Cloud condensation nucleus activity comparison of dry- and wet-generated mineral dust aerosol : the significance of soluble material
Thesis: S.M. in Atmospheric Science, Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences, 2014.
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| Format: | Thesis |
| Language: | eng |
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Massachusetts Institute of Technology
2014
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| Online Access: | http://hdl.handle.net/1721.1/90821 |
| _version_ | 1826209968285548544 |
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| author | Garimella, Sarvesh |
| author2 | Daniel J. Cziczo. |
| author_facet | Daniel J. Cziczo. Garimella, Sarvesh |
| author_sort | Garimella, Sarvesh |
| collection | MIT |
| description | Thesis: S.M. in Atmospheric Science, Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences, 2014. |
| first_indexed | 2024-09-23T14:36:51Z |
| format | Thesis |
| id | mit-1721.1/90821 |
| institution | Massachusetts Institute of Technology |
| language | eng |
| last_indexed | 2024-09-23T14:36:51Z |
| publishDate | 2014 |
| publisher | Massachusetts Institute of Technology |
| record_format | dspace |
| spelling | mit-1721.1/908212019-04-11T06:39:23Z Cloud condensation nucleus activity comparison of dry- and wet-generated mineral dust aerosol : the significance of soluble material Garimella, Sarvesh Daniel J. Cziczo. Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences. Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences. Earth, Atmospheric, and Planetary Sciences. Thesis: S.M. in Atmospheric Science, Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences, 2014. 70 Cataloged from PDF version of thesis. Includes bibliographical references (pages 60-65). This study examines the interaction of clay mineral particles and water vapor to determine the conditions required for cloud droplet formation. Droplet formation conditions are investigated for two common clay minerals, illite and sodium-rich montmorillonite, and an industrially derived sample, Arizona Test Dust. Using wet and dry particle generation coupled to a differential mobility analyzer (DMA) and cloud condensation nuclei counter, the critical activation of the clay mineral particles as cloud condensation nuclei is characterized. Electron microscopy (EM) is used to determine non-sphericity in particle shape. EM is also used to determine particle surface area and account for transmission of multiply charged particles by the DMA. Single particle mass spectrometry and ion chromatography are used to investigate soluble material in wet-generated samples and demonstrate that wet and dry generation yield compositionally different particles. Activation results are analyzed in the context of both K-Köhler theory (K-KT) and Frenkel, Halsey, and Hill (FHH) adsorption activation theory. This study has two main results: (1) K-KT is the suitable framework to describe clay mineral nucleation activity. Apparent differences in K with respect to size arise from an artifact introduced by improper size-selection methodology. For dust particles with mobility sizes larger than ~ 300 nm, i.e. ones that are in an atmospherically relevant size range, both K-KT and FHH theory yield similar critical supersaturations. However, the former requires a single hygroscopicity parameter instead of the two adjustable parameters required by the latter. For dry-generated particles, the size dependence of K is likely an artifact of the shape of the size distribution: there is a sharp drop-off in particle concentration at ~300 nm, and a large fraction of particles classified with a mobility diameter less than -300 nm are actually multiply charged, resulting in a much lower critical supersaturation for droplet activation than expected. For wet-generated particles, deviation from K-KT is likely a result of the dissolution and redistribution of soluble material. (2) Wet-generation is found to be unsuitable for simulating the lofting of fresh dry dust because it changes the size-dependent critical supersaturations by fractionating and re-partitioning soluble material. by Sarvesh Garimella. S.M. in Atmospheric Science 2014-10-09T14:12:25Z 2014-10-09T14:12:25Z 2014 2014 Thesis http://hdl.handle.net/1721.1/90821 890387319 eng M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission. http://dspace.mit.edu/handle/1721.1/7582 65 pages application/pdf Massachusetts Institute of Technology |
| spellingShingle | Earth, Atmospheric, and Planetary Sciences. Garimella, Sarvesh Cloud condensation nucleus activity comparison of dry- and wet-generated mineral dust aerosol : the significance of soluble material |
| title | Cloud condensation nucleus activity comparison of dry- and wet-generated mineral dust aerosol : the significance of soluble material |
| title_full | Cloud condensation nucleus activity comparison of dry- and wet-generated mineral dust aerosol : the significance of soluble material |
| title_fullStr | Cloud condensation nucleus activity comparison of dry- and wet-generated mineral dust aerosol : the significance of soluble material |
| title_full_unstemmed | Cloud condensation nucleus activity comparison of dry- and wet-generated mineral dust aerosol : the significance of soluble material |
| title_short | Cloud condensation nucleus activity comparison of dry- and wet-generated mineral dust aerosol : the significance of soluble material |
| title_sort | cloud condensation nucleus activity comparison of dry and wet generated mineral dust aerosol the significance of soluble material |
| topic | Earth, Atmospheric, and Planetary Sciences. |
| url | http://hdl.handle.net/1721.1/90821 |
| work_keys_str_mv | AT garimellasarvesh cloudcondensationnucleusactivitycomparisonofdryandwetgeneratedmineraldustaerosolthesignificanceofsolublematerial |