Speaker
Description
Over the past two decades, the use of Commercial Microwave Links (CMLs) as opportunistic rainfall sensors has evolved from proof-of-concept studies involving a limited number of links to the production of multi-year, country-wide rainfall maps. Despite this progress, (near-real time) operational applications of CML-derived rainfall products remain largely confined to pilot studies. Moreover, most applications have been concentrated in Western Europe, where dedicated ground-based rainfall monitoring networks (rain gauges, weather radars) already provide good coverage.
In this presentation, we introduce a unique initiative that addresses both limitations by developing a real-time weather application for Ghana. The product integrates rainfall information from CMLs, METEOSAT geostationary satellites, and rain gauges from the Ghana Meteorological Agency (GMet) and the Trans-African Hydro-Meteorological Observatory (TAHMO). This effort represents a collaboration between partners from industry (Rainboo B.V.), a mobile network operator (Airtel-Tigo Ghana), research institute (TU Delft), and TAHMO. We present both the organizational aspect of setting up a continuous operational data stream and some preliminary results of the merged rainfall product.
Particular emphasis is placed on the calibration of CML-based rainfall retrievals within this merged product. We identify the most suitable (pre-)processing steps with regards to the available reference rain gauge data and the subsequent merging with the satellite rainfall product. In addition, the CML retrieval algorithm is adapted to local climatological conditions using empirical drop size distributions collected in Ghana. Finally, we share the learnings, the challenges and opportunities of using CML data as a source of information in real-time rainfall monitoring and weather services in data-scarce tropical regions.