Spatio-temporal distribution and source partitioning of formaldehyde over Ethiopia and Kenya

Yang Liu, Zhipeng Tang, Temesgen Abera, Xuezhen Zhang, Hannele Hakola, Petri Pellikka, Eduardo Maeda

Research output: Contribution to journalArticleScientificpeer-review

Abstract

Understanding the local sources of atmospheric formaldehyde (HCHO) is a key step in accurately determining the inversion of biogenic volatile organic compounds (BVOCs). This study aims to clarify the main sources and emission patterns of local total HCHO column densities over Ethiopia and Kenya. Between 2005 and 2015, the total monthly HCHO varied from 3.7 x 10(15) molecules/cm(2) to 7.7 x 10(15) molecules/cm(2). Monthly HCHO showed a strong seasonal pattern with annual peaks on March, July (small peak) and October, which well matched with the rainy seasons in Ethiopia and Kenya. Natural sources contributed 36% to the total HCHO in the study area. Grassland and savannas showed high column densities in the long rainy season starting from March, with the monthly average emission value of 5.6 x 10(15) molecules/cm(2). Multiple regression result showed that vegetation contributed 3.5 x 10(13) molecules/cm(2) to monthly HCHO, with grassland and forest in eastern Kenya and the boundary of Ethiopia and Kenya were the main contributors in these regions. Biomass burning and methane contributed to HCHO emission in the western and northern Ethiopia with a magnitude of 1.4 x 10(14) molecules/cm(2) and 6.2 x 10(16) molecules/cm(2) per month, respectively. Economic activities showed negative response to HCHO columns, except over the two small-scale regions of Addis Ababa City and Nairobi City. This study quantified the HCHO from various sources and suggested that natural sources produce more HCHO than anthropogenic sources over Ethiopia and Kenya.

Original languageEnglish
Article number117706
JournalAtmospheric Environment
Volume237
Issue numberSept 2020
Number of pages9
ISSN1352-2310
DOIs
Publication statusPublished - 15 Sept 2020
MoE publication typeA1 Journal article-refereed

Fields of Science

  • 1172 Environmental sciences
  • Formaldehyde
  • distribution
  • Source partitioning
  • OMI
  • East Africa
  • VOLATILE ORGANIC-COMPOUNDS
  • ANTHROPOGENIC EMISSIONS
  • ISOPRENE EMISSIONS
  • CARBON-MONOXIDE
  • COLUMNS
  • SATELLITE
  • HCHO
  • TRENDS
  • MODEL

Cite this