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Please use this identifier to cite or link to this item: http://hdl.handle.net/123456789/3642

Title: OBSERVATION AND VALIDATION OF METHANE FROM FT-IR OVER ADDIS ABABA
Authors: Endale, Gemechu
Advisors: Dr. Gizaw Mengistu
Keywords: methane
Mid infra-red
Copyright: Jun-2011
Date Added: 6-Nov-2012
Publisher: AAU
Abstract: The concentration of methane, the most abundant organic trace gas in the atmosphere has increased dramatically, over the past few centuries, to more than double its value. The increase in its concentration is of special concern because of its e ects on climate and atmospheric chemistry. High resolution Mid infra-red (MIR) solar absorption FTIR spectra have been routinely recorded between May 2009 and Nov 2010 at Addis Ababa Observatory (9.01oN, 38.76oE). By analyzing the shape of the pressure dependent absorption lines and their di erent temperature sensitivities, the vertical distribution and column amount of methane is retrieved. Unique time series of the column abundances and volume mixing ratio (vmr) of methane are presented. The e ects of both dynamical and chemical seasonally varying trace gas cycles can be seen in the retrieved pro les. These include little variabilities in summer and winter seasons, which is typical of tropical atmosphere. Particular events are selected and origin of air mass ow is identi ed with the help of Air Resource Laboratory's (ARL) Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model. A detailed error analysis has been performed for each pro le. The output from Atmospheric Infra-Red Sounder (AIRS) is compared to the total column amount. Results agree well with a correlation coe cient of 0.8.
Description: A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE IN PHYSICS
URI: http://hdl.handle.net/123456789/3642
Appears in:Thesis - Physics

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