In 2020, GFZ started a new research project called AMUSE (Advanced MUlti-GNSS Array for Monitoring Severe Weather Events) funded by the German Research Funding DFG. AMUSE is aiming at improving the forecasts of strong precipitation events in Germany in cooperation with the German Weather Service DWD.
Using the in-house developed EPOS software, GFZ will process GNSS data of the German SAPOS network with a time delay shorter than 15 minutes after each hour (‘ultra-rapid’ processing). The GNSS-derived tropospheric products such as Zenith Total Delays (ZTDs) or Integrated Water Vapour (IWV) will be delivered to DWD for operational assimilation. Additionally, GFZ will provide Slant Total Delays (STDs) with a time resolution of 2.5 minutes. These specific data from up to 30 navigation satellites in parallel will be used to improve the precipitation forecasts of DWD.
The main innovations addressed by the AMUSE project are:
- developments to provide multi-GNSS instead of GPS-only data, including navigation satellite systems as GLONASS, Galileo and BeiDou, increasing the used transmitting satellites from around 30 (GPS only) to around 100;
- developments to provide validated high-quality slant observations, containing water vapour information along the line-of-sight from the respective ground stations;
- developments to shorten the delay between measurement and provision of the meteorological GNSS-based information at the main applicants, the meteorological services.
For monitoring purposes, the GNSS-derived tropospheric products are compared daily to the corresponding tropospheric parameters, derived from a global numerical weather model, the Global Forecast System (GFS) of the National Centers for Environmental Prediction (NCEP) www.ncep.noaa.gov). As an example the following animation shows a one-to-one comparison of Zenith Wet Delays:
The project work at TUB and GFZ will be complemented by a unique contribution of the German Weather Service (DWD) to investigate in detail and to quantify the forecast improvement, which can be reached by the new generation GNSS meteorology data. Several forecast experiments will be conducted with focus on the most challenging issue, the precipitation forecast in case of severe weather events.
Zus, F., Dousa, J., Kacmarik, M.,Václavovic, P., Dick, G., Wickert, J. (2019): Estimating the Impact of Global Navigation Satellite System Horizontal Delay Gradients in Variational Data Assimilation. - Remote Sensing, 11, 1, 41.
Zus, F., Dousa, J., Kacmarik, M.,Václavovic, P., Balidakis, K., Dick, G., Wickert, J. (2019): Improving GNSS Zenith Wet Delay Interpolation by Utilizing Tropospheric Gradients: Experiments with a Dense Station Network in Central Europe in the Warm Season. - Remote Sensing, 11, 6, 674.
Lammert, A., Hansen, A., Ament, F., Crewell, S., Dick, G., Grützun, V., Klein-Baltink, H., Lehmann, V., Macke, A., Pospichal, B., Schubotz, W., Seifert, P., Stamnas, E., Stevens, B. (2019): A Standardized Atmospheric Measurement Data Archive for Distributed Cloud and Precipitation Process-Oriented Observations in Central Europe. - Bulletin of the American Meteorological Society, 100, 7, 1299-1314.
Lu, C.,X. Chen, G. Liu, G. Dick, J. Wickert, X. Jiang, K. Zheng, and H. Schuh (2017b), Real-Time Tropospheric Delays Retrieved from Multi-GNSS Observations and IGS Real-Time Product Streams, Remote Sensing, 9, 12, 1317, DOI: doi.org/10.3390/rs9121317.