Dynamic and Statistical Analyses of Alaskan Surface Pressure Perturbations Using the USArray Network

Alaska’s expansive size, dynamic weather, and abundance of remote regions make it the ideal location for innovative atmospheric observation platforms. In 2015, EarthScope began deploying its USArray Transportable Array (TA) stations across the state of Alaska at an average spacing of 85 km.  The USArray TA was originally designed as an in-situ seismic monitoring network, but later was retrofitted with atmospheric sensors to expand the platform’s scientific reach.  The TA is equipped with a research-grade Setra-278 microbarograph, which samples atmospheric pressure at a rate of 1 Hz, producing an invaluable dataset in Alaska.  The high temporal resolution pressure data are filtered using Butterworth bandpass filtering techniques in order to isolate pressure perturbation signals on timescales relevant to meteorological phenomena (i.e. mesoscale, sub-synoptic, synoptic scale).  The resulting pressure perturbations are then examined in terms of seasonal statistics as well as case studies of large pressure perturbations.  The experimental Alaska High Resolution Rapid Refresh (HRRR) is being used to provide context for the large pressure perturbation events and help address Alaska forecasting challenges such as mountain waves and downslope wind events.