EGU21-12565, updated on 04 Mar 2021
https://doi.org/10.5194/egusphere-egu21-12565
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Using a new divergence method to quantify methane emissions with TROPOMI on Sentinel-5p

Mengyao Liu1, Ronald Van der A1,2, Michiel Van Weele1, Henk Eskes1, Xiao Lu3, Jos de Laat1, Hao Kong4, Jiyunting Sun1, Jieying Ding1, Yuanhong Zhao5, and Hongjian Weng4
Mengyao Liu et al.
  • 1Royal Netherlands Meteorological Institute, Satellite observation department, De Bilt, Netherlands (mengyao.liu@knmi.nl)
  • 2Nanjing University of Information Science & Technology (NUIST), Nanjing, China
  • 3School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
  • 4Department of Atmospheric and Oceanic Sciences, School of Physics, Peking University, Beijing, China
  • 5College of Oceanic and Atmospheric Sciences, Ocean University of China, Qingdao, China

The high-resolution Tropospheric Monitoring Instrument (TROPOMI) satellite observations of atmospheric methane offer a powerful tool to identify emission hot spots and quantify regional emissions. The divergence of horizontal fluxes of NO2 has already been proven to be an efficient way to resolve and quantify high sources on a global scale. Since the lifetime of CH4 is in the order of 10 years, the sinks can be ignored at the synoptic time scale which makes the divergence method even more applicable to CH4 than to short-lived NO2
Because plumes of newly emitted CH4 disperse within the Planetary Boundary Layer (PBL), we first convert the satellite observed total column average (XCH4) to a regional enhancement of methane in the PBL (∆XCH4_PBL) by using the CAMS global methane background reanalysis fields above the PBL. These model fields represent the transport- and chemically-modulated large-scale distribution of methane. Secondly, the divergence of ∆XCH4_PBL is derived by the use of the wind speeds halfway within the PBL. Based on the divergence, methane emissions are estimated on a 0.25°× 0.25° grid. We tested our new method for Texas in the United States and quantified methane emissions from the well-known oil-gas fields in the Permian Basin, as well as from – less well quantitatively established – oil-gas fields located in southern coastal areas. 
Compared to traditional inverse methods, our method is not restricted by an a priori emission inventory and so far unidentified local sources (i.e. emissions from livestock in feed yards) may be found. Due to its computational efficiency, the method might be applied in the near future globally on the current spatial resolution.

How to cite: Liu, M., Van der A, R., Van Weele, M., Eskes, H., Lu, X., de Laat, J., Kong, H., Sun, J., Ding, J., Zhao, Y., and Weng, H.: Using a new divergence method to quantify methane emissions with TROPOMI on Sentinel-5p, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-12565, https://doi.org/10.5194/egusphere-egu21-12565, 2021.

Corresponding presentation materials formerly uploaded have been withdrawn.