Xin Tian

TL;DR: The second Cabauw Intercomparison campaign for Nitrogen Dioxide measuring instruments (CINDI-2) as discussed by the authors was held in 2016 and the three major goals of the campaign were (1) characterising and better understanding the differences between a large number of multi-axis differential optical absorption (MAX-DOAS) and zenith-sky DOAS instruments, (2) defining a robust methodology for performance assessment of all participating instruments, and (3) contributing to a harmonisation of the measurement settings and retrieval methods.

TL;DR: Tan-Tan-Tracker as discussed by the authors is a data assimilation framework based on the PODEn4DVar approach, which includes both the atmospheric CO2 concentrations and the surface CO2 fluxes as part of the large state vector to be simultaneously estimated.

TL;DR: POMINO-TROPOMI as mentioned in this paper is a new product with explicit aerosol corrections for tropospheric nitrogen dioxide (NO2) vertical column densities (VCDs) over East Asia, based on the newly launched TROPOspheric Monitoring Instrument with an unprecedented high horizontal resolution.

TL;DR: Ground-based multi-axis differential optical absorption spectroscopy network in Eastern China is used to retrieve variations of NO2, SO2, and formaldehyde in the YRD area to explore transport of tropospheric trace gas pollution in YRD.

TL;DR: In this paper, a regional surface CO2 flux inversion system (Carbon Flux Inversion system and Community Multi-scale Air Quality, CFI-CMAQ) has been developed by applying the ensemble Kalman filter (EnKF) to constrain the CO2 concentrations and applying the EnKS to optimize the surface CO 2 fluxes.