Dresden 2011 – scientific programme

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UP: Fachverband Umweltphysik

UP 1: Poster Session

UP 1.20: Poster

Tuesday, March 15, 2011, 18:30–20:30, P2

Using MERIS cloud data to improve the spatial resolution of SCIAMACHY NO2 over Tokyo — •Agshin Heybatov, Andreas Hilboll, Andreas Richter, Cornelia Schlundt, and John P. Burrows — Institut für Umweltphysik, Universität Bremen, Deutschland

Satellite observations of tropospheric nitrogen dioxide (NO₂) provide a way of globally measuring atmospheric NO₂ abundances. While these measurements have been used for trend assessments and emission estimates on a regional scale, the relatively large pixel size (60x30km²) of the SCIAMACHY instrument on Envisat makes it difficult to attribute measured NO₂ slant columns to localized sources of NO₂ emissions, like cities.

Here, we investigate the use of MERIS cloud fraction data to improve the spatial resolution of SCIAMACHY NO₂ measurements over the hot-spot Tokyo. MERIS and SCIAMACHY observe the same scene at the same time, with MERIS providing high-resolution cloud information (1x1km²) within one SCIAMACHY scene. This information is used to re-distribute the NO₂ retrieved from SCIAMACHY on a sub-pixel level to the cloud-free MERIS pixels. The underlying assumption is that the NO₂ observed in partially cloudy pixels can be attributed to the cloud-free parts only. Thus, spatial structures of emissions at scales smaller than a SCIAMACHY pixel become detectable.

In this paper, the method is described, first results from an application over Tokyo are reported and compared to other data sets with higher spatial resolution (GOME-2 narrow swath, OMI).