Remote Monitoring of Mediterranean Hurricanes Using Infrasound

Abstract

Mediterranean hurricanes, or medicanes, are tropical-like cyclones forming once or twice per year over the waters of the Mediterranean Sea. These mesocyclones pose a serious threat to coastal infrastructure and lives because of their strong winds and intense rainfall. Infrasound technology has already been employed to investigate the acoustic signatures of severe weather events, and this study aims at characterizing, for the first time, the infrasound detections that can be related to medicanes. This work also contributes to infrasound source discrimination efforts in the context of the Comprehensive Nuclear-Test-Ban Treaty. We use data from the infrasound station IS48 of the International Monitoring System in Tunisia to investigate the infrasound signatures of mesocyclones using a multi-channel correlation algorithm. We discuss the detections using meteorological fields to assess the presence of stratospheric waveguides favoring propagation. We corroborate the detections by considering other datasets, such as satellite observations, a surface lightning detection network, and products mapping the simulated intensity of the swell. High- and low-frequency detections are evidenced for three medicanes at distances ranging between 250 and 1100 km from the station. Several cases of non-detection are also discussed. While deep convective systems, and mostly lightning within them, seem to be the main source of detections above 1 Hz, hotspots of swell (microbarom) related to the medicanes are evidenced between 0.1 and 0.5 Hz. In the latter case, simulations of microbarom detections are consistent with the observations. Multi-source situations are highlighted, stressing the need for more resilient detection-estimation algorithms. Cloud-to-ground lightning seems not to explain all high-frequency detections, suggesting that additional sources of electrical or dynamical origin may be at play that are related to deep convective systems.

Warm Core and Deep Convection in Medicanes: A Passive Microwave-Based Investigation

“…They also found that only DC in the upshear quadrants led to intensification periods, and that short-lived tropical-like structures develop only during symmetric convective activity. However, even in these cases, lightning activity in the proximity of the cyclone center is rarely observed during the TLC phase (see also [19,[23][24][25]). During the early phases, when the storm is under the influence of baroclinic forcing (pre-TLC phase in the following), the majority of clouds show convective characteristics, and lightning activity takes place close to the cyclone center.…”

Flood damage inspection and risk indexing data for an inventory of bridges in Central Greece

“…A few days after Medicane Ianos struck Greece, on September 17-20 2020, causing severe and widespread damage to infrastructure [1] , [2] , [3] , 5 , 7] , the US GEER Association deployed an interdisciplinary team of researchers and engineers to collect perishable field performance data from the affected regions. The mission made use of remote sensing technologies, employing optical and satellite imagery, in addition to conventional site characterization and structure inspections.…”

Infrasound Detection Using Polymer Networks in Liquid Films

“…The term infrasound typically refers to pressure variations at frequencies from around 20 Hz down to a few mHz which is below the human audible spectrum [1]. Infrasound is generated by a variety of sources, including weather events such as hurricanes [2], volcanic eruptions [3], earthquakes [4], ocean waves [5], and avalanches [6]. Moreover, infrasound can also be generated by human activity such as spacecrafts [7], vehicles [8], wind turbines [9], and nuclear tests [1], [10].…”

“…Moreover, infrasound can also be generated by human activity such as spacecrafts [7], vehicles [8], wind turbines [9], and nuclear tests [1], [10]. Such infrasound waves can travel over long distances in the atmosphere without strong attenuation [1], [2]. Hence, they can be used to study the types of events mentioned above with dedicated infrasound sensors or networks of sensors [1], [10].…”