Advanced MUlti-GNSS Array for Monitoring Severe Weather Events (AMUSE)
Atmospheric Science
Final Report Abstract
The goal of the project was to provide ultra-rapid, advanced multi-GNSS parameters, i.e. ZTDs, tropospheric gradients and STDs. It consisted of three working packages: 1) Ultra-rapid multi-GNSS tropospheric products, 2) Multi-technique validation and 3) Data assimilation into NWP models. In WP1, we worked on obtaining the tropospheric products. We shortened the provision time from hh:25 to hh:13 for some stations in Germany. The time is however also dependent on how fast can SAPOS provide the data to our operational data center. We implemented in the GFZ-developed software EPOS the processing of the GLONASS and Galileo data. The addition of these systems increased the number of the visible satellites by more than double. What is especially important is that now we have more observations for the low elevation and azimuth angles, which increases the satellite geometry and can be very beneficial for the data assimilation. Using the multi-GNSS data also reduces the formal error of the ZTD data. In WP2, we performed the multi-technique validation. We compared our GNSS estimates with the reference Numerical Weather Models and Water Vapor Radiometers. At first, the tests were conducted for the entire year 2020. Global comparisons with ERA5 showed biases of around 2mm with 8.5mm SDs for the ZTD. All three GNSS solutions showed very similar accuracy, however, the statistics were slightly better for the GRE solution. Then, we presented the comparisons of the three tropospheric parameters (ZTDs, tropospheric gradients and STDs) obtained from three NWMs (ERA5, ICON, GFS) and three GNSS solutions (G, GR, GRE) for a week in July 2021 that contained strong precipitation leading to deadly flooding. These comparisons showed again that all GNSS solutions were similar when compared to the NWMs. However, the biases from GR and GRE were slightly smaller than for the G solution and the SDs were slightly larger. From the comparisons for particular stations, we could see that the rise and drop in the ZTDs values were connected to high precipitation. The best agreement of GNSS data was achieved with the ICON model. We believe that this best agreement depends on few factors: 1) the horizontal resolution of ICON is much higher than of the other models, 2) we use the analysis data and not the forecast, 3) the tuning of the DWD for a specific region (here, Germany). On the other side, the GFS and ERA5 have low horizontal resolution and additionally, GFS is a free forecast, unlike ERA5, which is a reanalysis. In WP3, first tests of the assimilation of the GNSS parameters, i.e. ZTD and STD were performed by the DWD. The results showed that the assimilation of both ZTDs and STDs improves the forecasts of meteorological parameters by 1-4% and the additional impact of STDs as compared to ZTD only assimilation is 1-2%. Currently, more tests are being performed by the DWD with a new model ICON-D2, with higher resolution. The expected improvement of using the advanced multi-GNSS estimates is even higher. One more application of the advanced multi-GNSS products is also the GNSS tomography. We tested how different initial GNSS parameters influence the tomography solution and the GRE solution was the best fit, as it showed more patterns in the obtained total refractivity. Using the multi-GNSS also retrieved more forced voxels. In the future also the assimilation of the tomography retrieval in the NWMs is possible.
Publications
-
Advanced GNSS tropospheric products for assimilation into numerical weather models, Frontiers Of Geodetic Science Digital,, 13- 15.10.2020
Wilgan K., Dick G., Zus F., Wickert J., Schmidt T., Bender M. & Potthast R.
-
Advanced MUlti-GNSS Array for Monitoring Severe Weather Events (AMUSE): Project overview, EGU General Assembly, Online, 4- 8.05.2020
Wilgan, K., Wickert, J., Dick, G., Zus, F., Schmidt, T., Bender, M. & Potthast, R.
-
Comparison of tropospheric delays from GNSS and InSAR in alpine conditions, International Workshop on GNSS and InSAR Tropospheric Products for Meteorology, Luxembourg, 25-26.02.2020
Wilgan K., Siddique M.A,. Strozzi T., Geiger A. & Frey O.
-
Empirical estimates of refractivity coefficients using 16 years of re-analysis from ERA- Interim, International Workshop on GNSS and InSAR Tropospheric Products for Meteorology, Luxembourg, 25-26.02.2020
Brenot, H. & Wilgan, K.
-
GNSS Remote Sensing at GFZ: Overview and Recent Results. – ZfV: Zeitschrift für Geodäsie, Geoinformation und Landmanagement, 145, 5, 266-278
Wickert J., Dick G., Schmidt T., Asgarimehr M., Antonoglou N., Arras C., Brack A., Ge M., Kepkar A., Männel B., Nguyen C.T., Oluwadare T. S., Schuh H., Semmling M., Simeonov T., Vey S., Wilgan K. & Zus F.
-
Impact of GNSS groundbased observations on numerical weather forecasting: ZTDs, STDs and 3D tomography retrievals, International Workshop on GNSS and InSAR Tropospheric Products for Meteorology, Luxembourg, 25- 26.02.2020
Rohm, W., Trzcina, E., Hanna, N., Moeller, G., Hordyniec, P., Wilgan, K., Kryza, M. & Weber, R.
