Temporal variability of methane emissions from a closed landfill at Denmark

Konstantinos Kissas,Charlotte Scheutz,Andreas Ibrom,Peter Kjeldsen

doi:10.5194/egusphere-egu21-12518

Abstract

&lt;p&gt;Methane (CH&lt;sub&gt;4&lt;/sub&gt;) emissions from landfills contribute to global warming, impacting significantly the environment and human health. Landfill CH&lt;sub&gt;4&lt;/sub&gt; emissions strongly depend on changes in barometric pressure, inducing short-term CH&lt;sub&gt;4&lt;/sub&gt; emission variation of several orders of magnitude. Estimating the temporal variability of CH&lt;sub&gt;4&lt;/sub&gt; emitted into the atmosphere could help us reducing the uncertainties of annual emission estimates from landfills. In this study, we focus on the temporal variability of CH&lt;sub&gt;4&lt;/sub&gt; emissions under the impact of barometric pressure changes.&lt;/p&gt;&lt;p&gt;CH&lt;sub&gt;4&lt;/sub&gt; emissions of a closed landfill (Skellingsted, Western Zealand, Denmark) were measured with two different methods from December 2019 to June 2020; continuously with the eddy covariance method (EC) and discretely with the dynamic tracer dispersion method (TDM). The EC method allows continuous measurements from a confined surface area, with most likely limited representativeness of the whole landfill site due to the considerable horizontal heterogeneity. The TDM method is able to quantify the emission from the whole site insensitive of the topography with the limited representativeness for the temporal variability.&lt;/p&gt;&lt;p&gt;CH&lt;sub&gt;4&lt;/sub&gt; emissions to the atmosphere measured by the TDM and fluxes measured by the EC ranged from to 0 to almost 100 kg h&lt;sup&gt;-1&lt;/sup&gt; and from 0 to 10 &amp;#956;mol m&lt;sup&gt;-2&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;, respectively. The CH&lt;sub&gt;4&lt;/sub&gt; fluxes measured continuously using the EC method were highly correlated with the emissions from the periodic measurements using the TDM and fluctuated according to the pressure tendency. Under decreasing barometric pressure the highest CH&lt;sub&gt;4&lt;/sub&gt; emissions where observed, while increasing barometric pressure suppressed them almost to 0.&lt;/p&gt;&lt;p&gt;Our results demonstrate the value of implementing two different complementary measurement techniques in parallel that will help to quantify total annual CH&lt;sub&gt;4&lt;/sub&gt; emission from a landfill. EC method provides continuous measurements describing accurately the temporal variation of emissions, while TDM method is able to quantify emissions from the whole site.&lt;/p&gt;

Highlights

General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights
We focus on the temporal variability of CH4 emissions under the impact of barometric pressure changes
The tracer dispersion method (TDM) method is able to quantify the emission from the whole site insensitive of the topography with the limited representativeness for the temporal variability

Summary

Introduction

General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. Citation (APA): Kissas, K., Ibrom, A., Kjeldsen, P., & Scheutz, C.

Results

Conclusion