Speaker
Description
The Royal Netherlands Meteorological Institute (KNMI) operates a three-dimensional
microbarometer array at the Cabauw Experimental Site for Atmospheric Research observatory.
The array consists of five microbarometers on a meteorological tower up to an altitude of 200 m.
Ten ground-based microbarometers surround the tower with an array aperture of 800 m. This
unique setup allows for the study of infrasound propagation in three dimensions. The added
value of the vertical dimension is the sensitivity to wind and temperature in the atmospheric
boundary layer over multiple altitudes. In this study, we analyze infrasound generated by an
accidental chemical explosion at the Moerdijk petrochemical plant on 3 June 2014. The recordings
of the tower microbarometers show two sequential arrivals, whereas the recordings on the
ground show one wavefront. This arrival structure is interpreted to be the upgoing and
downgoing wavefronts. The observations are compared with propagation modeling results using
global-scale and mesoscale atmospheric models. Independent temperature and wind
measurements, which are available at the Cabauw Experimental Site for Atmospheric Research,
are used for comparison with model output. The modeling results explain the signal arrival times;
however, the tower wavefront arrivals are not explained. This study is important for
understanding the influence of the atmospheric boundary layer on infrasound detections and
propagation.
