New Insights Into the Dynamics of Wet Antenna Attenuation Based on In Situ Estimations Provided by the Dedicated Field Experiment ATTRRA2

Wet antenna attenuation (WAA) can cause significant overestimation of rainfall estimates from commercial microwave link (CML) data. Typically, WAA estimation is done by comparing CML rainfall estimates to reference data and attributing the residual to WAA. Due to the different spatio-temporal integration characteristics of CML and reference observations this does not allow a confident conclusion about the temporal dynamics of WAA. In this work, we present the world's first in situ WAA estimation for CML antennas, accompanied by sequences of images of the antennas as provided by our dedicated field experiment ATTRRA2. We show examples of surprising temporal dynamics, namely delayed wetting and strong WAA decrease during rainfall events. These results will support the future development of improved WAA estimation models, while, at the same time, highlighting the challenges any modeling approach will face due to the complexity of temporal WAA dynamics.