-
GNSS for the Global Climate Observing System: Precipitable Water Vapor Processing Centre at GFZ, Dick G., Zus F., Wickert J., Männel B., Bradke M., Ramatschi M., Balidakis K., Wilgan K., Schuh H., IAG 2021, 30.06.2021, Beijing, China + hybrid
Dick G., Zus F., Wickert J., Männel B., Bradke M., Ramatschi M., Balidakis K., Wilgan K. & Schuh H.
-
GNSS-based Precipitable Water Vapor: Certification for the Global Climate Observing System, 1st ICCC Workshop, online, 29-31.03.2021
Dick G., Jones J., Wang J., Rannat K., Wickert J., Zus F., Balidakis K. & Wilgan K.
-
Impact of Tropospheric Mismodelling in GNSS Precise Point Positioning: A Simulation Study Utilizing Ray-Traced Tropospheric Delays from a High-Resolution NWM. Remote Sensing, 13(19), 3944.
Zus, Florian; Balidakis, Kyriakos; Dick, Galina; Wilgan, Karina & Wickert, Jens
-
Multi-GNSS Meteorology: Computation of tropospheric delays and gradients at GFZ Potsdam, , IAG 2021, 29.06.2021, Beijing, China + hybrid
Wilgan K., Dick G., Zus F. & Wickert J.
-
Multi-GNSS tomography: Case study of the flood in Europe in July 2021, IAG Commission 4 Symposium, Potsdam, 6.09.2022
Wilgan, K., Brenot, H., Bender, M., Biondi, R., Dick, G., Zus, F. & Wickert, J.
-
Tomographic fusion strategies for the reconstruction of atmospheric water vapor, IAG 2021, 29.06.2021, Beijing, China + hybrid
Moeller G., Ao C., Adavi Z., Biondi R., Brenot H., Sá A., Hajj G., Hanna N., Kitpracha C., Pottiaux E., Rohm W.,Shehaj E., Trzcina E., Wang K.-N., Wilgan K., Zhang W. & Zhang K.
-
Tropospheric products as a signal of interest – overview of troposphere sensing techniques, vEGU2021, 29.04.2021 (Geodesy Division Outstanding Early Career Scientists Award 2020 lecture)
Wilgan K., Rohm W., Bosy J., Geiger A., Siddique M.A., Wickert J. & Dick G.
-
Comparisons of the tropospheric parameters from multi-GNSS and numerical weather models for severe floods in Germany in July 2021, 8th International Colloquium on Scientific and Fundamental Aspects of GNSS, Sofia, 15.09.2022
Wilgan, K., Dick, G., Zus, F. & Wickert, J.
-
GNSS for weather and climate studies, INTERGEO 2022 (panel discussion), Essen, Germany, 18.10.2022
Wilgan, K., Dick, G., Zus, F. & Wickert, J.
-
GNSS-derived Precipitable Water Vapour for Weather Forecast and Climate Research, Topic Days, Karlsruhe, 23-25.05.2022
Dick, G., Zus, F., Wickert, J. & Wilgan, K.
-
Multi-GNSS Meteorology at GFZ Potsdam: Severe flood events in Germany in July 2021, EGU 2022, Vienna, 23.05.2022
Wilgan K., Dick G., Zus F. & Wickert J.
-
Multi-GNSS tomography & comparison with ICON-D2 forecasts for the flood in Europe in July 2021, D4G 2022, Potsdam, Germany, 14.06.2022
Brenot H. Wilgan K., Bender M. & Biondi R.
-
Tomographic fusion strategies for the reconstruction of small-scale structures in the lower atmosphere, D4G 2022, Potsdam, Germany, 13.06.2022
Moeller, G., Adavi, Z., Wilgan, K., Brenot, H., Hanna, N., Kamm, B., Schenk, A., Pottiaux, E., Shehaj, E., Zhang, W., Trzcina, E. & Rohm, W.
-
Towards operational multi-GNSS tropospheric products at GFZ Potsdam. Atmospheric Measurement Techniques, 15(1), 21-39.
Wilgan, Karina; Dick, Galina; Zus, Florian & Wickert, Jens
-
Tropospheric Parameters from Multi-GNSS and Numerical Weather Models: Case Study of Severe Precipitation in Germany in July 2021, AGU Fall Meeting, Chicago, USA, 14.12.2022
Wilgan, K., Dick, G., Zus, F. & Wickert, J.
-
Multi-GNSS Tomography: Case Study of the July 2021 Flood in Germany. International Association of Geodesy Symposia, 79-86. Springer Nature Switzerland.
Wilgan, Karina; Brenot, Hugues; Biondi, Riccardo; Dick, Galina & Wickert, Jens
-
Tropospheric parameters from multi-GNSS and numerical weather models: case study of severe precipitation and flooding in Germany in July 2021. GPS Solutions, 27(1).
Wilgan, Karina; Dick, Galina; Zus, Florian & Wickert, Jens
