Central and Eastern U.S. Surface Pressure Variations Derived from the USArray Network

Abstract

Large-magnitude pressure signatures associated with a wide range of atmospheric phenomena (e.g., mesoscale gravity waves, convective complexes, tropical disturbances, and synoptic storm systems) are examined using a unique set of surface pressure sensors deployed as part of the National Science Foundation EarthScope USArray Transportable Array. As part of the USArray project, approximately 400 seismic stations were deployed in a pseudogrid fashion across a portion of the United States for 1-2 yr, then retrieved and redeployed farther east. Surface pressure observations at a sampling frequency of 1 Hz were examined during the period when the seismic array was transitioning from the central to eastern continental United States. Surface pressure time series at over 900 locations were bandpass filtered to examine pressure perturbations on three temporal scales: meso-(10 min-4 h), subsynoptic (4-30 h), and synoptic (30 h-5 days) scales.Case studies of strong pressure perturbations are analyzed using web tools developed to visualize and track tens of thousands of such events with respect to archived radar imagery and surface wind observations. Seasonal assessments of the bandpass-filtered variance and frequency of large-magnitude events are conducted to identify prominent areas of activity. Large-magnitude mesoscale pressure perturbations occurred most frequently during spring in the southern Great Plains and shifted northward during summer. Synopticscale pressure perturbations are strongest during winter in the northern states with maxima located near the East Coast associated with frequent synoptic development along the coastal storm track.

Relationships Between Gravity Waves Observed at Earth's Surface and in the Stratosphere Over the Central and Eastern United States

“…Figure shows a decrease in GW activity detected by the TA from 2011 to 2012—paralleling what is seen in the AIRS data. This is consistent with a study by Jacques et al () that observed a decline in mesoscale pressure perturbations on TA sensors after August 2011. The 2012 data also indicate that despite the overall lower GW occurrence rate, a decline in activity can still be observed from the western edge of the network (located where the GW activity was concentrated in 2011) to the eastern edge of the network.…”

“…A prominent region of mesoscale pressure perturbations was also found in this area by Jacques et al (, ). This feature was particularly prominent during the spring and summer months (Jacques et al, ). Mesoscale pressure perturbations over the Great Central Plains with large amplitudes (>100 Pa) and areal extents (>10,000 km 2 ) were tracked by Jacques et al (); their eastward motion and speeds are consistent with the GW phase velocities and propagation azimuths in this study.…”

“…However, that study found that over a 25 year period over the conterminous U.S., GW activity peaked at noon LT and exhibited a broad minimum from August through November. A prominent region of mesoscale pressure perturbations was also found in this area by Jacques et al (2015Jacques et al ( , 2017. This feature was particularly prominent during the spring and summer months (Jacques et al, 2015).…”

“…In a case study, Stephan et al (2016) linked TA surface pressure oscillations and GWs observed in the stratosphere to a common precipitating storm source using radar observations and the idealized GW-resolving method of Stephan and Alexander (2015). In other studies, Jacques et al (2015Jacques et al ( , 2017 used this network to identify mesoscale pressure fluctuations. and east-west lines across a region covering approximately 2,000,000 km 2 .…”

Meteorological Source Variability in Atmospheric Gravity Wave Parameters Derived From a Tropical Infrasound Station

“…The direction and velocity of wave propagation can be derived using arrays of three or more instruments (Blanc et al, 2014;Farges et al, 2003;le Pichon et al, 2002). Larger arrays of barometers such as those used in the USArray network have been used to detect convectively generated GWs at the surface with time periods of 2-6 hr (Balachandran, 1980;de Groot-Hedlin et al, 2017;Jacques et al, 2015). However, the microbarometer network used in de Groot-Hedlin et al (2017) only covers parts of the mainland United States.…”