1Institute of Geophysics, University of Hamburg, Hamburg, Germany
2Centre of Excellence Space-SI, Ljubljana, Slovenia
3Faculty of Electrical Engineering, University of Ljubljana, Ljubljana, Slovenia
Received: 01 Sep 2012 – Published in Atmos. Chem. Phys. Discuss.: 26 Sep 2012
Abstract. Volcanic ash cloud-top height (ACTH) can be monitored on the global level using satellite remote sensing. Here we propose a photogrammetric method based on the parallax between data retrieved from geostationary and polar orbiting satellites to overcome some limitations of the existing methods of ACTH retrieval. SEVIRI HRV band and MODIS band 1 are a good choice because of their high resolution. The procedure works well if the data from both satellites are retrieved nearly simultaneously. MODIS does not retrieve the data at exactly the same time as SEVIRI. To compensate for advection we use two sequential SEVIRI images (one before and one after the MODIS retrieval) and interpolate the cloud position from SEVIRI data to the time of MODIS retrieval. The proposed method was tested for the case of the Eyjafjallajökull eruption in April 2010. The parallax between MODIS and SEVIRI data can reach 30 km, which implies an ACTH of approximately 12 km at the beginning of the eruption. At the end of April eruption an ACTH of 3–4 km is observed. The accuracy of ACTH was estimated to be 0.6 km.
Revised: 14 Feb 2013 – Accepted: 15 Feb 2013 – Published: 05 Mar 2013
Zakšek, K., Hort, M., Zaletelj, J., and Langmann, B.: Monitoring volcanic ash cloud top height through simultaneous retrieval of optical data from polar orbiting and geostationary satellites, Atmos. Chem. Phys., 13, 2589-2606, doi:10.5194/acp-13-2589-2013, 2013.