Spatial Pressure Perturbation Analyses utilizing Earthscope's USArray Network

Short-term pressure perturbations are associated with numerous atmospheric phenomena including frontal passages, mesoscale convective systems (i.e. bow echoes, mesohighs, wake lows, etc.), and gravity waves. This study examines pressure perturbations derived from observational data to correct gridded perturbation products derived from numerical analyses. Observations are provided from the Earthscope US Transportable Array (USArray) in-situ seismic network. Stations with 1 Hz pressure data deployed initially in a pseudo-grid format across the central United States in 2010 report for 1-2 years, and then were redeployed on the eastern edge of the network. At present, most of the stations are finishing deployment along the east coast, with a less dense network being left in place across the central and eastern United States for successive years.

Time series at each reporting site are band-pass filtered and assessed for significant perturbation events to provide case examples of significant phenomena. Gridded pressure analyses from the Rapid Refresh (RAP) are also filtered to create perturbation background fields. Observations are combined with the background fields to produce spatial maps of pressure perturbations to assess the impact of the observations on the analyses in perturbation space. Examples are provided from several significant weather events that traversed the array and produced prominent pressure perturbations within the region.