Generation of Microbaroms by Deep-Ocean Hurricanes

Hetzer, Claus; Gilbert, Kenneth E.; Waxler, Roger; Talmadge, Carrick L.

doi:10.1007/978-1-4020-9508-5_8

Cited by 19 publications

(14 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…While Walker [2012] focused on ambient swell, Stopa et al [2012] studied microbarom generation during hurricane conditions. Microbaroms (and microseisms) have been observed worldwide; the associated frequency distribution is typically centered around a dominant frequency of 0.2 Hz [Baird and Banwell, 1940;Benioff and Gutenberg, 1939;Donn and Posmentier, 1967;Hetzer et al, 2010]. Large water bodies that support high-amplitude long-period swell, such as the Atlantic and Pacific Oceans, are efficient microbarom/microseism source regions.…”

Section: Journal Of Geophysical Research: Atmospheresmentioning

confidence: 99%

Bidirectional infrasonic ducts associated with sudden stratospheric warming events

et al. 2014

View full text Add to dashboard Cite

In January 2011, the state of the polar vortex in the midlatitudes changed significantly due to a minor sudden stratospheric warming event. As a result, a bidirectional duct for infrasound propagation developed in the middle atmosphere that persisted for 2 weeks. The ducts were due to two zonal wind jets, one between 30 and 50 km and the other around 70 km altitude. In this paper, using microbarom source modeling, a previously unidentified source region in the eastern Mediterranean is identified, besides the more well known microbarom source regions in the Atlantic Ocean. Infrasound data are then presented in which the above mentioned bidirectional duct is observed in microbarom signals recorded at the International Monitoring System station I48TN in Tunisia, from the Mediterranean region to the east and from the Atlantic Ocean to the west. While the frequency bands of the two sources overlap, the Mediterranean signal is coherent up to about 0.6 Hz. This observation is consistent with the microbarom source modeling; the discrepancy in the frequency band is related to differences in the ocean wave spectra for the two basins considered. This work demonstrates the sensitivity of infrasound to stratospheric dynamics and illustrates that the classic paradigm of a unidirectional stratospheric duct for infrasound propagation can be broken during a sudden stratospheric warming event.

show abstract

Section: Journal Of Geophysical Research: Atmospheresmentioning

confidence: 99%

Bidirectional infrasonic ducts associated with sudden stratospheric warming events

et al. 2014

View full text Add to dashboard Cite

show abstract

“…The results of Stopa et al (2011) and Stopa et al (2012) provide guidance for choosing observatories to minimize bearing errors. Hetzer et al (2008), Hetzer et al (2010, Stopa et al (2011), andStopa et al (2012) suggest practical uses for measurements of microbaroms from tropical cyclones. These include:…”

Section: Discussionmentioning

confidence: 99%

“…(2) Inferring the storm category from acoustic data (Stopa et al, 2011). (3) Infrasound could infer wind intensity continuously and cost effectively (Hetzer et al, 2010).…”

Section: Discussionmentioning

confidence: 99%

“…Michael.Jones@Colorado.edu published to date seem to indicate arrivals not from the direction of the vortex core, but rather from the periphery of the system (e.g., Hetzer et al, 2008;Hetzer et al, 2010;Stopa et al, 2011;Stopa et al, 2012). Such infrasound can be generated by wave-wave interaction between systems of counter-propagating ocean waves (e.g., Daniels, 1953;Brekhovskikh, 1966;Posmentier, 1967;Donn and Naini, 1973;Waxler and Gilbert, 2006).…”

Section: Effects Of Vortices On Sound Propagationmentioning

confidence: 97%

See 1 more Smart Citation

Infrasonic ray tracing applied to mesoscale atmospheric structures: Refraction by hurricanes

Bedard

Jones

2013

The Journal of the Acoustical Society of America

View full text Add to dashboard Cite

A ray-tracing program is used to estimate the refraction of infrasound by the temperature structure of the atmosphere and by hurricanes represented by a Rankine-combined vortex wind plus a temperature perturbation. Refraction by the hurricane winds is significant, giving rise to regions of focusing, defocusing, and virtual sources. The refraction of infrasound by the temperature anomaly associated with a hurricane is small, probably no larger than that from uncertainties in the wind field. The results are pertinent to interpreting ocean wave generated infrasound in the vicinities of tropical cyclones.

show abstract

“…Ultimately, this led to the construction of a global network of infrasound stations (Christie & Campus 2010), which is being deployed as one component of the International Monitoring System (IMS) and is designed to monitor nuclear explosions. Many natural sources are also detected at this network so that its development has rekindled interest in the use of infrasound to examine a wide variety of atmospheric and geophysical phenomena, including ocean swell (Garcés et al 2003; Hetzer et al 2010), ocean surf (Arrowsmith & Hedlin 2005), tsunamis (Le Pichon et al 2005a), earthquakes (Le Pichon et al 2006; Mutschlecner & Whitaker 2005), volcanoes (Matoza et al 2006; Fee & Garcés 2007; Matoza et al 2009) and meteors (Revelle et al 2004; Edwards 2010).…”

Section: Introductionmentioning

confidence: 99%

Finite difference synthesis of infrasound propagation through a windy, viscous atmosphere: application to a bolide explosion detected by seismic networks

Groot‐Hedlin

Hedlin

Walker

2011

Geophysical Journal International

View full text Add to dashboard Cite

S U M M A R YA finite-difference time-domain (FDTD) algorithm has been developed to model linear infrasound propagation through a windy, viscous medium. The algorithm has been used to model signals from a large bolide that burst above a dense seismic network in the US Pacific Northwest on 2008 February 19. We compare synthetics that have been computed using a G2S-ECMWF atmospheric model to signals recorded at the seismic networks located along an azimuth of 210 • from the source. The results show that the timing and the range extent of the direct, stratospherically ducted and thermospherically ducted acoustic branches are accurately predicted. However, estimates of absorption obtained from standard attenuation models (Sutherland-Bass) predict much greater attenuation for thermospheric returns at frequencies greater than 0.1 Hz than is observed. We conclude that either the standard absorption model for the thermospheric is incorrect, or that thermospheric returns undergo non-linear propagation at very high altitude. In the former case, a better understanding of atmospheric absorption at high altitudes is required; in the latter, a fully non-linear numerical method is needed to test our hypothesis that higher frequency arrivals from the thermosphere result from non-linear propagation at thermospheric altitudes.

show abstract

Generation of Microbaroms by Deep-Ocean Hurricanes

Cited by 19 publications

References 29 publications

Bidirectional infrasonic ducts associated with sudden stratospheric warming events

Bidirectional infrasonic ducts associated with sudden stratospheric warming events

Infrasonic ray tracing applied to mesoscale atmospheric structures: Refraction by hurricanes

Finite difference synthesis of infrasound propagation through a windy, viscous atmosphere: application to a bolide explosion detected by seismic networks

Contact Info

Product

Resources

About