THE INFRASONIC SIGNATURE OF POLAR LOW PRESSURE SYSTEMS
Authors: Sven Peter Näsholm (NORSAR); Jelle Assink (KNMI); Chantal Claud (CNRS/LMD); Pieter Smets (KNMI); Maxence Rojo (CNRS/LMD); Kathy Pol (CEA); Steven J. Gibbons (NORSAR); Mårten Blixt (NORSAR)
We consider a set of polar low pressure systems in the North Atlantic and their signature in data recorded at Scandinavian infrasound arrays.
The times and coordinates of the polar low events were listed by Senior Forecaster Gunnar Noer at the Norwegian Meteorological Institute based on visual inspection of AVHRR images. Also synoptic observations, METAR (airport observations), in situ soundings, and scatterometer winds were used when compiling the event list.
For each of the analyzed events and for each of the infrasound stations, a time-series of direction of arrival (backazimuth) of the dominating infrasound plane wave was estimated from the infrasound array data recordings. These bearings were then compared with the bearings between the infrasound stations and the listed event locations.
Based on the comparisons for each polar low event, we assess whether a signature was seen (or not seen) in the infrasound array network data.