Advances in methane retrieval algorithms using TROPOMI data on Sentinel-5P

As global climate change issues become increasingly severe, methane (CH4), important greenhouse gas, has garnered widespread attention. Remote sensing technology, especially the TROPOMI instrument on the Sentinel-5P satellite launched by the European Space Agency, provides unprecedented opportunities for extracting methane information globally. This review aims to systematically organize and analyze the main algorithms for methane retrieval using TROPOMI data. Firstly, the technical characteristics and data products of the TROPOMI instrument are introduced; subsequently, the common methane retrieval products and their applications are described. Finally, the widely used methane retrieval algorithms, including the RemoTeC full-physics algorithm, Differential Optical Absorption Spectroscopy (DOAS), and neural network algorithms, are introduced, and their advantages, disadvantages, and applicability are summarized. It is hoped that this review can provide comprehensive reference material for researchers and policymakers to better utilize remote sensing technology for monitoring and managing methane emissions.