Monitoring aerosols over Europe: an assessment of the potential benefit of assimilating the VIS04 measurements from the future MTG/FCI geostationary imager

Abstract

Abstract. The study assesses the possible benefit of assimilating aerosol optical depth (AOD) from the future space-borne sensor FCI (Flexible Combined Imager) for air quality monitoring in Europe. An observing system simulation experiment (OSSE) was designed and applied over a 4-month period, which includes a severe-pollution episode. The study focuses on the FCI channel centred at 444 nm, which is the shortest wavelength of FCI. A nature run (NR) and four different control runs of the MOCAGE chemistry transport model were designed and evaluated to guarantee the robustness of the OSSE results. The synthetic AOD observations from the NR were disturbed by errors that are typical of the FCI. The variance of the FCI AOD at 444 nm was deduced from a global sensitivity analysis that took into account the aerosol type, surface reflectance and different atmospheric optical properties. The experiments show a general benefit to all statistical indicators of the assimilation of the FCI AOD at 444 nm for aerosol concentrations at the surface over Europe, and also a positive impact during the severe-pollution event. The simulations with data assimilation reproduced spatial and temporal patterns of PM10 concentrations at the surface better than those without assimilation all along the simulations and especially during the pollution event. The advantage of assimilating AODs from a geostationary platform over a low Earth orbit satellite has also been quantified. This work demonstrates the capability of data from the future FCI sensor to bring added value to the MOCAGE aerosol simulations, and in general, to other chemistry transport models.

Modelling the volcanic ash plume from Eyjafjallajökull eruption (May 2010) over Europe: evaluation of the benefit of source term improvements and of the assimilation of aerosol measurements

“…The rather low impact of the assimilation of MODIS AOD on this case could be due to different reasons, one of them being the revisit time of polar-orbiting satellites. The assimilation of AOD from geostationary satellites, such as MTG in the future (Descheemaecker et al, 2019), by increasing the time frequency of the measurements, could increase the impact in space and time. The present study is the first one, to our knowledge, that assesses the impact of continuous assimilation of ground-based lidars on a volcanic ash cloud.…”

“…The observation operator for AOD in MOCAGE is described by Sič et al (2016), except that the optical properties have been updated by Descheemaecker et al (2019) since then. Volcanic ash optical properties are issued from Pollack et al (1973).…”

Modeling study of the impact of SO<sub>2</sub> volcanic passive emissions on the tropospheric sulfur budget

“…Both primary and secondary aerosols are represented in the model [Martet et al (2009), Sic et al (2015), Guth et al (2016), Descheemaecker et al (2019)]. All types of aerosols use the same set of six sectional size bins, ranging from 2 nm to 50 µm (with size bins limits of 2, 10, and 100 nm, and 1, 2.5, 10 and 50 µm).…”

“…Secondary organic aerosols (SOA) are estimated from the partition between particulate organic compounds and black carbon measured into observation samples [Castro et al (1999)]. Therefore it is implemented in the model as a ratio of the primary carbon species in the emission input [Descheemaecker et al (2019)].…”

Assessing the Potential of Geostationary Satellites for Aerosol Remote Sensing Based on Critical Surface Albedo

“…Similarly, the new channel IR022 may also help with the detection of coarser particles. This additional potential of MTG-I may help to improve the detection of aerosols [13] and to enhance chemical transport models through data assimilation [12]. Similar wavelengths to those of the two FCI channels considered in this work are already available for the Himawari-8/9 and GOES-16/17 platforms.…”