CML surface moisture maps
First Daily Mapping of Surface Moisture from Cellular Network Data and Comparison with Both Observations/ECMWF Product
Building on their initial work (David et al., 2009) IMAP researchers from Tel Aviv University have, for the first time, accomplished to derive daily mapping of surface moisture from CML data (Alpert and Rubin, 2018).
Since atmospheric humidity plays in important role in the rainfall generation process, it is a cardinal part in weather prediction. CML attenuation data can be used to derive humidity estimates, because atmospheric humidity leads to attenuation, in particular for CML frequencies close to 23 GHz. Here, for the first time CML-derived humidity maps were and compared to output from a forecast model from the European Centre for Medium‐Range Weather Forecasts. The CML humidity maps showed better correlations with weather stations, which represent the real humidity in the air. Good results were obtained also for other statistical skills, indicating the quality and the accuracy of the cellular measurements.
Humidity maps from 196 CMLs (a and d), from 39 IMS stations (b and e, 39 stations) and the ECMWF (European Centre for Medium‐Range Weather Forecasts) model output (c and f) with 0.125° × 0.125° resolution. Top row shows results for 12 April 2017, bottom row for 20 April 2017. The locations of the links are indicated in blue. (Source: Alpert and Rubin, 2018)
The humidity derived from CML attenuation data was found to be more accurate as compared to the forecast models. Consequently, the new humidity‐measuring method has to potential to improve weather prediction, in particular for heavy rainfall.