Preprints
https://doi.org/10.5194/egusphere-2024-770
https://doi.org/10.5194/egusphere-2024-770
08 Apr 2024
 | 08 Apr 2024
Status: this preprint is open for discussion and under review for Atmospheric Chemistry and Physics (ACP).

Atmospheric Black Carbon in the metropolitan area of La Paz and El Alto, Bolivia: concentration levels and emission sources

Valeria Mardoñez-Balderrama, Griša Močnik, Marco Pandolfi, Robin Modini, Fernando Velarde, Laura Renzi, Angela Marinoni, Jean-Luc Jaffrezo, Isabel Moreno R., Diego Aliaga, Federico Bianchi, Claudia Mohr, Martin Gysel-Beer, Patrick Ginot, Radovan Krejci, Alfred Widensohler, Gaëlle Uzu, Marcos Andrade, and Paolo Laj

Abstract. Black carbon (BC) is a major component of sub-micron particulate matter (PM) with significant health and climate impacts. Many cities in emerging countries lack comprehensive knowledge about BC emissions and exposure levels. This study investigates BC concentration levels, identify its emission sources, and characterize the optical properties of BC at urban background sites of the two largest high-altitude Bolivian cities: La Paz (LP) (3600 m above sea level) and El Alto (EA) (4050 m a.s.l.) where atmospheric oxygen levels and intense radiation may affect BC production. The study relies on concurrent measurements of equivalent black carbon (eBC), elemental carbon (EC), and refractory black carbon (rBC), and their comparison with analogous data collected at the nearby Global Atmosphere Watch-Chacaltaya station (5240 m a.s.l). The performance of two independent source-apportionment techniques was compared: a bilinear model and a least squares multilinear regression (MLR). Maximum eBC concentrations were observed during the local dry season (LP: eBC=1.5±1.6 μg m-3; EA: 1.9±2.0 μg m-3). While eBC concentrations are lower at the mountain station, daily transport from urban areas is evident. Average mass absorption cross sections of 6.6-8.2 m2 g-1 were found in the urban area at 637 nm. Both source apportionment methods exhibited a reasonable level of agreement in the contribution of biomass burning (BB) to absorption. The MLR method allowed the estimation of the contribution and the source-specific optical properties for multiple sources including open waste burning.

Publisher's note: Copernicus Publications remains neutral with regard to jurisdictional claims made in the text, published maps, institutional affiliations, or any other geographical representation in this preprint. The responsibility to include appropriate place names lies with the authors.
Valeria Mardoñez-Balderrama, Griša Močnik, Marco Pandolfi, Robin Modini, Fernando Velarde, Laura Renzi, Angela Marinoni, Jean-Luc Jaffrezo, Isabel Moreno R., Diego Aliaga, Federico Bianchi, Claudia Mohr, Martin Gysel-Beer, Patrick Ginot, Radovan Krejci, Alfred Widensohler, Gaëlle Uzu, Marcos Andrade, and Paolo Laj

Status: open (until 19 Jun 2024)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on egusphere-2024-770', Anonymous Referee #1, 10 May 2024 reply
Valeria Mardoñez-Balderrama, Griša Močnik, Marco Pandolfi, Robin Modini, Fernando Velarde, Laura Renzi, Angela Marinoni, Jean-Luc Jaffrezo, Isabel Moreno R., Diego Aliaga, Federico Bianchi, Claudia Mohr, Martin Gysel-Beer, Patrick Ginot, Radovan Krejci, Alfred Widensohler, Gaëlle Uzu, Marcos Andrade, and Paolo Laj
Valeria Mardoñez-Balderrama, Griša Močnik, Marco Pandolfi, Robin Modini, Fernando Velarde, Laura Renzi, Angela Marinoni, Jean-Luc Jaffrezo, Isabel Moreno R., Diego Aliaga, Federico Bianchi, Claudia Mohr, Martin Gysel-Beer, Patrick Ginot, Radovan Krejci, Alfred Widensohler, Gaëlle Uzu, Marcos Andrade, and Paolo Laj

Viewed

Total article views: 257 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
186 57 14 257 24 8 8
  • HTML: 186
  • PDF: 57
  • XML: 14
  • Total: 257
  • Supplement: 24
  • BibTeX: 8
  • EndNote: 8
Views and downloads (calculated since 08 Apr 2024)
Cumulative views and downloads (calculated since 08 Apr 2024)

Viewed (geographical distribution)

Total article views: 219 (including HTML, PDF, and XML) Thereof 219 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Latest update: 28 May 2024
Download
Short summary
Levels of black carbon (BC) are scarcely reported in the southern hemisphere, especially in high-altitude conditions. This study provides insight on the concentration level, variability, and optical properties of BC in the cities of La Paz and El Alto, and at the station GAW Chacaltaya Mountain station. Two methods of source apportionment of absorption were tested and compared showing traffic as the main contributor to absorption in the urban area, additionally to biomass and open waste burning.