PhD project: Quantifying the regional budget of methane using atmospheric concentration and isotopic composition measurements | Truls Andersen

Name: Truls Andersen

Supervisor: Dr. Huilin Chen (Centre for Isotope Research, ESRIG/RUG)
Started: October 2015 - October 2019

Summary of PhD project:

In 2010 it was estimated that methane emissions from agriculture accounted for close to half the Dutch methane emissions of 967 kiloton, while close to 26% is contributed by natural gas emissions. However, there is a large uncertainty in these estimates, and there have currently been no direct measurements to verify these estimates.

This PhD aims to quantify methane emissions with high precision and accuracy using atmospheric measurements of methane. It focuses on agricultural and natural gas derived methane emissions in the Netherlands. The atmospheric measurements are carried out on-board an unmanned aerial vehicle (UAV), also known as a drone. To obtain air samples for methane quantification, a modified version of the AirCore, currently used for stratospheric profiles, is being used. This modified version is much lighter, and actively samples air during both horizontal and vertical profiles. The total weight of this Active AirCore is close to 1 kg, making it suitable to be carried by the UAV, where continuous horizontal and vertical air sample profiles can be collected. The samples obtained during the flights are then analyzed in the laboratory for methane, providing horizontal and vertical methane profiles with high accuracy and precision. This is a unique way of obtaining high-precision methane profiles, and it makes it possible to quantify methane emissions from for instance certain methane hot spots. Currently, the Active AirCore has been successfully developed and tested at our atmospheric monitoring station at Lutjewad. The ultimate goal of this PhD is to quantify and partition methane sources on a regional scale, by making accurate atmospheric measurements of methane, as well as isotopic composition measurements of δ13C and δ2H in methane, reducing the overall uncertainty in methane emission estimates.