Optimal estimation of the surface fluxes of chloromethanes using a 3-D global atmospheric chemical transport
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 2008.
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| Format: | Thesis |
| Language: | eng |
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Massachusetts Institute of Technology
2009
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| Online Access: | http://hdl.handle.net/1721.1/45603 |
| _version_ | 1811071644762898432 |
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| author | Xiao, Xue, Ph. D. Massachusetts Institute of Technology |
| author2 | Ronald G. Prinn. |
| author_facet | Ronald G. Prinn. Xiao, Xue, Ph. D. Massachusetts Institute of Technology |
| author_sort | Xiao, Xue, Ph. D. Massachusetts Institute of Technology |
| collection | MIT |
| description | Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 2008. |
| first_indexed | 2024-09-23T08:54:27Z |
| format | Thesis |
| id | mit-1721.1/45603 |
| institution | Massachusetts Institute of Technology |
| language | eng |
| last_indexed | 2024-09-23T08:54:27Z |
| publishDate | 2009 |
| publisher | Massachusetts Institute of Technology |
| record_format | dspace |
| spelling | mit-1721.1/456032019-04-10T19:38:54Z Optimal estimation of the surface fluxes of chloromethanes using a 3-D global atmospheric chemical transport Xiao, Xue, Ph. D. Massachusetts Institute of Technology Ronald G. Prinn. Massachusetts Institute of Technology. Dept. of Earth, Atmospheric, and Planetary Sciences. Massachusetts Institute of Technology. Dept. of Earth, Atmospheric, and Planetary Sciences. Earth, Atmospheric, and Planetary Sciences. Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 2008. This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. Includes bibliographical references (p. 199-210). The four chloromethanes - methyl chloride (CH3Cl), dichloromethane (CH2Cl2), chloroform (CHCl3), and carbon tetrachloride (CCl4), are chlorine-containing gases contributing significantly to stratospheric ozone depletion and having adverse health effects. Large uncertainties in estimates of their source and sink magnitudes and temporal and spatial variations currently exist. GEIA inventories and other bottom-up emission estimates are used to construct a priori maps of surface fluxes of these species. The Model of Atmospheric Transport and CHemistry (MATCH), driven by NCEP interannually varying meteorological fields, is then used to simulate the trace gas mole fractions using the a priori emissions and to quantify the time series of sensitivities of tracer concentrations to different aseasonal, seasonal, and regional sources and sinks.We implement the Kalman filter (with the unit pulse response method) to estimate both constant (if applicable) and time-varying surface fluxes on regional/global scales at a monthly resolution for the three short-lived species between 2000-2004, and the continental industrial emissions and global oceanic sink for CCl4 at a 3-month resolution between 1996-2004. The high frequency observations from AGAGE, SOGE, NIES and NOAA/GMD HATS and other low frequency flask observations are used to constrain the source and sink magnitudes estimated as multiplying factors for the a priori fluxes and contained in the state vector in the Kalman filter. The CH3Cl inversion results indicate large CH3Cl emissions of 2240 ± 370 Gg yr-1 from tropical plants. The inversion implies greater seasonal oscillations of the natural sources and sink of CH3Cl compared to the a priori. Seasonal cycles have been derived for both the oceanic (for CHCl3 and CH2Cl2) and terrestrial (for CHCl3) sources, with summer maxima and winter minima emissions. Our inversion results show significant industrial sources of CH2Cl2 and CCl4 from the Southeast Asian region. Our inversions also exhibit the strong effects of the 2002/2003 globally wide-spread heat and drought conditions on the emissions of CH3Cl from tropical plants and global salt marshes, on the soil fluxes of CH3Cl and CHCl3, on the biomass burning sources of CH3Cl and CH2Cl2, and on the derived oceanic flux of CHCl3. by Xue Xiao. Ph.D. 2009-06-25T20:33:36Z 2009-06-25T20:33:36Z 2008 2008 Thesis http://hdl.handle.net/1721.1/45603 318453304 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 210 p. application/pdf Massachusetts Institute of Technology |
| spellingShingle | Earth, Atmospheric, and Planetary Sciences. Xiao, Xue, Ph. D. Massachusetts Institute of Technology Optimal estimation of the surface fluxes of chloromethanes using a 3-D global atmospheric chemical transport |
| title | Optimal estimation of the surface fluxes of chloromethanes using a 3-D global atmospheric chemical transport |
| title_full | Optimal estimation of the surface fluxes of chloromethanes using a 3-D global atmospheric chemical transport |
| title_fullStr | Optimal estimation of the surface fluxes of chloromethanes using a 3-D global atmospheric chemical transport |
| title_full_unstemmed | Optimal estimation of the surface fluxes of chloromethanes using a 3-D global atmospheric chemical transport |
| title_short | Optimal estimation of the surface fluxes of chloromethanes using a 3-D global atmospheric chemical transport |
| title_sort | optimal estimation of the surface fluxes of chloromethanes using a 3 d global atmospheric chemical transport |
| topic | Earth, Atmospheric, and Planetary Sciences. |
| url | http://hdl.handle.net/1721.1/45603 |
| work_keys_str_mv | AT xiaoxuephdmassachusettsinstituteoftechnology optimalestimationofthesurfacefluxesofchloromethanesusinga3dglobalatmosphericchemicaltransport |