Integrating Microwave Link Data For Analysis of Precipitation in Complex Terrain: Theoretical Aspects and Hydrometeorological Applications (IMAP)
Electronic Semiconductors, Components and Circuits, Integrated Systems, Sensor Technology, Theoretical Electrical Engineering
Atmospheric Science
Final Report Abstract
IMAP had the goal to improve rainfall and water vapor estimation from commercial microwave link (CML) attenuation data and to apply these to improve hydrological modeling. Significant progress was made with regard to CML-derived rainfall information. Within IMAP a new data acquisition system for CMLs was developed and set up in Germany, which is continuously collecting data in real-time for 4000 CMLs with a temporal resolution of one minute. This data allowed for the first long-term country-wide performance analysis of CML rainfall maps in Germany, which has gained considerable attention from national and international media. A great success also was the first acquisition and processing of CML data in Palestine supported by a dedicated field campaign with the installation of a dense network of rain gauges. Significant progress was also made with regard to water vapor estimation from CML data in Israel. For the first time, near-surface water vapor maps were derived from CML attenuation measurements and compared to station data as well as reanalysis. A follow-up study with a larger CML dataset from Germany is still in progress and close to finalization. Another important contribution from IMAP is the improved insight into the wet antenna attenuation (WAA) effect and its observation. Based on a lab experiment and an accompanying simulation it was found that antenna mismatch can be used as a reliable proxy for WAA estimation. These findings allowed to build a new dedicated microwave transmission field experiment, which is now a core component of a currently running follow-up project to further improve WAA estimation. Important insights have also been gained regarding the performance of different rainfall field reconstruction algorithms in relation to CML network density and the spatial characteristics of the rainfall fields. This work was extended in a joint analysis using semi-synthetic data as well as real CML data from Germany. Results from hydrological modeling have, however, been mixed. It was shown that CML data can improve runoff modeling with the improved coverage that the additional rainfall observations from CML provide. CML coverage is not uniform, though. In particular in the chosen fairly remote target regions with complex terrain (Ammer Mountains in the Alps and two Wadis close to the Jordan River and the Dead Sea) CML coverage was sparse. The performance of CML rainfall fields in hydrological modeling thus did depend too much on how good the CMLs did cover the actual rainfall fields. Hence, the IMAP goal to optimize CML data processing with feedback from hydrological modeling could not be reached. Nevertheless, within IMAP, the WRF-Hydro model setup at the associated project partner IHS (Israeli Hydrological Service) has been improved and a new setup for the target region Wadi Faria was installed at An-Najah National University. Furthermore, a new channel loss function was implemented for the setup targeting Wadi Faria. Due to the increasing tension between Israel and Palestine, the planned bilateral exchange was significantly hampered. Nevertheless, several joint project meetings, one of them in the West Bank, have been held and individual research stays as well as scientific cooperations have been made possible within IMAP. The results from IMAP have also stimulated several research project proposals and have already led to two follow-up projects in Germany.
Publications
- Real-time data acquisition of commercial microwave link networks for hydrometeorological applications, Atmos. Meas. Tech., 9, 991–999
Chwala, C., Keis, F., and Kunstmann, H.
(See online at https://doi.org/10.5194/amt-9-991-2016) - Potential of commercial microwave link network derived rainfall for river runoff simulations. Environmental Research Letters, 12(3), 034026
Smiatek, G., Keis, F., Chwala, C., Fersch, B., and Kunstmann, H.
(See online at https://doi.org/10.1088/1748-9326/aa5f46) - First daily mapping of surface moisture from cellular network data and comparison with both observations/ECMWF product, Geophy. Res. Lett., 45, 8619– 8628
Alpert, P., and Rubin, Y.
(See online at https://doi.org/10.1029/2018GL078661) - 2019. Analyzing the ability to reconstruct the moisture field using commercial microwave network data", Atm. Res., 219, 213-222
David, N., Sendik, O., Rubin, Y. , Messer, H., Gao. H.O., Rostkier-Edelstein, D. and Alpert, P.
(See online at https://doi.org/10.1016/j.atmosres.2018.12.025) - 2019. Commercial microwave link networks for rainfall observation: Assessment of the current status and future challenges. Wiley Interdiscip. Rev. Water 6, e1337
Chwala, C., and Kunstmann, H.
(See online at https://doi.org/10.1002/wat2.1337) - Rainfall Mapping in the Faria Catchment, Palestine – Comparison and Evaluation of Six Interpolation Methods. The Second International Conference on Civil Engineering, Palestine, November 2019
Shadeed, S. C. Chwala, A. Jayyousi, A. Khader, and H. Kunstmann
- Microwave Instrument for Simultaneous Wet Antenna Attenuation and Precipitation Measurement, IEEE Transactions on Instrumentation and Measurement, 69.8, August 2020, 5853–5861
Moroder, C., Siart, U., Chwala, C., and Kunstmann, H.
(See online at https://doi.org/10.1109/TIM.2019.2961498) - Modeling of Wet Antenna Attenuation for Precipitation Estimation From Microwave Links. IEEE Geosci. Remote Sens. Lett., 17.3, March 2020, 386–390
Moroder, C., Siart, U., Chwala, C., and Kunstmann, H.
(See online at https://doi.org/10.1109/LGRS.2019.2922768) - Rainfall estimation from a German-wide commercial microwave link network: optimized processing and validation for 1 year of data, Hydrol. Earth Syst. Sci., 24, 2931–2950
Graf, M., Chwala, C., Polz, J., and Kunstmann, H.
(See online at https://doi.org/10.5194/hess-24-2931-2020) - Quantitative Analysis of the Performance of Spatial Interpolation Methods for Rainfall Estimation Using Commercial Microwave Links. Journal of Hydrometeorology
Eshel, A., Messer, H., Kunstmann, H., Alpert, P., and Chwala, C.
(See online at https://doi.org/10.1175/JHM-D-20-0164.1)
