Tropospheric Ozone and its Precursors over Equatorial Eastern Africa: the Case of Addis Ababa, Ethiopia

The Equatorial Africa is known by its frequent occurrence of fire activity which injects burden of air pollutants in the atmosphere. In addition, the region usually experiences thunderstorm and lightening which undergo chemical transformations of some trace gases which alter the composition of the troposphere. Thus, studying the dispersion of pollutants and the stratosphere-troposphere exchange are among the biggest challenge of the region.
The FTIR spectrometer, installed in Addis Ababa, is among the instruments deployed to monitor the air quality in the region. The spectrometer is characterized by a 0.00775 cm-1 spectral resolution with the ability to resolve more than 30 trace gases in the atmosphere. In addition, sparse presence of FTIR instruments in the tropic and its unique presence in Africa, makes the instrument vital to our region in general and to the study domain in particular. We use the spectra obtained from the spectrometer (IFS 120/125HR) to retrieve the total column amount of trace gases and their volume mixing ratio at 44 pressure levels. PROFFIT is the most widely used retrieval algorithm in quantifying the chemical species.
We used FLEXPART model to simulate source-receptor relation ship especially when an outliers are detected during observation. The model was driven by National Centers for Environmental Prediction (NCEP) final (FNL) gridded analysis datasets for the winter periods of 2009 and 2010. The simulation reveals that the eastern part of the observation site is the most important region to be investigated more. The model is also capable of capturing the source regions contributing to the enhancement observed.


Institut für Meteorologie (BOKU-Met)
Sufa Gezahegn
Zielgruppe: Forscher/-innen
Zielgruppe: Studieninteressierte
Kontaktperson (allgem.)
Dr. Assoc.Prof. Petra Seibert

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