Preprints
https://doi.org/10.5194/egusphere-2024-1370
https://doi.org/10.5194/egusphere-2024-1370
03 Jun 2024
 | 03 Jun 2024
Status: this preprint is open for discussion and under review for Atmospheric Chemistry and Physics (ACP).

Estimation of seasonal methane fluxes over a Mediterranean rice paddy area using the Radon Tracer Method (RTM)

Roger Curcoll, Josep-Anton Morguí, Alba Àgueda, Lídia Cañas, Sílvia Borràs, Arturo Vargas, and Claudia Grossi

Abstract. The Ebro River Delta, in the northwestern Mediterranean basin, has an extension of 320 km2 and is mainly covered by rice fields. In the framework of the ClimaDat project, the greenhouse gases atmospheric station DEC was installed in this area in 2013. The DEC station was equipped, among others, with a Picarro G2301 instrument and an ARMON (Atmospheric Radon Monitor) to measure both CH4 and CO2, and 222Rn concentrations, respectively.

The variability of methane fluxes over this area and during the different phases of the rice production cycle was evaluated in this study by using the Radon Tracer Method (RTM). The RTM was carried out using: i) nocturnal hourly atmospheric measurements of CH4 and 222Rn between 2013 and 2019; and ii) FLEXPART-WRF back-trajectories coupled with radon flux maps for Europe with a resolution of 0.05º x 0.05º available thanks to the project traceRadon. Prior to the calculation of methane fluxes by RTM, the FLEXPART-WRF model and the traceRadon flux maps were evaluated by modelling atmospheric radon concentrations at DEC station and comparing them with observed data.

RTM based methane fluxes show a strong seasonality with maximums in October (13.9 mg CH4 m-2 h-1), corresponding with the period of harvest and straw incorporation in rice crop fields, and minimums between March and June (0.2 mg CH4 m-2 h‑1 to 0.6 mg CH4 m-2 h-1). The total estimated methane annual emission was about 262.8 kg CH4 ha‑1. These fluxes were compared with fluxes directly measured with static accumulation chambers by other researchers in the same area. Results show a stunning agreement between both methodologies, both having a very similar annual cycle and monthly mean absolute values.

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.
Roger Curcoll, Josep-Anton Morguí, Alba Àgueda, Lídia Cañas, Sílvia Borràs, Arturo Vargas, and Claudia Grossi

Status: open (until 15 Jul 2024)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
Roger Curcoll, Josep-Anton Morguí, Alba Àgueda, Lídia Cañas, Sílvia Borràs, Arturo Vargas, and Claudia Grossi
Roger Curcoll, Josep-Anton Morguí, Alba Àgueda, Lídia Cañas, Sílvia Borràs, Arturo Vargas, and Claudia Grossi

Viewed

Total article views: 112 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
89 18 5 112 17 2 4
  • HTML: 89
  • PDF: 18
  • XML: 5
  • Total: 112
  • Supplement: 17
  • BibTeX: 2
  • EndNote: 4
Views and downloads (calculated since 03 Jun 2024)
Cumulative views and downloads (calculated since 03 Jun 2024)

Viewed (geographical distribution)

Total article views: 94 (including HTML, PDF, and XML) Thereof 94 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Latest update: 12 Jun 2024
Download
Short summary
In this work, the methane emissions from the rice crops of the Ebro Delta were estimated with the Radon Tracer Method, using backtrajectories and radon and methane observations. Estimated fluxes show a strong seasonality with maximums in October, corresponding with the period of harvest and straw incorporation. The estimated annual methane emission was about 262.8 kg CH4 ha‑1. Results were compared with fluxes obtained with static chambers showing a stunning agreement between both methodologies.