Ammonia, carbon dioxide and methane in Mediterranean paddy fields along the 2019 crop season

Human activities implying land management are potential sources of greenhouse gases (GHGs) such as carbon dioxide (CO₂) and methane (CH₄). In addition, agricultural management practices enhances the presence of reactive gases in the atmosphere such as ammonia (NH₃).  Knowing the atmospheric variability of gases in relation to the different stages of the rice culture cycle and other anthropic activities could help to improve GHGs' mitigation strategies in deltas.

A mobile survey was undertaken through 2019 in the Ebro Delta as a part of the ClimaDat Network project (DEC station, www.climadat.es), to study the effect of land management in the spatial and temporal variability of greenhouse gases and NH₃ concentrations. We are broadening the scope of a survey undertaken in 2012 (Àgueda et al. 2017). In the new survey we increased the total number of transects and longitude every three weeks during a year, starting in December 2018.

Whereas atmospheric NH₃ concentration links with diurnal and seasonal cycles, the distribution of CO₂ and CH₄ shows a combination of spatial and temporal variability.   Our aim is to understand how we can use wind trajectories to find the principal sources of atmospheric variability. That is, can wind direction improve our comprehension of metabolic processes occurring in paddy lands? In this work, we use wind trajectories as means of spatial classification, to explore the spatiotemporal dynamic affecting the potential of CO₂ and CH₄ atmospheric concentration.