Journal cover Journal topic
Atmospheric Measurement Techniques An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

Journal metrics

  • IF value: 3.248 IF 3.248
  • IF 5-year value: 3.650 IF 5-year 3.650
  • CiteScore value: 3.37 CiteScore 3.37
  • SNIP value: 1.253 SNIP 1.253
  • SJR value: 1.869 SJR 1.869
  • IPP value: 3.29 IPP 3.29
  • h5-index value: 47 h5-index 47
  • Scimago H index value: 60 Scimago H index 60
Volume 10, issue 2 | Copyright
Atmos. Meas. Tech., 10, 409-429, 2017
https://doi.org/10.5194/amt-10-409-2017
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.

Research article 02 Feb 2017

Research article | 02 Feb 2017

Cloud and DNI nowcasting with MSG/SEVIRI for the optimized operation of concentrating solar power plants

Tobias Sirch1, Luca Bugliaro1, Tobias Zinner2, Matthias Möhrlein3, and Margarita Vazquez-Navarro1 Tobias Sirch et al.
  • 1Deutsches Zentrum für Luft- und Raumfahrt, Institut für Physik der Atmosphäre, Oberpfaffenhofen, Germany
  • 2Meteorologisches Institut, Ludwig-Maximilians-Universität, Munich, Germany
  • 3Nowcast GmbH, Albert-Roßhaupter-Str. 43, Munich, Germany

Abstract. A novel approach for the nowcasting of clouds and direct normal irradiance (DNI) based on the Spinning Enhanced Visible and Infrared Imager (SEVIRI) aboard the geostationary Meteosat Second Generation (MSG) satellite is presented for a forecast horizon up to 120min. The basis of the algorithm is an optical flow method to derive cloud motion vectors for all cloudy pixels. To facilitate forecasts over a relevant time period, a classification of clouds into objects and a weighted triangular interpolation of clear-sky regions are used. Low and high level clouds are forecasted separately because they show different velocities and motion directions. Additionally a distinction in advective and convective clouds together with an intensity correction for quickly thinning convective clouds is integrated. The DNI is calculated from the forecasted optical thickness of the low and high level clouds. In order to quantitatively assess the performance of the algorithm, a forecast validation against MSG/SEVIRI observations is performed for a period of 2 months. Error rates and Hanssen–Kuiper skill scores are derived for forecasted cloud masks. For a forecast of 5min for most cloud situations more than 95% of all pixels are predicted correctly cloudy or clear. This number decreases to 80–95% for a forecast of 2h depending on cloud type and vertical cloud level. Hanssen–Kuiper skill scores for cloud mask go down to 0.6–0.7 for a 2h forecast. Compared to persistence an improvement of forecast horizon by a factor of 2 is reached for all forecasts up to 2h. A comparison of forecasted optical thickness distributions and DNI against observations yields correlation coefficients larger than 0.9 for 15min forecasts and around 0.65 for 2h forecasts.

Publications Copernicus
Download
Short summary
A novel approach for the nowcasting of clouds and direct normal irradiance (DNI) based on the geostationary satellite MSG is presented. The basis of the algorithm is an optical flow method to derive cloud motion vectors for low and high level clouds separately. DNI is calculated from the forecasted optical thickness of the clouds. Validation against MSG observations shows good performance: compared to persistence an improvement of forecast horizon by a factor of 2 is reached for 2 h forecasts.
A novel approach for the nowcasting of clouds and direct normal irradiance (DNI) based on the...
Citation
Share