Validation of GEMS tropospheric NO2 with the GEMS IUP-UB NO2 product, the TROPOMI NO2 product, and ground-based DOAS measurements
- 1Institute of Environmental Physics, University of Bremen, Bremen, Germany (klange@iup.physik.uni-bremen.de)
- 2Royal Belgian Institute for Space Aeronomy, Brussels, Belgium
- 3Max Planck Institute for Chemistry, Mainz, Germany
- 4Environmental Satellite Center, National Institute of Environmental Research, Incheon, Republic of Korea
- 5Department of Civil, Urban, Earth and Environmental Engineering, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
- 6Research & Management Center for Particulate Matters at the Southeast Region of Korea, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
- 7School of Carbon Neutrality, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
- 8Division of Earth Environmental System Science, Major of Spatial Information Engineering, Pukyong National University, Busan, Republic of Korea
Nitrogen dioxide (NO2) is one of the most important air pollutants in the troposphere. NO2 can be retrieved by differential optical absorption spectroscopy measurements, which can be performed from various platforms.
Measurements from low earth satellites in sun-synchronous orbits provide a global overview and have already contributed valuable insights into understanding NO2. The latest instrument, TROPOMI, with its high spatial resolution of 3.5 x 5.5 km2, has given new opportunities to disentangle and analyze NOx sources. However, instruments in low-earth orbits usually provide only one measurement per day at each location.
To achieve diurnal cycles of trace gases, instruments on geostationary satellites are needed. The Korean instrument GEMS on GK2B, launched in February 2020, is the first instrument in geostationary orbit, delivering hourly daytime observations of NO2 with a spatial resolution of 3.5 x 8 km2 over a large part of Asia.
In this study, one year of tropospheric NO2 vertical column densities (VCDs) of the operational GEMS product are compared to the scientific GEMS IUP-UB NO2 VCD product, the operational TROPOMI NO2 VCD product, and ground-based DOAS measurements in Korea. The diurnal variation of NO2 observed by GEMS is compared to the diurnal variation observed at several ground-based MAX-DOAS stations located in different pollution regimes in Korea. The large variety of observed diurnal cycles are interpreted regarding potential influencing factors. In this respect, the ERA5 10 m wind data provide valuable insights into the influence of transport effects on the tropospheric NO2 VCD depending on station location and seasonality.
How to cite: Lange, K., Richter, A., Bösch, T., Zilker, B., Burrows, J. P., Bösch, H., Merlaud, A., Fayt, C., Friedrich, M. M., Van Roozendale, M., Ziegler, S., Ripperger-Lukosiunaite, S., Wagner, T., Kim, D., Chang, L.-S., Hong, H., Bae, K., Song, C.-K., and Lee, H.: Validation of GEMS tropospheric NO2 with the GEMS IUP-UB NO2 product, the TROPOMI NO2 product, and ground-based DOAS measurements, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-10891, https://doi.org/10.5194/egusphere-egu24-10891, 2024.
