Journal cover Journal topic
Atmospheric Measurement Techniques An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

Journal metrics

  • IF value: 3.400 IF 3.400
  • IF 5-year value: 3.841 IF 5-year
    3.841
  • CiteScore value: 3.71 CiteScore
    3.71
  • SNIP value: 1.472 SNIP 1.472
  • IPP value: 3.57 IPP 3.57
  • SJR value: 1.770 SJR 1.770
  • Scimago H <br class='hide-on-tablet hide-on-mobile'>index value: 70 Scimago H
    index 70
  • h5-index value: 49 h5-index 49
Discussion papers
https://doi.org/10.5194/amt-2019-170
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/amt-2019-170
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.

Submitted as: research article 28 May 2019

Submitted as: research article | 28 May 2019

Review status
This discussion paper is a preprint. A revision of the manuscript is under review for the journal Atmospheric Measurement Techniques (AMT).

Methane (CH4) and nitrous oxide (N2O) from ground-based FTIR at Addis Ababa: observations, error analysis and comparison with satellite data

Temesgen Yirdaw Berhe1, Gizaw Mengistu Tsidu1,2, Thomas Blumenstock3, Frank Hase3, and Gabriele P. Stiller3 Temesgen Yirdaw Berhe et al.
  • 1Department of Physics, Addis Ababa University, P.O.Box 1176, Addis Ababa, Ethiopia
  • 2Department of Earth and Environmental Sciences, College of Science, Botswana International University of Technology and Science (BIUST), Priv.Bag 16, Palapye, Botswana
  • 3Institute of Meteorology and Climate Research (IMK-ASF), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany

Abstract. A ground based high spectral resolution Fourier transform infrared (FTIR) spectrometer has been operational at Addis Ababa (9.0° N, 38.76° E, 2443 m a.s.l.) since May 2009 to obtain information on the total column abundances and vertical distribution of various constituents in the atmosphere. The retrieval strategy and the results on information content and corresponding full error budget evaluation for methane and nitrous oxide retrievals are presented. They reveal the high quality of FTIR measurements at Addis Ababa. The FTIR products of CH4 and N2O have been compared to coincident volume mixing ratio (VMR) measurements obtained from the reduced spectral resolution (Institute of Meteorology and Climate Research) IMK/IAA MIPAS satellite instrument (Version V5R_CH4_224 and V5R_N2O_224), the Microwave Limb Sounder on board of the Aura satellite (Aura/MLS) (MLS v3.3 of N2O and CH4 derived from MLS v3.3 products of CO, N2O and H2O) and the Atmospheric Infrared Sounder (AIRS). From comparison of FTIR CH4 and IMK/IAA MIPAS V5R_CH4_224, a statistically significant bias between −4.8 and +4.6 % in altitude ranges of the upper troposphere and lower stratosphere (15–27 km) are determined. The largest negative bias in FTIR CH4 is found in the altitude range of 11–19 km with a maximum difference of −0.08 ppmv (−4.8 %) at around 15 km, a positive bias of less than 0.14 ppmv (9 %) is found in the altitude range of 21 to 27 km with a maximum value at around 27 km with respect to AIRS. On the other hand, comparison of CH4 from ground based FTIR and MLS-derived CH4 (version 3.3) indicate existence of a significant positive bias of 2.3 % to 11 % in the altitude range of 20 to 27 km and a negative bias −1.7 % at 17 km. In the case of N2O derived from FTIR and MIPAS V5R_N2O_224 comparison, a significant positive bias of less than 15 % in the altitude range 22–27 km with a maximum value at around 25 km and a negative bias of −7 % have been found at 17 km. A positive bias of less than 18.6 % in FTIR N2O for the altitude below 27 km is noted when compared to MLS v3.3 N2O. Precision of ground based FTIR CH4 and N2O in the upper troposphere and lower stratosphere over Addis Ababa are better than 7.2 % and 9 %, respectively which are comparable to the bias obtained from the comparisons.

Temesgen Yirdaw Berhe et al.
Temesgen Yirdaw Berhe et al.
Viewed  
Total article views: 725 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
639 81 5 725 2 5
  • HTML: 639
  • PDF: 81
  • XML: 5
  • Total: 725
  • BibTeX: 2
  • EndNote: 5
Views and downloads (calculated since 28 May 2019)
Cumulative views and downloads (calculated since 28 May 2019)
Viewed (geographical distribution)  
Total article views: 536 (including HTML, PDF, and XML) Thereof 529 with geography defined and 7 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Cited  
Saved  
No saved metrics found.
Discussed  
No discussed metrics found.
Latest update: 13 Dec 2019
Publications Copernicus
Download
Short summary
A ground-based FTIR measurement at the Addis Ababa site has been launched since 2009 in collaboration with Karlsruhe Institute of technology, Germany to measure concentrations of various trace gases in the lower and middle atmosphere over Addis Ababa. The quality of ground based FTIR measurements of CH4 and N2O has been validated by MIPAS, MLS and AIRS. This is the first ground-based FTIR CH4 and N2O at equatorial station. Therefore, the performance of instruments, FTIR in tropics is vital.
A ground-based FTIR measurement at the Addis Ababa site has been launched since 2009 in...
Citation