Marcolli, Claudia, Koop, Thomas, Luo, Beiping P., Murphy, Daniel M., Lohmann, Ulrike, Zardini, Alessandro A., Krieger, Ulrich, Corti, Thierry, Cziczo, Daniel J., Fueglistaler, Stephan, Hudson, P.K., Thomson, D.S., Peter, Thomas |
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| Jazyk: | angličtina |
| Předmět: | |
| ISSN: | 1680-7375 1680-7367 |
| Popis: | Heterogeneous ice freezing points of aqueous solutions containing various immersed solid dicarboxylic acids (oxalic, adipic, succinic, phthalic and fumaric) have been measured with a differential scanning calorimeter. The results show that only the dihydrate of oxalic acid (OAD) acts as a heterogeneous ice nucleus, with an increase in freezing temperature between 2 and 5 K depending on solution composition. In several field campaigns, oxalic acid enriched particles have been detected in the upper troposphere with single particle aerosol mass spectrometry. Simulations with a microphysical box model indicate that the presence of OAD may reduce the ice particle number density in cirrus clouds by up to ~50% when compared to exclusively homogeneous cirrus formation without OAD. Using the ECHAM4 climate model we estimate the global net radiative effect caused by this heterogeneous freezing to result in a cooling as high as −0.3 Wm−2. Atmospheric Chemistry and Physics, 6 (10) ISSN:1680-7375 ISSN:1680-7367 |
| Databáze: | OpenAIRE |
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