2. MAX-DOAS network and satellite observations

We developed light-weighted MAX-DOAS instrument, which observes UV/vis spectra of scattered sunlight at selected elevation angles from ground/ship platforms to retrieve vertical profiles/column amount of NO2, HCHO, and aerosols. The instruments are distributed to form a Japan/Korea/China/Russia monitoring network, and on research vessels. More detailed information and numerical data are available in another page (link). The unique, large data set from 2007 till now is used to validate satellite observations, such as OMI, TROPOMI, and GEMS. Our findings are that satellite-based Tropospheric NO2 column density has low bias when aerosols are perturbing the radiative transfer and when NO2 is populated near the ground surface. Our previous proposal to measure NO2 at a dramatically improved spatial resolution, down to 1 x 1 km, has been integrated to GOSAT-GW (Global Observing SATellite for Greenhouse gases and Water cycle); with CO2 and methane, "single emission sources " will be identified and non-linear ozone photochemistry will be investigated.

More information

  • press release, August 2014
  • Choi, Y. et al. (2023). Changes in Tropospheric Nitrogen Dioxide Vertical Column Densities over Japan and Korea during the COVID-19 Using Pandora and MAX-DOAS. Aerosol Air Qual. Res. 23, 220145.
  • Choi, Y. et al. (2021). Long-term variation in the tropospheric nitrogen dioxide vertical column density over Korea and Japan from the MAX-DOAS network, 2007-2017. Remote Sens. 13, 1937.
  • Kanaya, Y. et al. (2014), Long-term MAX-DOAS network observations of NO2 in Russia and Asia (MADRAS) during 2007–2012: instrumentation, elucidation of climatology, and comparisons with OMI satellite observations and global model simulations, Atmos. Chem. Phys., 14, 7909-7927.
  • Irie, H. et al. (2008), First retrieval of tropospheric aerosol profiles using MAX-DOAS and comparison with lidar and sky radiometer measurements, Atmos. Chem. Phys., 8, 341-350.
  • Takashima, H. et al. (2009): Atmospheric aerosol variations at Okinawa Island in Japan observed by MAX-DOAS using a new cloud-screening method, J. Geophys. Res., 114, D18213